[PATCH openEuler-5.10-LTS-SP1 34/52] io_uring: import 5.15-stable io_uring

From: Jens Axboe axboe@kernel.dk

stable inclusion from stable-v5.10.162 commit 788d0824269bef539fe31a785b1517882eafed93 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6BTWC CVE: CVE-2023-0240

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v...

--------------------------------

No upstream commit exists.

This imports the io_uring codebase from 5.15.85, wholesale. Changes from that code base:

- Drop IOCB_ALLOC_CACHE, we don't have that in 5.10. - Drop MKDIRAT/SYMLINKAT/LINKAT. Would require further VFS backports, and we don't support these in 5.10 to begin with. - sock_from_file() old style calling convention. - Use compat_get_bitmap() only for CONFIG_COMPAT=y

Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Li Lingfeng lilingfeng3@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Reviewed-by: Wang Weiyang wangweiyang2@huawei.com Signed-off-by: Jialin Zhang zhangjialin11@huawei.com --- Makefile | 2 +- fs/Makefile | 2 - fs/io-wq.c | 1242 ----- include/linux/io_uring.h | 46 +- include/linux/sched.h | 3 + include/linux/syscalls.h | 2 +- include/trace/events/io_uring.h | 121 +- include/uapi/linux/io_uring.h | 115 +- io_uring/Makefile | 6 + io_uring/io-wq.c | 1398 +++++ {fs => io_uring}/io-wq.h | 47 +- {fs => io_uring}/io_uring.c | 9206 +++++++++++++++++-------------- kernel/exit.c | 2 +- kernel/fork.c | 1 + kernel/sched/core.c | 2 +- 15 files changed, 6714 insertions(+), 5481 deletions(-) delete mode 100644 fs/io-wq.c create mode 100644 io_uring/Makefile create mode 100644 io_uring/io-wq.c rename {fs => io_uring}/io-wq.h (81%) rename {fs => io_uring}/io_uring.c (51%)

diff --git a/Makefile b/Makefile index b606e8d3576f..aaa05a3e38d8 100644 --- a/Makefile +++ b/Makefile @@ -1129,7 +1129,7 @@ export MODORDER := $(extmod-prefix)modules.order export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps

ifeq ($(KBUILD_EXTMOD),) -core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/ +core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/ io_uring/

vmlinux-dirs := $(patsubst %/,%,$(filter %/, \ $(core-y) $(core-m) $(drivers-y) $(drivers-m) \ diff --git a/fs/Makefile b/fs/Makefile index d91d30ba8b4e..720fccc8bffa 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -32,8 +32,6 @@ obj-$(CONFIG_TIMERFD) += timerfd.o obj-$(CONFIG_EVENTFD) += eventfd.o obj-$(CONFIG_USERFAULTFD) += userfaultfd.o obj-$(CONFIG_AIO) += aio.o -obj-$(CONFIG_IO_URING) += io_uring.o -obj-$(CONFIG_IO_WQ) += io-wq.o obj-$(CONFIG_FS_DAX) += dax.o obj-$(CONFIG_FS_ENCRYPTION) += crypto/ obj-$(CONFIG_FS_VERITY) += verity/ diff --git a/fs/io-wq.c b/fs/io-wq.c deleted file mode 100644 index 3d5fc76b92d0..000000000000 --- a/fs/io-wq.c +++ /dev/null @@ -1,1242 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Basic worker thread pool for io_uring - * - * Copyright (C) 2019 Jens Axboe - * - */ -#include <linux/kernel.h> -#include <linux/init.h> -#include <linux/errno.h> -#include <linux/sched/signal.h> -#include <linux/mm.h> -#include <linux/sched/mm.h> -#include <linux/percpu.h> -#include <linux/slab.h> -#include <linux/kthread.h> -#include <linux/rculist_nulls.h> -#include <linux/fs_struct.h> -#include <linux/task_work.h> -#include <linux/blk-cgroup.h> -#include <linux/audit.h> -#include <linux/cpu.h> - -#include "../kernel/sched/sched.h" -#include "io-wq.h" - -#define WORKER_IDLE_TIMEOUT (5 * HZ) - -enum { - IO_WORKER_F_UP = 1, /* up and active */ - IO_WORKER_F_RUNNING = 2, /* account as running */ - IO_WORKER_F_FREE = 4, /* worker on free list */ - IO_WORKER_F_FIXED = 8, /* static idle worker */ - IO_WORKER_F_BOUND = 16, /* is doing bounded work */ -}; - -enum { - IO_WQ_BIT_EXIT = 0, /* wq exiting */ - IO_WQ_BIT_CANCEL = 1, /* cancel work on list */ - IO_WQ_BIT_ERROR = 2, /* error on setup */ -}; - -enum { - IO_WQE_FLAG_STALLED = 1, /* stalled on hash */ -}; - -/* - * One for each thread in a wqe pool - */ -struct io_worker { - refcount_t ref; - unsigned flags; - struct hlist_nulls_node nulls_node; - struct list_head all_list; - struct task_struct *task; - struct io_wqe *wqe; - - struct io_wq_work *cur_work; - spinlock_t lock; - - struct rcu_head rcu; - struct mm_struct *mm; -#ifdef CONFIG_BLK_CGROUP - struct cgroup_subsys_state *blkcg_css; -#endif - const struct cred *cur_creds; - const struct cred *saved_creds; - struct files_struct *restore_files; - struct nsproxy *restore_nsproxy; - struct fs_struct *restore_fs; -}; - -#if BITS_PER_LONG == 64 -#define IO_WQ_HASH_ORDER 6 -#else -#define IO_WQ_HASH_ORDER 5 -#endif - -#define IO_WQ_NR_HASH_BUCKETS (1u << IO_WQ_HASH_ORDER) - -struct io_wqe_acct { - unsigned nr_workers; - unsigned max_workers; - atomic_t nr_running; -}; - -enum { - IO_WQ_ACCT_BOUND, - IO_WQ_ACCT_UNBOUND, -}; - -/* - * Per-node worker thread pool - */ -struct io_wqe { - struct { - raw_spinlock_t lock; - struct io_wq_work_list work_list; - unsigned long hash_map; - unsigned flags; - } ____cacheline_aligned_in_smp; - - int node; - struct io_wqe_acct acct[2]; - - struct hlist_nulls_head free_list; - struct list_head all_list; - - struct io_wq *wq; - struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS]; -}; - -/* - * Per io_wq state - */ -struct io_wq { - struct io_wqe **wqes; - unsigned long state; - - free_work_fn *free_work; - io_wq_work_fn *do_work; - - struct task_struct *manager; - struct user_struct *user; - refcount_t refs; - struct completion done; - - struct hlist_node cpuhp_node; - - refcount_t use_refs; -}; - -static enum cpuhp_state io_wq_online; - -static bool io_worker_get(struct io_worker *worker) -{ - return refcount_inc_not_zero(&worker->ref); -} - -static void io_worker_release(struct io_worker *worker) -{ - if (refcount_dec_and_test(&worker->ref)) - wake_up_process(worker->task); -} - -/* - * Note: drops the wqe->lock if returning true! The caller must re-acquire - * the lock in that case. Some callers need to restart handling if this - * happens, so we can't just re-acquire the lock on behalf of the caller. - */ -static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker) -{ - bool dropped_lock = false; - - if (worker->saved_creds) { - revert_creds(worker->saved_creds); - worker->cur_creds = worker->saved_creds = NULL; - } - - if (current->files != worker->restore_files) { - __acquire(&wqe->lock); - raw_spin_unlock_irq(&wqe->lock); - dropped_lock = true; - - task_lock(current); - current->files = worker->restore_files; - current->nsproxy = worker->restore_nsproxy; - task_unlock(current); - } - - if (current->fs != worker->restore_fs) - current->fs = worker->restore_fs; - - /* - * If we have an active mm, we need to drop the wq lock before unusing - * it. If we do, return true and let the caller retry the idle loop. - */ - if (worker->mm) { - if (!dropped_lock) { - __acquire(&wqe->lock); - raw_spin_unlock_irq(&wqe->lock); - dropped_lock = true; - } - __set_current_state(TASK_RUNNING); - kthread_unuse_mm(worker->mm); - mmput(worker->mm); - worker->mm = NULL; - } - -#ifdef CONFIG_BLK_CGROUP - if (worker->blkcg_css) { - kthread_associate_blkcg(NULL); - worker->blkcg_css = NULL; - } -#endif - if (current->signal->rlim[RLIMIT_FSIZE].rlim_cur != RLIM_INFINITY) - current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; - return dropped_lock; -} - -static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe, - struct io_wq_work *work) -{ - if (work->flags & IO_WQ_WORK_UNBOUND) - return &wqe->acct[IO_WQ_ACCT_UNBOUND]; - - return &wqe->acct[IO_WQ_ACCT_BOUND]; -} - -static inline struct io_wqe_acct *io_wqe_get_acct(struct io_wqe *wqe, - struct io_worker *worker) -{ - if (worker->flags & IO_WORKER_F_BOUND) - return &wqe->acct[IO_WQ_ACCT_BOUND]; - - return &wqe->acct[IO_WQ_ACCT_UNBOUND]; -} - -static void io_worker_exit(struct io_worker *worker) -{ - struct io_wqe *wqe = worker->wqe; - struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker); - - /* - * If we're not at zero, someone else is holding a brief reference - * to the worker. Wait for that to go away. - */ - set_current_state(TASK_INTERRUPTIBLE); - if (!refcount_dec_and_test(&worker->ref)) - schedule(); - __set_current_state(TASK_RUNNING); - - preempt_disable(); - current->flags &= ~PF_IO_WORKER; - if (worker->flags & IO_WORKER_F_RUNNING) - atomic_dec(&acct->nr_running); - if (!(worker->flags & IO_WORKER_F_BOUND)) - atomic_dec(&wqe->wq->user->processes); - worker->flags = 0; - preempt_enable(); - - raw_spin_lock_irq(&wqe->lock); - hlist_nulls_del_rcu(&worker->nulls_node); - list_del_rcu(&worker->all_list); - if (__io_worker_unuse(wqe, worker)) { - __release(&wqe->lock); - raw_spin_lock_irq(&wqe->lock); - } - acct->nr_workers--; - raw_spin_unlock_irq(&wqe->lock); - - kfree_rcu(worker, rcu); - if (refcount_dec_and_test(&wqe->wq->refs)) - complete(&wqe->wq->done); -} - -static inline bool io_wqe_run_queue(struct io_wqe *wqe) - __must_hold(wqe->lock) -{ - if (!wq_list_empty(&wqe->work_list) && - !(wqe->flags & IO_WQE_FLAG_STALLED)) - return true; - return false; -} - -/* - * Check head of free list for an available worker. If one isn't available, - * caller must wake up the wq manager to create one. - */ -static bool io_wqe_activate_free_worker(struct io_wqe *wqe) - __must_hold(RCU) -{ - struct hlist_nulls_node *n; - struct io_worker *worker; - - n = rcu_dereference(hlist_nulls_first_rcu(&wqe->free_list)); - if (is_a_nulls(n)) - return false; - - worker = hlist_nulls_entry(n, struct io_worker, nulls_node); - if (io_worker_get(worker)) { - wake_up_process(worker->task); - io_worker_release(worker); - return true; - } - - return false; -} - -/* - * We need a worker. If we find a free one, we're good. If not, and we're - * below the max number of workers, wake up the manager to create one. - */ -static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct) -{ - bool ret; - - /* - * Most likely an attempt to queue unbounded work on an io_wq that - * wasn't setup with any unbounded workers. - */ - if (unlikely(!acct->max_workers)) - pr_warn_once("io-wq is not configured for unbound workers"); - - rcu_read_lock(); - ret = io_wqe_activate_free_worker(wqe); - rcu_read_unlock(); - - if (!ret && acct->nr_workers < acct->max_workers) - wake_up_process(wqe->wq->manager); -} - -static void io_wqe_inc_running(struct io_wqe *wqe, struct io_worker *worker) -{ - struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker); - - atomic_inc(&acct->nr_running); -} - -static void io_wqe_dec_running(struct io_wqe *wqe, struct io_worker *worker) - __must_hold(wqe->lock) -{ - struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker); - - if (atomic_dec_and_test(&acct->nr_running) && io_wqe_run_queue(wqe)) - io_wqe_wake_worker(wqe, acct); -} - -static void io_worker_start(struct io_wqe *wqe, struct io_worker *worker) -{ - allow_kernel_signal(SIGINT); - - current->flags |= PF_IO_WORKER; - - worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING); - worker->restore_files = current->files; - worker->restore_nsproxy = current->nsproxy; - worker->restore_fs = current->fs; - io_wqe_inc_running(wqe, worker); -} - -/* - * Worker will start processing some work. Move it to the busy list, if - * it's currently on the freelist - */ -static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker, - struct io_wq_work *work) - __must_hold(wqe->lock) -{ - bool worker_bound, work_bound; - - if (worker->flags & IO_WORKER_F_FREE) { - worker->flags &= ~IO_WORKER_F_FREE; - hlist_nulls_del_init_rcu(&worker->nulls_node); - } - - /* - * If worker is moving from bound to unbound (or vice versa), then - * ensure we update the running accounting. - */ - worker_bound = (worker->flags & IO_WORKER_F_BOUND) != 0; - work_bound = (work->flags & IO_WQ_WORK_UNBOUND) == 0; - if (worker_bound != work_bound) { - io_wqe_dec_running(wqe, worker); - if (work_bound) { - worker->flags |= IO_WORKER_F_BOUND; - wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers--; - wqe->acct[IO_WQ_ACCT_BOUND].nr_workers++; - atomic_dec(&wqe->wq->user->processes); - } else { - worker->flags &= ~IO_WORKER_F_BOUND; - wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers++; - wqe->acct[IO_WQ_ACCT_BOUND].nr_workers--; - atomic_inc(&wqe->wq->user->processes); - } - io_wqe_inc_running(wqe, worker); - } -} - -/* - * No work, worker going to sleep. Move to freelist, and unuse mm if we - * have one attached. Dropping the mm may potentially sleep, so we drop - * the lock in that case and return success. Since the caller has to - * retry the loop in that case (we changed task state), we don't regrab - * the lock if we return success. - */ -static bool __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker) - __must_hold(wqe->lock) -{ - if (!(worker->flags & IO_WORKER_F_FREE)) { - worker->flags |= IO_WORKER_F_FREE; - hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list); - } - - return __io_worker_unuse(wqe, worker); -} - -static inline unsigned int io_get_work_hash(struct io_wq_work *work) -{ - return work->flags >> IO_WQ_HASH_SHIFT; -} - -static struct io_wq_work *io_get_next_work(struct io_wqe *wqe) - __must_hold(wqe->lock) -{ - struct io_wq_work_node *node, *prev; - struct io_wq_work *work, *tail; - unsigned int hash; - - wq_list_for_each(node, prev, &wqe->work_list) { - work = container_of(node, struct io_wq_work, list); - - /* not hashed, can run anytime */ - if (!io_wq_is_hashed(work)) { - wq_list_del(&wqe->work_list, node, prev); - return work; - } - - /* hashed, can run if not already running */ - hash = io_get_work_hash(work); - if (!(wqe->hash_map & BIT(hash))) { - wqe->hash_map |= BIT(hash); - /* all items with this hash lie in [work, tail] */ - tail = wqe->hash_tail[hash]; - wqe->hash_tail[hash] = NULL; - wq_list_cut(&wqe->work_list, &tail->list, prev); - return work; - } - } - - return NULL; -} - -static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work) -{ - if (worker->mm) { - kthread_unuse_mm(worker->mm); - mmput(worker->mm); - worker->mm = NULL; - } - - if (mmget_not_zero(work->identity->mm)) { - kthread_use_mm(work->identity->mm); - worker->mm = work->identity->mm; - return; - } - - /* failed grabbing mm, ensure work gets cancelled */ - work->flags |= IO_WQ_WORK_CANCEL; -} - -static inline void io_wq_switch_blkcg(struct io_worker *worker, - struct io_wq_work *work) -{ -#ifdef CONFIG_BLK_CGROUP - if (!(work->flags & IO_WQ_WORK_BLKCG)) - return; - if (work->identity->blkcg_css != worker->blkcg_css) { - kthread_associate_blkcg(work->identity->blkcg_css); - worker->blkcg_css = work->identity->blkcg_css; - } -#endif -} - -static void io_wq_switch_creds(struct io_worker *worker, - struct io_wq_work *work) -{ - const struct cred *old_creds = override_creds(work->identity->creds); - - worker->cur_creds = work->identity->creds; - if (worker->saved_creds) - put_cred(old_creds); /* creds set by previous switch */ - else - worker->saved_creds = old_creds; -} - -static void io_impersonate_work(struct io_worker *worker, - struct io_wq_work *work) -{ - if ((work->flags & IO_WQ_WORK_FILES) && - current->files != work->identity->files) { - task_lock(current); - current->files = work->identity->files; - current->nsproxy = work->identity->nsproxy; - task_unlock(current); - if (!work->identity->files) { - /* failed grabbing files, ensure work gets cancelled */ - work->flags |= IO_WQ_WORK_CANCEL; - } - } - if ((work->flags & IO_WQ_WORK_FS) && current->fs != work->identity->fs) - current->fs = work->identity->fs; - if ((work->flags & IO_WQ_WORK_MM) && work->identity->mm != worker->mm) - io_wq_switch_mm(worker, work); - if ((work->flags & IO_WQ_WORK_CREDS) && - worker->cur_creds != work->identity->creds) - io_wq_switch_creds(worker, work); - if (work->flags & IO_WQ_WORK_FSIZE) - current->signal->rlim[RLIMIT_FSIZE].rlim_cur = work->identity->fsize; - else if (current->signal->rlim[RLIMIT_FSIZE].rlim_cur != RLIM_INFINITY) - current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; - io_wq_switch_blkcg(worker, work); -#ifdef CONFIG_AUDIT - current->loginuid = work->identity->loginuid; - current->sessionid = work->identity->sessionid; -#endif -} - -static void io_assign_current_work(struct io_worker *worker, - struct io_wq_work *work) -{ - if (work) { - /* flush pending signals before assigning new work */ - if (signal_pending(current)) - flush_signals(current); - cond_resched(); - } - -#ifdef CONFIG_AUDIT - current->loginuid = KUIDT_INIT(AUDIT_UID_UNSET); - current->sessionid = AUDIT_SID_UNSET; -#endif - - spin_lock_irq(&worker->lock); - worker->cur_work = work; - spin_unlock_irq(&worker->lock); -} - -static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work); - -static void io_worker_handle_work(struct io_worker *worker) - __releases(wqe->lock) -{ - struct io_wqe *wqe = worker->wqe; - struct io_wq *wq = wqe->wq; - - do { - struct io_wq_work *work; -get_next: - /* - * If we got some work, mark us as busy. If we didn't, but - * the list isn't empty, it means we stalled on hashed work. - * Mark us stalled so we don't keep looking for work when we - * can't make progress, any work completion or insertion will - * clear the stalled flag. - */ - work = io_get_next_work(wqe); - if (work) - __io_worker_busy(wqe, worker, work); - else if (!wq_list_empty(&wqe->work_list)) - wqe->flags |= IO_WQE_FLAG_STALLED; - - raw_spin_unlock_irq(&wqe->lock); - if (!work) - break; - io_assign_current_work(worker, work); - - /* handle a whole dependent link */ - do { - struct io_wq_work *old_work, *next_hashed, *linked; - unsigned int hash = io_get_work_hash(work); - - next_hashed = wq_next_work(work); - io_impersonate_work(worker, work); - /* - * OK to set IO_WQ_WORK_CANCEL even for uncancellable - * work, the worker function will do the right thing. - */ - if (test_bit(IO_WQ_BIT_CANCEL, &wq->state)) - work->flags |= IO_WQ_WORK_CANCEL; - - old_work = work; - linked = wq->do_work(work); - - work = next_hashed; - if (!work && linked && !io_wq_is_hashed(linked)) { - work = linked; - linked = NULL; - } - io_assign_current_work(worker, work); - wq->free_work(old_work); - - if (linked) - io_wqe_enqueue(wqe, linked); - - if (hash != -1U && !next_hashed) { - raw_spin_lock_irq(&wqe->lock); - wqe->hash_map &= ~BIT_ULL(hash); - wqe->flags &= ~IO_WQE_FLAG_STALLED; - /* skip unnecessary unlock-lock wqe->lock */ - if (!work) - goto get_next; - raw_spin_unlock_irq(&wqe->lock); - } - } while (work); - - raw_spin_lock_irq(&wqe->lock); - } while (1); -} - -static int io_wqe_worker(void *data) -{ - struct io_worker *worker = data; - struct io_wqe *wqe = worker->wqe; - struct io_wq *wq = wqe->wq; - - io_worker_start(wqe, worker); - - while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) { - set_current_state(TASK_INTERRUPTIBLE); -loop: - raw_spin_lock_irq(&wqe->lock); - if (io_wqe_run_queue(wqe)) { - __set_current_state(TASK_RUNNING); - io_worker_handle_work(worker); - goto loop; - } - /* drops the lock on success, retry */ - if (__io_worker_idle(wqe, worker)) { - __release(&wqe->lock); - goto loop; - } - raw_spin_unlock_irq(&wqe->lock); - if (signal_pending(current)) - flush_signals(current); - if (schedule_timeout(WORKER_IDLE_TIMEOUT)) - continue; - /* timed out, exit unless we're the fixed worker */ - if (test_bit(IO_WQ_BIT_EXIT, &wq->state) || - !(worker->flags & IO_WORKER_F_FIXED)) - break; - } - - if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) { - raw_spin_lock_irq(&wqe->lock); - if (!wq_list_empty(&wqe->work_list)) - io_worker_handle_work(worker); - else - raw_spin_unlock_irq(&wqe->lock); - } - - io_worker_exit(worker); - return 0; -} - -/* - * Called when a worker is scheduled in. Mark us as currently running. - */ -void io_wq_worker_running(struct task_struct *tsk) -{ - struct io_worker *worker = kthread_data(tsk); - struct io_wqe *wqe = worker->wqe; - - if (!(worker->flags & IO_WORKER_F_UP)) - return; - if (worker->flags & IO_WORKER_F_RUNNING) - return; - worker->flags |= IO_WORKER_F_RUNNING; - io_wqe_inc_running(wqe, worker); -} - -/* - * Called when worker is going to sleep. If there are no workers currently - * running and we have work pending, wake up a free one or have the manager - * set one up. - */ -void io_wq_worker_sleeping(struct task_struct *tsk) -{ - struct io_worker *worker = kthread_data(tsk); - struct io_wqe *wqe = worker->wqe; - - if (!(worker->flags & IO_WORKER_F_UP)) - return; - if (!(worker->flags & IO_WORKER_F_RUNNING)) - return; - - worker->flags &= ~IO_WORKER_F_RUNNING; - - raw_spin_lock_irq(&wqe->lock); - io_wqe_dec_running(wqe, worker); - raw_spin_unlock_irq(&wqe->lock); -} - -static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index) -{ - struct io_wqe_acct *acct = &wqe->acct[index]; - struct io_worker *worker; - - worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node); - if (!worker) - return false; - - refcount_set(&worker->ref, 1); - worker->nulls_node.pprev = NULL; - worker->wqe = wqe; - spin_lock_init(&worker->lock); - - worker->task = kthread_create_on_node(io_wqe_worker, worker, wqe->node, - "io_wqe_worker-%d/%d", index, wqe->node); - if (IS_ERR(worker->task)) { - kfree(worker); - return false; - } - kthread_bind_mask(worker->task, cpumask_of_node(wqe->node)); - - raw_spin_lock_irq(&wqe->lock); - hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list); - list_add_tail_rcu(&worker->all_list, &wqe->all_list); - worker->flags |= IO_WORKER_F_FREE; - if (index == IO_WQ_ACCT_BOUND) - worker->flags |= IO_WORKER_F_BOUND; - if (!acct->nr_workers && (worker->flags & IO_WORKER_F_BOUND)) - worker->flags |= IO_WORKER_F_FIXED; - acct->nr_workers++; - raw_spin_unlock_irq(&wqe->lock); - - if (index == IO_WQ_ACCT_UNBOUND) - atomic_inc(&wq->user->processes); - - refcount_inc(&wq->refs); - wake_up_process(worker->task); - return true; -} - -static inline bool io_wqe_need_worker(struct io_wqe *wqe, int index) - __must_hold(wqe->lock) -{ - struct io_wqe_acct *acct = &wqe->acct[index]; - - /* if we have available workers or no work, no need */ - if (!hlist_nulls_empty(&wqe->free_list) || !io_wqe_run_queue(wqe)) - return false; - return acct->nr_workers < acct->max_workers; -} - -static bool io_wqe_worker_send_sig(struct io_worker *worker, void *data) -{ - send_sig(SIGINT, worker->task, 1); - return false; -} - -/* - * Iterate the passed in list and call the specific function for each - * worker that isn't exiting - */ -static bool io_wq_for_each_worker(struct io_wqe *wqe, - bool (*func)(struct io_worker *, void *), - void *data) -{ - struct io_worker *worker; - bool ret = false; - - list_for_each_entry_rcu(worker, &wqe->all_list, all_list) { - if (io_worker_get(worker)) { - /* no task if node is/was offline */ - if (worker->task) - ret = func(worker, data); - io_worker_release(worker); - if (ret) - break; - } - } - - return ret; -} - -static bool io_wq_worker_wake(struct io_worker *worker, void *data) -{ - wake_up_process(worker->task); - return false; -} - -/* - * Manager thread. Tasked with creating new workers, if we need them. - */ -static int io_wq_manager(void *data) -{ - struct io_wq *wq = data; - int node; - - /* create fixed workers */ - refcount_set(&wq->refs, 1); - for_each_node(node) { - if (!node_online(node)) - continue; - if (create_io_worker(wq, wq->wqes[node], IO_WQ_ACCT_BOUND)) - continue; - set_bit(IO_WQ_BIT_ERROR, &wq->state); - set_bit(IO_WQ_BIT_EXIT, &wq->state); - goto out; - } - - complete(&wq->done); - - while (!kthread_should_stop()) { - if (current->task_works) - task_work_run(); - - for_each_node(node) { - struct io_wqe *wqe = wq->wqes[node]; - bool fork_worker[2] = { false, false }; - - if (!node_online(node)) - continue; - - raw_spin_lock_irq(&wqe->lock); - if (io_wqe_need_worker(wqe, IO_WQ_ACCT_BOUND)) - fork_worker[IO_WQ_ACCT_BOUND] = true; - if (io_wqe_need_worker(wqe, IO_WQ_ACCT_UNBOUND)) - fork_worker[IO_WQ_ACCT_UNBOUND] = true; - raw_spin_unlock_irq(&wqe->lock); - if (fork_worker[IO_WQ_ACCT_BOUND]) - create_io_worker(wq, wqe, IO_WQ_ACCT_BOUND); - if (fork_worker[IO_WQ_ACCT_UNBOUND]) - create_io_worker(wq, wqe, IO_WQ_ACCT_UNBOUND); - } - set_current_state(TASK_INTERRUPTIBLE); - schedule_timeout(HZ); - } - - if (current->task_works) - task_work_run(); - -out: - if (refcount_dec_and_test(&wq->refs)) { - complete(&wq->done); - return 0; - } - /* if ERROR is set and we get here, we have workers to wake */ - if (test_bit(IO_WQ_BIT_ERROR, &wq->state)) { - rcu_read_lock(); - for_each_node(node) - io_wq_for_each_worker(wq->wqes[node], io_wq_worker_wake, NULL); - rcu_read_unlock(); - } - return 0; -} - -static bool io_wq_can_queue(struct io_wqe *wqe, struct io_wqe_acct *acct, - struct io_wq_work *work) -{ - bool free_worker; - - if (!(work->flags & IO_WQ_WORK_UNBOUND)) - return true; - if (atomic_read(&acct->nr_running)) - return true; - - rcu_read_lock(); - free_worker = !hlist_nulls_empty(&wqe->free_list); - rcu_read_unlock(); - if (free_worker) - return true; - - if (atomic_read(&wqe->wq->user->processes) >= acct->max_workers && - !(capable(CAP_SYS_RESOURCE) || capable(CAP_SYS_ADMIN))) - return false; - - return true; -} - -static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe) -{ - struct io_wq *wq = wqe->wq; - - do { - struct io_wq_work *old_work = work; - - work->flags |= IO_WQ_WORK_CANCEL; - work = wq->do_work(work); - wq->free_work(old_work); - } while (work); -} - -static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work) -{ - unsigned int hash; - struct io_wq_work *tail; - - if (!io_wq_is_hashed(work)) { -append: - wq_list_add_tail(&work->list, &wqe->work_list); - return; - } - - hash = io_get_work_hash(work); - tail = wqe->hash_tail[hash]; - wqe->hash_tail[hash] = work; - if (!tail) - goto append; - - wq_list_add_after(&work->list, &tail->list, &wqe->work_list); -} - -static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) -{ - struct io_wqe_acct *acct = io_work_get_acct(wqe, work); - bool do_wake; - unsigned long flags; - - /* - * Do early check to see if we need a new unbound worker, and if we do, - * if we're allowed to do so. This isn't 100% accurate as there's a - * gap between this check and incrementing the value, but that's OK. - * It's close enough to not be an issue, fork() has the same delay. - */ - if (unlikely(!io_wq_can_queue(wqe, acct, work))) { - io_run_cancel(work, wqe); - return; - } - - raw_spin_lock_irqsave(&wqe->lock, flags); - io_wqe_insert_work(wqe, work); - wqe->flags &= ~IO_WQE_FLAG_STALLED; - do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) || - !atomic_read(&acct->nr_running); - raw_spin_unlock_irqrestore(&wqe->lock, flags); - - if (do_wake) - io_wqe_wake_worker(wqe, acct); -} - -void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work) -{ - struct io_wqe *wqe = wq->wqes[numa_node_id()]; - - io_wqe_enqueue(wqe, work); -} - -/* - * Work items that hash to the same value will not be done in parallel. - * Used to limit concurrent writes, generally hashed by inode. - */ -void io_wq_hash_work(struct io_wq_work *work, void *val) -{ - unsigned int bit; - - bit = hash_ptr(val, IO_WQ_HASH_ORDER); - work->flags |= (IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT)); -} - -void io_wq_cancel_all(struct io_wq *wq) -{ - int node; - - set_bit(IO_WQ_BIT_CANCEL, &wq->state); - - rcu_read_lock(); - for_each_node(node) { - struct io_wqe *wqe = wq->wqes[node]; - - io_wq_for_each_worker(wqe, io_wqe_worker_send_sig, NULL); - } - rcu_read_unlock(); -} - -struct io_cb_cancel_data { - work_cancel_fn *fn; - void *data; - int nr_running; - int nr_pending; - bool cancel_all; -}; - -static bool io_wq_worker_cancel(struct io_worker *worker, void *data) -{ - struct io_cb_cancel_data *match = data; - unsigned long flags; - - /* - * Hold the lock to avoid ->cur_work going out of scope, caller - * may dereference the passed in work. - */ - spin_lock_irqsave(&worker->lock, flags); - if (worker->cur_work && - !(worker->cur_work->flags & IO_WQ_WORK_NO_CANCEL) && - match->fn(worker->cur_work, match->data)) { - send_sig(SIGINT, worker->task, 1); - match->nr_running++; - } - spin_unlock_irqrestore(&worker->lock, flags); - - return match->nr_running && !match->cancel_all; -} - -static inline void io_wqe_remove_pending(struct io_wqe *wqe, - struct io_wq_work *work, - struct io_wq_work_node *prev) -{ - unsigned int hash = io_get_work_hash(work); - struct io_wq_work *prev_work = NULL; - - if (io_wq_is_hashed(work) && work == wqe->hash_tail[hash]) { - if (prev) - prev_work = container_of(prev, struct io_wq_work, list); - if (prev_work && io_get_work_hash(prev_work) == hash) - wqe->hash_tail[hash] = prev_work; - else - wqe->hash_tail[hash] = NULL; - } - wq_list_del(&wqe->work_list, &work->list, prev); -} - -static void io_wqe_cancel_pending_work(struct io_wqe *wqe, - struct io_cb_cancel_data *match) -{ - struct io_wq_work_node *node, *prev; - struct io_wq_work *work; - unsigned long flags; - -retry: - raw_spin_lock_irqsave(&wqe->lock, flags); - wq_list_for_each(node, prev, &wqe->work_list) { - work = container_of(node, struct io_wq_work, list); - if (!match->fn(work, match->data)) - continue; - io_wqe_remove_pending(wqe, work, prev); - raw_spin_unlock_irqrestore(&wqe->lock, flags); - io_run_cancel(work, wqe); - match->nr_pending++; - if (!match->cancel_all) - return; - - /* not safe to continue after unlock */ - goto retry; - } - raw_spin_unlock_irqrestore(&wqe->lock, flags); -} - -static void io_wqe_cancel_running_work(struct io_wqe *wqe, - struct io_cb_cancel_data *match) -{ - rcu_read_lock(); - io_wq_for_each_worker(wqe, io_wq_worker_cancel, match); - rcu_read_unlock(); -} - -enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, - void *data, bool cancel_all) -{ - struct io_cb_cancel_data match = { - .fn = cancel, - .data = data, - .cancel_all = cancel_all, - }; - int node; - - /* - * First check pending list, if we're lucky we can just remove it - * from there. CANCEL_OK means that the work is returned as-new, - * no completion will be posted for it. - */ - for_each_node(node) { - struct io_wqe *wqe = wq->wqes[node]; - - io_wqe_cancel_pending_work(wqe, &match); - if (match.nr_pending && !match.cancel_all) - return IO_WQ_CANCEL_OK; - } - - /* - * Now check if a free (going busy) or busy worker has the work - * currently running. If we find it there, we'll return CANCEL_RUNNING - * as an indication that we attempt to signal cancellation. The - * completion will run normally in this case. - */ - for_each_node(node) { - struct io_wqe *wqe = wq->wqes[node]; - - io_wqe_cancel_running_work(wqe, &match); - if (match.nr_running && !match.cancel_all) - return IO_WQ_CANCEL_RUNNING; - } - - if (match.nr_running) - return IO_WQ_CANCEL_RUNNING; - if (match.nr_pending) - return IO_WQ_CANCEL_OK; - return IO_WQ_CANCEL_NOTFOUND; -} - -struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) -{ - int ret = -ENOMEM, node; - struct io_wq *wq; - - if (WARN_ON_ONCE(!data->free_work || !data->do_work)) - return ERR_PTR(-EINVAL); - if (WARN_ON_ONCE(!bounded)) - return ERR_PTR(-EINVAL); - - wq = kzalloc(sizeof(*wq), GFP_KERNEL); - if (!wq) - return ERR_PTR(-ENOMEM); - - wq->wqes = kcalloc(nr_node_ids, sizeof(struct io_wqe *), GFP_KERNEL); - if (!wq->wqes) - goto err_wq; - - ret = cpuhp_state_add_instance_nocalls(io_wq_online, &wq->cpuhp_node); - if (ret) - goto err_wqes; - - wq->free_work = data->free_work; - wq->do_work = data->do_work; - - /* caller must already hold a reference to this */ - wq->user = data->user; - - ret = -ENOMEM; - for_each_node(node) { - struct io_wqe *wqe; - int alloc_node = node; - - if (!node_online(alloc_node)) - alloc_node = NUMA_NO_NODE; - wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, alloc_node); - if (!wqe) - goto err; - wq->wqes[node] = wqe; - wqe->node = alloc_node; - wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded; - atomic_set(&wqe->acct[IO_WQ_ACCT_BOUND].nr_running, 0); - if (wq->user) { - wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers = - task_rlimit(current, RLIMIT_NPROC); - } - atomic_set(&wqe->acct[IO_WQ_ACCT_UNBOUND].nr_running, 0); - wqe->wq = wq; - raw_spin_lock_init(&wqe->lock); - INIT_WQ_LIST(&wqe->work_list); - INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0); - INIT_LIST_HEAD(&wqe->all_list); - } - - init_completion(&wq->done); - - wq->manager = kthread_create(io_wq_manager, wq, "io_wq_manager"); - if (!IS_ERR(wq->manager)) { - wake_up_process(wq->manager); - wait_for_completion(&wq->done); - if (test_bit(IO_WQ_BIT_ERROR, &wq->state)) { - ret = -ENOMEM; - goto err; - } - refcount_set(&wq->use_refs, 1); - reinit_completion(&wq->done); - return wq; - } - - ret = PTR_ERR(wq->manager); - complete(&wq->done); -err: - cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node); - for_each_node(node) - kfree(wq->wqes[node]); -err_wqes: - kfree(wq->wqes); -err_wq: - kfree(wq); - return ERR_PTR(ret); -} - -bool io_wq_get(struct io_wq *wq, struct io_wq_data *data) -{ - if (data->free_work != wq->free_work || data->do_work != wq->do_work) - return false; - - return refcount_inc_not_zero(&wq->use_refs); -} - -static void __io_wq_destroy(struct io_wq *wq) -{ - int node; - - cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node); - - set_bit(IO_WQ_BIT_EXIT, &wq->state); - if (wq->manager) - kthread_stop(wq->manager); - - rcu_read_lock(); - for_each_node(node) - io_wq_for_each_worker(wq->wqes[node], io_wq_worker_wake, NULL); - rcu_read_unlock(); - - wait_for_completion(&wq->done); - - for_each_node(node) - kfree(wq->wqes[node]); - kfree(wq->wqes); - kfree(wq); -} - -void io_wq_destroy(struct io_wq *wq) -{ - if (refcount_dec_and_test(&wq->use_refs)) - __io_wq_destroy(wq); -} - -struct task_struct *io_wq_get_task(struct io_wq *wq) -{ - return wq->manager; -} - -static bool io_wq_worker_affinity(struct io_worker *worker, void *data) -{ - struct task_struct *task = worker->task; - struct rq_flags rf; - struct rq *rq; - - rq = task_rq_lock(task, &rf); - do_set_cpus_allowed(task, cpumask_of_node(worker->wqe->node)); - task->flags |= PF_NO_SETAFFINITY; - task_rq_unlock(rq, task, &rf); - return false; -} - -static int io_wq_cpu_online(unsigned int cpu, struct hlist_node *node) -{ - struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node); - int i; - - rcu_read_lock(); - for_each_node(i) - io_wq_for_each_worker(wq->wqes[i], io_wq_worker_affinity, NULL); - rcu_read_unlock(); - return 0; -} - -static __init int io_wq_init(void) -{ - int ret; - - ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "io-wq/online", - io_wq_cpu_online, NULL); - if (ret < 0) - return ret; - io_wq_online = ret; - return 0; -} -subsys_initcall(io_wq_init); diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h index 35b2d845704d..649a4d7c241b 100644 --- a/include/linux/io_uring.h +++ b/include/linux/io_uring.h @@ -5,50 +5,20 @@ #include <linux/sched.h> #include <linux/xarray.h>

-struct io_identity { - struct files_struct *files; - struct mm_struct *mm; -#ifdef CONFIG_BLK_CGROUP - struct cgroup_subsys_state *blkcg_css; -#endif - const struct cred *creds; - struct nsproxy *nsproxy; - struct fs_struct *fs; - unsigned long fsize; -#ifdef CONFIG_AUDIT - kuid_t loginuid; - unsigned int sessionid; -#endif - refcount_t count; -}; - -struct io_uring_task { - /* submission side */ - struct xarray xa; - struct wait_queue_head wait; - struct file *last; - struct percpu_counter inflight; - struct io_identity __identity; - struct io_identity *identity; - atomic_t in_idle; - bool sqpoll; -}; - #if defined(CONFIG_IO_URING) struct sock *io_uring_get_socket(struct file *file); -void __io_uring_task_cancel(void); -void __io_uring_files_cancel(struct files_struct *files); +void __io_uring_cancel(bool cancel_all); void __io_uring_free(struct task_struct *tsk);

-static inline void io_uring_task_cancel(void) +static inline void io_uring_files_cancel(void) { - if (current->io_uring && !xa_empty(&current->io_uring->xa)) - __io_uring_task_cancel(); + if (current->io_uring) + __io_uring_cancel(false); } -static inline void io_uring_files_cancel(struct files_struct *files) +static inline void io_uring_task_cancel(void) { - if (current->io_uring && !xa_empty(&current->io_uring->xa)) - __io_uring_files_cancel(files); + if (current->io_uring) + __io_uring_cancel(true); } static inline void io_uring_free(struct task_struct *tsk) { @@ -63,7 +33,7 @@ static inline struct sock *io_uring_get_socket(struct file *file) static inline void io_uring_task_cancel(void) { } -static inline void io_uring_files_cancel(struct files_struct *files) +static inline void io_uring_files_cancel(void) { } static inline void io_uring_free(struct task_struct *tsk) diff --git a/include/linux/sched.h b/include/linux/sched.h index a84372945f9e..961acc4fa738 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -925,6 +925,9 @@ struct task_struct { /* CLONE_CHILD_CLEARTID: */ int __user *clear_child_tid;

+ /* PF_IO_WORKER */ + void *pf_io_worker; + u64 utime; u64 stime; #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index aea0ce9f3b74..a058c96cf213 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -341,7 +341,7 @@ asmlinkage long sys_io_uring_setup(u32 entries, struct io_uring_params __user *p); asmlinkage long sys_io_uring_enter(unsigned int fd, u32 to_submit, u32 min_complete, u32 flags, - const sigset_t __user *sig, size_t sigsz); + const void __user *argp, size_t argsz); asmlinkage long sys_io_uring_register(unsigned int fd, unsigned int op, void __user *arg, unsigned int nr_args);

diff --git a/include/trace/events/io_uring.h b/include/trace/events/io_uring.h index 9f0d3b7d56b0..0dd30de00e5b 100644 --- a/include/trace/events/io_uring.h +++ b/include/trace/events/io_uring.h @@ -12,11 +12,11 @@ struct io_wq_work; /** * io_uring_create - called after a new io_uring context was prepared * - * @fd: corresponding file descriptor - * @ctx: pointer to a ring context structure + * @fd: corresponding file descriptor + * @ctx: pointer to a ring context structure * @sq_entries: actual SQ size * @cq_entries: actual CQ size - * @flags: SQ ring flags, provided to io_uring_setup(2) + * @flags: SQ ring flags, provided to io_uring_setup(2) * * Allows to trace io_uring creation and provide pointer to a context, that can * be used later to find correlated events. @@ -49,15 +49,15 @@ TRACE_EVENT(io_uring_create, );

/** - * io_uring_register - called after a buffer/file/eventfd was succesfully + * io_uring_register - called after a buffer/file/eventfd was successfully * registered for a ring * - * @ctx: pointer to a ring context structure - * @opcode: describes which operation to perform + * @ctx: pointer to a ring context structure + * @opcode: describes which operation to perform * @nr_user_files: number of registered files * @nr_user_bufs: number of registered buffers * @cq_ev_fd: whether eventfs registered or not - * @ret: return code + * @ret: return code * * Allows to trace fixed files/buffers/eventfds, that could be registered to * avoid an overhead of getting references to them for every operation. This @@ -142,16 +142,16 @@ TRACE_EVENT(io_uring_queue_async_work, TP_ARGS(ctx, rw, req, work, flags),

TP_STRUCT__entry ( - __field( void *, ctx ) - __field( int, rw ) - __field( void *, req ) + __field( void *, ctx ) + __field( int, rw ) + __field( void *, req ) __field( struct io_wq_work *, work ) __field( unsigned int, flags ) ),

TP_fast_assign( __entry->ctx = ctx; - __entry->rw = rw; + __entry->rw = rw; __entry->req = req; __entry->work = work; __entry->flags = flags; @@ -196,10 +196,10 @@ TRACE_EVENT(io_uring_defer,

/** * io_uring_link - called before the io_uring request added into link_list of - * another request + * another request * - * @ctx: pointer to a ring context structure - * @req: pointer to a linked request + * @ctx: pointer to a ring context structure + * @req: pointer to a linked request * @target_req: pointer to a previous request, that would contain @req * * Allows to track linked requests, to understand dependencies between requests @@ -212,8 +212,8 @@ TRACE_EVENT(io_uring_link, TP_ARGS(ctx, req, target_req),

TP_STRUCT__entry ( - __field( void *, ctx ) - __field( void *, req ) + __field( void *, ctx ) + __field( void *, req ) __field( void *, target_req ) ),

@@ -244,7 +244,7 @@ TRACE_EVENT(io_uring_cqring_wait, TP_ARGS(ctx, min_events),

TP_STRUCT__entry ( - __field( void *, ctx ) + __field( void *, ctx ) __field( int, min_events ) ),

@@ -272,7 +272,7 @@ TRACE_EVENT(io_uring_fail_link, TP_ARGS(req, link),

TP_STRUCT__entry ( - __field( void *, req ) + __field( void *, req ) __field( void *, link ) ),

@@ -290,38 +290,42 @@ TRACE_EVENT(io_uring_fail_link, * @ctx: pointer to a ring context structure * @user_data: user data associated with the request * @res: result of the request + * @cflags: completion flags * */ TRACE_EVENT(io_uring_complete,

- TP_PROTO(void *ctx, u64 user_data, long res), + TP_PROTO(void *ctx, u64 user_data, int res, unsigned cflags),

- TP_ARGS(ctx, user_data, res), + TP_ARGS(ctx, user_data, res, cflags),

TP_STRUCT__entry ( __field( void *, ctx ) __field( u64, user_data ) - __field( long, res ) + __field( int, res ) + __field( unsigned, cflags ) ),

TP_fast_assign( __entry->ctx = ctx; __entry->user_data = user_data; __entry->res = res; + __entry->cflags = cflags; ),

- TP_printk("ring %p, user_data 0x%llx, result %ld", + TP_printk("ring %p, user_data 0x%llx, result %d, cflags %x", __entry->ctx, (unsigned long long)__entry->user_data, - __entry->res) + __entry->res, __entry->cflags) );

- /** * io_uring_submit_sqe - called before submitting one SQE * * @ctx: pointer to a ring context structure + * @req: pointer to a submitted request * @opcode: opcode of request * @user_data: user data associated with the request + * @flags request flags * @force_nonblock: whether a context blocking or not * @sq_thread: true if sq_thread has submitted this SQE * @@ -330,41 +334,60 @@ TRACE_EVENT(io_uring_complete, */ TRACE_EVENT(io_uring_submit_sqe,

- TP_PROTO(void *ctx, u8 opcode, u64 user_data, bool force_nonblock, - bool sq_thread), + TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data, u32 flags, + bool force_nonblock, bool sq_thread),

- TP_ARGS(ctx, opcode, user_data, force_nonblock, sq_thread), + TP_ARGS(ctx, req, opcode, user_data, flags, force_nonblock, sq_thread),

TP_STRUCT__entry ( __field( void *, ctx ) + __field( void *, req ) __field( u8, opcode ) __field( u64, user_data ) + __field( u32, flags ) __field( bool, force_nonblock ) __field( bool, sq_thread ) ),

TP_fast_assign( __entry->ctx = ctx; + __entry->req = req; __entry->opcode = opcode; __entry->user_data = user_data; + __entry->flags = flags; __entry->force_nonblock = force_nonblock; __entry->sq_thread = sq_thread; ),

- TP_printk("ring %p, op %d, data 0x%llx, non block %d, sq_thread %d", - __entry->ctx, __entry->opcode, - (unsigned long long) __entry->user_data, - __entry->force_nonblock, __entry->sq_thread) + TP_printk("ring %p, req %p, op %d, data 0x%llx, flags %u, " + "non block %d, sq_thread %d", __entry->ctx, __entry->req, + __entry->opcode, (unsigned long long)__entry->user_data, + __entry->flags, __entry->force_nonblock, __entry->sq_thread) );

+/* + * io_uring_poll_arm - called after arming a poll wait if successful + * + * @ctx: pointer to a ring context structure + * @req: pointer to the armed request + * @opcode: opcode of request + * @user_data: user data associated with the request + * @mask: request poll events mask + * @events: registered events of interest + * + * Allows to track which fds are waiting for and what are the events of + * interest. + */ TRACE_EVENT(io_uring_poll_arm,

- TP_PROTO(void *ctx, u8 opcode, u64 user_data, int mask, int events), + TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data, + int mask, int events),

- TP_ARGS(ctx, opcode, user_data, mask, events), + TP_ARGS(ctx, req, opcode, user_data, mask, events),

TP_STRUCT__entry ( __field( void *, ctx ) + __field( void *, req ) __field( u8, opcode ) __field( u64, user_data ) __field( int, mask ) @@ -373,16 +396,17 @@ TRACE_EVENT(io_uring_poll_arm,

TP_fast_assign( __entry->ctx = ctx; + __entry->req = req; __entry->opcode = opcode; __entry->user_data = user_data; __entry->mask = mask; __entry->events = events; ),

- TP_printk("ring %p, op %d, data 0x%llx, mask 0x%x, events 0x%x", - __entry->ctx, __entry->opcode, - (unsigned long long) __entry->user_data, - __entry->mask, __entry->events) + TP_printk("ring %p, req %p, op %d, data 0x%llx, mask 0x%x, events 0x%x", + __entry->ctx, __entry->req, __entry->opcode, + (unsigned long long) __entry->user_data, + __entry->mask, __entry->events) );

TRACE_EVENT(io_uring_poll_wake, @@ -437,27 +461,40 @@ TRACE_EVENT(io_uring_task_add, __entry->mask) );

+/* + * io_uring_task_run - called when task_work_run() executes the poll events + * notification callbacks + * + * @ctx: pointer to a ring context structure + * @req: pointer to the armed request + * @opcode: opcode of request + * @user_data: user data associated with the request + * + * Allows to track when notified poll events are processed + */ TRACE_EVENT(io_uring_task_run,

- TP_PROTO(void *ctx, u8 opcode, u64 user_data), + TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data),

- TP_ARGS(ctx, opcode, user_data), + TP_ARGS(ctx, req, opcode, user_data),

TP_STRUCT__entry ( __field( void *, ctx ) + __field( void *, req ) __field( u8, opcode ) __field( u64, user_data ) ),

TP_fast_assign( __entry->ctx = ctx; + __entry->req = req; __entry->opcode = opcode; __entry->user_data = user_data; ),

- TP_printk("ring %p, op %d, data 0x%llx", - __entry->ctx, __entry->opcode, - (unsigned long long) __entry->user_data) + TP_printk("ring %p, req %p, op %d, data 0x%llx", + __entry->ctx, __entry->req, __entry->opcode, + (unsigned long long) __entry->user_data) );

#endif /* _TRACE_IO_URING_H */ diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 98d8e06dea22..6481db937002 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -42,23 +42,25 @@ struct io_uring_sqe { __u32 statx_flags; __u32 fadvise_advice; __u32 splice_flags; + __u32 rename_flags; + __u32 unlink_flags; + __u32 hardlink_flags; }; __u64 user_data; /* data to be passed back at completion time */ + /* pack this to avoid bogus arm OABI complaints */ union { - struct { - /* pack this to avoid bogus arm OABI complaints */ - union { - /* index into fixed buffers, if used */ - __u16 buf_index; - /* for grouped buffer selection */ - __u16 buf_group; - } __attribute__((packed)); - /* personality to use, if used */ - __u16 personality; - __s32 splice_fd_in; - }; - __u64 __pad2[3]; + /* index into fixed buffers, if used */ + __u16 buf_index; + /* for grouped buffer selection */ + __u16 buf_group; + } __attribute__((packed)); + /* personality to use, if used */ + __u16 personality; + union { + __s32 splice_fd_in; + __u32 file_index; }; + __u64 __pad2[2]; };

enum { @@ -132,6 +134,9 @@ enum { IORING_OP_PROVIDE_BUFFERS, IORING_OP_REMOVE_BUFFERS, IORING_OP_TEE, + IORING_OP_SHUTDOWN, + IORING_OP_RENAMEAT, + IORING_OP_UNLINKAT,

/* this goes last, obviously */ IORING_OP_LAST, @@ -145,14 +150,34 @@ enum { /* * sqe->timeout_flags */ -#define IORING_TIMEOUT_ABS (1U << 0) - +#define IORING_TIMEOUT_ABS (1U << 0) +#define IORING_TIMEOUT_UPDATE (1U << 1) +#define IORING_TIMEOUT_BOOTTIME (1U << 2) +#define IORING_TIMEOUT_REALTIME (1U << 3) +#define IORING_LINK_TIMEOUT_UPDATE (1U << 4) +#define IORING_TIMEOUT_CLOCK_MASK (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME) +#define IORING_TIMEOUT_UPDATE_MASK (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE) /* * sqe->splice_flags * extends splice(2) flags */ #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */

+/* + * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the + * command flags for POLL_ADD are stored in sqe->len. + * + * IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if + * the poll handler will continue to report + * CQEs on behalf of the same SQE. + * + * IORING_POLL_UPDATE Update existing poll request, matching + * sqe->addr as the old user_data field. + */ +#define IORING_POLL_ADD_MULTI (1U << 0) +#define IORING_POLL_UPDATE_EVENTS (1U << 1) +#define IORING_POLL_UPDATE_USER_DATA (1U << 2) + /* * IO completion data structure (Completion Queue Entry) */ @@ -166,8 +191,10 @@ struct io_uring_cqe { * cqe->flags * * IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID + * IORING_CQE_F_MORE If set, parent SQE will generate more CQE entries */ #define IORING_CQE_F_BUFFER (1U << 0) +#define IORING_CQE_F_MORE (1U << 1)

enum { IORING_CQE_BUFFER_SHIFT = 16, @@ -226,6 +253,7 @@ struct io_cqring_offsets { #define IORING_ENTER_GETEVENTS (1U << 0) #define IORING_ENTER_SQ_WAKEUP (1U << 1) #define IORING_ENTER_SQ_WAIT (1U << 2) +#define IORING_ENTER_EXT_ARG (1U << 3)

/* * Passed in for io_uring_setup(2). Copied back with updated info on success @@ -253,6 +281,10 @@ struct io_uring_params { #define IORING_FEAT_CUR_PERSONALITY (1U << 4) #define IORING_FEAT_FAST_POLL (1U << 5) #define IORING_FEAT_POLL_32BITS (1U << 6) +#define IORING_FEAT_SQPOLL_NONFIXED (1U << 7) +#define IORING_FEAT_EXT_ARG (1U << 8) +#define IORING_FEAT_NATIVE_WORKERS (1U << 9) +#define IORING_FEAT_RSRC_TAGS (1U << 10)

/* * io_uring_register(2) opcodes and arguments @@ -272,16 +304,62 @@ enum { IORING_REGISTER_RESTRICTIONS = 11, IORING_REGISTER_ENABLE_RINGS = 12,

+ /* extended with tagging */ + IORING_REGISTER_FILES2 = 13, + IORING_REGISTER_FILES_UPDATE2 = 14, + IORING_REGISTER_BUFFERS2 = 15, + IORING_REGISTER_BUFFERS_UPDATE = 16, + + /* set/clear io-wq thread affinities */ + IORING_REGISTER_IOWQ_AFF = 17, + IORING_UNREGISTER_IOWQ_AFF = 18, + + /* set/get max number of io-wq workers */ + IORING_REGISTER_IOWQ_MAX_WORKERS = 19, + /* this goes last */ IORING_REGISTER_LAST };

+/* io-wq worker categories */ +enum { + IO_WQ_BOUND, + IO_WQ_UNBOUND, +}; + +/* deprecated, see struct io_uring_rsrc_update */ struct io_uring_files_update { __u32 offset; __u32 resv; __aligned_u64 /* __s32 * */ fds; };

+struct io_uring_rsrc_register { + __u32 nr; + __u32 resv; + __u64 resv2; + __aligned_u64 data; + __aligned_u64 tags; +}; + +struct io_uring_rsrc_update { + __u32 offset; + __u32 resv; + __aligned_u64 data; +}; + +struct io_uring_rsrc_update2 { + __u32 offset; + __u32 resv; + __aligned_u64 data; + __aligned_u64 tags; + __u32 nr; + __u32 resv2; +}; + +/* Skip updating fd indexes set to this value in the fd table */ +#define IORING_REGISTER_FILES_SKIP (-2) + #define IO_URING_OP_SUPPORTED (1U << 0)

struct io_uring_probe_op { @@ -329,4 +407,11 @@ enum { IORING_RESTRICTION_LAST };

+struct io_uring_getevents_arg { + __u64 sigmask; + __u32 sigmask_sz; + __u32 pad; + __u64 ts; +}; + #endif diff --git a/io_uring/Makefile b/io_uring/Makefile new file mode 100644 index 000000000000..3680425df947 --- /dev/null +++ b/io_uring/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for io_uring + +obj-$(CONFIG_IO_URING) += io_uring.o +obj-$(CONFIG_IO_WQ) += io-wq.o diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c new file mode 100644 index 000000000000..6031fb319d87 --- /dev/null +++ b/io_uring/io-wq.c @@ -0,0 +1,1398 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Basic worker thread pool for io_uring + * + * Copyright (C) 2019 Jens Axboe + * + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/sched/signal.h> +#include <linux/percpu.h> +#include <linux/slab.h> +#include <linux/rculist_nulls.h> +#include <linux/cpu.h> +#include <linux/tracehook.h> +#include <uapi/linux/io_uring.h> + +#include "io-wq.h" + +#define WORKER_IDLE_TIMEOUT (5 * HZ) + +enum { + IO_WORKER_F_UP = 1, /* up and active */ + IO_WORKER_F_RUNNING = 2, /* account as running */ + IO_WORKER_F_FREE = 4, /* worker on free list */ + IO_WORKER_F_BOUND = 8, /* is doing bounded work */ +}; + +enum { + IO_WQ_BIT_EXIT = 0, /* wq exiting */ +}; + +enum { + IO_ACCT_STALLED_BIT = 0, /* stalled on hash */ +}; + +/* + * One for each thread in a wqe pool + */ +struct io_worker { + refcount_t ref; + unsigned flags; + struct hlist_nulls_node nulls_node; + struct list_head all_list; + struct task_struct *task; + struct io_wqe *wqe; + + struct io_wq_work *cur_work; + spinlock_t lock; + + struct completion ref_done; + + unsigned long create_state; + struct callback_head create_work; + int create_index; + + union { + struct rcu_head rcu; + struct work_struct work; + }; +}; + +#if BITS_PER_LONG == 64 +#define IO_WQ_HASH_ORDER 6 +#else +#define IO_WQ_HASH_ORDER 5 +#endif + +#define IO_WQ_NR_HASH_BUCKETS (1u << IO_WQ_HASH_ORDER) + +struct io_wqe_acct { + unsigned nr_workers; + unsigned max_workers; + int index; + atomic_t nr_running; + struct io_wq_work_list work_list; + unsigned long flags; +}; + +enum { + IO_WQ_ACCT_BOUND, + IO_WQ_ACCT_UNBOUND, + IO_WQ_ACCT_NR, +}; + +/* + * Per-node worker thread pool + */ +struct io_wqe { + raw_spinlock_t lock; + struct io_wqe_acct acct[2]; + + int node; + + struct hlist_nulls_head free_list; + struct list_head all_list; + + struct wait_queue_entry wait; + + struct io_wq *wq; + struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS]; + + cpumask_var_t cpu_mask; +}; + +/* + * Per io_wq state + */ +struct io_wq { + unsigned long state; + + free_work_fn *free_work; + io_wq_work_fn *do_work; + + struct io_wq_hash *hash; + + atomic_t worker_refs; + struct completion worker_done; + + struct hlist_node cpuhp_node; + + struct task_struct *task; + + struct io_wqe *wqes[]; +}; + +static enum cpuhp_state io_wq_online; + +struct io_cb_cancel_data { + work_cancel_fn *fn; + void *data; + int nr_running; + int nr_pending; + bool cancel_all; +}; + +static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index); +static void io_wqe_dec_running(struct io_worker *worker); +static bool io_acct_cancel_pending_work(struct io_wqe *wqe, + struct io_wqe_acct *acct, + struct io_cb_cancel_data *match); +static void create_worker_cb(struct callback_head *cb); +static void io_wq_cancel_tw_create(struct io_wq *wq); + +static bool io_worker_get(struct io_worker *worker) +{ + return refcount_inc_not_zero(&worker->ref); +} + +static void io_worker_release(struct io_worker *worker) +{ + if (refcount_dec_and_test(&worker->ref)) + complete(&worker->ref_done); +} + +static inline struct io_wqe_acct *io_get_acct(struct io_wqe *wqe, bool bound) +{ + return &wqe->acct[bound ? IO_WQ_ACCT_BOUND : IO_WQ_ACCT_UNBOUND]; +} + +static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe, + struct io_wq_work *work) +{ + return io_get_acct(wqe, !(work->flags & IO_WQ_WORK_UNBOUND)); +} + +static inline struct io_wqe_acct *io_wqe_get_acct(struct io_worker *worker) +{ + return io_get_acct(worker->wqe, worker->flags & IO_WORKER_F_BOUND); +} + +static void io_worker_ref_put(struct io_wq *wq) +{ + if (atomic_dec_and_test(&wq->worker_refs)) + complete(&wq->worker_done); +} + +static void io_worker_cancel_cb(struct io_worker *worker) +{ + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + struct io_wqe *wqe = worker->wqe; + struct io_wq *wq = wqe->wq; + + atomic_dec(&acct->nr_running); + raw_spin_lock(&worker->wqe->lock); + acct->nr_workers--; + raw_spin_unlock(&worker->wqe->lock); + io_worker_ref_put(wq); + clear_bit_unlock(0, &worker->create_state); + io_worker_release(worker); +} + +static bool io_task_worker_match(struct callback_head *cb, void *data) +{ + struct io_worker *worker; + + if (cb->func != create_worker_cb) + return false; + worker = container_of(cb, struct io_worker, create_work); + return worker == data; +} + +static void io_worker_exit(struct io_worker *worker) +{ + struct io_wqe *wqe = worker->wqe; + struct io_wq *wq = wqe->wq; + + while (1) { + struct callback_head *cb = task_work_cancel_match(wq->task, + io_task_worker_match, worker); + + if (!cb) + break; + io_worker_cancel_cb(worker); + } + + if (refcount_dec_and_test(&worker->ref)) + complete(&worker->ref_done); + wait_for_completion(&worker->ref_done); + + raw_spin_lock(&wqe->lock); + if (worker->flags & IO_WORKER_F_FREE) + hlist_nulls_del_rcu(&worker->nulls_node); + list_del_rcu(&worker->all_list); + preempt_disable(); + io_wqe_dec_running(worker); + worker->flags = 0; + current->flags &= ~PF_IO_WORKER; + preempt_enable(); + raw_spin_unlock(&wqe->lock); + + kfree_rcu(worker, rcu); + io_worker_ref_put(wqe->wq); + do_exit(0); +} + +static inline bool io_acct_run_queue(struct io_wqe_acct *acct) +{ + if (!wq_list_empty(&acct->work_list) && + !test_bit(IO_ACCT_STALLED_BIT, &acct->flags)) + return true; + return false; +} + +/* + * Check head of free list for an available worker. If one isn't available, + * caller must create one. + */ +static bool io_wqe_activate_free_worker(struct io_wqe *wqe, + struct io_wqe_acct *acct) + __must_hold(RCU) +{ + struct hlist_nulls_node *n; + struct io_worker *worker; + + /* + * Iterate free_list and see if we can find an idle worker to + * activate. If a given worker is on the free_list but in the process + * of exiting, keep trying. + */ + hlist_nulls_for_each_entry_rcu(worker, n, &wqe->free_list, nulls_node) { + if (!io_worker_get(worker)) + continue; + if (io_wqe_get_acct(worker) != acct) { + io_worker_release(worker); + continue; + } + if (wake_up_process(worker->task)) { + io_worker_release(worker); + return true; + } + io_worker_release(worker); + } + + return false; +} + +/* + * We need a worker. If we find a free one, we're good. If not, and we're + * below the max number of workers, create one. + */ +static bool io_wqe_create_worker(struct io_wqe *wqe, struct io_wqe_acct *acct) +{ + /* + * Most likely an attempt to queue unbounded work on an io_wq that + * wasn't setup with any unbounded workers. + */ + if (unlikely(!acct->max_workers)) + pr_warn_once("io-wq is not configured for unbound workers"); + + raw_spin_lock(&wqe->lock); + if (acct->nr_workers >= acct->max_workers) { + raw_spin_unlock(&wqe->lock); + return true; + } + acct->nr_workers++; + raw_spin_unlock(&wqe->lock); + atomic_inc(&acct->nr_running); + atomic_inc(&wqe->wq->worker_refs); + return create_io_worker(wqe->wq, wqe, acct->index); +} + +static void io_wqe_inc_running(struct io_worker *worker) +{ + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + + atomic_inc(&acct->nr_running); +} + +static void create_worker_cb(struct callback_head *cb) +{ + struct io_worker *worker; + struct io_wq *wq; + struct io_wqe *wqe; + struct io_wqe_acct *acct; + bool do_create = false; + + worker = container_of(cb, struct io_worker, create_work); + wqe = worker->wqe; + wq = wqe->wq; + acct = &wqe->acct[worker->create_index]; + raw_spin_lock(&wqe->lock); + if (acct->nr_workers < acct->max_workers) { + acct->nr_workers++; + do_create = true; + } + raw_spin_unlock(&wqe->lock); + if (do_create) { + create_io_worker(wq, wqe, worker->create_index); + } else { + atomic_dec(&acct->nr_running); + io_worker_ref_put(wq); + } + clear_bit_unlock(0, &worker->create_state); + io_worker_release(worker); +} + +static bool io_queue_worker_create(struct io_worker *worker, + struct io_wqe_acct *acct, + task_work_func_t func) +{ + struct io_wqe *wqe = worker->wqe; + struct io_wq *wq = wqe->wq; + + /* raced with exit, just ignore create call */ + if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) + goto fail; + if (!io_worker_get(worker)) + goto fail; + /* + * create_state manages ownership of create_work/index. We should + * only need one entry per worker, as the worker going to sleep + * will trigger the condition, and waking will clear it once it + * runs the task_work. + */ + if (test_bit(0, &worker->create_state) || + test_and_set_bit_lock(0, &worker->create_state)) + goto fail_release; + + atomic_inc(&wq->worker_refs); + init_task_work(&worker->create_work, func); + worker->create_index = acct->index; + if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL)) { + /* + * EXIT may have been set after checking it above, check after + * adding the task_work and remove any creation item if it is + * now set. wq exit does that too, but we can have added this + * work item after we canceled in io_wq_exit_workers(). + */ + if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) + io_wq_cancel_tw_create(wq); + io_worker_ref_put(wq); + return true; + } + io_worker_ref_put(wq); + clear_bit_unlock(0, &worker->create_state); +fail_release: + io_worker_release(worker); +fail: + atomic_dec(&acct->nr_running); + io_worker_ref_put(wq); + return false; +} + +static void io_wqe_dec_running(struct io_worker *worker) + __must_hold(wqe->lock) +{ + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + struct io_wqe *wqe = worker->wqe; + + if (!(worker->flags & IO_WORKER_F_UP)) + return; + + if (atomic_dec_and_test(&acct->nr_running) && io_acct_run_queue(acct)) { + atomic_inc(&acct->nr_running); + atomic_inc(&wqe->wq->worker_refs); + raw_spin_unlock(&wqe->lock); + io_queue_worker_create(worker, acct, create_worker_cb); + raw_spin_lock(&wqe->lock); + } +} + +/* + * Worker will start processing some work. Move it to the busy list, if + * it's currently on the freelist + */ +static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker, + struct io_wq_work *work) + __must_hold(wqe->lock) +{ + if (worker->flags & IO_WORKER_F_FREE) { + worker->flags &= ~IO_WORKER_F_FREE; + hlist_nulls_del_init_rcu(&worker->nulls_node); + } +} + +/* + * No work, worker going to sleep. Move to freelist, and unuse mm if we + * have one attached. Dropping the mm may potentially sleep, so we drop + * the lock in that case and return success. Since the caller has to + * retry the loop in that case (we changed task state), we don't regrab + * the lock if we return success. + */ +static void __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker) + __must_hold(wqe->lock) +{ + if (!(worker->flags & IO_WORKER_F_FREE)) { + worker->flags |= IO_WORKER_F_FREE; + hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list); + } +} + +static inline unsigned int io_get_work_hash(struct io_wq_work *work) +{ + return work->flags >> IO_WQ_HASH_SHIFT; +} + +static bool io_wait_on_hash(struct io_wqe *wqe, unsigned int hash) +{ + struct io_wq *wq = wqe->wq; + bool ret = false; + + spin_lock_irq(&wq->hash->wait.lock); + if (list_empty(&wqe->wait.entry)) { + __add_wait_queue(&wq->hash->wait, &wqe->wait); + if (!test_bit(hash, &wq->hash->map)) { + __set_current_state(TASK_RUNNING); + list_del_init(&wqe->wait.entry); + ret = true; + } + } + spin_unlock_irq(&wq->hash->wait.lock); + return ret; +} + +static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct, + struct io_worker *worker) + __must_hold(wqe->lock) +{ + struct io_wq_work_node *node, *prev; + struct io_wq_work *work, *tail; + unsigned int stall_hash = -1U; + struct io_wqe *wqe = worker->wqe; + + wq_list_for_each(node, prev, &acct->work_list) { + unsigned int hash; + + work = container_of(node, struct io_wq_work, list); + + /* not hashed, can run anytime */ + if (!io_wq_is_hashed(work)) { + wq_list_del(&acct->work_list, node, prev); + return work; + } + + hash = io_get_work_hash(work); + /* all items with this hash lie in [work, tail] */ + tail = wqe->hash_tail[hash]; + + /* hashed, can run if not already running */ + if (!test_and_set_bit(hash, &wqe->wq->hash->map)) { + wqe->hash_tail[hash] = NULL; + wq_list_cut(&acct->work_list, &tail->list, prev); + return work; + } + if (stall_hash == -1U) + stall_hash = hash; + /* fast forward to a next hash, for-each will fix up @prev */ + node = &tail->list; + } + + if (stall_hash != -1U) { + bool unstalled; + + /* + * Set this before dropping the lock to avoid racing with new + * work being added and clearing the stalled bit. + */ + set_bit(IO_ACCT_STALLED_BIT, &acct->flags); + raw_spin_unlock(&wqe->lock); + unstalled = io_wait_on_hash(wqe, stall_hash); + raw_spin_lock(&wqe->lock); + if (unstalled) { + clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); + if (wq_has_sleeper(&wqe->wq->hash->wait)) + wake_up(&wqe->wq->hash->wait); + } + } + + return NULL; +} + +static bool io_flush_signals(void) +{ + if (unlikely(test_thread_flag(TIF_NOTIFY_SIGNAL))) { + __set_current_state(TASK_RUNNING); + tracehook_notify_signal(); + return true; + } + return false; +} + +static void io_assign_current_work(struct io_worker *worker, + struct io_wq_work *work) +{ + if (work) { + io_flush_signals(); + cond_resched(); + } + + spin_lock(&worker->lock); + worker->cur_work = work; + spin_unlock(&worker->lock); +} + +static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work); + +static void io_worker_handle_work(struct io_worker *worker) + __releases(wqe->lock) +{ + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + struct io_wqe *wqe = worker->wqe; + struct io_wq *wq = wqe->wq; + bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state); + + do { + struct io_wq_work *work; +get_next: + /* + * If we got some work, mark us as busy. If we didn't, but + * the list isn't empty, it means we stalled on hashed work. + * Mark us stalled so we don't keep looking for work when we + * can't make progress, any work completion or insertion will + * clear the stalled flag. + */ + work = io_get_next_work(acct, worker); + if (work) + __io_worker_busy(wqe, worker, work); + + raw_spin_unlock(&wqe->lock); + if (!work) + break; + io_assign_current_work(worker, work); + __set_current_state(TASK_RUNNING); + + /* handle a whole dependent link */ + do { + struct io_wq_work *next_hashed, *linked; + unsigned int hash = io_get_work_hash(work); + + next_hashed = wq_next_work(work); + + if (unlikely(do_kill) && (work->flags & IO_WQ_WORK_UNBOUND)) + work->flags |= IO_WQ_WORK_CANCEL; + wq->do_work(work); + io_assign_current_work(worker, NULL); + + linked = wq->free_work(work); + work = next_hashed; + if (!work && linked && !io_wq_is_hashed(linked)) { + work = linked; + linked = NULL; + } + io_assign_current_work(worker, work); + if (linked) + io_wqe_enqueue(wqe, linked); + + if (hash != -1U && !next_hashed) { + /* serialize hash clear with wake_up() */ + spin_lock_irq(&wq->hash->wait.lock); + clear_bit(hash, &wq->hash->map); + clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); + spin_unlock_irq(&wq->hash->wait.lock); + if (wq_has_sleeper(&wq->hash->wait)) + wake_up(&wq->hash->wait); + raw_spin_lock(&wqe->lock); + /* skip unnecessary unlock-lock wqe->lock */ + if (!work) + goto get_next; + raw_spin_unlock(&wqe->lock); + } + } while (work); + + raw_spin_lock(&wqe->lock); + } while (1); +} + +static int io_wqe_worker(void *data) +{ + struct io_worker *worker = data; + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + struct io_wqe *wqe = worker->wqe; + struct io_wq *wq = wqe->wq; + bool last_timeout = false; + char buf[TASK_COMM_LEN]; + + worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING); + + snprintf(buf, sizeof(buf), "iou-wrk-%d", wq->task->pid); + set_task_comm(current, buf); + + while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) { + long ret; + + set_current_state(TASK_INTERRUPTIBLE); +loop: + raw_spin_lock(&wqe->lock); + if (io_acct_run_queue(acct)) { + io_worker_handle_work(worker); + goto loop; + } + /* timed out, exit unless we're the last worker */ + if (last_timeout && acct->nr_workers > 1) { + acct->nr_workers--; + raw_spin_unlock(&wqe->lock); + __set_current_state(TASK_RUNNING); + break; + } + last_timeout = false; + __io_worker_idle(wqe, worker); + raw_spin_unlock(&wqe->lock); + if (io_flush_signals()) + continue; + ret = schedule_timeout(WORKER_IDLE_TIMEOUT); + if (signal_pending(current)) { + struct ksignal ksig; + + if (!get_signal(&ksig)) + continue; + break; + } + last_timeout = !ret; + } + + if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) { + raw_spin_lock(&wqe->lock); + io_worker_handle_work(worker); + } + + io_worker_exit(worker); + return 0; +} + +/* + * Called when a worker is scheduled in. Mark us as currently running. + */ +void io_wq_worker_running(struct task_struct *tsk) +{ + struct io_worker *worker = tsk->pf_io_worker; + + if (!worker) + return; + if (!(worker->flags & IO_WORKER_F_UP)) + return; + if (worker->flags & IO_WORKER_F_RUNNING) + return; + worker->flags |= IO_WORKER_F_RUNNING; + io_wqe_inc_running(worker); +} + +/* + * Called when worker is going to sleep. If there are no workers currently + * running and we have work pending, wake up a free one or create a new one. + */ +void io_wq_worker_sleeping(struct task_struct *tsk) +{ + struct io_worker *worker = tsk->pf_io_worker; + + if (!worker) + return; + if (!(worker->flags & IO_WORKER_F_UP)) + return; + if (!(worker->flags & IO_WORKER_F_RUNNING)) + return; + + worker->flags &= ~IO_WORKER_F_RUNNING; + + raw_spin_lock(&worker->wqe->lock); + io_wqe_dec_running(worker); + raw_spin_unlock(&worker->wqe->lock); +} + +static void io_init_new_worker(struct io_wqe *wqe, struct io_worker *worker, + struct task_struct *tsk) +{ + tsk->pf_io_worker = worker; + worker->task = tsk; + set_cpus_allowed_ptr(tsk, wqe->cpu_mask); + tsk->flags |= PF_NO_SETAFFINITY; + + raw_spin_lock(&wqe->lock); + hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list); + list_add_tail_rcu(&worker->all_list, &wqe->all_list); + worker->flags |= IO_WORKER_F_FREE; + raw_spin_unlock(&wqe->lock); + wake_up_new_task(tsk); +} + +static bool io_wq_work_match_all(struct io_wq_work *work, void *data) +{ + return true; +} + +static inline bool io_should_retry_thread(long err) +{ + /* + * Prevent perpetual task_work retry, if the task (or its group) is + * exiting. + */ + if (fatal_signal_pending(current)) + return false; + + switch (err) { + case -EAGAIN: + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTARTNOHAND: + return true; + default: + return false; + } +} + +static void create_worker_cont(struct callback_head *cb) +{ + struct io_worker *worker; + struct task_struct *tsk; + struct io_wqe *wqe; + + worker = container_of(cb, struct io_worker, create_work); + clear_bit_unlock(0, &worker->create_state); + wqe = worker->wqe; + tsk = create_io_thread(io_wqe_worker, worker, wqe->node); + if (!IS_ERR(tsk)) { + io_init_new_worker(wqe, worker, tsk); + io_worker_release(worker); + return; + } else if (!io_should_retry_thread(PTR_ERR(tsk))) { + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + + atomic_dec(&acct->nr_running); + raw_spin_lock(&wqe->lock); + acct->nr_workers--; + if (!acct->nr_workers) { + struct io_cb_cancel_data match = { + .fn = io_wq_work_match_all, + .cancel_all = true, + }; + + while (io_acct_cancel_pending_work(wqe, acct, &match)) + raw_spin_lock(&wqe->lock); + } + raw_spin_unlock(&wqe->lock); + io_worker_ref_put(wqe->wq); + kfree(worker); + return; + } + + /* re-create attempts grab a new worker ref, drop the existing one */ + io_worker_release(worker); + schedule_work(&worker->work); +} + +static void io_workqueue_create(struct work_struct *work) +{ + struct io_worker *worker = container_of(work, struct io_worker, work); + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + + if (!io_queue_worker_create(worker, acct, create_worker_cont)) + kfree(worker); +} + +static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index) +{ + struct io_wqe_acct *acct = &wqe->acct[index]; + struct io_worker *worker; + struct task_struct *tsk; + + __set_current_state(TASK_RUNNING); + + worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node); + if (!worker) { +fail: + atomic_dec(&acct->nr_running); + raw_spin_lock(&wqe->lock); + acct->nr_workers--; + raw_spin_unlock(&wqe->lock); + io_worker_ref_put(wq); + return false; + } + + refcount_set(&worker->ref, 1); + worker->wqe = wqe; + spin_lock_init(&worker->lock); + init_completion(&worker->ref_done); + + if (index == IO_WQ_ACCT_BOUND) + worker->flags |= IO_WORKER_F_BOUND; + + tsk = create_io_thread(io_wqe_worker, worker, wqe->node); + if (!IS_ERR(tsk)) { + io_init_new_worker(wqe, worker, tsk); + } else if (!io_should_retry_thread(PTR_ERR(tsk))) { + kfree(worker); + goto fail; + } else { + INIT_WORK(&worker->work, io_workqueue_create); + schedule_work(&worker->work); + } + + return true; +} + +/* + * Iterate the passed in list and call the specific function for each + * worker that isn't exiting + */ +static bool io_wq_for_each_worker(struct io_wqe *wqe, + bool (*func)(struct io_worker *, void *), + void *data) +{ + struct io_worker *worker; + bool ret = false; + + list_for_each_entry_rcu(worker, &wqe->all_list, all_list) { + if (io_worker_get(worker)) { + /* no task if node is/was offline */ + if (worker->task) + ret = func(worker, data); + io_worker_release(worker); + if (ret) + break; + } + } + + return ret; +} + +static bool io_wq_worker_wake(struct io_worker *worker, void *data) +{ + set_notify_signal(worker->task); + wake_up_process(worker->task); + return false; +} + +static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe) +{ + struct io_wq *wq = wqe->wq; + + do { + work->flags |= IO_WQ_WORK_CANCEL; + wq->do_work(work); + work = wq->free_work(work); + } while (work); +} + +static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work) +{ + struct io_wqe_acct *acct = io_work_get_acct(wqe, work); + unsigned int hash; + struct io_wq_work *tail; + + if (!io_wq_is_hashed(work)) { +append: + wq_list_add_tail(&work->list, &acct->work_list); + return; + } + + hash = io_get_work_hash(work); + tail = wqe->hash_tail[hash]; + wqe->hash_tail[hash] = work; + if (!tail) + goto append; + + wq_list_add_after(&work->list, &tail->list, &acct->work_list); +} + +static bool io_wq_work_match_item(struct io_wq_work *work, void *data) +{ + return work == data; +} + +static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) +{ + struct io_wqe_acct *acct = io_work_get_acct(wqe, work); + unsigned work_flags = work->flags; + bool do_create; + + /* + * If io-wq is exiting for this task, or if the request has explicitly + * been marked as one that should not get executed, cancel it here. + */ + if (test_bit(IO_WQ_BIT_EXIT, &wqe->wq->state) || + (work->flags & IO_WQ_WORK_CANCEL)) { + io_run_cancel(work, wqe); + return; + } + + raw_spin_lock(&wqe->lock); + io_wqe_insert_work(wqe, work); + clear_bit(IO_ACCT_STALLED_BIT, &acct->flags); + + rcu_read_lock(); + do_create = !io_wqe_activate_free_worker(wqe, acct); + rcu_read_unlock(); + + raw_spin_unlock(&wqe->lock); + + if (do_create && ((work_flags & IO_WQ_WORK_CONCURRENT) || + !atomic_read(&acct->nr_running))) { + bool did_create; + + did_create = io_wqe_create_worker(wqe, acct); + if (likely(did_create)) + return; + + raw_spin_lock(&wqe->lock); + /* fatal condition, failed to create the first worker */ + if (!acct->nr_workers) { + struct io_cb_cancel_data match = { + .fn = io_wq_work_match_item, + .data = work, + .cancel_all = false, + }; + + if (io_acct_cancel_pending_work(wqe, acct, &match)) + raw_spin_lock(&wqe->lock); + } + raw_spin_unlock(&wqe->lock); + } +} + +void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work) +{ + struct io_wqe *wqe = wq->wqes[numa_node_id()]; + + io_wqe_enqueue(wqe, work); +} + +/* + * Work items that hash to the same value will not be done in parallel. + * Used to limit concurrent writes, generally hashed by inode. + */ +void io_wq_hash_work(struct io_wq_work *work, void *val) +{ + unsigned int bit; + + bit = hash_ptr(val, IO_WQ_HASH_ORDER); + work->flags |= (IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT)); +} + +static bool io_wq_worker_cancel(struct io_worker *worker, void *data) +{ + struct io_cb_cancel_data *match = data; + + /* + * Hold the lock to avoid ->cur_work going out of scope, caller + * may dereference the passed in work. + */ + spin_lock(&worker->lock); + if (worker->cur_work && + match->fn(worker->cur_work, match->data)) { + set_notify_signal(worker->task); + match->nr_running++; + } + spin_unlock(&worker->lock); + + return match->nr_running && !match->cancel_all; +} + +static inline void io_wqe_remove_pending(struct io_wqe *wqe, + struct io_wq_work *work, + struct io_wq_work_node *prev) +{ + struct io_wqe_acct *acct = io_work_get_acct(wqe, work); + unsigned int hash = io_get_work_hash(work); + struct io_wq_work *prev_work = NULL; + + if (io_wq_is_hashed(work) && work == wqe->hash_tail[hash]) { + if (prev) + prev_work = container_of(prev, struct io_wq_work, list); + if (prev_work && io_get_work_hash(prev_work) == hash) + wqe->hash_tail[hash] = prev_work; + else + wqe->hash_tail[hash] = NULL; + } + wq_list_del(&acct->work_list, &work->list, prev); +} + +static bool io_acct_cancel_pending_work(struct io_wqe *wqe, + struct io_wqe_acct *acct, + struct io_cb_cancel_data *match) + __releases(wqe->lock) +{ + struct io_wq_work_node *node, *prev; + struct io_wq_work *work; + + wq_list_for_each(node, prev, &acct->work_list) { + work = container_of(node, struct io_wq_work, list); + if (!match->fn(work, match->data)) + continue; + io_wqe_remove_pending(wqe, work, prev); + raw_spin_unlock(&wqe->lock); + io_run_cancel(work, wqe); + match->nr_pending++; + /* not safe to continue after unlock */ + return true; + } + + return false; +} + +static void io_wqe_cancel_pending_work(struct io_wqe *wqe, + struct io_cb_cancel_data *match) +{ + int i; +retry: + raw_spin_lock(&wqe->lock); + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + struct io_wqe_acct *acct = io_get_acct(wqe, i == 0); + + if (io_acct_cancel_pending_work(wqe, acct, match)) { + if (match->cancel_all) + goto retry; + return; + } + } + raw_spin_unlock(&wqe->lock); +} + +static void io_wqe_cancel_running_work(struct io_wqe *wqe, + struct io_cb_cancel_data *match) +{ + rcu_read_lock(); + io_wq_for_each_worker(wqe, io_wq_worker_cancel, match); + rcu_read_unlock(); +} + +enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, + void *data, bool cancel_all) +{ + struct io_cb_cancel_data match = { + .fn = cancel, + .data = data, + .cancel_all = cancel_all, + }; + int node; + + /* + * First check pending list, if we're lucky we can just remove it + * from there. CANCEL_OK means that the work is returned as-new, + * no completion will be posted for it. + */ + for_each_node(node) { + struct io_wqe *wqe = wq->wqes[node]; + + io_wqe_cancel_pending_work(wqe, &match); + if (match.nr_pending && !match.cancel_all) + return IO_WQ_CANCEL_OK; + } + + /* + * Now check if a free (going busy) or busy worker has the work + * currently running. If we find it there, we'll return CANCEL_RUNNING + * as an indication that we attempt to signal cancellation. The + * completion will run normally in this case. + */ + for_each_node(node) { + struct io_wqe *wqe = wq->wqes[node]; + + io_wqe_cancel_running_work(wqe, &match); + if (match.nr_running && !match.cancel_all) + return IO_WQ_CANCEL_RUNNING; + } + + if (match.nr_running) + return IO_WQ_CANCEL_RUNNING; + if (match.nr_pending) + return IO_WQ_CANCEL_OK; + return IO_WQ_CANCEL_NOTFOUND; +} + +static int io_wqe_hash_wake(struct wait_queue_entry *wait, unsigned mode, + int sync, void *key) +{ + struct io_wqe *wqe = container_of(wait, struct io_wqe, wait); + int i; + + list_del_init(&wait->entry); + + rcu_read_lock(); + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + struct io_wqe_acct *acct = &wqe->acct[i]; + + if (test_and_clear_bit(IO_ACCT_STALLED_BIT, &acct->flags)) + io_wqe_activate_free_worker(wqe, acct); + } + rcu_read_unlock(); + return 1; +} + +struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) +{ + int ret, node, i; + struct io_wq *wq; + + if (WARN_ON_ONCE(!data->free_work || !data->do_work)) + return ERR_PTR(-EINVAL); + if (WARN_ON_ONCE(!bounded)) + return ERR_PTR(-EINVAL); + + wq = kzalloc(struct_size(wq, wqes, nr_node_ids), GFP_KERNEL); + if (!wq) + return ERR_PTR(-ENOMEM); + ret = cpuhp_state_add_instance_nocalls(io_wq_online, &wq->cpuhp_node); + if (ret) + goto err_wq; + + refcount_inc(&data->hash->refs); + wq->hash = data->hash; + wq->free_work = data->free_work; + wq->do_work = data->do_work; + + ret = -ENOMEM; + for_each_node(node) { + struct io_wqe *wqe; + int alloc_node = node; + + if (!node_online(alloc_node)) + alloc_node = NUMA_NO_NODE; + wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, alloc_node); + if (!wqe) + goto err; + wq->wqes[node] = wqe; + if (!alloc_cpumask_var(&wqe->cpu_mask, GFP_KERNEL)) + goto err; + cpumask_copy(wqe->cpu_mask, cpumask_of_node(node)); + wqe->node = alloc_node; + wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded; + wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers = + task_rlimit(current, RLIMIT_NPROC); + INIT_LIST_HEAD(&wqe->wait.entry); + wqe->wait.func = io_wqe_hash_wake; + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + struct io_wqe_acct *acct = &wqe->acct[i]; + + acct->index = i; + atomic_set(&acct->nr_running, 0); + INIT_WQ_LIST(&acct->work_list); + } + wqe->wq = wq; + raw_spin_lock_init(&wqe->lock); + INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0); + INIT_LIST_HEAD(&wqe->all_list); + } + + wq->task = get_task_struct(data->task); + atomic_set(&wq->worker_refs, 1); + init_completion(&wq->worker_done); + return wq; +err: + io_wq_put_hash(data->hash); + cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node); + for_each_node(node) { + if (!wq->wqes[node]) + continue; + free_cpumask_var(wq->wqes[node]->cpu_mask); + kfree(wq->wqes[node]); + } +err_wq: + kfree(wq); + return ERR_PTR(ret); +} + +static bool io_task_work_match(struct callback_head *cb, void *data) +{ + struct io_worker *worker; + + if (cb->func != create_worker_cb && cb->func != create_worker_cont) + return false; + worker = container_of(cb, struct io_worker, create_work); + return worker->wqe->wq == data; +} + +void io_wq_exit_start(struct io_wq *wq) +{ + set_bit(IO_WQ_BIT_EXIT, &wq->state); +} + +static void io_wq_cancel_tw_create(struct io_wq *wq) +{ + struct callback_head *cb; + + while ((cb = task_work_cancel_match(wq->task, io_task_work_match, wq)) != NULL) { + struct io_worker *worker; + + worker = container_of(cb, struct io_worker, create_work); + io_worker_cancel_cb(worker); + } +} + +static void io_wq_exit_workers(struct io_wq *wq) +{ + int node; + + if (!wq->task) + return; + + io_wq_cancel_tw_create(wq); + + rcu_read_lock(); + for_each_node(node) { + struct io_wqe *wqe = wq->wqes[node]; + + io_wq_for_each_worker(wqe, io_wq_worker_wake, NULL); + } + rcu_read_unlock(); + io_worker_ref_put(wq); + wait_for_completion(&wq->worker_done); + + for_each_node(node) { + spin_lock_irq(&wq->hash->wait.lock); + list_del_init(&wq->wqes[node]->wait.entry); + spin_unlock_irq(&wq->hash->wait.lock); + } + put_task_struct(wq->task); + wq->task = NULL; +} + +static void io_wq_destroy(struct io_wq *wq) +{ + int node; + + cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node); + + for_each_node(node) { + struct io_wqe *wqe = wq->wqes[node]; + struct io_cb_cancel_data match = { + .fn = io_wq_work_match_all, + .cancel_all = true, + }; + io_wqe_cancel_pending_work(wqe, &match); + free_cpumask_var(wqe->cpu_mask); + kfree(wqe); + } + io_wq_put_hash(wq->hash); + kfree(wq); +} + +void io_wq_put_and_exit(struct io_wq *wq) +{ + WARN_ON_ONCE(!test_bit(IO_WQ_BIT_EXIT, &wq->state)); + + io_wq_exit_workers(wq); + io_wq_destroy(wq); +} + +struct online_data { + unsigned int cpu; + bool online; +}; + +static bool io_wq_worker_affinity(struct io_worker *worker, void *data) +{ + struct online_data *od = data; + + if (od->online) + cpumask_set_cpu(od->cpu, worker->wqe->cpu_mask); + else + cpumask_clear_cpu(od->cpu, worker->wqe->cpu_mask); + return false; +} + +static int __io_wq_cpu_online(struct io_wq *wq, unsigned int cpu, bool online) +{ + struct online_data od = { + .cpu = cpu, + .online = online + }; + int i; + + rcu_read_lock(); + for_each_node(i) + io_wq_for_each_worker(wq->wqes[i], io_wq_worker_affinity, &od); + rcu_read_unlock(); + return 0; +} + +static int io_wq_cpu_online(unsigned int cpu, struct hlist_node *node) +{ + struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node); + + return __io_wq_cpu_online(wq, cpu, true); +} + +static int io_wq_cpu_offline(unsigned int cpu, struct hlist_node *node) +{ + struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node); + + return __io_wq_cpu_online(wq, cpu, false); +} + +int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask) +{ + int i; + + rcu_read_lock(); + for_each_node(i) { + struct io_wqe *wqe = wq->wqes[i]; + + if (mask) + cpumask_copy(wqe->cpu_mask, mask); + else + cpumask_copy(wqe->cpu_mask, cpumask_of_node(i)); + } + rcu_read_unlock(); + return 0; +} + +/* + * Set max number of unbounded workers, returns old value. If new_count is 0, + * then just return the old value. + */ +int io_wq_max_workers(struct io_wq *wq, int *new_count) +{ + int prev[IO_WQ_ACCT_NR]; + bool first_node = true; + int i, node; + + BUILD_BUG_ON((int) IO_WQ_ACCT_BOUND != (int) IO_WQ_BOUND); + BUILD_BUG_ON((int) IO_WQ_ACCT_UNBOUND != (int) IO_WQ_UNBOUND); + BUILD_BUG_ON((int) IO_WQ_ACCT_NR != 2); + + for (i = 0; i < 2; i++) { + if (new_count[i] > task_rlimit(current, RLIMIT_NPROC)) + new_count[i] = task_rlimit(current, RLIMIT_NPROC); + } + + for (i = 0; i < IO_WQ_ACCT_NR; i++) + prev[i] = 0; + + rcu_read_lock(); + for_each_node(node) { + struct io_wqe *wqe = wq->wqes[node]; + struct io_wqe_acct *acct; + + raw_spin_lock(&wqe->lock); + for (i = 0; i < IO_WQ_ACCT_NR; i++) { + acct = &wqe->acct[i]; + if (first_node) + prev[i] = max_t(int, acct->max_workers, prev[i]); + if (new_count[i]) + acct->max_workers = new_count[i]; + } + raw_spin_unlock(&wqe->lock); + first_node = false; + } + rcu_read_unlock(); + + for (i = 0; i < IO_WQ_ACCT_NR; i++) + new_count[i] = prev[i]; + + return 0; +} + +static __init int io_wq_init(void) +{ + int ret; + + ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "io-wq/online", + io_wq_cpu_online, io_wq_cpu_offline); + if (ret < 0) + return ret; + io_wq_online = ret; + return 0; +} +subsys_initcall(io_wq_init); diff --git a/fs/io-wq.h b/io_uring/io-wq.h similarity index 81% rename from fs/io-wq.h rename to io_uring/io-wq.h index 75113bcd5889..bf5c4c533760 100644 --- a/fs/io-wq.h +++ b/io_uring/io-wq.h @@ -1,7 +1,7 @@ #ifndef INTERNAL_IO_WQ_H #define INTERNAL_IO_WQ_H

-#include <linux/io_uring.h> +#include <linux/refcount.h>

struct io_wq;

@@ -9,16 +9,8 @@ enum { IO_WQ_WORK_CANCEL = 1, IO_WQ_WORK_HASHED = 2, IO_WQ_WORK_UNBOUND = 4, - IO_WQ_WORK_NO_CANCEL = 8, IO_WQ_WORK_CONCURRENT = 16,

- IO_WQ_WORK_FILES = 32, - IO_WQ_WORK_FS = 64, - IO_WQ_WORK_MM = 128, - IO_WQ_WORK_CREDS = 256, - IO_WQ_WORK_BLKCG = 512, - IO_WQ_WORK_FSIZE = 1024, - IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */ };

@@ -52,6 +44,7 @@ static inline void wq_list_add_after(struct io_wq_work_node *node, static inline void wq_list_add_tail(struct io_wq_work_node *node, struct io_wq_work_list *list) { + node->next = NULL; if (!list->first) { list->last = node; WRITE_ONCE(list->first, node); @@ -59,7 +52,6 @@ static inline void wq_list_add_tail(struct io_wq_work_node *node, list->last->next = node; list->last = node; } - node->next = NULL; }

static inline void wq_list_cut(struct io_wq_work_list *list, @@ -95,7 +87,6 @@ static inline void wq_list_del(struct io_wq_work_list *list,

struct io_wq_work { struct io_wq_work_node list; - struct io_identity *identity; unsigned flags; };

@@ -107,37 +98,48 @@ static inline struct io_wq_work *wq_next_work(struct io_wq_work *work) return container_of(work->list.next, struct io_wq_work, list); }

-typedef void (free_work_fn)(struct io_wq_work *); -typedef struct io_wq_work *(io_wq_work_fn)(struct io_wq_work *); +typedef struct io_wq_work *(free_work_fn)(struct io_wq_work *); +typedef void (io_wq_work_fn)(struct io_wq_work *);

-struct io_wq_data { - struct user_struct *user; +struct io_wq_hash { + refcount_t refs; + unsigned long map; + struct wait_queue_head wait; +}; + +static inline void io_wq_put_hash(struct io_wq_hash *hash) +{ + if (refcount_dec_and_test(&hash->refs)) + kfree(hash); +}

+struct io_wq_data { + struct io_wq_hash *hash; + struct task_struct *task; io_wq_work_fn *do_work; free_work_fn *free_work; };

struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data); -bool io_wq_get(struct io_wq *wq, struct io_wq_data *data); -void io_wq_destroy(struct io_wq *wq); +void io_wq_exit_start(struct io_wq *wq); +void io_wq_put_and_exit(struct io_wq *wq);

void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work); void io_wq_hash_work(struct io_wq_work *work, void *val);

+int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask); +int io_wq_max_workers(struct io_wq *wq, int *new_count); + static inline bool io_wq_is_hashed(struct io_wq_work *work) { return work->flags & IO_WQ_WORK_HASHED; }

-void io_wq_cancel_all(struct io_wq *wq); - typedef bool (work_cancel_fn)(struct io_wq_work *, void *);

enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, void *data, bool cancel_all);

-struct task_struct *io_wq_get_task(struct io_wq *wq); - #if defined(CONFIG_IO_WQ) extern void io_wq_worker_sleeping(struct task_struct *); extern void io_wq_worker_running(struct task_struct *); @@ -152,6 +154,7 @@ static inline void io_wq_worker_running(struct task_struct *tsk)

static inline bool io_wq_current_is_worker(void) { - return in_task() && (current->flags & PF_IO_WORKER); + return in_task() && (current->flags & PF_IO_WORKER) && + current->pf_io_worker; } #endif diff --git a/fs/io_uring.c b/io_uring/io_uring.c similarity index 51% rename from fs/io_uring.c rename to io_uring/io_uring.c index 1d8173741310..473dbd1830a3 100644 --- a/fs/io_uring.c +++ b/io_uring/io_uring.c @@ -11,7 +11,7 @@ * before writing the tail (using smp_load_acquire to read the tail will * do). It also needs a smp_mb() before updating CQ head (ordering the * entry load(s) with the head store), pairing with an implicit barrier - * through a control-dependency in io_get_cqring (smp_store_release to + * through a control-dependency in io_get_cqe (smp_store_release to * store head will do). Failure to do so could lead to reading invalid * CQ entries. * @@ -57,7 +57,6 @@ #include <linux/mman.h> #include <linux/percpu.h> #include <linux/slab.h> -#include <linux/kthread.h> #include <linux/blkdev.h> #include <linux/bvec.h> #include <linux/net.h> @@ -75,35 +74,43 @@ #include <linux/fsnotify.h> #include <linux/fadvise.h> #include <linux/eventpoll.h> -#include <linux/fs_struct.h> #include <linux/splice.h> #include <linux/task_work.h> #include <linux/pagemap.h> #include <linux/io_uring.h> -#include <linux/blk-cgroup.h> -#include <linux/audit.h> +#include <linux/tracehook.h>

#define CREATE_TRACE_POINTS #include <trace/events/io_uring.h>

#include <uapi/linux/io_uring.h>

-#include "internal.h" +#include "../fs/internal.h" #include "io-wq.h"

#define IORING_MAX_ENTRIES 32768 #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) +#define IORING_SQPOLL_CAP_ENTRIES_VALUE 8

-/* - * Shift of 9 is 512 entries, or exactly one page on 64-bit archs - */ -#define IORING_FILE_TABLE_SHIFT 9 -#define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT) -#define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1) -#define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE) +/* only define max */ +#define IORING_MAX_FIXED_FILES (1U << 15) #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \ IORING_REGISTER_LAST + IORING_OP_LAST)

+#define IO_RSRC_TAG_TABLE_SHIFT (PAGE_SHIFT - 3) +#define IO_RSRC_TAG_TABLE_MAX (1U << IO_RSRC_TAG_TABLE_SHIFT) +#define IO_RSRC_TAG_TABLE_MASK (IO_RSRC_TAG_TABLE_MAX - 1) + +#define IORING_MAX_REG_BUFFERS (1U << 14) + +#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \ + IOSQE_IO_HARDLINK | IOSQE_ASYNC | \ + IOSQE_BUFFER_SELECT) +#define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \ + REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS) + +#define IO_TCTX_REFS_CACHE_NR (1U << 10) + struct io_uring { u32 head ____cacheline_aligned_in_smp; u32 tail ____cacheline_aligned_in_smp; @@ -162,7 +169,7 @@ struct io_rings { * Written by the application, shouldn't be modified by the * kernel. */ - u32 cq_flags; + u32 cq_flags; /* * Number of completion events lost because the queue was full; * this should be avoided by the application by making sure @@ -187,36 +194,64 @@ struct io_rings { struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp; };

+enum io_uring_cmd_flags { + IO_URING_F_NONBLOCK = 1, + IO_URING_F_COMPLETE_DEFER = 2, +}; + struct io_mapped_ubuf { u64 ubuf; - size_t len; - struct bio_vec *bvec; + u64 ubuf_end; unsigned int nr_bvecs; unsigned long acct_pages; + struct bio_vec bvec[]; +}; + +struct io_ring_ctx; + +struct io_overflow_cqe { + struct io_uring_cqe cqe; + struct list_head list; +}; + +struct io_fixed_file { + /* file * with additional FFS_* flags */ + unsigned long file_ptr; +}; + +struct io_rsrc_put { + struct list_head list; + u64 tag; + union { + void *rsrc; + struct file *file; + struct io_mapped_ubuf *buf; + }; };

-struct fixed_file_table { - struct file **files; +struct io_file_table { + struct io_fixed_file *files; };

-struct fixed_file_ref_node { +struct io_rsrc_node { struct percpu_ref refs; struct list_head node; - struct list_head file_list; - struct fixed_file_data *file_data; + struct list_head rsrc_list; + struct io_rsrc_data *rsrc_data; struct llist_node llist; bool done; };

-struct fixed_file_data { - struct fixed_file_table *table; +typedef void (rsrc_put_fn)(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc); + +struct io_rsrc_data { struct io_ring_ctx *ctx;

- struct fixed_file_ref_node *node; - struct percpu_ref refs; + u64 **tags; + unsigned int nr; + rsrc_put_fn *do_put; + atomic_t refs; struct completion done; - struct list_head ref_list; - spinlock_t lock; bool quiesce; };

@@ -235,33 +270,81 @@ struct io_restriction { bool registered; };

+enum { + IO_SQ_THREAD_SHOULD_STOP = 0, + IO_SQ_THREAD_SHOULD_PARK, +}; + struct io_sq_data { refcount_t refs; + atomic_t park_pending; struct mutex lock;

/* ctx's that are using this sqd */ struct list_head ctx_list; - struct list_head ctx_new_list; - struct mutex ctx_lock;

struct task_struct *thread; struct wait_queue_head wait; + + unsigned sq_thread_idle; + int sq_cpu; + pid_t task_pid; + pid_t task_tgid; + + unsigned long state; + struct completion exited; +}; + +#define IO_COMPL_BATCH 32 +#define IO_REQ_CACHE_SIZE 32 +#define IO_REQ_ALLOC_BATCH 8 + +struct io_submit_link { + struct io_kiocb *head; + struct io_kiocb *last; +}; + +struct io_submit_state { + struct blk_plug plug; + struct io_submit_link link; + + /* + * io_kiocb alloc cache + */ + void *reqs[IO_REQ_CACHE_SIZE]; + unsigned int free_reqs; + + bool plug_started; + + /* + * Batch completion logic + */ + struct io_kiocb *compl_reqs[IO_COMPL_BATCH]; + unsigned int compl_nr; + /* inline/task_work completion list, under ->uring_lock */ + struct list_head free_list; + + unsigned int ios_left; };

struct io_ring_ctx { + /* const or read-mostly hot data */ struct { struct percpu_ref refs; - } ____cacheline_aligned_in_smp;

- struct { + struct io_rings *rings; unsigned int flags; unsigned int compat: 1; - unsigned int limit_mem: 1; - unsigned int cq_overflow_flushed: 1; unsigned int drain_next: 1; unsigned int eventfd_async: 1; unsigned int restricted: 1; - unsigned int sqo_dead: 1; + unsigned int off_timeout_used: 1; + unsigned int drain_active: 1; + } ____cacheline_aligned_in_smp; + + /* submission data */ + struct { + struct mutex uring_lock;

/* * Ring buffer of indices into array of io_uring_sqe, which is @@ -275,101 +358,59 @@ struct io_ring_ctx { * array. */ u32 *sq_array; + struct io_uring_sqe *sq_sqes; unsigned cached_sq_head; unsigned sq_entries; - unsigned sq_mask; - unsigned sq_thread_idle; - unsigned cached_sq_dropped; - unsigned cached_cq_overflow; - unsigned long sq_check_overflow; - struct list_head defer_list; + + /* + * Fixed resources fast path, should be accessed only under + * uring_lock, and updated through io_uring_register(2) + */ + struct io_rsrc_node *rsrc_node; + struct io_file_table file_table; + unsigned nr_user_files; + unsigned nr_user_bufs; + struct io_mapped_ubuf **user_bufs; + + struct io_submit_state submit_state; struct list_head timeout_list; + struct list_head ltimeout_list; struct list_head cq_overflow_list; - - struct io_uring_sqe *sq_sqes; + struct xarray io_buffers; + struct xarray personalities; + u32 pers_next; + unsigned sq_thread_idle; } ____cacheline_aligned_in_smp;

- struct io_rings *rings; - - /* IO offload */ - struct io_wq *io_wq; - - /* - * For SQPOLL usage - we hold a reference to the parent task, so we - * have access to the ->files - */ - struct task_struct *sqo_task; - - /* Only used for accounting purposes */ - struct mm_struct *mm_account; - -#ifdef CONFIG_BLK_CGROUP - struct cgroup_subsys_state *sqo_blkcg_css; -#endif + /* IRQ completion list, under ->completion_lock */ + struct list_head locked_free_list; + unsigned int locked_free_nr;

+ const struct cred *sq_creds; /* cred used for __io_sq_thread() */ struct io_sq_data *sq_data; /* if using sq thread polling */

struct wait_queue_head sqo_sq_wait; - struct wait_queue_entry sqo_wait_entry; struct list_head sqd_list;

- /* - * If used, fixed file set. Writers must ensure that ->refs is dead, - * readers must ensure that ->refs is alive as long as the file* is - * used. Only updated through io_uring_register(2). - */ - struct fixed_file_data *file_data; - unsigned nr_user_files; - - /* if used, fixed mapped user buffers */ - unsigned nr_user_bufs; - struct io_mapped_ubuf *user_bufs; - - struct user_struct *user; - - const struct cred *creds; - -#ifdef CONFIG_AUDIT - kuid_t loginuid; - unsigned int sessionid; -#endif - - struct completion ref_comp; - struct completion sq_thread_comp; - - /* if all else fails... */ - struct io_kiocb *fallback_req; - -#if defined(CONFIG_UNIX) - struct socket *ring_sock; -#endif - - struct xarray io_buffers; - - struct xarray personalities; - u32 pers_next; + unsigned long check_cq_overflow;

struct { unsigned cached_cq_tail; unsigned cq_entries; - unsigned cq_mask; + struct eventfd_ctx *cq_ev_fd; + struct wait_queue_head poll_wait; + struct wait_queue_head cq_wait; + unsigned cq_extra; atomic_t cq_timeouts; unsigned cq_last_tm_flush; - unsigned long cq_check_overflow; - struct wait_queue_head cq_wait; - struct fasync_struct *cq_fasync; - struct eventfd_ctx *cq_ev_fd; - } ____cacheline_aligned_in_smp; - - struct { - struct mutex uring_lock; - wait_queue_head_t wait; } ____cacheline_aligned_in_smp;

struct { spinlock_t completion_lock;

+ spinlock_t timeout_lock; + /* * ->iopoll_list is protected by the ctx->uring_lock for * io_uring instances that don't use IORING_SETUP_SQPOLL. @@ -379,17 +420,62 @@ struct io_ring_ctx { struct list_head iopoll_list; struct hlist_head *cancel_hash; unsigned cancel_hash_bits; - bool poll_multi_file; - - spinlock_t inflight_lock; - struct list_head inflight_list; + bool poll_multi_queue; } ____cacheline_aligned_in_smp;

- struct delayed_work file_put_work; - struct llist_head file_put_llist; - - struct work_struct exit_work; struct io_restriction restrictions; + + /* slow path rsrc auxilary data, used by update/register */ + struct { + struct io_rsrc_node *rsrc_backup_node; + struct io_mapped_ubuf *dummy_ubuf; + struct io_rsrc_data *file_data; + struct io_rsrc_data *buf_data; + + struct delayed_work rsrc_put_work; + struct llist_head rsrc_put_llist; + struct list_head rsrc_ref_list; + spinlock_t rsrc_ref_lock; + }; + + /* Keep this last, we don't need it for the fast path */ + struct { + #if defined(CONFIG_UNIX) + struct socket *ring_sock; + #endif + /* hashed buffered write serialization */ + struct io_wq_hash *hash_map; + + /* Only used for accounting purposes */ + struct user_struct *user; + struct mm_struct *mm_account; + + /* ctx exit and cancelation */ + struct llist_head fallback_llist; + struct delayed_work fallback_work; + struct work_struct exit_work; + struct list_head tctx_list; + struct completion ref_comp; + u32 iowq_limits[2]; + bool iowq_limits_set; + }; +}; + +struct io_uring_task { + /* submission side */ + int cached_refs; + struct xarray xa; + struct wait_queue_head wait; + const struct io_ring_ctx *last; + struct io_wq *io_wq; + struct percpu_counter inflight; + atomic_t inflight_tracked; + atomic_t in_idle; + + spinlock_t task_lock; + struct io_wq_work_list task_list; + struct callback_head task_work; + bool task_running; };

/* @@ -398,20 +484,24 @@ struct io_ring_ctx { */ struct io_poll_iocb { struct file *file; - union { - struct wait_queue_head *head; - u64 addr; - }; + struct wait_queue_head *head; __poll_t events; - bool done; - bool canceled; struct wait_queue_entry wait; };

+struct io_poll_update { + struct file *file; + u64 old_user_data; + u64 new_user_data; + __poll_t events; + bool update_events; + bool update_user_data; +}; + struct io_close { struct file *file; - struct file *put_file; int fd; + u32 file_slot; };

struct io_timeout_data { @@ -419,6 +509,7 @@ struct io_timeout_data { struct hrtimer timer; struct timespec64 ts; enum hrtimer_mode mode; + u32 flags; };

struct io_accept { @@ -426,6 +517,7 @@ struct io_accept { struct sockaddr __user *addr; int __user *addr_len; int flags; + u32 file_slot; unsigned long nofile; };

@@ -447,11 +539,20 @@ struct io_timeout { u32 off; u32 target_seq; struct list_head list; + /* head of the link, used by linked timeouts only */ + struct io_kiocb *head; + /* for linked completions */ + struct io_kiocb *prev; };

struct io_timeout_rem { struct file *file; u64 addr; + + /* timeout update */ + struct timespec64 ts; + u32 flags; + bool ltimeout; };

struct io_rw { @@ -470,8 +571,9 @@ struct io_connect { struct io_sr_msg { struct file *file; union { - struct user_msghdr __user *umsg; - void __user *buf; + struct compat_msghdr __user *umsg_compat; + struct user_msghdr __user *umsg; + void __user *buf; }; int msg_flags; int bgid; @@ -482,13 +584,13 @@ struct io_sr_msg { struct io_open { struct file *file; int dfd; - bool ignore_nonblock; + u32 file_slot; struct filename *filename; struct open_how how; unsigned long nofile; };

-struct io_files_update { +struct io_rsrc_update { struct file *file; u64 arg; u32 nr_args; @@ -519,10 +621,10 @@ struct io_epoll {

struct io_splice { struct file *file_out; - struct file *file_in; loff_t off_out; loff_t off_in; u64 len; + int splice_fd_in; unsigned int flags; };

@@ -544,9 +646,52 @@ struct io_statx { struct statx __user *buffer; };

+struct io_shutdown { + struct file *file; + int how; +}; + +struct io_rename { + struct file *file; + int old_dfd; + int new_dfd; + struct filename *oldpath; + struct filename *newpath; + int flags; +}; + +struct io_unlink { + struct file *file; + int dfd; + int flags; + struct filename *filename; +}; + +struct io_mkdir { + struct file *file; + int dfd; + umode_t mode; + struct filename *filename; +}; + +struct io_symlink { + struct file *file; + int new_dfd; + struct filename *oldpath; + struct filename *newpath; +}; + +struct io_hardlink { + struct file *file; + int old_dfd; + int new_dfd; + struct filename *oldpath; + struct filename *newpath; + int flags; +}; + struct io_completion { struct file *file; - struct list_head list; u32 cflags; };

@@ -556,7 +701,8 @@ struct io_async_connect {

struct io_async_msghdr { struct iovec fast_iov[UIO_FASTIOV]; - struct iovec *iov; + /* points to an allocated iov, if NULL we use fast_iov instead */ + struct iovec *free_iov; struct sockaddr __user *uaddr; struct msghdr msg; struct sockaddr_storage addr; @@ -566,6 +712,7 @@ struct io_async_rw { struct iovec fast_iov[UIO_FASTIOV]; const struct iovec *free_iovec; struct iov_iter iter; + struct iov_iter_state iter_state; size_t bytes_done; struct wait_page_queue wpq; }; @@ -578,19 +725,24 @@ enum { REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT, REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,

- REQ_F_LINK_HEAD_BIT, - REQ_F_FAIL_LINK_BIT, + /* first byte is taken by user flags, shift it to not overlap */ + REQ_F_FAIL_BIT = 8, REQ_F_INFLIGHT_BIT, REQ_F_CUR_POS_BIT, REQ_F_NOWAIT_BIT, REQ_F_LINK_TIMEOUT_BIT, - REQ_F_ISREG_BIT, REQ_F_NEED_CLEANUP_BIT, REQ_F_POLLED_BIT, REQ_F_BUFFER_SELECTED_BIT, - REQ_F_NO_FILE_TABLE_BIT, - REQ_F_WORK_INITIALIZED_BIT, - REQ_F_LTIMEOUT_ACTIVE_BIT, + REQ_F_COMPLETE_INLINE_BIT, + REQ_F_REISSUE_BIT, + REQ_F_CREDS_BIT, + REQ_F_REFCOUNT_BIT, + REQ_F_ARM_LTIMEOUT_BIT, + /* keep async read/write and isreg together and in order */ + REQ_F_NOWAIT_READ_BIT, + REQ_F_NOWAIT_WRITE_BIT, + REQ_F_ISREG_BIT,

/* not a real bit, just to check we're not overflowing the space */ __REQ_F_LAST_BIT, @@ -610,11 +762,9 @@ enum { /* IOSQE_BUFFER_SELECT */ REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),

- /* head of a link */ - REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT), /* fail rest of links */ - REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT), - /* on inflight list */ + REQ_F_FAIL = BIT(REQ_F_FAIL_BIT), + /* on inflight list, should be cancelled and waited on exit reliably */ REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT), /* read/write uses file position */ REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT), @@ -622,20 +772,28 @@ enum { REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT), /* has or had linked timeout */ REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT), - /* regular file */ - REQ_F_ISREG = BIT(REQ_F_ISREG_BIT), /* needs cleanup */ REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT), /* already went through poll handler */ REQ_F_POLLED = BIT(REQ_F_POLLED_BIT), /* buffer already selected */ REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT), - /* doesn't need file table for this request */ - REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT), - /* io_wq_work is initialized */ - REQ_F_WORK_INITIALIZED = BIT(REQ_F_WORK_INITIALIZED_BIT), - /* linked timeout is active, i.e. prepared by link's head */ - REQ_F_LTIMEOUT_ACTIVE = BIT(REQ_F_LTIMEOUT_ACTIVE_BIT), + /* completion is deferred through io_comp_state */ + REQ_F_COMPLETE_INLINE = BIT(REQ_F_COMPLETE_INLINE_BIT), + /* caller should reissue async */ + REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT), + /* supports async reads */ + REQ_F_NOWAIT_READ = BIT(REQ_F_NOWAIT_READ_BIT), + /* supports async writes */ + REQ_F_NOWAIT_WRITE = BIT(REQ_F_NOWAIT_WRITE_BIT), + /* regular file */ + REQ_F_ISREG = BIT(REQ_F_ISREG_BIT), + /* has creds assigned */ + REQ_F_CREDS = BIT(REQ_F_CREDS_BIT), + /* skip refcounting if not set */ + REQ_F_REFCOUNT = BIT(REQ_F_REFCOUNT_BIT), + /* there is a linked timeout that has to be armed */ + REQ_F_ARM_LTIMEOUT = BIT(REQ_F_ARM_LTIMEOUT_BIT), };

struct async_poll { @@ -643,6 +801,21 @@ struct async_poll { struct io_poll_iocb *double_poll; };

+typedef void (*io_req_tw_func_t)(struct io_kiocb *req, bool *locked); + +struct io_task_work { + union { + struct io_wq_work_node node; + struct llist_node fallback_node; + }; + io_req_tw_func_t func; +}; + +enum { + IORING_RSRC_FILE = 0, + IORING_RSRC_BUFFER = 1, +}; + /* * NOTE! Each of the iocb union members has the file pointer * as the first entry in their struct definition. So you can @@ -654,6 +827,7 @@ struct io_kiocb { struct file *file; struct io_rw rw; struct io_poll_iocb poll; + struct io_poll_update poll_update; struct io_accept accept; struct io_sync sync; struct io_cancel cancel; @@ -663,13 +837,19 @@ struct io_kiocb { struct io_sr_msg sr_msg; struct io_open open; struct io_close close; - struct io_files_update files_update; + struct io_rsrc_update rsrc_update; struct io_fadvise fadvise; struct io_madvise madvise; struct io_epoll epoll; struct io_splice splice; struct io_provide_buf pbuf; struct io_statx statx; + struct io_shutdown shutdown; + struct io_rename rename; + struct io_unlink unlink; + struct io_mkdir mkdir; + struct io_symlink symlink; + struct io_hardlink hardlink; /* use only after cleaning per-op data, see io_clean_op() */ struct io_completion compl; }; @@ -685,70 +865,44 @@ struct io_kiocb {

struct io_ring_ctx *ctx; unsigned int flags; - refcount_t refs; + atomic_t refs; struct task_struct *task; u64 user_data;

- struct list_head link_list; + struct io_kiocb *link; + struct percpu_ref *fixed_rsrc_refs;

- /* - * 1. used with ctx->iopoll_list with reads/writes - * 2. to track reqs with ->files (see io_op_def::file_table) - */ + /* used with ctx->iopoll_list with reads/writes */ struct list_head inflight_entry; - - struct list_head iopoll_entry; - - struct percpu_ref *fixed_file_refs; - struct callback_head task_work; + struct io_task_work io_task_work; /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */ struct hlist_node hash_node; struct async_poll *apoll; struct io_wq_work work; -}; + const struct cred *creds;

-struct io_defer_entry { - struct list_head list; - struct io_kiocb *req; - u32 seq; + /* store used ubuf, so we can prevent reloading */ + struct io_mapped_ubuf *imu; + /* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */ + struct io_buffer *kbuf; + atomic_t poll_refs; };

-#define IO_IOPOLL_BATCH 8 - -struct io_comp_state { - unsigned int nr; - struct list_head list; +struct io_tctx_node { + struct list_head ctx_node; + struct task_struct *task; struct io_ring_ctx *ctx; };

-struct io_submit_state { - struct blk_plug plug; - - /* - * io_kiocb alloc cache - */ - void *reqs[IO_IOPOLL_BATCH]; - unsigned int free_reqs; - - /* - * Batch completion logic - */ - struct io_comp_state comp; - - /* - * File reference cache - */ - struct file *file; - unsigned int fd; - unsigned int has_refs; - unsigned int ios_left; +struct io_defer_entry { + struct list_head list; + struct io_kiocb *req; + u32 seq; };

struct io_op_def { /* needs req->file assigned */ unsigned needs_file : 1; - /* don't fail if file grab fails */ - unsigned needs_file_no_error : 1; /* hash wq insertion if file is a regular file */ unsigned hash_reg_file : 1; /* unbound wq insertion if file is a non-regular file */ @@ -760,11 +914,12 @@ struct io_op_def { unsigned pollout : 1; /* op supports buffer selection */ unsigned buffer_select : 1; - /* must always have async data allocated */ - unsigned needs_async_data : 1; + /* do prep async if is going to be punted */ + unsigned needs_async_setup : 1; + /* should block plug */ + unsigned plug : 1; /* size of async data needed, if any */ unsigned short async_size; - unsigned work_flags; };

static const struct io_op_def io_op_defs[] = { @@ -774,41 +929,36 @@ static const struct io_op_def io_op_defs[] = { .unbound_nonreg_file = 1, .pollin = 1, .buffer_select = 1, - .needs_async_data = 1, + .needs_async_setup = 1, + .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FILES, }, [IORING_OP_WRITEV] = { .needs_file = 1, .hash_reg_file = 1, .unbound_nonreg_file = 1, .pollout = 1, - .needs_async_data = 1, + .needs_async_setup = 1, + .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FSIZE | IO_WQ_WORK_FILES, }, [IORING_OP_FSYNC] = { .needs_file = 1, - .work_flags = IO_WQ_WORK_BLKCG, }, [IORING_OP_READ_FIXED] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, + .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM | - IO_WQ_WORK_FILES, }, [IORING_OP_WRITE_FIXED] = { .needs_file = 1, .hash_reg_file = 1, .unbound_nonreg_file = 1, .pollout = 1, + .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE | - IO_WQ_WORK_MM | IO_WQ_WORK_FILES, }, [IORING_OP_POLL_ADD] = { .needs_file = 1, @@ -817,126 +967,91 @@ static const struct io_op_def io_op_defs[] = { [IORING_OP_POLL_REMOVE] = {}, [IORING_OP_SYNC_FILE_RANGE] = { .needs_file = 1, - .work_flags = IO_WQ_WORK_BLKCG, }, [IORING_OP_SENDMSG] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollout = 1, - .needs_async_data = 1, + .needs_async_setup = 1, .async_size = sizeof(struct io_async_msghdr), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FS, }, [IORING_OP_RECVMSG] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, .buffer_select = 1, - .needs_async_data = 1, + .needs_async_setup = 1, .async_size = sizeof(struct io_async_msghdr), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FS, }, [IORING_OP_TIMEOUT] = { - .needs_async_data = 1, .async_size = sizeof(struct io_timeout_data), - .work_flags = IO_WQ_WORK_MM, }, - [IORING_OP_TIMEOUT_REMOVE] = {}, + [IORING_OP_TIMEOUT_REMOVE] = { + /* used by timeout updates' prep() */ + }, [IORING_OP_ACCEPT] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES, }, [IORING_OP_ASYNC_CANCEL] = {}, [IORING_OP_LINK_TIMEOUT] = { - .needs_async_data = 1, .async_size = sizeof(struct io_timeout_data), - .work_flags = IO_WQ_WORK_MM, }, [IORING_OP_CONNECT] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollout = 1, - .needs_async_data = 1, + .needs_async_setup = 1, .async_size = sizeof(struct io_async_connect), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FS, }, [IORING_OP_FALLOCATE] = { .needs_file = 1, - .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE, - }, - [IORING_OP_OPENAT] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FS, - }, - [IORING_OP_CLOSE] = { - .needs_file = 1, - .needs_file_no_error = 1, - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG, - }, - [IORING_OP_FILES_UPDATE] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM, - }, - [IORING_OP_STATX] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM | - IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG, }, + [IORING_OP_OPENAT] = {}, + [IORING_OP_CLOSE] = {}, + [IORING_OP_FILES_UPDATE] = {}, + [IORING_OP_STATX] = {}, [IORING_OP_READ] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, .buffer_select = 1, + .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FILES, }, [IORING_OP_WRITE] = { .needs_file = 1, .hash_reg_file = 1, .unbound_nonreg_file = 1, .pollout = 1, + .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FSIZE | IO_WQ_WORK_FILES, }, [IORING_OP_FADVISE] = { .needs_file = 1, - .work_flags = IO_WQ_WORK_BLKCG, - }, - [IORING_OP_MADVISE] = { - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG, }, + [IORING_OP_MADVISE] = {}, [IORING_OP_SEND] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollout = 1, - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FS, }, [IORING_OP_RECV] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, .buffer_select = 1, - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FS, }, [IORING_OP_OPENAT2] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_FS | - IO_WQ_WORK_BLKCG, }, [IORING_OP_EPOLL_CTL] = { .unbound_nonreg_file = 1, - .work_flags = IO_WQ_WORK_FILES, }, [IORING_OP_SPLICE] = { .needs_file = 1, .hash_reg_file = 1, .unbound_nonreg_file = 1, - .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FILES, }, [IORING_OP_PROVIDE_BUFFERS] = {}, [IORING_OP_REMOVE_BUFFERS] = {}, @@ -945,43 +1060,47 @@ static const struct io_op_def io_op_defs[] = { .hash_reg_file = 1, .unbound_nonreg_file = 1, }, + [IORING_OP_SHUTDOWN] = { + .needs_file = 1, + }, + [IORING_OP_RENAMEAT] = {}, + [IORING_OP_UNLINKAT] = {}, };

-enum io_mem_account { - ACCT_LOCKED, - ACCT_PINNED, -}; +/* requests with any of those set should undergo io_disarm_next() */ +#define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL)

-static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node); -static struct fixed_file_ref_node *alloc_fixed_file_ref_node( - struct io_ring_ctx *ctx); +static bool io_disarm_next(struct io_kiocb *req); +static void io_uring_del_tctx_node(unsigned long index); +static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, + struct task_struct *task, + bool cancel_all); +static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd); + +static void io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags);

-static void __io_complete_rw(struct io_kiocb *req, long res, long res2, - struct io_comp_state *cs); -static void io_cqring_fill_event(struct io_kiocb *req, long res); static void io_put_req(struct io_kiocb *req); -static void io_put_req_deferred(struct io_kiocb *req, int nr); -static void io_double_put_req(struct io_kiocb *req); -static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req); -static void __io_queue_linked_timeout(struct io_kiocb *req); +static void io_put_req_deferred(struct io_kiocb *req); +static void io_dismantle_req(struct io_kiocb *req); static void io_queue_linked_timeout(struct io_kiocb *req); -static int __io_sqe_files_update(struct io_ring_ctx *ctx, - struct io_uring_files_update *ip, - unsigned nr_args); -static void __io_clean_op(struct io_kiocb *req); -static struct file *io_file_get(struct io_submit_state *state, +static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type, + struct io_uring_rsrc_update2 *up, + unsigned nr_args); +static void io_clean_op(struct io_kiocb *req); +static struct file *io_file_get(struct io_ring_ctx *ctx, struct io_kiocb *req, int fd, bool fixed); -static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs); -static void io_file_put_work(struct work_struct *work); +static void __io_queue_sqe(struct io_kiocb *req); +static void io_rsrc_put_work(struct work_struct *work);

-static ssize_t io_import_iovec(int rw, struct io_kiocb *req, - struct iovec **iovec, struct iov_iter *iter, - bool needs_lock); -static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, - const struct iovec *fast_iov, - struct iov_iter *iter, bool force); -static void io_req_drop_files(struct io_kiocb *req); static void io_req_task_queue(struct io_kiocb *req); +static void io_submit_flush_completions(struct io_ring_ctx *ctx); +static int io_req_prep_async(struct io_kiocb *req); + +static int io_install_fixed_file(struct io_kiocb *req, struct file *file, + unsigned int issue_flags, u32 slot_index); +static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags); + +static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer);

static struct kmem_cache *req_cachep;

@@ -1000,21 +1119,67 @@ struct sock *io_uring_get_socket(struct file *file) } EXPORT_SYMBOL(io_uring_get_socket);

-static inline void io_clean_op(struct io_kiocb *req) +static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked) +{ + if (!*locked) { + mutex_lock(&ctx->uring_lock); + *locked = true; + } +} + +#define io_for_each_link(pos, head) \ + for (pos = (head); pos; pos = pos->link) + +/* + * Shamelessly stolen from the mm implementation of page reference checking, + * see commit f958d7b528b1 for details. + */ +#define req_ref_zero_or_close_to_overflow(req) \ + ((unsigned int) atomic_read(&(req->refs)) + 127u <= 127u) + +static inline bool req_ref_inc_not_zero(struct io_kiocb *req) { - if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED)) - __io_clean_op(req); + WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); + return atomic_inc_not_zero(&req->refs); }

-static inline bool __io_match_files(struct io_kiocb *req, - struct files_struct *files) +static inline bool req_ref_put_and_test(struct io_kiocb *req) { - if (req->file && req->file->f_op == &io_uring_fops) + if (likely(!(req->flags & REQ_F_REFCOUNT))) return true;

- return ((req->flags & REQ_F_WORK_INITIALIZED) && - (req->work.flags & IO_WQ_WORK_FILES)) && - req->work.identity->files == files; + WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); + return atomic_dec_and_test(&req->refs); +} + +static inline void req_ref_get(struct io_kiocb *req) +{ + WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); + WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); + atomic_inc(&req->refs); +} + +static inline void __io_req_set_refcount(struct io_kiocb *req, int nr) +{ + if (!(req->flags & REQ_F_REFCOUNT)) { + req->flags |= REQ_F_REFCOUNT; + atomic_set(&req->refs, nr); + } +} + +static inline void io_req_set_refcount(struct io_kiocb *req) +{ + __io_req_set_refcount(req, 1); +} + +static inline void io_req_set_rsrc_node(struct io_kiocb *req) +{ + struct io_ring_ctx *ctx = req->ctx; + + if (!req->fixed_rsrc_refs) { + req->fixed_rsrc_refs = &ctx->rsrc_node->refs; + percpu_ref_get(req->fixed_rsrc_refs); + } }

static void io_refs_resurrect(struct percpu_ref *ref, struct completion *compl) @@ -1029,169 +1194,104 @@ static void io_refs_resurrect(struct percpu_ref *ref, struct completion *compl) percpu_ref_put(ref); }

-static bool io_match_task(struct io_kiocb *head, - struct task_struct *task, - struct files_struct *files) +static bool io_match_task(struct io_kiocb *head, struct task_struct *task, + bool cancel_all) + __must_hold(&req->ctx->timeout_lock) { - struct io_kiocb *link; + struct io_kiocb *req;

- if (task && head->task != task) { - /* in terms of cancelation, always match if req task is dead */ - if (head->task->flags & PF_EXITING) - return true; + if (task && head->task != task) return false; - } - if (!files) - return true; - if (__io_match_files(head, files)) + if (cancel_all) return true; - if (head->flags & REQ_F_LINK_HEAD) { - list_for_each_entry(link, &head->link_list, link_list) { - if (__io_match_files(link, files)) - return true; - } + + io_for_each_link(req, head) { + if (req->flags & REQ_F_INFLIGHT) + return true; } return false; }

- -static void io_sq_thread_drop_mm(void) +static bool io_match_linked(struct io_kiocb *head) { - struct mm_struct *mm = current->mm; + struct io_kiocb *req;

- if (mm) { - kthread_unuse_mm(mm); - mmput(mm); - current->mm = NULL; + io_for_each_link(req, head) { + if (req->flags & REQ_F_INFLIGHT) + return true; } + return false; }

-static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx) +/* + * As io_match_task() but protected against racing with linked timeouts. + * User must not hold timeout_lock. + */ +static bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task, + bool cancel_all) { - struct mm_struct *mm; - - if (current->flags & PF_EXITING) - return -EFAULT; - if (current->mm) - return 0; + bool matched;

- /* Should never happen */ - if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL))) - return -EFAULT; + if (task && head->task != task) + return false; + if (cancel_all) + return true;

- task_lock(ctx->sqo_task); - mm = ctx->sqo_task->mm; - if (unlikely(!mm || !mmget_not_zero(mm))) - mm = NULL; - task_unlock(ctx->sqo_task); + if (head->flags & REQ_F_LINK_TIMEOUT) { + struct io_ring_ctx *ctx = head->ctx;

- if (mm) { - kthread_use_mm(mm); - return 0; + /* protect against races with linked timeouts */ + spin_lock_irq(&ctx->timeout_lock); + matched = io_match_linked(head); + spin_unlock_irq(&ctx->timeout_lock); + } else { + matched = io_match_linked(head); } + return matched; +}

- return -EFAULT; -} - -static int io_sq_thread_acquire_mm(struct io_ring_ctx *ctx, - struct io_kiocb *req) -{ - if (!(io_op_defs[req->opcode].work_flags & IO_WQ_WORK_MM)) - return 0; - return __io_sq_thread_acquire_mm(ctx); -} - -static void io_sq_thread_associate_blkcg(struct io_ring_ctx *ctx, - struct cgroup_subsys_state **cur_css) - +static inline void req_set_fail(struct io_kiocb *req) { -#ifdef CONFIG_BLK_CGROUP - /* puts the old one when swapping */ - if (*cur_css != ctx->sqo_blkcg_css) { - kthread_associate_blkcg(ctx->sqo_blkcg_css); - *cur_css = ctx->sqo_blkcg_css; - } -#endif -} - -static void io_sq_thread_unassociate_blkcg(void) -{ -#ifdef CONFIG_BLK_CGROUP - kthread_associate_blkcg(NULL); -#endif + req->flags |= REQ_F_FAIL; }

-static inline void req_set_fail_links(struct io_kiocb *req) +static inline void req_fail_link_node(struct io_kiocb *req, int res) { - if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK) - req->flags |= REQ_F_FAIL_LINK; + req_set_fail(req); + req->result = res; }

-/* - * None of these are dereferenced, they are simply used to check if any of - * them have changed. If we're under current and check they are still the - * same, we're fine to grab references to them for actual out-of-line use. - */ -static void io_init_identity(struct io_identity *id) +static void io_ring_ctx_ref_free(struct percpu_ref *ref) { - id->files = current->files; - id->mm = current->mm; -#ifdef CONFIG_BLK_CGROUP - rcu_read_lock(); - id->blkcg_css = blkcg_css(); - rcu_read_unlock(); -#endif - id->creds = current_cred(); - id->nsproxy = current->nsproxy; - id->fs = current->fs; - id->fsize = rlimit(RLIMIT_FSIZE); -#ifdef CONFIG_AUDIT - id->loginuid = current->loginuid; - id->sessionid = current->sessionid; -#endif - refcount_set(&id->count, 1); -} + struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);

-static inline void __io_req_init_async(struct io_kiocb *req) -{ - memset(&req->work, 0, sizeof(req->work)); - req->flags |= REQ_F_WORK_INITIALIZED; + complete(&ctx->ref_comp); }

-/* - * Note: must call io_req_init_async() for the first time you - * touch any members of io_wq_work. - */ -static inline void io_req_init_async(struct io_kiocb *req) +static inline bool io_is_timeout_noseq(struct io_kiocb *req) { - struct io_uring_task *tctx = req->task->io_uring; - - if (req->flags & REQ_F_WORK_INITIALIZED) - return; - - __io_req_init_async(req); - - /* Grab a ref if this isn't our static identity */ - req->work.identity = tctx->identity; - if (tctx->identity != &tctx->__identity) - refcount_inc(&req->work.identity->count); + return !req->timeout.off; }

-static inline bool io_async_submit(struct io_ring_ctx *ctx) +static void io_fallback_req_func(struct work_struct *work) { - return ctx->flags & IORING_SETUP_SQPOLL; -} + struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, + fallback_work.work); + struct llist_node *node = llist_del_all(&ctx->fallback_llist); + struct io_kiocb *req, *tmp; + bool locked = false;

-static void io_ring_ctx_ref_free(struct percpu_ref *ref) -{ - struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); + percpu_ref_get(&ctx->refs); + llist_for_each_entry_safe(req, tmp, node, io_task_work.fallback_node) + req->io_task_work.func(req, &locked);

- complete(&ctx->ref_comp); -} + if (locked) { + if (ctx->submit_state.compl_nr) + io_submit_flush_completions(ctx); + mutex_unlock(&ctx->uring_lock); + } + percpu_ref_put(&ctx->refs);

-static inline bool io_is_timeout_noseq(struct io_kiocb *req) -{ - return !req->timeout.off; }

static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) @@ -1203,10 +1303,6 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) if (!ctx) return NULL;

- ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL); - if (!ctx->fallback_req) - goto err; - /* * Use 5 bits less than the max cq entries, that should give us around * 32 entries per hash list if totally full and uniformly spread. @@ -1222,6 +1318,12 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) goto err; __hash_init(ctx->cancel_hash, 1U << hash_bits);

+ ctx->dummy_ubuf = kzalloc(sizeof(*ctx->dummy_ubuf), GFP_KERNEL); + if (!ctx->dummy_ubuf) + goto err; + /* set invalid range, so io_import_fixed() fails meeting it */ + ctx->dummy_ubuf->ubuf = -1UL; + if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) goto err; @@ -1229,232 +1331,109 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) ctx->flags = p->flags; init_waitqueue_head(&ctx->sqo_sq_wait); INIT_LIST_HEAD(&ctx->sqd_list); - init_waitqueue_head(&ctx->cq_wait); + init_waitqueue_head(&ctx->poll_wait); INIT_LIST_HEAD(&ctx->cq_overflow_list); init_completion(&ctx->ref_comp); - init_completion(&ctx->sq_thread_comp); xa_init_flags(&ctx->io_buffers, XA_FLAGS_ALLOC1); xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1); mutex_init(&ctx->uring_lock); - init_waitqueue_head(&ctx->wait); + init_waitqueue_head(&ctx->cq_wait); spin_lock_init(&ctx->completion_lock); + spin_lock_init(&ctx->timeout_lock); INIT_LIST_HEAD(&ctx->iopoll_list); INIT_LIST_HEAD(&ctx->defer_list); INIT_LIST_HEAD(&ctx->timeout_list); - spin_lock_init(&ctx->inflight_lock); - INIT_LIST_HEAD(&ctx->inflight_list); - INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work); - init_llist_head(&ctx->file_put_llist); + INIT_LIST_HEAD(&ctx->ltimeout_list); + spin_lock_init(&ctx->rsrc_ref_lock); + INIT_LIST_HEAD(&ctx->rsrc_ref_list); + INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work); + init_llist_head(&ctx->rsrc_put_llist); + INIT_LIST_HEAD(&ctx->tctx_list); + INIT_LIST_HEAD(&ctx->submit_state.free_list); + INIT_LIST_HEAD(&ctx->locked_free_list); + INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func); return ctx; err: - if (ctx->fallback_req) - kmem_cache_free(req_cachep, ctx->fallback_req); + kfree(ctx->dummy_ubuf); kfree(ctx->cancel_hash); kfree(ctx); return NULL; }

+static void io_account_cq_overflow(struct io_ring_ctx *ctx) +{ + struct io_rings *r = ctx->rings; + + WRITE_ONCE(r->cq_overflow, READ_ONCE(r->cq_overflow) + 1); + ctx->cq_extra--; +} + static bool req_need_defer(struct io_kiocb *req, u32 seq) { if (unlikely(req->flags & REQ_F_IO_DRAIN)) { struct io_ring_ctx *ctx = req->ctx;

- return seq != ctx->cached_cq_tail - + READ_ONCE(ctx->cached_cq_overflow); + return seq + READ_ONCE(ctx->cq_extra) != ctx->cached_cq_tail; }

return false; }

-static void __io_commit_cqring(struct io_ring_ctx *ctx) -{ - struct io_rings *rings = ctx->rings; - - /* order cqe stores with ring update */ - smp_store_release(&rings->cq.tail, ctx->cached_cq_tail); -} +#define FFS_ASYNC_READ 0x1UL +#define FFS_ASYNC_WRITE 0x2UL +#ifdef CONFIG_64BIT +#define FFS_ISREG 0x4UL +#else +#define FFS_ISREG 0x0UL +#endif +#define FFS_MASK ~(FFS_ASYNC_READ|FFS_ASYNC_WRITE|FFS_ISREG)

-static void io_put_identity(struct io_uring_task *tctx, struct io_kiocb *req) +static inline bool io_req_ffs_set(struct io_kiocb *req) { - if (req->work.identity == &tctx->__identity) - return; - if (refcount_dec_and_test(&req->work.identity->count)) - kfree(req->work.identity); + return IS_ENABLED(CONFIG_64BIT) && (req->flags & REQ_F_FIXED_FILE); }

-static void io_req_clean_work(struct io_kiocb *req) +static void io_req_track_inflight(struct io_kiocb *req) { - if (!(req->flags & REQ_F_WORK_INITIALIZED)) - return; - - req->flags &= ~REQ_F_WORK_INITIALIZED; - - if (req->work.flags & IO_WQ_WORK_MM) { - mmdrop(req->work.identity->mm); - req->work.flags &= ~IO_WQ_WORK_MM; - } -#ifdef CONFIG_BLK_CGROUP - if (req->work.flags & IO_WQ_WORK_BLKCG) { - css_put(req->work.identity->blkcg_css); - req->work.flags &= ~IO_WQ_WORK_BLKCG; - } -#endif - if (req->work.flags & IO_WQ_WORK_CREDS) { - put_cred(req->work.identity->creds); - req->work.flags &= ~IO_WQ_WORK_CREDS; - } - if (req->work.flags & IO_WQ_WORK_FS) { - struct fs_struct *fs = req->work.identity->fs; - - spin_lock(&req->work.identity->fs->lock); - if (--fs->users) - fs = NULL; - spin_unlock(&req->work.identity->fs->lock); - if (fs) - free_fs_struct(fs); - req->work.flags &= ~IO_WQ_WORK_FS; + if (!(req->flags & REQ_F_INFLIGHT)) { + req->flags |= REQ_F_INFLIGHT; + atomic_inc(&req->task->io_uring->inflight_tracked); } - if (req->flags & REQ_F_INFLIGHT) - io_req_drop_files(req); - - io_put_identity(req->task->io_uring, req); }

-/* - * Create a private copy of io_identity, since some fields don't match - * the current context. - */ -static bool io_identity_cow(struct io_kiocb *req) +static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req) { - struct io_uring_task *tctx = req->task->io_uring; - const struct cred *creds = NULL; - struct io_identity *id; - - if (req->work.flags & IO_WQ_WORK_CREDS) - creds = req->work.identity->creds; - - id = kmemdup(req->work.identity, sizeof(*id), GFP_KERNEL); - if (unlikely(!id)) { - req->work.flags |= IO_WQ_WORK_CANCEL; - return false; - } - - /* - * We can safely just re-init the creds we copied Either the field - * matches the current one, or we haven't grabbed it yet. The only - * exception is ->creds, through registered personalities, so handle - * that one separately. - */ - io_init_identity(id); - if (creds) - id->creds = creds; - - /* add one for this request */ - refcount_inc(&id->count); + if (WARN_ON_ONCE(!req->link)) + return NULL;

- /* drop tctx and req identity references, if needed */ - if (tctx->identity != &tctx->__identity && - refcount_dec_and_test(&tctx->identity->count)) - kfree(tctx->identity); - if (req->work.identity != &tctx->__identity && - refcount_dec_and_test(&req->work.identity->count)) - kfree(req->work.identity); + req->flags &= ~REQ_F_ARM_LTIMEOUT; + req->flags |= REQ_F_LINK_TIMEOUT;

- req->work.identity = id; - tctx->identity = id; - return true; + /* linked timeouts should have two refs once prep'ed */ + io_req_set_refcount(req); + __io_req_set_refcount(req->link, 2); + return req->link; }

-static bool io_grab_identity(struct io_kiocb *req) +static inline struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) { - const struct io_op_def *def = &io_op_defs[req->opcode]; - struct io_identity *id = req->work.identity; - struct io_ring_ctx *ctx = req->ctx; - - if (def->work_flags & IO_WQ_WORK_FSIZE) { - if (id->fsize != rlimit(RLIMIT_FSIZE)) - return false; - req->work.flags |= IO_WQ_WORK_FSIZE; - } -#ifdef CONFIG_BLK_CGROUP - if (!(req->work.flags & IO_WQ_WORK_BLKCG) && - (def->work_flags & IO_WQ_WORK_BLKCG)) { - rcu_read_lock(); - if (id->blkcg_css != blkcg_css()) { - rcu_read_unlock(); - return false; - } - /* - * This should be rare, either the cgroup is dying or the task - * is moving cgroups. Just punt to root for the handful of ios. - */ - if (css_tryget_online(id->blkcg_css)) - req->work.flags |= IO_WQ_WORK_BLKCG; - rcu_read_unlock(); - } -#endif - if (!(req->work.flags & IO_WQ_WORK_CREDS)) { - if (id->creds != current_cred()) - return false; - get_cred(id->creds); - req->work.flags |= IO_WQ_WORK_CREDS; - } -#ifdef CONFIG_AUDIT - if (!uid_eq(current->loginuid, id->loginuid) || - current->sessionid != id->sessionid) - return false; -#endif - if (!(req->work.flags & IO_WQ_WORK_FS) && - (def->work_flags & IO_WQ_WORK_FS)) { - if (current->fs != id->fs) - return false; - spin_lock(&id->fs->lock); - if (!id->fs->in_exec) { - id->fs->users++; - req->work.flags |= IO_WQ_WORK_FS; - } else { - req->work.flags |= IO_WQ_WORK_CANCEL; - } - spin_unlock(&current->fs->lock); - } - if (!(req->work.flags & IO_WQ_WORK_FILES) && - (def->work_flags & IO_WQ_WORK_FILES) && - !(req->flags & REQ_F_NO_FILE_TABLE)) { - if (id->files != current->files || - id->nsproxy != current->nsproxy) - return false; - atomic_inc(&id->files->count); - get_nsproxy(id->nsproxy); - - if (!(req->flags & REQ_F_INFLIGHT)) { - req->flags |= REQ_F_INFLIGHT; - - spin_lock_irq(&ctx->inflight_lock); - list_add(&req->inflight_entry, &ctx->inflight_list); - spin_unlock_irq(&ctx->inflight_lock); - } - req->work.flags |= IO_WQ_WORK_FILES; - } - if (!(req->work.flags & IO_WQ_WORK_MM) && - (def->work_flags & IO_WQ_WORK_MM)) { - if (id->mm != current->mm) - return false; - mmgrab(id->mm); - req->work.flags |= IO_WQ_WORK_MM; - } - - return true; + if (likely(!(req->flags & REQ_F_ARM_LTIMEOUT))) + return NULL; + return __io_prep_linked_timeout(req); }

static void io_prep_async_work(struct io_kiocb *req) { const struct io_op_def *def = &io_op_defs[req->opcode]; struct io_ring_ctx *ctx = req->ctx; - struct io_identity *id;

- io_req_init_async(req); - id = req->work.identity; + if (!(req->flags & REQ_F_CREDS)) { + req->flags |= REQ_F_CREDS; + req->creds = get_current_cred(); + }

+ req->work.list.next = NULL; + req->work.flags = 0; if (req->flags & REQ_F_FORCE_ASYNC) req->work.flags |= IO_WQ_WORK_CONCURRENT;

@@ -1465,92 +1444,77 @@ static void io_prep_async_work(struct io_kiocb *req) if (def->unbound_nonreg_file) req->work.flags |= IO_WQ_WORK_UNBOUND; } - - /* if we fail grabbing identity, we must COW, regrab, and retry */ - if (io_grab_identity(req)) - return; - - if (!io_identity_cow(req)) - return; - - /* can't fail at this point */ - if (!io_grab_identity(req)) - WARN_ON(1); }

static void io_prep_async_link(struct io_kiocb *req) { struct io_kiocb *cur;

- io_prep_async_work(req); - if (req->flags & REQ_F_LINK_HEAD) - list_for_each_entry(cur, &req->link_list, link_list) + if (req->flags & REQ_F_LINK_TIMEOUT) { + struct io_ring_ctx *ctx = req->ctx; + + spin_lock_irq(&ctx->timeout_lock); + io_for_each_link(cur, req) io_prep_async_work(cur); + spin_unlock_irq(&ctx->timeout_lock); + } else { + io_for_each_link(cur, req) + io_prep_async_work(cur); + } }

-static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req) +static void io_queue_async_work(struct io_kiocb *req, bool *locked) { struct io_ring_ctx *ctx = req->ctx; struct io_kiocb *link = io_prep_linked_timeout(req); + struct io_uring_task *tctx = req->task->io_uring;

- trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req, - &req->work, req->flags); - io_wq_enqueue(ctx->io_wq, &req->work); - return link; -} + /* must not take the lock, NULL it as a precaution */ + locked = NULL;

-static void io_queue_async_work(struct io_kiocb *req) -{ - struct io_kiocb *link; + BUG_ON(!tctx); + BUG_ON(!tctx->io_wq);

/* init ->work of the whole link before punting */ io_prep_async_link(req); - link = __io_queue_async_work(req);

+ /* + * Not expected to happen, but if we do have a bug where this _can_ + * happen, catch it here and ensure the request is marked as + * canceled. That will make io-wq go through the usual work cancel + * procedure rather than attempt to run this request (or create a new + * worker for it). + */ + if (WARN_ON_ONCE(!same_thread_group(req->task, current))) + req->work.flags |= IO_WQ_WORK_CANCEL; + + trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req, + &req->work, req->flags); + io_wq_enqueue(tctx->io_wq, &req->work); if (link) io_queue_linked_timeout(link); }

static void io_kill_timeout(struct io_kiocb *req, int status) + __must_hold(&req->ctx->completion_lock) + __must_hold(&req->ctx->timeout_lock) { struct io_timeout_data *io = req->async_data; - int ret;

- ret = hrtimer_try_to_cancel(&io->timer); - if (ret != -1) { + if (hrtimer_try_to_cancel(&io->timer) != -1) { if (status) - req_set_fail_links(req); + req_set_fail(req); atomic_set(&req->ctx->cq_timeouts, atomic_read(&req->ctx->cq_timeouts) + 1); list_del_init(&req->timeout.list); - io_cqring_fill_event(req, status); - io_put_req_deferred(req, 1); - } -} - -/* - * Returns true if we found and killed one or more timeouts - */ -static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk, - struct files_struct *files) -{ - struct io_kiocb *req, *tmp; - int canceled = 0; - - spin_lock_irq(&ctx->completion_lock); - list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) { - if (io_match_task(req, tsk, files)) { - io_kill_timeout(req, -ECANCELED); - canceled++; - } + io_fill_cqe_req(req, status, 0); + io_put_req_deferred(req); } - spin_unlock_irq(&ctx->completion_lock); - return canceled != 0; }

-static void __io_queue_deferred(struct io_ring_ctx *ctx) +static void io_queue_deferred(struct io_ring_ctx *ctx) { - do { + while (!list_empty(&ctx->defer_list)) { struct io_defer_entry *de = list_first_entry(&ctx->defer_list, struct io_defer_entry, list);

@@ -1559,19 +1523,16 @@ static void __io_queue_deferred(struct io_ring_ctx *ctx) list_del_init(&de->list); io_req_task_queue(de->req); kfree(de); - } while (!list_empty(&ctx->defer_list)); + } }

static void io_flush_timeouts(struct io_ring_ctx *ctx) + __must_hold(&ctx->completion_lock) { + u32 seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); struct io_kiocb *req, *tmp; - u32 seq; - - if (list_empty(&ctx->timeout_list)) - return; - - seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);

+ spin_lock_irq(&ctx->timeout_lock); list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) { u32 events_needed, events_got;

@@ -1592,441 +1553,564 @@ static void io_flush_timeouts(struct io_ring_ctx *ctx)

io_kill_timeout(req, 0); } - ctx->cq_last_tm_flush = seq; + spin_unlock_irq(&ctx->timeout_lock); }

-static void io_commit_cqring(struct io_ring_ctx *ctx) +static void __io_commit_cqring_flush(struct io_ring_ctx *ctx) { - io_flush_timeouts(ctx); - __io_commit_cqring(ctx); + if (ctx->off_timeout_used) + io_flush_timeouts(ctx); + if (ctx->drain_active) + io_queue_deferred(ctx); +}

- if (unlikely(!list_empty(&ctx->defer_list))) - __io_queue_deferred(ctx); +static inline void io_commit_cqring(struct io_ring_ctx *ctx) +{ + if (unlikely(ctx->off_timeout_used || ctx->drain_active)) + __io_commit_cqring_flush(ctx); + /* order cqe stores with ring update */ + smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail); }

static inline bool io_sqring_full(struct io_ring_ctx *ctx) { struct io_rings *r = ctx->rings;

- return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries; + return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries; }

-static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) +static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx) +{ + return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head); +} + +static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx) { struct io_rings *rings = ctx->rings; - unsigned tail; + unsigned tail, mask = ctx->cq_entries - 1;

- tail = ctx->cached_cq_tail; /* * writes to the cq entry need to come after reading head; the * control dependency is enough as we're using WRITE_ONCE to * fill the cq entry */ - if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries) + if (__io_cqring_events(ctx) == ctx->cq_entries) return NULL;

- ctx->cached_cq_tail++; - return &rings->cqes[tail & ctx->cq_mask]; + tail = ctx->cached_cq_tail++; + return &rings->cqes[tail & mask]; }

static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx) { - if (!ctx->cq_ev_fd) + if (likely(!ctx->cq_ev_fd)) return false; if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED) return false; - if (!ctx->eventfd_async) - return true; - return io_wq_current_is_worker(); + return !ctx->eventfd_async || io_wq_current_is_worker(); }

+/* + * This should only get called when at least one event has been posted. + * Some applications rely on the eventfd notification count only changing + * IFF a new CQE has been added to the CQ ring. There's no depedency on + * 1:1 relationship between how many times this function is called (and + * hence the eventfd count) and number of CQEs posted to the CQ ring. + */ static void io_cqring_ev_posted(struct io_ring_ctx *ctx) { - if (wq_has_sleeper(&ctx->cq_wait)) { - wake_up_interruptible(&ctx->cq_wait); - kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); - } - if (waitqueue_active(&ctx->wait)) - wake_up(&ctx->wait); + /* + * wake_up_all() may seem excessive, but io_wake_function() and + * io_should_wake() handle the termination of the loop and only + * wake as many waiters as we need to. + */ + if (wq_has_sleeper(&ctx->cq_wait)) + wake_up_all(&ctx->cq_wait); if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait)) wake_up(&ctx->sq_data->wait); if (io_should_trigger_evfd(ctx)) eventfd_signal(ctx->cq_ev_fd, 1); + if (waitqueue_active(&ctx->poll_wait)) + wake_up_interruptible(&ctx->poll_wait); }

-static void io_cqring_mark_overflow(struct io_ring_ctx *ctx) +static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx) { - if (list_empty(&ctx->cq_overflow_list)) { - clear_bit(0, &ctx->sq_check_overflow); - clear_bit(0, &ctx->cq_check_overflow); - ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW; + /* see waitqueue_active() comment */ + smp_mb(); + + if (ctx->flags & IORING_SETUP_SQPOLL) { + if (waitqueue_active(&ctx->cq_wait)) + wake_up_all(&ctx->cq_wait); } + if (io_should_trigger_evfd(ctx)) + eventfd_signal(ctx->cq_ev_fd, 1); + if (waitqueue_active(&ctx->poll_wait)) + wake_up_interruptible(&ctx->poll_wait); }

/* Returns true if there are no backlogged entries after the flush */ -static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force, - struct task_struct *tsk, - struct files_struct *files) +static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force) { - struct io_rings *rings = ctx->rings; - struct io_kiocb *req, *tmp; - struct io_uring_cqe *cqe; - unsigned long flags; - LIST_HEAD(list); - - if (!force) { - if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) == - rings->cq_ring_entries)) - return false; - } + bool all_flushed, posted;

- spin_lock_irqsave(&ctx->completion_lock, flags); + if (!force && __io_cqring_events(ctx) == ctx->cq_entries) + return false;

- cqe = NULL; - list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) { - if (!io_match_task(req, tsk, files)) - continue; + posted = false; + spin_lock(&ctx->completion_lock); + while (!list_empty(&ctx->cq_overflow_list)) { + struct io_uring_cqe *cqe = io_get_cqe(ctx); + struct io_overflow_cqe *ocqe;

- cqe = io_get_cqring(ctx); if (!cqe && !force) break; + ocqe = list_first_entry(&ctx->cq_overflow_list, + struct io_overflow_cqe, list); + if (cqe) + memcpy(cqe, &ocqe->cqe, sizeof(*cqe)); + else + io_account_cq_overflow(ctx);

- list_move(&req->compl.list, &list); - if (cqe) { - WRITE_ONCE(cqe->user_data, req->user_data); - WRITE_ONCE(cqe->res, req->result); - WRITE_ONCE(cqe->flags, req->compl.cflags); - } else { - ctx->cached_cq_overflow++; - WRITE_ONCE(ctx->rings->cq_overflow, - ctx->cached_cq_overflow); - } + posted = true; + list_del(&ocqe->list); + kfree(ocqe); }

- io_commit_cqring(ctx); - io_cqring_mark_overflow(ctx); - - spin_unlock_irqrestore(&ctx->completion_lock, flags); - io_cqring_ev_posted(ctx); - - while (!list_empty(&list)) { - req = list_first_entry(&list, struct io_kiocb, compl.list); - list_del(&req->compl.list); - io_put_req(req); + all_flushed = list_empty(&ctx->cq_overflow_list); + if (all_flushed) { + clear_bit(0, &ctx->check_cq_overflow); + WRITE_ONCE(ctx->rings->sq_flags, + ctx->rings->sq_flags & ~IORING_SQ_CQ_OVERFLOW); }

- return cqe != NULL; + if (posted) + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock); + if (posted) + io_cqring_ev_posted(ctx); + return all_flushed; }

-static void io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force, - struct task_struct *tsk, - struct files_struct *files) +static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx) { - if (test_bit(0, &ctx->cq_check_overflow)) { + bool ret = true; + + if (test_bit(0, &ctx->check_cq_overflow)) { /* iopoll syncs against uring_lock, not completion_lock */ if (ctx->flags & IORING_SETUP_IOPOLL) mutex_lock(&ctx->uring_lock); - __io_cqring_overflow_flush(ctx, force, tsk, files); + ret = __io_cqring_overflow_flush(ctx, false); if (ctx->flags & IORING_SETUP_IOPOLL) mutex_unlock(&ctx->uring_lock); } + + return ret; }

-static void __io_cqring_fill_event(struct io_kiocb *req, long res, - unsigned int cflags) +/* must to be called somewhat shortly after putting a request */ +static inline void io_put_task(struct task_struct *task, int nr) { - struct io_ring_ctx *ctx = req->ctx; - struct io_uring_cqe *cqe; - - trace_io_uring_complete(ctx, req->user_data, res); + struct io_uring_task *tctx = task->io_uring;

- /* - * If we can't get a cq entry, userspace overflowed the - * submission (by quite a lot). Increment the overflow count in - * the ring. - */ - cqe = io_get_cqring(ctx); - if (likely(cqe)) { - WRITE_ONCE(cqe->user_data, req->user_data); - WRITE_ONCE(cqe->res, res); - WRITE_ONCE(cqe->flags, cflags); - } else if (ctx->cq_overflow_flushed || - atomic_read(&req->task->io_uring->in_idle)) { - /* - * If we're in ring overflow flush mode, or in task cancel mode, - * then we cannot store the request for later flushing, we need - * to drop it on the floor. - */ - ctx->cached_cq_overflow++; - WRITE_ONCE(ctx->rings->cq_overflow, ctx->cached_cq_overflow); + if (likely(task == current)) { + tctx->cached_refs += nr; } else { - if (list_empty(&ctx->cq_overflow_list)) { - set_bit(0, &ctx->sq_check_overflow); - set_bit(0, &ctx->cq_check_overflow); - ctx->rings->sq_flags |= IORING_SQ_CQ_OVERFLOW; - } - io_clean_op(req); - req->result = res; - req->compl.cflags = cflags; - refcount_inc(&req->refs); - list_add_tail(&req->compl.list, &ctx->cq_overflow_list); + percpu_counter_sub(&tctx->inflight, nr); + if (unlikely(atomic_read(&tctx->in_idle))) + wake_up(&tctx->wait); + put_task_struct_many(task, nr); } }

-static void io_cqring_fill_event(struct io_kiocb *req, long res) +static void io_task_refs_refill(struct io_uring_task *tctx) { - __io_cqring_fill_event(req, res, 0); + unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR; + + percpu_counter_add(&tctx->inflight, refill); + refcount_add(refill, &current->usage); + tctx->cached_refs += refill; }

-static void io_cqring_add_event(struct io_kiocb *req, long res, long cflags) +static inline void io_get_task_refs(int nr) { - struct io_ring_ctx *ctx = req->ctx; - unsigned long flags; - - spin_lock_irqsave(&ctx->completion_lock, flags); - __io_cqring_fill_event(req, res, cflags); - io_commit_cqring(ctx); - spin_unlock_irqrestore(&ctx->completion_lock, flags); + struct io_uring_task *tctx = current->io_uring;

- io_cqring_ev_posted(ctx); + tctx->cached_refs -= nr; + if (unlikely(tctx->cached_refs < 0)) + io_task_refs_refill(tctx); }

-static void io_submit_flush_completions(struct io_comp_state *cs) +static __cold void io_uring_drop_tctx_refs(struct task_struct *task) { - struct io_ring_ctx *ctx = cs->ctx; + struct io_uring_task *tctx = task->io_uring; + unsigned int refs = tctx->cached_refs;

- spin_lock_irq(&ctx->completion_lock); - while (!list_empty(&cs->list)) { - struct io_kiocb *req; + if (refs) { + tctx->cached_refs = 0; + percpu_counter_sub(&tctx->inflight, refs); + put_task_struct_many(task, refs); + } +}

- req = list_first_entry(&cs->list, struct io_kiocb, compl.list); - list_del(&req->compl.list); - __io_cqring_fill_event(req, req->result, req->compl.cflags); +static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data, + s32 res, u32 cflags) +{ + struct io_overflow_cqe *ocqe;

+ ocqe = kmalloc(sizeof(*ocqe), GFP_ATOMIC | __GFP_ACCOUNT); + if (!ocqe) { /* - * io_free_req() doesn't care about completion_lock unless one - * of these flags is set. REQ_F_WORK_INITIALIZED is in the list - * because of a potential deadlock with req->work.fs->lock + * If we're in ring overflow flush mode, or in task cancel mode, + * or cannot allocate an overflow entry, then we need to drop it + * on the floor. */ - if (req->flags & (REQ_F_FAIL_LINK|REQ_F_LINK_TIMEOUT - |REQ_F_WORK_INITIALIZED)) { - spin_unlock_irq(&ctx->completion_lock); - io_put_req(req); - spin_lock_irq(&ctx->completion_lock); - } else { - io_put_req(req); - } + io_account_cq_overflow(ctx); + return false; } - io_commit_cqring(ctx); - spin_unlock_irq(&ctx->completion_lock); + if (list_empty(&ctx->cq_overflow_list)) { + set_bit(0, &ctx->check_cq_overflow); + WRITE_ONCE(ctx->rings->sq_flags, + ctx->rings->sq_flags | IORING_SQ_CQ_OVERFLOW);

- io_cqring_ev_posted(ctx); - cs->nr = 0; + } + ocqe->cqe.user_data = user_data; + ocqe->cqe.res = res; + ocqe->cqe.flags = cflags; + list_add_tail(&ocqe->list, &ctx->cq_overflow_list); + return true; }

-static void __io_req_complete(struct io_kiocb *req, long res, unsigned cflags, - struct io_comp_state *cs) +static inline bool __io_fill_cqe(struct io_ring_ctx *ctx, u64 user_data, + s32 res, u32 cflags) { - if (!cs) { - io_cqring_add_event(req, res, cflags); - io_put_req(req); - } else { - io_clean_op(req); - req->result = res; - req->compl.cflags = cflags; - list_add_tail(&req->compl.list, &cs->list); - if (++cs->nr >= 32) - io_submit_flush_completions(cs); + struct io_uring_cqe *cqe; + + trace_io_uring_complete(ctx, user_data, res, cflags); + + /* + * If we can't get a cq entry, userspace overflowed the + * submission (by quite a lot). Increment the overflow count in + * the ring. + */ + cqe = io_get_cqe(ctx); + if (likely(cqe)) { + WRITE_ONCE(cqe->user_data, user_data); + WRITE_ONCE(cqe->res, res); + WRITE_ONCE(cqe->flags, cflags); + return true; } + return io_cqring_event_overflow(ctx, user_data, res, cflags); }

-static void io_req_complete(struct io_kiocb *req, long res) +static noinline void io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags) { - __io_req_complete(req, res, 0, NULL); + __io_fill_cqe(req->ctx, req->user_data, res, cflags); }

-static inline bool io_is_fallback_req(struct io_kiocb *req) +static noinline bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, + s32 res, u32 cflags) { - return req == (struct io_kiocb *) - ((unsigned long) req->ctx->fallback_req & ~1UL); + ctx->cq_extra++; + return __io_fill_cqe(ctx, user_data, res, cflags); }

-static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx) +static void io_req_complete_post(struct io_kiocb *req, s32 res, + u32 cflags) { - struct io_kiocb *req; - - req = ctx->fallback_req; - if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req)) - return req; + struct io_ring_ctx *ctx = req->ctx;

- return NULL; -} + spin_lock(&ctx->completion_lock); + __io_fill_cqe(ctx, req->user_data, res, cflags); + /* + * If we're the last reference to this request, add to our locked + * free_list cache. + */ + if (req_ref_put_and_test(req)) { + if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) { + if (req->flags & IO_DISARM_MASK) + io_disarm_next(req); + if (req->link) { + io_req_task_queue(req->link); + req->link = NULL; + } + } + io_dismantle_req(req); + io_put_task(req->task, 1); + list_add(&req->inflight_entry, &ctx->locked_free_list); + ctx->locked_free_nr++; + } else { + if (!percpu_ref_tryget(&ctx->refs)) + req = NULL; + } + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock);

-static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx, - struct io_submit_state *state) + if (req) { + io_cqring_ev_posted(ctx); + percpu_ref_put(&ctx->refs); + } +} + +static inline bool io_req_needs_clean(struct io_kiocb *req) { - if (!state->free_reqs) { - gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; - size_t sz; - int ret; + return req->flags & IO_REQ_CLEAN_FLAGS; +} + +static inline void io_req_complete_state(struct io_kiocb *req, s32 res, + u32 cflags) +{ + if (io_req_needs_clean(req)) + io_clean_op(req); + req->result = res; + req->compl.cflags = cflags; + req->flags |= REQ_F_COMPLETE_INLINE; +}

- sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs)); - ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs); +static inline void __io_req_complete(struct io_kiocb *req, unsigned issue_flags, + s32 res, u32 cflags) +{ + if (issue_flags & IO_URING_F_COMPLETE_DEFER) + io_req_complete_state(req, res, cflags); + else + io_req_complete_post(req, res, cflags); +}

- /* - * Bulk alloc is all-or-nothing. If we fail to get a batch, - * retry single alloc to be on the safe side. - */ - if (unlikely(ret <= 0)) { - state->reqs[0] = kmem_cache_alloc(req_cachep, gfp); - if (!state->reqs[0]) - goto fallback; - ret = 1; - } - state->free_reqs = ret; +static inline void io_req_complete(struct io_kiocb *req, s32 res) +{ + __io_req_complete(req, 0, res, 0); +} + +static void io_req_complete_failed(struct io_kiocb *req, s32 res) +{ + req_set_fail(req); + io_req_complete_post(req, res, 0); +} + +static void io_req_complete_fail_submit(struct io_kiocb *req) +{ + /* + * We don't submit, fail them all, for that replace hardlinks with + * normal links. Extra REQ_F_LINK is tolerated. + */ + req->flags &= ~REQ_F_HARDLINK; + req->flags |= REQ_F_LINK; + io_req_complete_failed(req, req->result); +} + +/* + * Don't initialise the fields below on every allocation, but do that in + * advance and keep them valid across allocations. + */ +static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx) +{ + req->ctx = ctx; + req->link = NULL; + req->async_data = NULL; + /* not necessary, but safer to zero */ + req->result = 0; +} + +static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx, + struct io_submit_state *state) +{ + spin_lock(&ctx->completion_lock); + list_splice_init(&ctx->locked_free_list, &state->free_list); + ctx->locked_free_nr = 0; + spin_unlock(&ctx->completion_lock); +} + +/* Returns true IFF there are requests in the cache */ +static bool io_flush_cached_reqs(struct io_ring_ctx *ctx) +{ + struct io_submit_state *state = &ctx->submit_state; + int nr; + + /* + * If we have more than a batch's worth of requests in our IRQ side + * locked cache, grab the lock and move them over to our submission + * side cache. + */ + if (READ_ONCE(ctx->locked_free_nr) > IO_COMPL_BATCH) + io_flush_cached_locked_reqs(ctx, state); + + nr = state->free_reqs; + while (!list_empty(&state->free_list)) { + struct io_kiocb *req = list_first_entry(&state->free_list, + struct io_kiocb, inflight_entry); + + list_del(&req->inflight_entry); + state->reqs[nr++] = req; + if (nr == ARRAY_SIZE(state->reqs)) + break; + } + + state->free_reqs = nr; + return nr != 0; +} + +/* + * A request might get retired back into the request caches even before opcode + * handlers and io_issue_sqe() are done with it, e.g. inline completion path. + * Because of that, io_alloc_req() should be called only under ->uring_lock + * and with extra caution to not get a request that is still worked on. + */ +static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx) + __must_hold(&ctx->uring_lock) +{ + struct io_submit_state *state = &ctx->submit_state; + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; + int ret, i; + + BUILD_BUG_ON(ARRAY_SIZE(state->reqs) < IO_REQ_ALLOC_BATCH); + + if (likely(state->free_reqs || io_flush_cached_reqs(ctx))) + goto got_req; + + ret = kmem_cache_alloc_bulk(req_cachep, gfp, IO_REQ_ALLOC_BATCH, + state->reqs); + + /* + * Bulk alloc is all-or-nothing. If we fail to get a batch, + * retry single alloc to be on the safe side. + */ + if (unlikely(ret <= 0)) { + state->reqs[0] = kmem_cache_alloc(req_cachep, gfp); + if (!state->reqs[0]) + return NULL; + ret = 1; }

+ for (i = 0; i < ret; i++) + io_preinit_req(state->reqs[i], ctx); + state->free_reqs = ret; +got_req: state->free_reqs--; return state->reqs[state->free_reqs]; -fallback: - return io_get_fallback_req(ctx); }

-static inline void io_put_file(struct io_kiocb *req, struct file *file, - bool fixed) +static inline void io_put_file(struct file *file) { - if (fixed) - percpu_ref_put(req->fixed_file_refs); - else + if (file) fput(file); }

static void io_dismantle_req(struct io_kiocb *req) { - io_clean_op(req); + unsigned int flags = req->flags;

- if (req->async_data) + if (io_req_needs_clean(req)) + io_clean_op(req); + if (!(flags & REQ_F_FIXED_FILE)) + io_put_file(req->file); + if (req->fixed_rsrc_refs) + percpu_ref_put(req->fixed_rsrc_refs); + if (req->async_data) { kfree(req->async_data); - if (req->file) - io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE)); - - io_req_clean_work(req); + req->async_data = NULL; + } }

static void __io_free_req(struct io_kiocb *req) { - struct io_uring_task *tctx = req->task->io_uring; struct io_ring_ctx *ctx = req->ctx;

io_dismantle_req(req); + io_put_task(req->task, 1);

- percpu_counter_dec(&tctx->inflight); - if (atomic_read(&tctx->in_idle)) - wake_up(&tctx->wait); - put_task_struct(req->task); + spin_lock(&ctx->completion_lock); + list_add(&req->inflight_entry, &ctx->locked_free_list); + ctx->locked_free_nr++; + spin_unlock(&ctx->completion_lock);

- if (likely(!io_is_fallback_req(req))) - kmem_cache_free(req_cachep, req); - else - clear_bit_unlock(0, (unsigned long *) &ctx->fallback_req); percpu_ref_put(&ctx->refs); }

-static void io_kill_linked_timeout(struct io_kiocb *req) +static inline void io_remove_next_linked(struct io_kiocb *req) { - struct io_ring_ctx *ctx = req->ctx; - struct io_kiocb *link; - bool cancelled = false; - unsigned long flags; + struct io_kiocb *nxt = req->link;

- spin_lock_irqsave(&ctx->completion_lock, flags); - link = list_first_entry_or_null(&req->link_list, struct io_kiocb, - link_list); - /* - * Can happen if a linked timeout fired and link had been like - * req -> link t-out -> link t-out [-> ...] - */ - if (link && (link->flags & REQ_F_LTIMEOUT_ACTIVE)) { - struct io_timeout_data *io = link->async_data; - int ret; - - list_del_init(&link->link_list); - ret = hrtimer_try_to_cancel(&io->timer); - if (ret != -1) { - io_cqring_fill_event(link, -ECANCELED); - io_commit_cqring(ctx); - cancelled = true; - } - } - req->flags &= ~REQ_F_LINK_TIMEOUT; - spin_unlock_irqrestore(&ctx->completion_lock, flags); - - if (cancelled) { - io_cqring_ev_posted(ctx); - io_put_req(link); - } + req->link = nxt->link; + nxt->link = NULL; }

-static struct io_kiocb *io_req_link_next(struct io_kiocb *req) +static bool io_kill_linked_timeout(struct io_kiocb *req) + __must_hold(&req->ctx->completion_lock) + __must_hold(&req->ctx->timeout_lock) { - struct io_kiocb *nxt; + struct io_kiocb *link = req->link;

- /* - * The list should never be empty when we are called here. But could - * potentially happen if the chain is messed up, check to be on the - * safe side. - */ - if (unlikely(list_empty(&req->link_list))) - return NULL; + if (link && link->opcode == IORING_OP_LINK_TIMEOUT) { + struct io_timeout_data *io = link->async_data;

- nxt = list_first_entry(&req->link_list, struct io_kiocb, link_list); - list_del_init(&req->link_list); - if (!list_empty(&nxt->link_list)) - nxt->flags |= REQ_F_LINK_HEAD; - return nxt; + io_remove_next_linked(req); + link->timeout.head = NULL; + if (hrtimer_try_to_cancel(&io->timer) != -1) { + list_del(&link->timeout.list); + io_fill_cqe_req(link, -ECANCELED, 0); + io_put_req_deferred(link); + return true; + } + } + return false; }

-/* - * Called if REQ_F_LINK_HEAD is set, and we fail the head request - */ static void io_fail_links(struct io_kiocb *req) + __must_hold(&req->ctx->completion_lock) { - struct io_ring_ctx *ctx = req->ctx; - unsigned long flags; + struct io_kiocb *nxt, *link = req->link;

- spin_lock_irqsave(&ctx->completion_lock, flags); - while (!list_empty(&req->link_list)) { - struct io_kiocb *link = list_first_entry(&req->link_list, - struct io_kiocb, link_list); + req->link = NULL; + while (link) { + long res = -ECANCELED;

- list_del_init(&link->link_list); - trace_io_uring_fail_link(req, link); + if (link->flags & REQ_F_FAIL) + res = link->result;

- io_cqring_fill_event(link, -ECANCELED); + nxt = link->link; + link->link = NULL;

- /* - * It's ok to free under spinlock as they're not linked anymore, - * but avoid REQ_F_WORK_INITIALIZED because it may deadlock on - * work.fs->lock. - */ - if (link->flags & REQ_F_WORK_INITIALIZED) - io_put_req_deferred(link, 2); - else - io_double_put_req(link); + trace_io_uring_fail_link(req, link); + io_fill_cqe_req(link, res, 0); + io_put_req_deferred(link); + link = nxt; } +}

- io_commit_cqring(ctx); - spin_unlock_irqrestore(&ctx->completion_lock, flags); +static bool io_disarm_next(struct io_kiocb *req) + __must_hold(&req->ctx->completion_lock) +{ + bool posted = false;

- io_cqring_ev_posted(ctx); + if (req->flags & REQ_F_ARM_LTIMEOUT) { + struct io_kiocb *link = req->link; + + req->flags &= ~REQ_F_ARM_LTIMEOUT; + if (link && link->opcode == IORING_OP_LINK_TIMEOUT) { + io_remove_next_linked(req); + io_fill_cqe_req(link, -ECANCELED, 0); + io_put_req_deferred(link); + posted = true; + } + } else if (req->flags & REQ_F_LINK_TIMEOUT) { + struct io_ring_ctx *ctx = req->ctx; + + spin_lock_irq(&ctx->timeout_lock); + posted = io_kill_linked_timeout(req); + spin_unlock_irq(&ctx->timeout_lock); + } + if (unlikely((req->flags & REQ_F_FAIL) && + !(req->flags & REQ_F_HARDLINK))) { + posted |= (req->link != NULL); + io_fail_links(req); + } + return posted; }

static struct io_kiocb *__io_req_find_next(struct io_kiocb *req) { - req->flags &= ~REQ_F_LINK_HEAD; - if (req->flags & REQ_F_LINK_TIMEOUT) - io_kill_linked_timeout(req); + struct io_kiocb *nxt;

/* * If LINK is set, we have dependent requests in this chain. If we @@ -2034,28 +2118,112 @@ static struct io_kiocb *__io_req_find_next(struct io_kiocb *req) * dependencies to the next request. In case of failure, fail the rest * of the chain. */ - if (likely(!(req->flags & REQ_F_FAIL_LINK))) - return io_req_link_next(req); - io_fail_links(req); - return NULL; + if (req->flags & IO_DISARM_MASK) { + struct io_ring_ctx *ctx = req->ctx; + bool posted; + + spin_lock(&ctx->completion_lock); + posted = io_disarm_next(req); + if (posted) + io_commit_cqring(req->ctx); + spin_unlock(&ctx->completion_lock); + if (posted) + io_cqring_ev_posted(ctx); + } + nxt = req->link; + req->link = NULL; + return nxt; }

-static struct io_kiocb *io_req_find_next(struct io_kiocb *req) +static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req) { - if (likely(!(req->flags & REQ_F_LINK_HEAD))) + if (likely(!(req->flags & (REQ_F_LINK|REQ_F_HARDLINK)))) return NULL; return __io_req_find_next(req); }

-static int io_req_task_work_add(struct io_kiocb *req, bool twa_signal_ok) +static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked) +{ + if (!ctx) + return; + if (*locked) { + if (ctx->submit_state.compl_nr) + io_submit_flush_completions(ctx); + mutex_unlock(&ctx->uring_lock); + *locked = false; + } + percpu_ref_put(&ctx->refs); +} + +static void tctx_task_work(struct callback_head *cb) +{ + bool locked = false; + struct io_ring_ctx *ctx = NULL; + struct io_uring_task *tctx = container_of(cb, struct io_uring_task, + task_work); + + while (1) { + struct io_wq_work_node *node; + + if (!tctx->task_list.first && locked && ctx->submit_state.compl_nr) + io_submit_flush_completions(ctx); + + spin_lock_irq(&tctx->task_lock); + node = tctx->task_list.first; + INIT_WQ_LIST(&tctx->task_list); + if (!node) + tctx->task_running = false; + spin_unlock_irq(&tctx->task_lock); + if (!node) + break; + + do { + struct io_wq_work_node *next = node->next; + struct io_kiocb *req = container_of(node, struct io_kiocb, + io_task_work.node); + + if (req->ctx != ctx) { + ctx_flush_and_put(ctx, &locked); + ctx = req->ctx; + /* if not contended, grab and improve batching */ + locked = mutex_trylock(&ctx->uring_lock); + percpu_ref_get(&ctx->refs); + } + req->io_task_work.func(req, &locked); + node = next; + } while (node); + + cond_resched(); + } + + ctx_flush_and_put(ctx, &locked); + + /* relaxed read is enough as only the task itself sets ->in_idle */ + if (unlikely(atomic_read(&tctx->in_idle))) + io_uring_drop_tctx_refs(current); +} + +static void io_req_task_work_add(struct io_kiocb *req) { struct task_struct *tsk = req->task; - struct io_ring_ctx *ctx = req->ctx; + struct io_uring_task *tctx = tsk->io_uring; enum task_work_notify_mode notify; - int ret; + struct io_wq_work_node *node; + unsigned long flags; + bool running; + + WARN_ON_ONCE(!tctx); + + spin_lock_irqsave(&tctx->task_lock, flags); + wq_list_add_tail(&req->io_task_work.node, &tctx->task_list); + running = tctx->task_running; + if (!running) + tctx->task_running = true; + spin_unlock_irqrestore(&tctx->task_lock, flags);

- if (tsk->flags & PF_EXITING) - return -ESRCH; + /* task_work already pending, we're done */ + if (running) + return;

/* * SQPOLL kernel thread doesn't need notification, just a wakeup. For @@ -2063,85 +2231,68 @@ static int io_req_task_work_add(struct io_kiocb *req, bool twa_signal_ok) * processing task_work. There's no reliable way to tell if TWA_RESUME * will do the job. */ - notify = TWA_NONE; - if (!(ctx->flags & IORING_SETUP_SQPOLL) && twa_signal_ok) - notify = TWA_SIGNAL; - - ret = task_work_add(tsk, &req->task_work, notify); - if (!ret) + notify = (req->ctx->flags & IORING_SETUP_SQPOLL) ? TWA_NONE : TWA_SIGNAL; + if (!task_work_add(tsk, &tctx->task_work, notify)) { wake_up_process(tsk); + return; + }

- return ret; -} - -static void __io_req_task_cancel(struct io_kiocb *req, int error) -{ - struct io_ring_ctx *ctx = req->ctx; - - spin_lock_irq(&ctx->completion_lock); - io_cqring_fill_event(req, error); - io_commit_cqring(ctx); - spin_unlock_irq(&ctx->completion_lock); + spin_lock_irqsave(&tctx->task_lock, flags); + tctx->task_running = false; + node = tctx->task_list.first; + INIT_WQ_LIST(&tctx->task_list); + spin_unlock_irqrestore(&tctx->task_lock, flags);

- io_cqring_ev_posted(ctx); - req_set_fail_links(req); - io_double_put_req(req); + while (node) { + req = container_of(node, struct io_kiocb, io_task_work.node); + node = node->next; + if (llist_add(&req->io_task_work.fallback_node, + &req->ctx->fallback_llist)) + schedule_delayed_work(&req->ctx->fallback_work, 1); + } }

-static void io_req_task_cancel(struct callback_head *cb) +static void io_req_task_cancel(struct io_kiocb *req, bool *locked) { - struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); struct io_ring_ctx *ctx = req->ctx;

- mutex_lock(&ctx->uring_lock); - __io_req_task_cancel(req, -ECANCELED); - mutex_unlock(&ctx->uring_lock); - percpu_ref_put(&ctx->refs); + /* not needed for normal modes, but SQPOLL depends on it */ + io_tw_lock(ctx, locked); + io_req_complete_failed(req, req->result); }

-static void __io_req_task_submit(struct io_kiocb *req) +static void io_req_task_submit(struct io_kiocb *req, bool *locked) { struct io_ring_ctx *ctx = req->ctx;

- mutex_lock(&ctx->uring_lock); - if (!ctx->sqo_dead && !__io_sq_thread_acquire_mm(ctx)) - __io_queue_sqe(req, NULL); + io_tw_lock(ctx, locked); + /* req->task == current here, checking PF_EXITING is safe */ + if (likely(!(req->task->flags & PF_EXITING))) + __io_queue_sqe(req); else - __io_req_task_cancel(req, -EFAULT); - mutex_unlock(&ctx->uring_lock); - - if (ctx->flags & IORING_SETUP_SQPOLL) - io_sq_thread_drop_mm(); + io_req_complete_failed(req, -EFAULT); }

-static void io_req_task_submit(struct callback_head *cb) +static void io_req_task_queue_fail(struct io_kiocb *req, int ret) { - struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); - struct io_ring_ctx *ctx = req->ctx; - - __io_req_task_submit(req); - percpu_ref_put(&ctx->refs); + req->result = ret; + req->io_task_work.func = io_req_task_cancel; + io_req_task_work_add(req); }

static void io_req_task_queue(struct io_kiocb *req) { - int ret; - - init_task_work(&req->task_work, io_req_task_submit); - percpu_ref_get(&req->ctx->refs); - - ret = io_req_task_work_add(req, true); - if (unlikely(ret)) { - struct task_struct *tsk; + req->io_task_work.func = io_req_task_submit; + io_req_task_work_add(req); +}

- init_task_work(&req->task_work, io_req_task_cancel); - tsk = io_wq_get_task(req->ctx->io_wq); - task_work_add(tsk, &req->task_work, TWA_NONE); - wake_up_process(tsk); - } +static void io_req_task_queue_reissue(struct io_kiocb *req) +{ + req->io_task_work.func = io_queue_async_work; + io_req_task_work_add(req); }

-static void io_queue_next(struct io_kiocb *req) +static inline void io_queue_next(struct io_kiocb *req) { struct io_kiocb *nxt = io_req_find_next(req);

@@ -2155,153 +2306,118 @@ static void io_free_req(struct io_kiocb *req) __io_free_req(req); }

-struct req_batch { - void *reqs[IO_IOPOLL_BATCH]; - int to_free; +static void io_free_req_work(struct io_kiocb *req, bool *locked) +{ + io_free_req(req); +}

+struct req_batch { struct task_struct *task; int task_refs; + int ctx_refs; };

static inline void io_init_req_batch(struct req_batch *rb) { - rb->to_free = 0; rb->task_refs = 0; + rb->ctx_refs = 0; rb->task = NULL; }

-static void __io_req_free_batch_flush(struct io_ring_ctx *ctx, - struct req_batch *rb) +static void io_req_free_batch_finish(struct io_ring_ctx *ctx, + struct req_batch *rb) { - kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs); - percpu_ref_put_many(&ctx->refs, rb->to_free); - rb->to_free = 0; + if (rb->ctx_refs) + percpu_ref_put_many(&ctx->refs, rb->ctx_refs); + if (rb->task) + io_put_task(rb->task, rb->task_refs); }

-static void io_req_free_batch_finish(struct io_ring_ctx *ctx, - struct req_batch *rb) +static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req, + struct io_submit_state *state) { - if (rb->to_free) - __io_req_free_batch_flush(ctx, rb); - if (rb->task) { - struct io_uring_task *tctx = rb->task->io_uring; + io_queue_next(req); + io_dismantle_req(req);

- percpu_counter_sub(&tctx->inflight, rb->task_refs); - if (atomic_read(&tctx->in_idle)) - wake_up(&tctx->wait); - put_task_struct_many(rb->task, rb->task_refs); - rb->task = NULL; + if (req->task != rb->task) { + if (rb->task) + io_put_task(rb->task, rb->task_refs); + rb->task = req->task; + rb->task_refs = 0; } + rb->task_refs++; + rb->ctx_refs++; + + if (state->free_reqs != ARRAY_SIZE(state->reqs)) + state->reqs[state->free_reqs++] = req; + else + list_add(&req->inflight_entry, &state->free_list); }

-static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req) +static void io_submit_flush_completions(struct io_ring_ctx *ctx) + __must_hold(&ctx->uring_lock) { - if (unlikely(io_is_fallback_req(req))) { - io_free_req(req); - return; + struct io_submit_state *state = &ctx->submit_state; + int i, nr = state->compl_nr; + struct req_batch rb; + + spin_lock(&ctx->completion_lock); + for (i = 0; i < nr; i++) { + struct io_kiocb *req = state->compl_reqs[i]; + + __io_fill_cqe(ctx, req->user_data, req->result, + req->compl.cflags); } - if (req->flags & REQ_F_LINK_HEAD) - io_queue_next(req); + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock); + io_cqring_ev_posted(ctx);

- if (req->task != rb->task) { - if (rb->task) { - struct io_uring_task *tctx = rb->task->io_uring; + io_init_req_batch(&rb); + for (i = 0; i < nr; i++) { + struct io_kiocb *req = state->compl_reqs[i];

- percpu_counter_sub(&tctx->inflight, rb->task_refs); - if (atomic_read(&tctx->in_idle)) - wake_up(&tctx->wait); - put_task_struct_many(rb->task, rb->task_refs); - } - rb->task = req->task; - rb->task_refs = 0; + if (req_ref_put_and_test(req)) + io_req_free_batch(&rb, req, &ctx->submit_state); } - rb->task_refs++;

- io_dismantle_req(req); - rb->reqs[rb->to_free++] = req; - if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs))) - __io_req_free_batch_flush(req->ctx, rb); + io_req_free_batch_finish(ctx, &rb); + state->compl_nr = 0; }

/* * Drop reference to request, return next in chain (if there is one) if this * was the last reference to this request. */ -static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req) +static inline struct io_kiocb *io_put_req_find_next(struct io_kiocb *req) { struct io_kiocb *nxt = NULL;

- if (refcount_dec_and_test(&req->refs)) { + if (req_ref_put_and_test(req)) { nxt = io_req_find_next(req); __io_free_req(req); } return nxt; }

-static void io_put_req(struct io_kiocb *req) +static inline void io_put_req(struct io_kiocb *req) { - if (refcount_dec_and_test(&req->refs)) + if (req_ref_put_and_test(req)) io_free_req(req); }

-static void io_put_req_deferred_cb(struct callback_head *cb) -{ - struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); - - io_free_req(req); -} - -static void io_free_req_deferred(struct io_kiocb *req) +static inline void io_put_req_deferred(struct io_kiocb *req) { - int ret; - - init_task_work(&req->task_work, io_put_req_deferred_cb); - ret = io_req_task_work_add(req, true); - if (unlikely(ret)) { - struct task_struct *tsk; - - tsk = io_wq_get_task(req->ctx->io_wq); - task_work_add(tsk, &req->task_work, TWA_NONE); - wake_up_process(tsk); + if (req_ref_put_and_test(req)) { + req->io_task_work.func = io_free_req_work; + io_req_task_work_add(req); } }

-static inline void io_put_req_deferred(struct io_kiocb *req, int refs) -{ - if (refcount_sub_and_test(refs, &req->refs)) - io_free_req_deferred(req); -} - -static struct io_wq_work *io_steal_work(struct io_kiocb *req) -{ - struct io_kiocb *nxt; - - /* - * A ref is owned by io-wq in which context we're. So, if that's the - * last one, it's safe to steal next work. False negatives are Ok, - * it just will be re-punted async in io_put_work() - */ - if (refcount_read(&req->refs) != 1) - return NULL; - - nxt = io_req_find_next(req); - return nxt ? &nxt->work : NULL; -} - -static void io_double_put_req(struct io_kiocb *req) -{ - /* drop both submit and complete references */ - if (refcount_sub_and_test(2, &req->refs)) - io_free_req(req); -} - static unsigned io_cqring_events(struct io_ring_ctx *ctx) { - struct io_rings *rings = ctx->rings; - /* See comment at the top of this file */ smp_rmb(); - return ctx->cached_cq_tail - READ_ONCE(rings->cq.head); + return __io_cqring_events(ctx); }

static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) @@ -2327,38 +2443,23 @@ static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req) { struct io_buffer *kbuf;

+ if (likely(!(req->flags & REQ_F_BUFFER_SELECTED))) + return 0; kbuf = (struct io_buffer *) (unsigned long) req->rw.addr; return io_put_kbuf(req, kbuf); }

static inline bool io_run_task_work(void) { - /* - * Not safe to run on exiting task, and the task_work handling will - * not add work to such a task. - */ - if (unlikely(current->flags & PF_EXITING)) - return false; - if (current->task_works) { + if (test_thread_flag(TIF_NOTIFY_SIGNAL) || current->task_works) { __set_current_state(TASK_RUNNING); - task_work_run(); + tracehook_notify_signal(); return true; }

return false; }

-static void io_iopoll_queue(struct list_head *again) -{ - struct io_kiocb *req; - - do { - req = list_first_entry(again, struct io_kiocb, iopoll_entry); - list_del(&req->iopoll_entry); - __io_complete_rw(req, -EAGAIN, 0, NULL); - } while (!list_empty(again)); -} - /* * Find and free completed poll iocbs */ @@ -2367,41 +2468,25 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, { struct req_batch rb; struct io_kiocb *req; - LIST_HEAD(again);

/* order with ->result store in io_complete_rw_iopoll() */ smp_rmb();

io_init_req_batch(&rb); while (!list_empty(done)) { - int cflags = 0; - - req = list_first_entry(done, struct io_kiocb, iopoll_entry); - if (READ_ONCE(req->result) == -EAGAIN) { - req->result = 0; - req->iopoll_completed = 0; - list_move_tail(&req->iopoll_entry, &again); - continue; - } - list_del(&req->iopoll_entry); - - if (req->flags & REQ_F_BUFFER_SELECTED) - cflags = io_put_rw_kbuf(req); + req = list_first_entry(done, struct io_kiocb, inflight_entry); + list_del(&req->inflight_entry);

- __io_cqring_fill_event(req, req->result, cflags); + io_fill_cqe_req(req, req->result, io_put_rw_kbuf(req)); (*nr_events)++;

- if (refcount_dec_and_test(&req->refs)) - io_req_free_batch(&rb, req); + if (req_ref_put_and_test(req)) + io_req_free_batch(&rb, req, &ctx->submit_state); }

io_commit_cqring(ctx); - if (ctx->flags & IORING_SETUP_SQPOLL) - io_cqring_ev_posted(ctx); + io_cqring_ev_posted_iopoll(ctx); io_req_free_batch_finish(ctx, &rb); - - if (!list_empty(&again)) - io_iopoll_queue(&again); }

static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, @@ -2410,17 +2495,16 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, struct io_kiocb *req, *tmp; LIST_HEAD(done); bool spin; - int ret;

/* * Only spin for completions if we don't have multiple devices hanging * off our complete list, and we're under the requested amount. */ - spin = !ctx->poll_multi_file && *nr_events < min; + spin = !ctx->poll_multi_queue && *nr_events < min;

- ret = 0; - list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, iopoll_entry) { + list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) { struct kiocb *kiocb = &req->rw.kiocb; + int ret;

/* * Move completed and retryable entries to our local lists. @@ -2428,50 +2512,27 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, * and complete those lists first, if we have entries there. */ if (READ_ONCE(req->iopoll_completed)) { - list_move_tail(&req->iopoll_entry, &done); + list_move_tail(&req->inflight_entry, &done); continue; } if (!list_empty(&done)) break;

ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin); - if (ret < 0) - break; + if (unlikely(ret < 0)) + return ret; + else if (ret) + spin = false;

/* iopoll may have completed current req */ if (READ_ONCE(req->iopoll_completed)) - list_move_tail(&req->iopoll_entry, &done); - - if (ret && spin) - spin = false; - ret = 0; + list_move_tail(&req->inflight_entry, &done); }

if (!list_empty(&done)) io_iopoll_complete(ctx, nr_events, &done);

- return ret; -} - -/* - * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a - * non-spinning poll check - we'll still enter the driver poll loop, but only - * as a non-spinning completion check. - */ -static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events, - long min) -{ - while (!list_empty(&ctx->iopoll_list) && !need_resched()) { - int ret; - - ret = io_do_iopoll(ctx, nr_events, min); - if (ret < 0) - return ret; - if (*nr_events >= min) - return 0; - } - - return 1; + return 0; }

/* @@ -2509,7 +2570,7 @@ static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx) static int io_iopoll_check(struct io_ring_ctx *ctx, long min) { unsigned int nr_events = 0; - int iters = 0, ret = 0; + int ret = 0;

/* * We disallow the app entering submit/complete with polling, but we @@ -2517,17 +2578,16 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min) * that got punted to a workqueue. */ mutex_lock(&ctx->uring_lock); + /* + * Don't enter poll loop if we already have events pending. + * If we do, we can potentially be spinning for commands that + * already triggered a CQE (eg in error). + */ + if (test_bit(0, &ctx->check_cq_overflow)) + __io_cqring_overflow_flush(ctx, false); + if (io_cqring_events(ctx)) + goto out; do { - /* - * Don't enter poll loop if we already have events pending. - * If we do, we can potentially be spinning for commands that - * already triggered a CQE (eg in error). - */ - if (test_bit(0, &ctx->cq_check_overflow)) - __io_cqring_overflow_flush(ctx, false, NULL, NULL); - if (io_cqring_events(ctx)) - break; - /* * If a submit got punted to a workqueue, we can have the * application entering polling for a command before it gets @@ -2538,18 +2598,21 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min) * forever, while the workqueue is stuck trying to acquire the * very same mutex. */ - if (!(++iters & 7)) { + if (list_empty(&ctx->iopoll_list)) { + u32 tail = ctx->cached_cq_tail; + mutex_unlock(&ctx->uring_lock); io_run_task_work(); mutex_lock(&ctx->uring_lock); - } - - ret = io_iopoll_getevents(ctx, &nr_events, min); - if (ret <= 0) - break; - ret = 0; - } while (min && !nr_events && !need_resched());

+ /* some requests don't go through iopoll_list */ + if (tail != ctx->cached_cq_tail || + list_empty(&ctx->iopoll_list)) + break; + } + ret = io_do_iopoll(ctx, &nr_events, min); + } while (!ret && nr_events < min && !need_resched()); +out: mutex_unlock(&ctx->uring_lock); return ret; } @@ -2561,79 +2624,129 @@ static void kiocb_end_write(struct io_kiocb *req) * thread. */ if (req->flags & REQ_F_ISREG) { - struct inode *inode = file_inode(req->file); + struct super_block *sb = file_inode(req->file)->i_sb;

- __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); + __sb_writers_acquired(sb, SB_FREEZE_WRITE); + sb_end_write(sb); } - file_end_write(req->file); -} - -static void io_complete_rw_common(struct kiocb *kiocb, long res, - struct io_comp_state *cs) -{ - struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); - int cflags = 0; - - if (kiocb->ki_flags & IOCB_WRITE) - kiocb_end_write(req); - - if (res != req->result) - req_set_fail_links(req); - if (req->flags & REQ_F_BUFFER_SELECTED) - cflags = io_put_rw_kbuf(req); - __io_req_complete(req, res, cflags, cs); }

#ifdef CONFIG_BLOCK -static bool io_resubmit_prep(struct io_kiocb *req, int error) +static bool io_resubmit_prep(struct io_kiocb *req) { - req_set_fail_links(req); - return false; + struct io_async_rw *rw = req->async_data; + + if (!rw) + return !io_req_prep_async(req); + iov_iter_restore(&rw->iter, &rw->iter_state); + return true; } -#endif

-static bool io_rw_reissue(struct io_kiocb *req, long res) +static bool io_rw_should_reissue(struct io_kiocb *req) { -#ifdef CONFIG_BLOCK umode_t mode = file_inode(req->file)->i_mode; - int ret; + struct io_ring_ctx *ctx = req->ctx;

if (!S_ISBLK(mode) && !S_ISREG(mode)) return false; - if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker()) + if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() && + !(ctx->flags & IORING_SETUP_IOPOLL))) return false; /* * If ref is dying, we might be running poll reap from the exit work. * Don't attempt to reissue from that path, just let it fail with * -EAGAIN. */ - if (percpu_ref_is_dying(&req->ctx->refs)) + if (percpu_ref_is_dying(&ctx->refs)) + return false; + /* + * Play it safe and assume not safe to re-import and reissue if we're + * not in the original thread group (or in task context). + */ + if (!same_thread_group(req->task, current) || !in_task()) return false; + return true; +} +#else +static bool io_resubmit_prep(struct io_kiocb *req) +{ + return false; +} +static bool io_rw_should_reissue(struct io_kiocb *req) +{ + return false; +} +#endif + +static bool __io_complete_rw_common(struct io_kiocb *req, long res) +{ + if (req->rw.kiocb.ki_flags & IOCB_WRITE) { + kiocb_end_write(req); + fsnotify_modify(req->file); + } else { + fsnotify_access(req->file); + } + if (res != req->result) { + if ((res == -EAGAIN || res == -EOPNOTSUPP) && + io_rw_should_reissue(req)) { + req->flags |= REQ_F_REISSUE; + return true; + } + req_set_fail(req); + req->result = res; + } + return false; +}

- ret = io_sq_thread_acquire_mm(req->ctx, req); +static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res) +{ + struct io_async_rw *io = req->async_data;

- if (io_resubmit_prep(req, ret)) { - refcount_inc(&req->refs); - io_queue_async_work(req); - return true; + /* add previously done IO, if any */ + if (io && io->bytes_done > 0) { + if (res < 0) + res = io->bytes_done; + else + res += io->bytes_done; } + return res; +}

-#endif - return false; +static void io_req_task_complete(struct io_kiocb *req, bool *locked) +{ + unsigned int cflags = io_put_rw_kbuf(req); + int res = req->result; + + if (*locked) { + struct io_ring_ctx *ctx = req->ctx; + struct io_submit_state *state = &ctx->submit_state; + + io_req_complete_state(req, res, cflags); + state->compl_reqs[state->compl_nr++] = req; + if (state->compl_nr == ARRAY_SIZE(state->compl_reqs)) + io_submit_flush_completions(ctx); + } else { + io_req_complete_post(req, res, cflags); + } }

static void __io_complete_rw(struct io_kiocb *req, long res, long res2, - struct io_comp_state *cs) + unsigned int issue_flags) { - if (!io_rw_reissue(req, res)) - io_complete_rw_common(&req->rw.kiocb, res, cs); + if (__io_complete_rw_common(req, res)) + return; + __io_req_complete(req, issue_flags, io_fixup_rw_res(req, res), io_put_rw_kbuf(req)); }

static void io_complete_rw(struct kiocb *kiocb, long res, long res2) { struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);

- __io_complete_rw(req, res, res2, NULL); + if (__io_complete_rw_common(req, res)) + return; + req->result = io_fixup_rw_res(req, res); + req->io_task_work.func = io_req_task_complete; + io_req_task_work_add(req); }

static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) @@ -2642,12 +2755,15 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)

if (kiocb->ki_flags & IOCB_WRITE) kiocb_end_write(req); - - if (res != -EAGAIN && res != req->result) - req_set_fail_links(req); + if (unlikely(res != req->result)) { + if (res == -EAGAIN && io_rw_should_reissue(req)) { + req->flags |= REQ_F_REISSUE; + return; + } + }

WRITE_ONCE(req->result, res); - /* order with io_poll_complete() checking ->result */ + /* order with io_iopoll_complete() checking ->result */ smp_wmb(); WRITE_ONCE(req->iopoll_completed, 1); } @@ -2655,12 +2771,17 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) /* * After the iocb has been issued, it's safe to be found on the poll list. * Adding the kiocb to the list AFTER submission ensures that we don't - * find it from a io_iopoll_getevents() thread before the issuer is done + * find it from a io_do_iopoll() thread before the issuer is done * accessing the kiocb cookie. */ static void io_iopoll_req_issued(struct io_kiocb *req) { struct io_ring_ctx *ctx = req->ctx; + const bool in_async = io_wq_current_is_worker(); + + /* workqueue context doesn't hold uring_lock, grab it now */ + if (unlikely(in_async)) + mutex_lock(&ctx->uring_lock);

/* * Track whether we have multiple files in our lists. This will impact @@ -2668,14 +2789,22 @@ static void io_iopoll_req_issued(struct io_kiocb *req) * different devices. */ if (list_empty(&ctx->iopoll_list)) { - ctx->poll_multi_file = false; - } else if (!ctx->poll_multi_file) { + ctx->poll_multi_queue = false; + } else if (!ctx->poll_multi_queue) { struct io_kiocb *list_req; + unsigned int queue_num0, queue_num1;

list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb, - iopoll_entry); - if (list_req->file != req->file) - ctx->poll_multi_file = true; + inflight_entry); + + if (list_req->file != req->file) { + ctx->poll_multi_queue = true; + } else { + queue_num0 = blk_qc_t_to_queue_num(list_req->rw.kiocb.ki_cookie); + queue_num1 = blk_qc_t_to_queue_num(req->rw.kiocb.ki_cookie); + if (queue_num0 != queue_num1) + ctx->poll_multi_queue = true; + } }

/* @@ -2683,61 +2812,28 @@ static void io_iopoll_req_issued(struct io_kiocb *req) * it to the front so we find it first. */ if (READ_ONCE(req->iopoll_completed)) - list_add(&req->iopoll_entry, &ctx->iopoll_list); + list_add(&req->inflight_entry, &ctx->iopoll_list); else - list_add_tail(&req->iopoll_entry, &ctx->iopoll_list); - - if ((ctx->flags & IORING_SETUP_SQPOLL) && - wq_has_sleeper(&ctx->sq_data->wait)) - wake_up(&ctx->sq_data->wait); -} - -static void __io_state_file_put(struct io_submit_state *state) -{ - if (state->has_refs) - fput_many(state->file, state->has_refs); - state->file = NULL; -} - -static inline void io_state_file_put(struct io_submit_state *state) -{ - if (state->file) - __io_state_file_put(state); -} + list_add_tail(&req->inflight_entry, &ctx->iopoll_list);

-/* - * Get as many references to a file as we have IOs left in this submission, - * assuming most submissions are for one file, or at least that each file - * has more than one submission. - */ -static struct file *__io_file_get(struct io_submit_state *state, int fd) -{ - if (!state) - return fget(fd); + if (unlikely(in_async)) { + /* + * If IORING_SETUP_SQPOLL is enabled, sqes are either handle + * in sq thread task context or in io worker task context. If + * current task context is sq thread, we don't need to check + * whether should wake up sq thread. + */ + if ((ctx->flags & IORING_SETUP_SQPOLL) && + wq_has_sleeper(&ctx->sq_data->wait)) + wake_up(&ctx->sq_data->wait);

- if (state->file) { - if (state->fd == fd) { - state->has_refs--; - return state->file; - } - __io_state_file_put(state); + mutex_unlock(&ctx->uring_lock); } - state->file = fget_many(fd, state->ios_left); - if (!state->file) - return NULL; - - state->fd = fd; - state->has_refs = state->ios_left - 1; - return state->file; }

static bool io_bdev_nowait(struct block_device *bdev) { -#ifdef CONFIG_BLOCK return !bdev || blk_queue_nowait(bdev_get_queue(bdev)); -#else - return true; -#endif }

/* @@ -2745,19 +2841,21 @@ static bool io_bdev_nowait(struct block_device *bdev) * any file. For now, just ensure that anything potentially problematic is done * inline. */ -static bool io_file_supports_async(struct file *file, int rw) +static bool __io_file_supports_nowait(struct file *file, int rw) { umode_t mode = file_inode(file)->i_mode;

if (S_ISBLK(mode)) { - if (io_bdev_nowait(file->f_inode->i_bdev)) + if (IS_ENABLED(CONFIG_BLOCK) && + io_bdev_nowait(I_BDEV(file->f_mapping->host))) return true; return false; } if (S_ISSOCK(mode)) return true; if (S_ISREG(mode)) { - if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) && + if (IS_ENABLED(CONFIG_BLOCK) && + io_bdev_nowait(file->f_inode->i_sb->s_bdev) && file->f_op != &io_uring_fops) return true; return false; @@ -2776,20 +2874,36 @@ static bool io_file_supports_async(struct file *file, int rw) return file->f_op->write_iter != NULL; }

-static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static bool io_file_supports_nowait(struct io_kiocb *req, int rw) +{ + if (rw == READ && (req->flags & REQ_F_NOWAIT_READ)) + return true; + else if (rw == WRITE && (req->flags & REQ_F_NOWAIT_WRITE)) + return true; + + return __io_file_supports_nowait(req->file, rw); +} + +static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, + int rw) { struct io_ring_ctx *ctx = req->ctx; struct kiocb *kiocb = &req->rw.kiocb; + struct file *file = req->file; unsigned ioprio; int ret;

- if (S_ISREG(file_inode(req->file)->i_mode)) + if (!io_req_ffs_set(req) && S_ISREG(file_inode(file)->i_mode)) req->flags |= REQ_F_ISREG;

kiocb->ki_pos = READ_ONCE(sqe->off); - if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) { - req->flags |= REQ_F_CUR_POS; - kiocb->ki_pos = req->file->f_pos; + if (kiocb->ki_pos == -1) { + if (!(file->f_mode & FMODE_STREAM)) { + req->flags |= REQ_F_CUR_POS; + kiocb->ki_pos = file->f_pos; + } else { + kiocb->ki_pos = 0; + } } kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); kiocb->ki_flags = iocb_flags(kiocb->ki_filp); @@ -2797,6 +2911,15 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (unlikely(ret)) return ret;

+ /* + * If the file is marked O_NONBLOCK, still allow retry for it if it + * supports async. Otherwise it's impossible to use O_NONBLOCK files + * reliably. If not, or it IOCB_NOWAIT is set, don't retry. + */ + if ((kiocb->ki_flags & IOCB_NOWAIT) || + ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw))) + req->flags |= REQ_F_NOWAIT; + ioprio = READ_ONCE(sqe->ioprio); if (ioprio) { ret = ioprio_check_cap(ioprio); @@ -2807,10 +2930,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) } else kiocb->ki_ioprio = get_current_ioprio();

- /* don't allow async punt if RWF_NOWAIT was requested */ - if (kiocb->ki_flags & IOCB_NOWAIT) - req->flags |= REQ_F_NOWAIT; - if (ctx->flags & IORING_SETUP_IOPOLL) { if (!(kiocb->ki_flags & IOCB_DIRECT) || !kiocb->ki_filp->f_op->iopoll) @@ -2825,9 +2944,24 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) kiocb->ki_complete = io_complete_rw; }

+ /* used for fixed read/write too - just read unconditionally */ + req->buf_index = READ_ONCE(sqe->buf_index); + req->imu = NULL; + + if (req->opcode == IORING_OP_READ_FIXED || + req->opcode == IORING_OP_WRITE_FIXED) { + struct io_ring_ctx *ctx = req->ctx; + u16 index; + + if (unlikely(req->buf_index >= ctx->nr_user_bufs)) + return -EFAULT; + index = array_index_nospec(req->buf_index, ctx->nr_user_bufs); + req->imu = ctx->user_bufs[index]; + io_req_set_rsrc_node(req); + } + req->rw.addr = READ_ONCE(sqe->addr); req->rw.len = READ_ONCE(sqe->len); - req->buf_index = READ_ONCE(sqe->buf_index); return 0; }

@@ -2853,48 +2987,49 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) }

static void kiocb_done(struct kiocb *kiocb, ssize_t ret, - struct io_comp_state *cs) + unsigned int issue_flags) { struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); - struct io_async_rw *io = req->async_data; - - /* add previously done IO, if any */ - if (io && io->bytes_done > 0) { - if (ret < 0) - ret = io->bytes_done; - else - ret += io->bytes_done; - }

if (req->flags & REQ_F_CUR_POS) req->file->f_pos = kiocb->ki_pos; - if (ret >= 0 && kiocb->ki_complete == io_complete_rw) - __io_complete_rw(req, ret, 0, cs); + if (ret >= 0 && (kiocb->ki_complete == io_complete_rw)) + __io_complete_rw(req, ret, 0, issue_flags); else io_rw_done(kiocb, ret); + + if (req->flags & REQ_F_REISSUE) { + req->flags &= ~REQ_F_REISSUE; + if (io_resubmit_prep(req)) { + io_req_task_queue_reissue(req); + } else { + unsigned int cflags = io_put_rw_kbuf(req); + struct io_ring_ctx *ctx = req->ctx; + + ret = io_fixup_rw_res(req, ret); + req_set_fail(req); + if (!(issue_flags & IO_URING_F_NONBLOCK)) { + mutex_lock(&ctx->uring_lock); + __io_req_complete(req, issue_flags, ret, cflags); + mutex_unlock(&ctx->uring_lock); + } else { + __io_req_complete(req, issue_flags, ret, cflags); + } + } + } }

-static ssize_t io_import_fixed(struct io_kiocb *req, int rw, - struct iov_iter *iter) +static int __io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter, + struct io_mapped_ubuf *imu) { - struct io_ring_ctx *ctx = req->ctx; size_t len = req->rw.len; - struct io_mapped_ubuf *imu; - u16 index, buf_index = req->buf_index; + u64 buf_end, buf_addr = req->rw.addr; size_t offset; - u64 buf_addr;

- if (unlikely(buf_index >= ctx->nr_user_bufs)) - return -EFAULT; - index = array_index_nospec(buf_index, ctx->nr_user_bufs); - imu = &ctx->user_bufs[index]; - buf_addr = req->rw.addr; - - /* overflow */ - if (buf_addr + len < buf_addr) + if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end))) return -EFAULT; /* not inside the mapped region */ - if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len) + if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end)) return -EFAULT;

/* @@ -2939,7 +3074,14 @@ static ssize_t io_import_fixed(struct io_kiocb *req, int rw, } }

- return len; + return 0; +} + +static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter) +{ + if (WARN_ON_ONCE(!req->imu)) + return -EFAULT; + return __io_import_fixed(req, rw, iter, req->imu); }

static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock) @@ -3080,16 +3222,14 @@ static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov, return __io_iov_buffer_select(req, iov, needs_lock); }

-static ssize_t __io_import_iovec(int rw, struct io_kiocb *req, - struct iovec **iovec, struct iov_iter *iter, - bool needs_lock) +static int io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, + struct iov_iter *iter, bool needs_lock) { void __user *buf = u64_to_user_ptr(req->rw.addr); size_t sqe_len = req->rw.len; + u8 opcode = req->opcode; ssize_t ret; - u8 opcode;

- opcode = req->opcode; if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { *iovec = NULL; return io_import_fixed(req, rw, iter); @@ -3114,10 +3254,8 @@ static ssize_t __io_import_iovec(int rw, struct io_kiocb *req,

if (req->flags & REQ_F_BUFFER_SELECT) { ret = io_iov_buffer_select(req, *iovec, needs_lock); - if (!ret) { - ret = (*iovec)->iov_len; - iov_iter_init(iter, rw, *iovec, 1, ret); - } + if (!ret) + iov_iter_init(iter, rw, *iovec, 1, (*iovec)->iov_len); *iovec = NULL; return ret; } @@ -3126,18 +3264,6 @@ static ssize_t __io_import_iovec(int rw, struct io_kiocb *req, req->ctx->compat); }

-static ssize_t io_import_iovec(int rw, struct io_kiocb *req, - struct iovec **iovec, struct iov_iter *iter, - bool needs_lock) -{ - struct io_async_rw *iorw = req->async_data; - - if (!iorw) - return __io_import_iovec(rw, req, iovec, iter, needs_lock); - *iovec = NULL; - return 0; -} - static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) { return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos; @@ -3230,32 +3356,31 @@ static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec, } }

-static inline int __io_alloc_async_data(struct io_kiocb *req) +static inline int io_alloc_async_data(struct io_kiocb *req) { WARN_ON_ONCE(!io_op_defs[req->opcode].async_size); req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL); return req->async_data == NULL; }

-static int io_alloc_async_data(struct io_kiocb *req) -{ - if (!io_op_defs[req->opcode].needs_async_data) - return 0; - - return __io_alloc_async_data(req); -} - static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, const struct iovec *fast_iov, struct iov_iter *iter, bool force) { - if (!force && !io_op_defs[req->opcode].needs_async_data) + if (!force && !io_op_defs[req->opcode].needs_async_setup) return 0; if (!req->async_data) { - if (__io_alloc_async_data(req)) + struct io_async_rw *iorw; + + if (io_alloc_async_data(req)) { + kfree(iovec); return -ENOMEM; + }

io_req_map_rw(req, iovec, fast_iov, iter); + iorw = req->async_data; + /* we've copied and mapped the iter, ensure state is saved */ + iov_iter_save_state(&iorw->iter, &iorw->iter_state); } return 0; } @@ -3264,9 +3389,9 @@ static inline int io_rw_prep_async(struct io_kiocb *req, int rw) { struct io_async_rw *iorw = req->async_data; struct iovec *iov = iorw->fast_iov; - ssize_t ret; + int ret;

- ret = __io_import_iovec(rw, req, &iov, &iorw->iter, false); + ret = io_import_iovec(rw, req, &iov, &iorw->iter, false); if (unlikely(ret < 0)) return ret;

@@ -3274,24 +3399,15 @@ static inline int io_rw_prep_async(struct io_kiocb *req, int rw) iorw->free_iovec = iov; if (iov) req->flags |= REQ_F_NEED_CLEANUP; + iov_iter_save_state(&iorw->iter, &iorw->iter_state); return 0; }

static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - ssize_t ret; - - ret = io_prep_rw(req, sqe); - if (ret) - return ret; - if (unlikely(!(req->file->f_mode & FMODE_READ))) return -EBADF; - - /* either don't need iovec imported or already have it */ - if (!req->async_data) - return 0; - return io_rw_prep_async(req, READ); + return io_prep_rw(req, sqe, READ); }

/* @@ -3310,7 +3426,6 @@ static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, struct wait_page_queue *wpq; struct io_kiocb *req = wait->private; struct wait_page_key *key = arg; - int ret;

wpq = container_of(wait, struct wait_page_queue, wait);

@@ -3319,22 +3434,7 @@ static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,

req->rw.kiocb.ki_flags &= ~IOCB_WAITQ; list_del_init(&wait->entry); - - init_task_work(&req->task_work, io_req_task_submit); - percpu_ref_get(&req->ctx->refs); - - /* submit ref gets dropped, acquire a new one */ - refcount_inc(&req->refs); - ret = io_req_task_work_add(req, true); - if (unlikely(ret)) { - struct task_struct *tsk; - - /* queue just for cancelation */ - init_task_work(&req->task_work, io_req_task_cancel); - tsk = io_wq_get_task(req->ctx->io_wq); - task_work_add(tsk, &req->task_work, TWA_NONE); - wake_up_process(tsk); - } + io_req_task_queue(req); return 1; }

@@ -3381,7 +3481,7 @@ static bool io_rw_should_retry(struct io_kiocb *req) return true; }

-static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter) +static inline int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter) { if (req->file->f_op->read_iter) return call_read_iter(req->file, &req->rw.kiocb, iter); @@ -3391,27 +3491,40 @@ static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter) return -EINVAL; }

-static int io_read(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static bool need_read_all(struct io_kiocb *req) +{ + return req->flags & REQ_F_ISREG || + S_ISBLK(file_inode(req->file)->i_mode); +} + +static int io_read(struct io_kiocb *req, unsigned int issue_flags) { struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; struct kiocb *kiocb = &req->rw.kiocb; struct iov_iter __iter, *iter = &__iter; - struct iov_iter iter_cp; struct io_async_rw *rw = req->async_data; - ssize_t io_size, ret, ret2; - bool no_async; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + struct iov_iter_state __state, *state; + ssize_t ret, ret2;

- if (rw) + if (rw) { iter = &rw->iter; - - ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock); - if (ret < 0) - return ret; - iter_cp = *iter; - io_size = iov_iter_count(iter); - req->result = io_size; - ret = 0; + state = &rw->iter_state; + /* + * We come here from an earlier attempt, restore our state to + * match in case it doesn't. It's cheap enough that we don't + * need to make this conditional. + */ + iov_iter_restore(iter, state); + iovec = NULL; + } else { + ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock); + if (ret < 0) + return ret; + state = &__state; + iov_iter_save_state(iter, state); + } + req->result = iov_iter_count(iter);

/* Ensure we clear previously set non-block flag */ if (!force_nonblock) @@ -3419,127 +3532,130 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, else kiocb->ki_flags |= IOCB_NOWAIT;

- /* If the file doesn't support async, just async punt */ - no_async = force_nonblock && !io_file_supports_async(req->file, READ); - if (no_async) - goto copy_iov; + if (force_nonblock && !io_file_supports_nowait(req, READ)) { + ret = io_setup_async_rw(req, iovec, inline_vecs, iter, true); + return ret ?: -EAGAIN; + }

- ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), io_size); - if (unlikely(ret)) - goto out_free; + ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result); + if (unlikely(ret)) { + kfree(iovec); + return ret; + }

ret = io_iter_do_read(req, iter);

- if (!ret) { - goto done; - } else if (ret == -EIOCBQUEUED) { - ret = 0; - goto out_free; - } else if (ret == -EAGAIN) { + if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) { + req->flags &= ~REQ_F_REISSUE; /* IOPOLL retry should happen for io-wq threads */ if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) goto done; - /* no retry on NONBLOCK marked file */ - if (req->file->f_flags & O_NONBLOCK) + /* no retry on NONBLOCK nor RWF_NOWAIT */ + if (req->flags & REQ_F_NOWAIT) goto done; - /* some cases will consume bytes even on error returns */ - *iter = iter_cp; ret = 0; - goto copy_iov; - } else if (ret < 0) { - /* make sure -ERESTARTSYS -> -EINTR is done */ + } else if (ret == -EIOCBQUEUED) { + goto out_free; + } else if (ret <= 0 || ret == req->result || !force_nonblock || + (req->flags & REQ_F_NOWAIT) || !need_read_all(req)) { + /* read all, failed, already did sync or don't want to retry */ goto done; }

- /* read it all, or we did blocking attempt. no retry. */ - if (!iov_iter_count(iter) || !force_nonblock || - (req->file->f_flags & O_NONBLOCK) || !(req->flags & REQ_F_ISREG)) - goto done; + /* + * Don't depend on the iter state matching what was consumed, or being + * untouched in case of error. Restore it and we'll advance it + * manually if we need to. + */ + iov_iter_restore(iter, state);

- io_size -= ret; -copy_iov: ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true); - if (ret2) { - ret = ret2; - goto out_free; - } - if (no_async) - return -EAGAIN; - rw = req->async_data; - /* it's copied and will be cleaned with ->io */ - iovec = NULL; - /* now use our persistent iterator, if we aren't already */ - iter = &rw->iter; -retry: - rw->bytes_done += ret; - /* if we can retry, do so with the callbacks armed */ - if (!io_rw_should_retry(req)) { - kiocb->ki_flags &= ~IOCB_WAITQ; - return -EAGAIN; - } + if (ret2) + return ret2;

+ iovec = NULL; + rw = req->async_data; /* - * Now retry read with the IOCB_WAITQ parts set in the iocb. If we - * get -EIOCBQUEUED, then we'll get a notification when the desired - * page gets unlocked. We can also get a partial read here, and if we - * do, then just retry at the new offset. + * Now use our persistent iterator and state, if we aren't already. + * We've restored and mapped the iter to match. */ - ret = io_iter_do_read(req, iter); - if (ret == -EIOCBQUEUED) { - ret = 0; - goto out_free; - } else if (ret > 0 && ret < io_size) { + if (iter != &rw->iter) { + iter = &rw->iter; + state = &rw->iter_state; + } + + do { + /* + * We end up here because of a partial read, either from + * above or inside this loop. Advance the iter by the bytes + * that were consumed. + */ + iov_iter_advance(iter, ret); + if (!iov_iter_count(iter)) + break; + rw->bytes_done += ret; + iov_iter_save_state(iter, state); + + /* if we can retry, do so with the callbacks armed */ + if (!io_rw_should_retry(req)) { + kiocb->ki_flags &= ~IOCB_WAITQ; + return -EAGAIN; + } + + req->result = iov_iter_count(iter); + /* + * Now retry read with the IOCB_WAITQ parts set in the iocb. If + * we get -EIOCBQUEUED, then we'll get a notification when the + * desired page gets unlocked. We can also get a partial read + * here, and if we do, then just retry at the new offset. + */ + ret = io_iter_do_read(req, iter); + if (ret == -EIOCBQUEUED) + return 0; /* we got some bytes, but not all. retry. */ kiocb->ki_flags &= ~IOCB_WAITQ; - goto retry; - } + iov_iter_restore(iter, state); + } while (ret > 0); done: - kiocb_done(kiocb, ret, cs); - ret = 0; + kiocb_done(kiocb, ret, issue_flags); out_free: - /* it's reportedly faster than delegating the null check to kfree() */ + /* it's faster to check here then delegate to kfree */ if (iovec) kfree(iovec); - return ret; + return 0; }

static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - ssize_t ret; - - ret = io_prep_rw(req, sqe); - if (ret) - return ret; - if (unlikely(!(req->file->f_mode & FMODE_WRITE))) return -EBADF; - - /* either don't need iovec imported or already have it */ - if (!req->async_data) - return 0; - return io_rw_prep_async(req, WRITE); + return io_prep_rw(req, sqe, WRITE); }

-static int io_write(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_write(struct io_kiocb *req, unsigned int issue_flags) { struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; struct kiocb *kiocb = &req->rw.kiocb; struct iov_iter __iter, *iter = &__iter; - struct iov_iter iter_cp; struct io_async_rw *rw = req->async_data; - ssize_t ret, ret2, io_size; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + struct iov_iter_state __state, *state; + ssize_t ret, ret2;

- if (rw) + if (rw) { iter = &rw->iter; - - ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock); - if (ret < 0) - return ret; - iter_cp = *iter; - io_size = iov_iter_count(iter); - req->result = io_size; + state = &rw->iter_state; + iov_iter_restore(iter, state); + iovec = NULL; + } else { + ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock); + if (ret < 0) + return ret; + state = &__state; + iov_iter_save_state(iter, state); + } + req->result = iov_iter_count(iter);

/* Ensure we clear previously set non-block flag */ if (!force_nonblock) @@ -3548,7 +3664,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, kiocb->ki_flags |= IOCB_NOWAIT;

/* If the file doesn't support async, just async punt */ - if (force_nonblock && !io_file_supports_async(req->file, WRITE)) + if (force_nonblock && !io_file_supports_nowait(req, WRITE)) goto copy_iov;

/* file path doesn't support NOWAIT for non-direct_IO */ @@ -3556,7 +3672,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, (req->flags & REQ_F_ISREG)) goto copy_iov;

- ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), io_size); + ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result); if (unlikely(ret)) goto out_free;

@@ -3581,28 +3697,36 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, else ret2 = -EINVAL;

+ if (req->flags & REQ_F_REISSUE) { + req->flags &= ~REQ_F_REISSUE; + ret2 = -EAGAIN; + } + /* * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just * retry them without IOCB_NOWAIT. */ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) ret2 = -EAGAIN; - /* no retry on NONBLOCK marked file */ - if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK)) + /* no retry on NONBLOCK nor RWF_NOWAIT */ + if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT)) goto done; if (!force_nonblock || ret2 != -EAGAIN) { /* IOPOLL retry should happen for io-wq threads */ if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN) goto copy_iov; done: - kiocb_done(kiocb, ret2, cs); + kiocb_done(kiocb, ret2, issue_flags); } else { copy_iov: - /* some cases will consume bytes even on error returns */ - *iter = iter_cp; + iov_iter_restore(iter, state); ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false); - if (!ret) + if (!ret) { + if (kiocb->ki_flags & IOCB_WRITE) + kiocb_end_write(req); return -EAGAIN; + } + return ret; } out_free: /* it's reportedly faster than delegating the null check to kfree() */ @@ -3611,37 +3735,160 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, return ret; }

-static int __io_splice_prep(struct io_kiocb *req, +static int io_renameat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - struct io_splice* sp = &req->splice; - unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL; + struct io_rename *ren = &req->rename; + const char __user *oldf, *newf;

if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; + if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) + return -EBADF;

- sp->file_in = NULL; - sp->len = READ_ONCE(sqe->len); - sp->flags = READ_ONCE(sqe->splice_flags); + ren->old_dfd = READ_ONCE(sqe->fd); + oldf = u64_to_user_ptr(READ_ONCE(sqe->addr)); + newf = u64_to_user_ptr(READ_ONCE(sqe->addr2)); + ren->new_dfd = READ_ONCE(sqe->len); + ren->flags = READ_ONCE(sqe->rename_flags);

- if (unlikely(sp->flags & ~valid_flags)) - return -EINVAL; + ren->oldpath = getname(oldf); + if (IS_ERR(ren->oldpath)) + return PTR_ERR(ren->oldpath);

- sp->file_in = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in), - (sp->flags & SPLICE_F_FD_IN_FIXED)); - if (!sp->file_in) + ren->newpath = getname(newf); + if (IS_ERR(ren->newpath)) { + putname(ren->oldpath); + return PTR_ERR(ren->newpath); + } + + req->flags |= REQ_F_NEED_CLEANUP; + return 0; +} + +static int io_renameat(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_rename *ren = &req->rename; + int ret; + + if (issue_flags & IO_URING_F_NONBLOCK) + return -EAGAIN; + + ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd, + ren->newpath, ren->flags); + + req->flags &= ~REQ_F_NEED_CLEANUP; + if (ret < 0) + req_set_fail(req); + io_req_complete(req, ret); + return 0; +} + +static int io_unlinkat_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + struct io_unlink *un = &req->unlink; + const char __user *fname; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index || + sqe->splice_fd_in) + return -EINVAL; + if (unlikely(req->flags & REQ_F_FIXED_FILE)) return -EBADF; + + un->dfd = READ_ONCE(sqe->fd); + + un->flags = READ_ONCE(sqe->unlink_flags); + if (un->flags & ~AT_REMOVEDIR) + return -EINVAL; + + fname = u64_to_user_ptr(READ_ONCE(sqe->addr)); + un->filename = getname(fname); + if (IS_ERR(un->filename)) + return PTR_ERR(un->filename); + req->flags |= REQ_F_NEED_CLEANUP; + return 0; +}

- if (!S_ISREG(file_inode(sp->file_in)->i_mode)) { - /* - * Splice operation will be punted aync, and here need to - * modify io_wq_work.flags, so initialize io_wq_work firstly. - */ - io_req_init_async(req); - req->work.flags |= IO_WQ_WORK_UNBOUND; - } +static int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_unlink *un = &req->unlink; + int ret; + + if (issue_flags & IO_URING_F_NONBLOCK) + return -EAGAIN; + + if (un->flags & AT_REMOVEDIR) + ret = do_rmdir(un->dfd, un->filename); + else + ret = do_unlinkat(un->dfd, un->filename); + + req->flags &= ~REQ_F_NEED_CLEANUP; + if (ret < 0) + req_set_fail(req); + io_req_complete(req, ret); + return 0; +} + +static int io_shutdown_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ +#if defined(CONFIG_NET) + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (unlikely(sqe->ioprio || sqe->off || sqe->addr || sqe->rw_flags || + sqe->buf_index || sqe->splice_fd_in)) + return -EINVAL; + + req->shutdown.how = READ_ONCE(sqe->len); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int io_shutdown(struct io_kiocb *req, unsigned int issue_flags) +{ +#if defined(CONFIG_NET) + struct socket *sock; + int ret; + + if (issue_flags & IO_URING_F_NONBLOCK) + return -EAGAIN; + + sock = sock_from_file(req->file, &ret); + if (unlikely(!sock)) + return ret; + + ret = __sys_shutdown_sock(sock, req->shutdown.how); + if (ret < 0) + req_set_fail(req); + io_req_complete(req, ret); + return 0; +#else + return -EOPNOTSUPP; +#endif +} + +static int __io_splice_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + struct io_splice *sp = &req->splice; + unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;

+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + + sp->len = READ_ONCE(sqe->len); + sp->flags = READ_ONCE(sqe->splice_flags); + if (unlikely(sp->flags & ~valid_flags)) + return -EINVAL; + sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in); return 0; }

@@ -3653,60 +3900,75 @@ static int io_tee_prep(struct io_kiocb *req, return __io_splice_prep(req, sqe); }

-static int io_tee(struct io_kiocb *req, bool force_nonblock) +static int io_tee(struct io_kiocb *req, unsigned int issue_flags) { struct io_splice *sp = &req->splice; - struct file *in = sp->file_in; struct file *out = sp->file_out; unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED; + struct file *in; long ret = 0;

- if (force_nonblock) + if (issue_flags & IO_URING_F_NONBLOCK) return -EAGAIN; + + in = io_file_get(req->ctx, req, sp->splice_fd_in, + (sp->flags & SPLICE_F_FD_IN_FIXED)); + if (!in) { + ret = -EBADF; + goto done; + } + if (sp->len) ret = do_tee(in, out, sp->len, flags);

- io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED)); - req->flags &= ~REQ_F_NEED_CLEANUP; - + if (!(sp->flags & SPLICE_F_FD_IN_FIXED)) + io_put_file(in); +done: if (ret != sp->len) - req_set_fail_links(req); + req_set_fail(req); io_req_complete(req, ret); return 0; }

static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - struct io_splice* sp = &req->splice; + struct io_splice *sp = &req->splice;

sp->off_in = READ_ONCE(sqe->splice_off_in); sp->off_out = READ_ONCE(sqe->off); return __io_splice_prep(req, sqe); }

-static int io_splice(struct io_kiocb *req, bool force_nonblock) +static int io_splice(struct io_kiocb *req, unsigned int issue_flags) { struct io_splice *sp = &req->splice; - struct file *in = sp->file_in; struct file *out = sp->file_out; unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED; loff_t *poff_in, *poff_out; + struct file *in; long ret = 0;

- if (force_nonblock) + if (issue_flags & IO_URING_F_NONBLOCK) return -EAGAIN;

+ in = io_file_get(req->ctx, req, sp->splice_fd_in, + (sp->flags & SPLICE_F_FD_IN_FIXED)); + if (!in) { + ret = -EBADF; + goto done; + } + poff_in = (sp->off_in == -1) ? NULL : &sp->off_in; poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;

if (sp->len) ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);

- io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED)); - req->flags &= ~REQ_F_NEED_CLEANUP; - + if (!(sp->flags & SPLICE_F_FD_IN_FIXED)) + io_put_file(in); +done: if (ret != sp->len) - req_set_fail_links(req); + req_set_fail(req); io_req_complete(req, ret); return 0; } @@ -3714,24 +3976,21 @@ static int io_splice(struct io_kiocb *req, bool force_nonblock) /* * IORING_OP_NOP just posts a completion event, nothing else. */ -static int io_nop(struct io_kiocb *req, struct io_comp_state *cs) +static int io_nop(struct io_kiocb *req, unsigned int issue_flags) { struct io_ring_ctx *ctx = req->ctx;

if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL;

- __io_req_complete(req, 0, 0, cs); + __io_req_complete(req, issue_flags, 0, 0); return 0; }

-static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_ring_ctx *ctx = req->ctx;

- if (!req->file) - return -EBADF; - if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index || @@ -3747,20 +4006,20 @@ static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) return 0; }

-static int io_fsync(struct io_kiocb *req, bool force_nonblock) +static int io_fsync(struct io_kiocb *req, unsigned int issue_flags) { loff_t end = req->sync.off + req->sync.len; int ret;

/* fsync always requires a blocking context */ - if (force_nonblock) + if (issue_flags & IO_URING_F_NONBLOCK) return -EAGAIN;

ret = vfs_fsync_range(req->file, req->sync.off, end > 0 ? end : LLONG_MAX, req->sync.flags & IORING_FSYNC_DATASYNC); if (ret < 0) - req_set_fail_links(req); + req_set_fail(req); io_req_complete(req, ret); return 0; } @@ -3780,17 +4039,19 @@ static int io_fallocate_prep(struct io_kiocb *req, return 0; }

-static int io_fallocate(struct io_kiocb *req, bool force_nonblock) +static int io_fallocate(struct io_kiocb *req, unsigned int issue_flags) { int ret;

/* fallocate always requiring blocking context */ - if (force_nonblock) + if (issue_flags & IO_URING_F_NONBLOCK) return -EAGAIN; ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off, req->sync.len); if (ret < 0) - req_set_fail_links(req); + req_set_fail(req); + else + fsnotify_modify(req->file); io_req_complete(req, ret); return 0; } @@ -3800,7 +4061,9 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe const char __user *fname; int ret;

- if (unlikely(sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)) + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (unlikely(sqe->ioprio || sqe->buf_index)) return -EINVAL; if (unlikely(req->flags & REQ_F_FIXED_FILE)) return -EBADF; @@ -3817,20 +4080,21 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe req->open.filename = NULL; return ret; } + + req->open.file_slot = READ_ONCE(sqe->file_index); + if (req->open.file_slot && (req->open.how.flags & O_CLOEXEC)) + return -EINVAL; + req->open.nofile = rlimit(RLIMIT_NOFILE); - req->open.ignore_nonblock = false; req->flags |= REQ_F_NEED_CLEANUP; return 0; }

static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - u64 flags, mode; + u64 mode = READ_ONCE(sqe->len); + u64 flags = READ_ONCE(sqe->open_flags);

- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) - return -EINVAL; - mode = READ_ONCE(sqe->len); - flags = READ_ONCE(sqe->open_flags); req->open.how = build_open_how(flags, mode); return __io_openat_prep(req, sqe); } @@ -3841,8 +4105,6 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) size_t len; int ret;

- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) - return -EINVAL; how = u64_to_user_ptr(READ_ONCE(sqe->addr2)); len = READ_ONCE(sqe->len); if (len < OPEN_HOW_SIZE_VER0) @@ -3856,58 +4118,75 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return __io_openat_prep(req, sqe); }

-static int io_openat2(struct io_kiocb *req, bool force_nonblock) +static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) { struct open_flags op; struct file *file; + bool resolve_nonblock, nonblock_set; + bool fixed = !!req->open.file_slot; int ret;

- if (force_nonblock && !req->open.ignore_nonblock) - return -EAGAIN; - ret = build_open_flags(&req->open.how, &op); if (ret) goto err; + nonblock_set = op.open_flag & O_NONBLOCK; + resolve_nonblock = req->open.how.resolve & RESOLVE_CACHED; + if (issue_flags & IO_URING_F_NONBLOCK) { + /* + * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open, + * it'll always -EAGAIN + */ + if (req->open.how.flags & (O_TRUNC | O_CREAT | O_TMPFILE)) + return -EAGAIN; + op.lookup_flags |= LOOKUP_CACHED; + op.open_flag |= O_NONBLOCK; + }

- ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile); - if (ret < 0) - goto err; + if (!fixed) { + ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile); + if (ret < 0) + goto err; + }

file = do_filp_open(req->open.dfd, req->open.filename, &op); if (IS_ERR(file)) { - put_unused_fd(ret); - ret = PTR_ERR(file); /* - * A work-around to ensure that /proc/self works that way - * that it should - if we get -EOPNOTSUPP back, then assume - * that proc_self_get_link() failed us because we're in async - * context. We should be safe to retry this from the task - * itself with force_nonblock == false set, as it should not - * block on lookup. Would be nice to know this upfront and - * avoid the async dance, but doesn't seem feasible. + * We could hang on to this 'fd' on retrying, but seems like + * marginal gain for something that is now known to be a slower + * path. So just put it, and we'll get a new one when we retry. */ - if (ret == -EOPNOTSUPP && io_wq_current_is_worker()) { - req->open.ignore_nonblock = true; - refcount_inc(&req->refs); - io_req_task_queue(req); - return 0; - } - } else { - fsnotify_open(file); - fd_install(ret, file); + if (!fixed) + put_unused_fd(ret); + + ret = PTR_ERR(file); + /* only retry if RESOLVE_CACHED wasn't already set by application */ + if (ret == -EAGAIN && + (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK))) + return -EAGAIN; + goto err; } + + if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set) + file->f_flags &= ~O_NONBLOCK; + fsnotify_open(file); + + if (!fixed) + fd_install(ret, file); + else + ret = io_install_fixed_file(req, file, issue_flags, + req->open.file_slot - 1); err: putname(req->open.filename); req->flags &= ~REQ_F_NEED_CLEANUP; if (ret < 0) - req_set_fail_links(req); - io_req_complete(req, ret); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, 0); return 0; }

-static int io_openat(struct io_kiocb *req, bool force_nonblock) +static int io_openat(struct io_kiocb *req, unsigned int issue_flags) { - return io_openat2(req, force_nonblock); + return io_openat2(req, issue_flags); }

static int io_remove_buffers_prep(struct io_kiocb *req, @@ -3948,6 +4227,7 @@ static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf, kfree(nxt); if (++i == nbufs) return i; + cond_resched(); } i++; kfree(buf); @@ -3956,13 +4236,13 @@ static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf, return i; }

-static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags) { struct io_provide_buf *p = &req->pbuf; struct io_ring_ctx *ctx = req->ctx; struct io_buffer *head; int ret = 0; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;

io_ring_submit_lock(ctx, !force_nonblock);

@@ -3973,16 +4253,11 @@ static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock, if (head) ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs); if (ret < 0) - req_set_fail_links(req); + req_set_fail(req);

- /* need to hold the lock to complete IOPOLL requests */ - if (ctx->flags & IORING_SETUP_IOPOLL) { - __io_req_complete(req, ret, 0, cs); - io_ring_submit_unlock(ctx, !force_nonblock); - } else { - io_ring_submit_unlock(ctx, !force_nonblock); - __io_req_complete(req, ret, 0, cs); - } + /* complete before unlock, IOPOLL may need the lock */ + __io_req_complete(req, issue_flags, ret, 0); + io_ring_submit_unlock(ctx, !force_nonblock); return 0; }

@@ -4049,13 +4324,13 @@ static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head) return i ? i : -ENOMEM; }

-static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags) { struct io_provide_buf *p = &req->pbuf; struct io_ring_ctx *ctx = req->ctx; struct io_buffer *head, *list; int ret = 0; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;

io_ring_submit_lock(ctx, !force_nonblock);

@@ -4065,21 +4340,16 @@ static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock,

ret = io_add_buffers(p, &head); if (ret >= 0 && !list) { - ret = xa_insert(&ctx->io_buffers, p->bgid, head, GFP_KERNEL); + ret = xa_insert(&ctx->io_buffers, p->bgid, head, + GFP_KERNEL_ACCOUNT); if (ret < 0) __io_remove_buffers(ctx, head, p->bgid, -1U); } if (ret < 0) - req_set_fail_links(req); - - /* need to hold the lock to complete IOPOLL requests */ - if (ctx->flags & IORING_SETUP_IOPOLL) { - __io_req_complete(req, ret, 0, cs); - io_ring_submit_unlock(ctx, !force_nonblock); - } else { - io_ring_submit_unlock(ctx, !force_nonblock); - __io_req_complete(req, ret, 0, cs); - } + req_set_fail(req); + /* complete before unlock, IOPOLL may need the lock */ + __io_req_complete(req, issue_flags, ret, 0); + io_ring_submit_unlock(ctx, !force_nonblock); return 0; }

@@ -4089,7 +4359,7 @@ static int io_epoll_ctl_prep(struct io_kiocb *req, #if defined(CONFIG_EPOLL) if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in) return -EINVAL; - if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL))) + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL;

req->epoll.epfd = READ_ONCE(sqe->fd); @@ -4110,20 +4380,20 @@ static int io_epoll_ctl_prep(struct io_kiocb *req, #endif }

-static int io_epoll_ctl(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags) { #if defined(CONFIG_EPOLL) struct io_epoll *ie = &req->epoll; int ret; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;

ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock); if (force_nonblock && ret == -EAGAIN) return -EAGAIN;

if (ret < 0) - req_set_fail_links(req); - __io_req_complete(req, ret, 0, cs); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, 0); return 0; #else return -EOPNOTSUPP; @@ -4147,18 +4417,18 @@ static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) #endif }

-static int io_madvise(struct io_kiocb *req, bool force_nonblock) +static int io_madvise(struct io_kiocb *req, unsigned int issue_flags) { #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU) struct io_madvise *ma = &req->madvise; int ret;

- if (force_nonblock) + if (issue_flags & IO_URING_F_NONBLOCK) return -EAGAIN;

ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice); if (ret < 0) - req_set_fail_links(req); + req_set_fail(req); io_req_complete(req, ret); return 0; #else @@ -4179,12 +4449,12 @@ static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return 0; }

-static int io_fadvise(struct io_kiocb *req, bool force_nonblock) +static int io_fadvise(struct io_kiocb *req, unsigned int issue_flags) { struct io_fadvise *fa = &req->fadvise; int ret;

- if (force_nonblock) { + if (issue_flags & IO_URING_F_NONBLOCK) { switch (fa->advice) { case POSIX_FADV_NORMAL: case POSIX_FADV_RANDOM: @@ -4197,14 +4467,14 @@ static int io_fadvise(struct io_kiocb *req, bool force_nonblock)

ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice); if (ret < 0) - req_set_fail_links(req); - io_req_complete(req, ret); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, 0); return 0; }

static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL))) + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in) return -EINVAL; @@ -4220,89 +4490,96 @@ static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return 0; }

-static int io_statx(struct io_kiocb *req, bool force_nonblock) +static int io_statx(struct io_kiocb *req, unsigned int issue_flags) { struct io_statx *ctx = &req->statx; int ret;

- if (force_nonblock) + if (issue_flags & IO_URING_F_NONBLOCK) return -EAGAIN;

ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask, ctx->buffer);

if (ret < 0) - req_set_fail_links(req); + req_set_fail(req); io_req_complete(req, ret); return 0; }

static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - /* - * If we queue this for async, it must not be cancellable. That would - * leave the 'file' in an undeterminate state, and here need to modify - * io_wq_work.flags, so initialize io_wq_work firstly. - */ - io_req_init_async(req); - - if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (sqe->ioprio || sqe->off || sqe->addr || sqe->len || - sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in) + sqe->rw_flags || sqe->buf_index) return -EINVAL; if (req->flags & REQ_F_FIXED_FILE) return -EBADF;

req->close.fd = READ_ONCE(sqe->fd); - if ((req->file && req->file->f_op == &io_uring_fops)) - return -EBADF; + req->close.file_slot = READ_ONCE(sqe->file_index); + if (req->close.file_slot && req->close.fd) + return -EINVAL;

- req->close.put_file = NULL; return 0; }

-static int io_close(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_close(struct io_kiocb *req, unsigned int issue_flags) { + struct files_struct *files = current->files; struct io_close *close = &req->close; - int ret; + struct fdtable *fdt; + struct file *file = NULL; + int ret = -EBADF;

- /* might be already done during nonblock submission */ - if (!close->put_file) { - ret = close_fd_get_file(close->fd, &close->put_file); - if (ret < 0) - return (ret == -ENOENT) ? -EBADF : ret; + if (req->close.file_slot) { + ret = io_close_fixed(req, issue_flags); + goto err; + } + + spin_lock(&files->file_lock); + fdt = files_fdtable(files); + if (close->fd >= fdt->max_fds) { + spin_unlock(&files->file_lock); + goto err; + } + file = fdt->fd[close->fd]; + if (!file || file->f_op == &io_uring_fops) { + spin_unlock(&files->file_lock); + file = NULL; + goto err; }

/* if the file has a flush method, be safe and punt to async */ - if (close->put_file->f_op->flush && force_nonblock) { - /* not safe to cancel at this point */ - req->work.flags |= IO_WQ_WORK_NO_CANCEL; - /* was never set, but play safe */ - req->flags &= ~REQ_F_NOWAIT; - /* avoid grabbing files - we don't need the files */ - req->flags |= REQ_F_NO_FILE_TABLE; + if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) { + spin_unlock(&files->file_lock); return -EAGAIN; }

+ ret = __close_fd_get_file(close->fd, &file); + spin_unlock(&files->file_lock); + if (ret < 0) { + if (ret == -ENOENT) + ret = -EBADF; + goto err; + } + /* No ->flush() or already async, safely close from here */ - ret = filp_close(close->put_file, req->work.identity->files); + ret = filp_close(file, current->files); +err: if (ret < 0) - req_set_fail_links(req); - fput(close->put_file); - close->put_file = NULL; - __io_req_complete(req, ret, 0, cs); + req_set_fail(req); + if (file) + fput(file); + __io_req_complete(req, issue_flags, ret, 0); return 0; }

-static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_ring_ctx *ctx = req->ctx;

- if (!req->file) - return -EBADF; - if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index || @@ -4315,18 +4592,18 @@ static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe) return 0; }

-static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock) +static int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags) { int ret;

/* sync_file_range always requires a blocking context */ - if (force_nonblock) + if (issue_flags & IO_URING_F_NONBLOCK) return -EAGAIN;

ret = sync_file_range(req->file, req->sync.off, req->sync.len, req->sync.flags); if (ret < 0) - req_set_fail_links(req); + req_set_fail(req); io_req_complete(req, ret); return 0; } @@ -4340,55 +4617,65 @@ static int io_setup_async_msg(struct io_kiocb *req, if (async_msg) return -EAGAIN; if (io_alloc_async_data(req)) { - if (kmsg->iov != kmsg->fast_iov) - kfree(kmsg->iov); + kfree(kmsg->free_iov); return -ENOMEM; } async_msg = req->async_data; req->flags |= REQ_F_NEED_CLEANUP; memcpy(async_msg, kmsg, sizeof(*kmsg)); + if (async_msg->msg.msg_name) + async_msg->msg.msg_name = &async_msg->addr; + /* if were using fast_iov, set it to the new one */ + if (!async_msg->free_iov) + async_msg->msg.msg_iter.iov = async_msg->fast_iov; + return -EAGAIN; }

static int io_sendmsg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg) { - iomsg->iov = iomsg->fast_iov; iomsg->msg.msg_name = &iomsg->addr; + iomsg->free_iov = iomsg->fast_iov; return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg, - req->sr_msg.msg_flags, &iomsg->iov); + req->sr_msg.msg_flags, &iomsg->free_iov); }

-static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static int io_sendmsg_prep_async(struct io_kiocb *req) { - struct io_async_msghdr *async_msg = req->async_data; - struct io_sr_msg *sr = &req->sr_msg; int ret;

+ ret = io_sendmsg_copy_hdr(req, req->async_data); + if (!ret) + req->flags |= REQ_F_NEED_CLEANUP; + return ret; +} + +static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sr_msg *sr = &req->sr_msg; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; - if (unlikely(sqe->addr2 || sqe->splice_fd_in || sqe->ioprio)) + if (unlikely(sqe->addr2 || sqe->file_index)) + return -EINVAL; + if (unlikely(sqe->addr2 || sqe->file_index || sqe->ioprio)) return -EINVAL;

- sr->msg_flags = READ_ONCE(sqe->msg_flags); sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); sr->len = READ_ONCE(sqe->len); + sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL; + if (sr->msg_flags & MSG_DONTWAIT) + req->flags |= REQ_F_NOWAIT;

#ifdef CONFIG_COMPAT if (req->ctx->compat) sr->msg_flags |= MSG_CMSG_COMPAT; #endif - - if (!async_msg || !io_op_defs[req->opcode].needs_async_data) - return 0; - ret = io_sendmsg_copy_hdr(req, async_msg); - if (!ret) - req->flags |= REQ_F_NEED_CLEANUP; - return ret; + return 0; }

-static int io_sendmsg(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) { struct io_async_msghdr iomsg, *kmsg; struct socket *sock; @@ -4400,46 +4687,37 @@ static int io_sendmsg(struct io_kiocb *req, bool force_nonblock, if (unlikely(!sock)) return ret;

- if (req->async_data) { - kmsg = req->async_data; - kmsg->msg.msg_name = &kmsg->addr; - /* if iov is set, it's allocated already */ - if (!kmsg->iov) - kmsg->iov = kmsg->fast_iov; - kmsg->msg.msg_iter.iov = kmsg->iov; - } else { + kmsg = req->async_data; + if (!kmsg) { ret = io_sendmsg_copy_hdr(req, &iomsg); if (ret) return ret; kmsg = &iomsg; }

- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL; - if (flags & MSG_DONTWAIT) - req->flags |= REQ_F_NOWAIT; - else if (force_nonblock) + flags = req->sr_msg.msg_flags; + if (issue_flags & IO_URING_F_NONBLOCK) flags |= MSG_DONTWAIT; - if (flags & MSG_WAITALL) min_ret = iov_iter_count(&kmsg->msg.msg_iter);

ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags); - if (force_nonblock && ret == -EAGAIN) + if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN) return io_setup_async_msg(req, kmsg); if (ret == -ERESTARTSYS) ret = -EINTR;

- if (kmsg->iov != kmsg->fast_iov) - kfree(kmsg->iov); + /* fast path, check for non-NULL to avoid function call */ + if (kmsg->free_iov) + kfree(kmsg->free_iov); req->flags &= ~REQ_F_NEED_CLEANUP; if (ret < min_ret) - req_set_fail_links(req); - __io_req_complete(req, ret, 0, cs); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, 0); return 0; }

-static int io_send(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_send(struct io_kiocb *req, unsigned int issue_flags) { struct io_sr_msg *sr = &req->sr_msg; struct msghdr msg; @@ -4462,25 +4740,22 @@ static int io_send(struct io_kiocb *req, bool force_nonblock, msg.msg_controllen = 0; msg.msg_namelen = 0;

- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL; - if (flags & MSG_DONTWAIT) - req->flags |= REQ_F_NOWAIT; - else if (force_nonblock) + flags = req->sr_msg.msg_flags; + if (issue_flags & IO_URING_F_NONBLOCK) flags |= MSG_DONTWAIT; - if (flags & MSG_WAITALL) min_ret = iov_iter_count(&msg.msg_iter);

msg.msg_flags = flags; ret = sock_sendmsg(sock, &msg); - if (force_nonblock && ret == -EAGAIN) + if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN) return -EAGAIN; if (ret == -ERESTARTSYS) ret = -EINTR;

if (ret < min_ret) - req_set_fail_links(req); - __io_req_complete(req, ret, 0, cs); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, 0); return 0; }

@@ -4500,15 +4775,14 @@ static int __io_recvmsg_copy_hdr(struct io_kiocb *req, if (req->flags & REQ_F_BUFFER_SELECT) { if (iov_len > 1) return -EINVAL; - if (copy_from_user(iomsg->iov, uiov, sizeof(*uiov))) + if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov))) return -EFAULT; - sr->len = iomsg->iov[0].iov_len; - iov_iter_init(&iomsg->msg.msg_iter, READ, iomsg->iov, 1, - sr->len); - iomsg->iov = NULL; + sr->len = iomsg->fast_iov[0].iov_len; + iomsg->free_iov = NULL; } else { + iomsg->free_iov = iomsg->fast_iov; ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV, - &iomsg->iov, &iomsg->msg.msg_iter, + &iomsg->free_iov, &iomsg->msg.msg_iter, false); if (ret > 0) ret = 0; @@ -4521,16 +4795,14 @@ static int __io_recvmsg_copy_hdr(struct io_kiocb *req, static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg) { - struct compat_msghdr __user *msg_compat; struct io_sr_msg *sr = &req->sr_msg; struct compat_iovec __user *uiov; compat_uptr_t ptr; compat_size_t len; int ret;

- msg_compat = (struct compat_msghdr __user *) sr->umsg; - ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr, - &ptr, &len); + ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr, + &ptr, &len); if (ret) return ret;

@@ -4547,11 +4819,11 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req, if (clen < 0) return -EINVAL; sr->len = clen; - iomsg->iov[0].iov_len = clen; - iomsg->iov = NULL; + iomsg->free_iov = NULL; } else { + iomsg->free_iov = iomsg->fast_iov; ret = __import_iovec(READ, (struct iovec __user *)uiov, len, - UIO_FASTIOV, &iomsg->iov, + UIO_FASTIOV, &iomsg->free_iov, &iomsg->msg.msg_iter, true); if (ret < 0) return ret; @@ -4565,7 +4837,6 @@ static int io_recvmsg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg) { iomsg->msg.msg_name = &iomsg->addr; - iomsg->iov = iomsg->fast_iov;

#ifdef CONFIG_COMPAT if (req->ctx->compat) @@ -4595,38 +4866,42 @@ static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req) return io_put_kbuf(req, req->sr_msg.kbuf); }

-static int io_recvmsg_prep(struct io_kiocb *req, - const struct io_uring_sqe *sqe) +static int io_recvmsg_prep_async(struct io_kiocb *req) { - struct io_async_msghdr *async_msg = req->async_data; - struct io_sr_msg *sr = &req->sr_msg; int ret;

+ ret = io_recvmsg_copy_hdr(req, req->async_data); + if (!ret) + req->flags |= REQ_F_NEED_CLEANUP; + return ret; +} + +static int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + struct io_sr_msg *sr = &req->sr_msg; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; - if (unlikely(sqe->addr2 || sqe->splice_fd_in || sqe->ioprio)) + if (unlikely(sqe->addr2 || sqe->file_index)) + return -EINVAL; + if (unlikely(sqe->addr2 || sqe->file_index || sqe->ioprio)) return -EINVAL;

- sr->msg_flags = READ_ONCE(sqe->msg_flags); sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr)); sr->len = READ_ONCE(sqe->len); sr->bgid = READ_ONCE(sqe->buf_group); + sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL; + if (sr->msg_flags & MSG_DONTWAIT) + req->flags |= REQ_F_NOWAIT;

#ifdef CONFIG_COMPAT if (req->ctx->compat) sr->msg_flags |= MSG_CMSG_COMPAT; #endif - - if (!async_msg || !io_op_defs[req->opcode].needs_async_data) - return 0; - ret = io_recvmsg_copy_hdr(req, async_msg); - if (!ret) - req->flags |= REQ_F_NEED_CLEANUP; - return ret; + return 0; }

-static int io_recvmsg(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) { struct io_async_msghdr iomsg, *kmsg; struct socket *sock; @@ -4634,19 +4909,14 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock, unsigned flags; int min_ret = 0; int ret, cflags = 0; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;

sock = sock_from_file(req->file, &ret); if (unlikely(!sock)) return ret;

- if (req->async_data) { - kmsg = req->async_data; - kmsg->msg.msg_name = &kmsg->addr; - /* if iov is set, it's allocated already */ - if (!kmsg->iov) - kmsg->iov = kmsg->fast_iov; - kmsg->msg.msg_iter.iov = kmsg->iov; - } else { + kmsg = req->async_data; + if (!kmsg) { ret = io_recvmsg_copy_hdr(req, &iomsg); if (ret) return ret; @@ -4658,16 +4928,14 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock, if (IS_ERR(kbuf)) return PTR_ERR(kbuf); kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr); - iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov, + kmsg->fast_iov[0].iov_len = req->sr_msg.len; + iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->fast_iov, 1, req->sr_msg.len); }

- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL; - if (flags & MSG_DONTWAIT) - req->flags |= REQ_F_NOWAIT; - else if (force_nonblock) + flags = req->sr_msg.msg_flags; + if (force_nonblock) flags |= MSG_DONTWAIT; - if (flags & MSG_WAITALL) min_ret = iov_iter_count(&kmsg->msg.msg_iter);

@@ -4680,17 +4948,17 @@ static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,

if (req->flags & REQ_F_BUFFER_SELECTED) cflags = io_put_recv_kbuf(req); - if (kmsg->iov != kmsg->fast_iov) - kfree(kmsg->iov); + /* fast path, check for non-NULL to avoid function call */ + if (kmsg->free_iov) + kfree(kmsg->free_iov); req->flags &= ~REQ_F_NEED_CLEANUP; if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC)))) - req_set_fail_links(req); - __io_req_complete(req, ret, cflags, cs); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, cflags); return 0; }

-static int io_recv(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_recv(struct io_kiocb *req, unsigned int issue_flags) { struct io_buffer *kbuf; struct io_sr_msg *sr = &req->sr_msg; @@ -4701,6 +4969,7 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock, unsigned flags; int min_ret = 0; int ret, cflags = 0; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;

sock = sock_from_file(req->file, &ret); if (unlikely(!sock)) @@ -4724,12 +4993,9 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock, msg.msg_iocb = NULL; msg.msg_flags = 0;

- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL; - if (flags & MSG_DONTWAIT) - req->flags |= REQ_F_NOWAIT; - else if (force_nonblock) + flags = req->sr_msg.msg_flags; + if (force_nonblock) flags |= MSG_DONTWAIT; - if (flags & MSG_WAITALL) min_ret = iov_iter_count(&msg.msg_iter);

@@ -4742,8 +5008,8 @@ static int io_recv(struct io_kiocb *req, bool force_nonblock, if (req->flags & REQ_F_BUFFER_SELECTED) cflags = io_put_recv_kbuf(req); if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC)))) - req_set_fail_links(req); - __io_req_complete(req, ret, cflags, cs); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, cflags); return 0; }

@@ -4751,48 +5017,79 @@ static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_accept *accept = &req->accept;

- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; - if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->splice_fd_in) + if (sqe->ioprio || sqe->len || sqe->buf_index) return -EINVAL;

accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2)); accept->flags = READ_ONCE(sqe->accept_flags); accept->nofile = rlimit(RLIMIT_NOFILE); + + accept->file_slot = READ_ONCE(sqe->file_index); + if (accept->file_slot && (accept->flags & SOCK_CLOEXEC)) + return -EINVAL; + if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK)) + return -EINVAL; + if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK)) + accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK; return 0; }

-static int io_accept(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_accept(struct io_kiocb *req, unsigned int issue_flags) { struct io_accept *accept = &req->accept; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0; - int ret; + bool fixed = !!accept->file_slot; + struct file *file; + int ret, fd;

if (req->file->f_flags & O_NONBLOCK) req->flags |= REQ_F_NOWAIT;

- ret = __sys_accept4_file(req->file, file_flags, accept->addr, - accept->addr_len, accept->flags, - accept->nofile); - if (ret == -EAGAIN && force_nonblock) - return -EAGAIN; - if (ret < 0) { + if (!fixed) { + fd = __get_unused_fd_flags(accept->flags, accept->nofile); + if (unlikely(fd < 0)) + return fd; + } + file = do_accept(req->file, file_flags, accept->addr, accept->addr_len, + accept->flags); + + if (IS_ERR(file)) { + if (!fixed) + put_unused_fd(fd); + ret = PTR_ERR(file); + if (ret == -EAGAIN && force_nonblock) + return -EAGAIN; if (ret == -ERESTARTSYS) ret = -EINTR; - req_set_fail_links(req); + req_set_fail(req); + } else if (!fixed) { + fd_install(fd, file); + ret = fd; + } else { + ret = io_install_fixed_file(req, file, issue_flags, + accept->file_slot - 1); } - __io_req_complete(req, ret, 0, cs); + __io_req_complete(req, issue_flags, ret, 0); return 0; }

+static int io_connect_prep_async(struct io_kiocb *req) +{ + struct io_async_connect *io = req->async_data; + struct io_connect *conn = &req->connect; + + return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address); +} + static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_connect *conn = &req->connect; - struct io_async_connect *io = req->async_data;

- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in) @@ -4800,20 +5097,15 @@ static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); conn->addr_len = READ_ONCE(sqe->addr2); - - if (!io) - return 0; - - return move_addr_to_kernel(conn->addr, conn->addr_len, - &io->address); + return 0; }

-static int io_connect(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_connect(struct io_kiocb *req, unsigned int issue_flags) { struct io_async_connect __io, *io; unsigned file_flags; int ret; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;

if (req->async_data) { io = req->async_data; @@ -4837,7 +5129,6 @@ static int io_connect(struct io_kiocb *req, bool force_nonblock, ret = -ENOMEM; goto out; } - io = req->async_data; memcpy(req->async_data, &__io, sizeof(__io)); return -EAGAIN; } @@ -4845,248 +5136,352 @@ static int io_connect(struct io_kiocb *req, bool force_nonblock, ret = -EINTR; out: if (ret < 0) - req_set_fail_links(req); - __io_req_complete(req, ret, 0, cs); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, 0); return 0; } #else /* !CONFIG_NET */ -static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +#define IO_NETOP_FN(op) \ +static int io_##op(struct io_kiocb *req, unsigned int issue_flags) \ +{ \ + return -EOPNOTSUPP; \ +} + +#define IO_NETOP_PREP(op) \ +IO_NETOP_FN(op) \ +static int io_##op##_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) \ +{ \ + return -EOPNOTSUPP; \ +} \ + +#define IO_NETOP_PREP_ASYNC(op) \ +IO_NETOP_PREP(op) \ +static int io_##op##_prep_async(struct io_kiocb *req) \ +{ \ + return -EOPNOTSUPP; \ +} + +IO_NETOP_PREP_ASYNC(sendmsg); +IO_NETOP_PREP_ASYNC(recvmsg); +IO_NETOP_PREP_ASYNC(connect); +IO_NETOP_PREP(accept); +IO_NETOP_FN(send); +IO_NETOP_FN(recv); +#endif /* CONFIG_NET */ + +struct io_poll_table { + struct poll_table_struct pt; + struct io_kiocb *req; + int nr_entries; + int error; +}; + +#define IO_POLL_CANCEL_FLAG BIT(31) +#define IO_POLL_RETRY_FLAG BIT(30) +#define IO_POLL_REF_MASK GENMASK(29, 0) + +/* + * We usually have 1-2 refs taken, 128 is more than enough and we want to + * maximise the margin between this amount and the moment when it overflows. + */ +#define IO_POLL_REF_BIAS 128 + +static bool io_poll_get_ownership_slowpath(struct io_kiocb *req) { - return -EOPNOTSUPP; + int v; + + /* + * poll_refs are already elevated and we don't have much hope for + * grabbing the ownership. Instead of incrementing set a retry flag + * to notify the loop that there might have been some change. + */ + v = atomic_fetch_or(IO_POLL_RETRY_FLAG, &req->poll_refs); + if (v & IO_POLL_REF_MASK) + return false; + return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK); }

-static int io_sendmsg(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +/* + * If refs part of ->poll_refs (see IO_POLL_REF_MASK) is 0, it's free. We can + * bump it and acquire ownership. It's disallowed to modify requests while not + * owning it, that prevents from races for enqueueing task_work's and b/w + * arming poll and wakeups. + */ +static inline bool io_poll_get_ownership(struct io_kiocb *req) { - return -EOPNOTSUPP; + if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) + return io_poll_get_ownership_slowpath(req); + return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK); }

-static int io_send(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static void io_poll_mark_cancelled(struct io_kiocb *req) { - return -EOPNOTSUPP; + atomic_or(IO_POLL_CANCEL_FLAG, &req->poll_refs); }

-static int io_recvmsg_prep(struct io_kiocb *req, - const struct io_uring_sqe *sqe) +static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req) { - return -EOPNOTSUPP; + /* pure poll stashes this in ->async_data, poll driven retry elsewhere */ + if (req->opcode == IORING_OP_POLL_ADD) + return req->async_data; + return req->apoll->double_poll; }

-static int io_recvmsg(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req) { - return -EOPNOTSUPP; + if (req->opcode == IORING_OP_POLL_ADD) + return &req->poll; + return &req->apoll->poll; }

-static int io_recv(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static void io_poll_req_insert(struct io_kiocb *req) { - return -EOPNOTSUPP; + struct io_ring_ctx *ctx = req->ctx; + struct hlist_head *list; + + list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)]; + hlist_add_head(&req->hash_node, list); }

-static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events, + wait_queue_func_t wake_func) { - return -EOPNOTSUPP; + poll->head = NULL; +#define IO_POLL_UNMASK (EPOLLERR|EPOLLHUP|EPOLLNVAL|EPOLLRDHUP) + /* mask in events that we always want/need */ + poll->events = events | IO_POLL_UNMASK; + INIT_LIST_HEAD(&poll->wait.entry); + init_waitqueue_func_entry(&poll->wait, wake_func); }

-static int io_accept(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static inline void io_poll_remove_entry(struct io_poll_iocb *poll) { - return -EOPNOTSUPP; + struct wait_queue_head *head = smp_load_acquire(&poll->head); + + if (head) { + spin_lock_irq(&head->lock); + list_del_init(&poll->wait.entry); + poll->head = NULL; + spin_unlock_irq(&head->lock); + } }

-static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static void io_poll_remove_entries(struct io_kiocb *req) { - return -EOPNOTSUPP; + struct io_poll_iocb *poll = io_poll_get_single(req); + struct io_poll_iocb *poll_double = io_poll_get_double(req); + + /* + * While we hold the waitqueue lock and the waitqueue is nonempty, + * wake_up_pollfree() will wait for us. However, taking the waitqueue + * lock in the first place can race with the waitqueue being freed. + * + * We solve this as eventpoll does: by taking advantage of the fact that + * all users of wake_up_pollfree() will RCU-delay the actual free. If + * we enter rcu_read_lock() and see that the pointer to the queue is + * non-NULL, we can then lock it without the memory being freed out from + * under us. + * + * Keep holding rcu_read_lock() as long as we hold the queue lock, in + * case the caller deletes the entry from the queue, leaving it empty. + * In that case, only RCU prevents the queue memory from being freed. + */ + rcu_read_lock(); + io_poll_remove_entry(poll); + if (poll_double) + io_poll_remove_entry(poll_double); + rcu_read_unlock(); }

-static int io_connect(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +/* + * All poll tw should go through this. Checks for poll events, manages + * references, does rewait, etc. + * + * Returns a negative error on failure. >0 when no action require, which is + * either spurious wakeup or multishot CQE is served. 0 when it's done with + * the request, then the mask is stored in req->result. + */ +static int io_poll_check_events(struct io_kiocb *req) { - return -EOPNOTSUPP; -} -#endif /* CONFIG_NET */ + struct io_ring_ctx *ctx = req->ctx; + struct io_poll_iocb *poll = io_poll_get_single(req); + int v;

-struct io_poll_table { - struct poll_table_struct pt; - struct io_kiocb *req; - int nr_entries; - int error; -}; + /* req->task == current here, checking PF_EXITING is safe */ + if (unlikely(req->task->flags & PF_EXITING)) + io_poll_mark_cancelled(req);

-static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll, - __poll_t mask, task_work_func_t func) -{ - bool twa_signal_ok; - int ret; + do { + v = atomic_read(&req->poll_refs);

- /* for instances that support it check for an event match first: */ - if (mask && !(mask & poll->events)) - return 0; + /* tw handler should be the owner, and so have some references */ + if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK))) + return 0; + if (v & IO_POLL_CANCEL_FLAG) + return -ECANCELED; + /* + * cqe.res contains only events of the first wake up + * and all others are be lost. Redo vfs_poll() to get + * up to date state. + */ + if ((v & IO_POLL_REF_MASK) != 1) + req->result = 0; + if (v & IO_POLL_RETRY_FLAG) { + req->result = 0; + /* + * We won't find new events that came in between + * vfs_poll and the ref put unless we clear the + * flag in advance. + */ + atomic_andnot(IO_POLL_RETRY_FLAG, &req->poll_refs); + v &= ~IO_POLL_RETRY_FLAG; + }

- trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask); + if (!req->result) { + struct poll_table_struct pt = { ._key = poll->events };

- list_del_init(&poll->wait.entry); + req->result = vfs_poll(req->file, &pt) & poll->events; + }

- req->result = mask; - init_task_work(&req->task_work, func); - percpu_ref_get(&req->ctx->refs); + /* multishot, just fill an CQE and proceed */ + if (req->result && !(poll->events & EPOLLONESHOT)) { + __poll_t mask = mangle_poll(req->result & poll->events); + bool filled;

- /* - * If we using the signalfd wait_queue_head for this wakeup, then - * it's not safe to use TWA_SIGNAL as we could be recursing on the - * tsk->sighand->siglock on doing the wakeup. Should not be needed - * either, as the normal wakeup will suffice. - */ - twa_signal_ok = (poll->head != &req->task->sighand->signalfd_wqh); + spin_lock(&ctx->completion_lock); + filled = io_fill_cqe_aux(ctx, req->user_data, mask, + IORING_CQE_F_MORE); + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock); + if (unlikely(!filled)) + return -ECANCELED; + io_cqring_ev_posted(ctx); + } else if (req->result) { + return 0; + }

- /* - * If this fails, then the task is exiting. When a task exits, the - * work gets canceled, so just cancel this request as well instead - * of executing it. We can't safely execute it anyway, as we may not - * have the needed state needed for it anyway. - */ - ret = io_req_task_work_add(req, twa_signal_ok); - if (unlikely(ret)) { - struct task_struct *tsk; + /* force the next iteration to vfs_poll() */ + req->result = 0; + + /* + * Release all references, retry if someone tried to restart + * task_work while we were executing it. + */ + } while (atomic_sub_return(v & IO_POLL_REF_MASK, &req->poll_refs) & + IO_POLL_REF_MASK);

- WRITE_ONCE(poll->canceled, true); - tsk = io_wq_get_task(req->ctx->io_wq); - task_work_add(tsk, &req->task_work, TWA_NONE); - wake_up_process(tsk); - } return 1; }

-static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll) - __acquires(&req->ctx->completion_lock) +static void io_poll_task_func(struct io_kiocb *req, bool *locked) { struct io_ring_ctx *ctx = req->ctx; + int ret;

- if (!req->result && !READ_ONCE(poll->canceled)) { - struct poll_table_struct pt = { ._key = poll->events }; - - req->result = vfs_poll(req->file, &pt) & poll->events; - } + ret = io_poll_check_events(req); + if (ret > 0) + return;

- spin_lock_irq(&ctx->completion_lock); - if (!req->result && !READ_ONCE(poll->canceled)) { - add_wait_queue(poll->head, &poll->wait); - return true; + if (!ret) { + req->result = mangle_poll(req->result & req->poll.events); + } else { + req->result = ret; + req_set_fail(req); }

- return false; -} - -static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req) -{ - /* pure poll stashes this in ->async_data, poll driven retry elsewhere */ - if (req->opcode == IORING_OP_POLL_ADD) - return req->async_data; - return req->apoll->double_poll; -} - -static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req) -{ - if (req->opcode == IORING_OP_POLL_ADD) - return &req->poll; - return &req->apoll->poll; + io_poll_remove_entries(req); + spin_lock(&ctx->completion_lock); + hash_del(&req->hash_node); + spin_unlock(&ctx->completion_lock); + io_req_complete_post(req, req->result, 0); }

-static void io_poll_remove_double(struct io_kiocb *req) +static void io_apoll_task_func(struct io_kiocb *req, bool *locked) { - struct io_poll_iocb *poll = io_poll_get_double(req); + struct io_ring_ctx *ctx = req->ctx; + int ret;

- lockdep_assert_held(&req->ctx->completion_lock); + ret = io_poll_check_events(req); + if (ret > 0) + return;

- if (poll && poll->head) { - struct wait_queue_head *head = poll->head; + io_poll_remove_entries(req); + spin_lock(&ctx->completion_lock); + hash_del(&req->hash_node); + spin_unlock(&ctx->completion_lock);

- spin_lock(&head->lock); - list_del_init(&poll->wait.entry); - if (poll->wait.private) - refcount_dec(&req->refs); - poll->head = NULL; - spin_unlock(&head->lock); - } + if (!ret) + io_req_task_submit(req, locked); + else + io_req_complete_failed(req, ret); }

-static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error) +static void __io_poll_execute(struct io_kiocb *req, int mask) { - struct io_ring_ctx *ctx = req->ctx; + req->result = mask; + if (req->opcode == IORING_OP_POLL_ADD) + req->io_task_work.func = io_poll_task_func; + else + req->io_task_work.func = io_apoll_task_func;

- io_poll_remove_double(req); - req->poll.done = true; - io_cqring_fill_event(req, error ? error : mangle_poll(mask)); - io_commit_cqring(ctx); + trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask); + io_req_task_work_add(req); }

-static void io_poll_task_func(struct callback_head *cb) +static inline void io_poll_execute(struct io_kiocb *req, int res) { - struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); - struct io_ring_ctx *ctx = req->ctx; - struct io_kiocb *nxt; - - if (io_poll_rewait(req, &req->poll)) { - spin_unlock_irq(&ctx->completion_lock); - } else { - hash_del(&req->hash_node); - io_poll_complete(req, req->result, 0); - spin_unlock_irq(&ctx->completion_lock); - - nxt = io_put_req_find_next(req); - io_cqring_ev_posted(ctx); - if (nxt) - __io_req_task_submit(nxt); - } + if (io_poll_get_ownership(req)) + __io_poll_execute(req, res); +}

- percpu_ref_put(&ctx->refs); +static void io_poll_cancel_req(struct io_kiocb *req) +{ + io_poll_mark_cancelled(req); + /* kick tw, which should complete the request */ + io_poll_execute(req, 0); }

-static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode, - int sync, void *key) +static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, + void *key) { struct io_kiocb *req = wait->private; - struct io_poll_iocb *poll = io_poll_get_single(req); + struct io_poll_iocb *poll = container_of(wait, struct io_poll_iocb, + wait); __poll_t mask = key_to_poll(key);

- /* for instances that support it check for an event match first: */ - if (mask && !(mask & poll->events)) - return 0; + if (unlikely(mask & POLLFREE)) { + io_poll_mark_cancelled(req); + /* we have to kick tw in case it's not already */ + io_poll_execute(req, 0);

- list_del_init(&wait->entry); + /* + * If the waitqueue is being freed early but someone is already + * holds ownership over it, we have to tear down the request as + * best we can. That means immediately removing the request from + * its waitqueue and preventing all further accesses to the + * waitqueue via the request. + */ + list_del_init(&poll->wait.entry);

- if (poll && poll->head) { - bool done; - - spin_lock(&poll->head->lock); - done = list_empty(&poll->wait.entry); - if (!done) - list_del_init(&poll->wait.entry); - /* make sure double remove sees this as being gone */ - wait->private = NULL; - spin_unlock(&poll->head->lock); - if (!done) { - /* use wait func handler, so it matches the rq type */ - poll->wait.func(&poll->wait, mode, sync, key); - } + /* + * Careful: this *must* be the last step, since as soon + * as req->head is NULL'ed out, the request can be + * completed and freed, since aio_poll_complete_work() + * will no longer need to take the waitqueue lock. + */ + smp_store_release(&poll->head, NULL); + return 1; } - refcount_dec(&req->refs); + + /* for instances that support it check for an event match first */ + if (mask && !(mask & poll->events)) + return 0; + + if (io_poll_get_ownership(req)) + __io_poll_execute(req, mask); return 1; }

-static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events, - wait_queue_func_t wake_func) -{ - poll->head = NULL; - poll->done = false; - poll->canceled = false; - poll->events = events; - INIT_LIST_HEAD(&poll->wait.entry); - init_waitqueue_func_entry(&poll->wait, wake_func); -} - static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, struct wait_queue_head *head, struct io_poll_iocb **poll_ptr) @@ -5099,29 +5494,31 @@ static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, * if this happens. */ if (unlikely(pt->nr_entries)) { - struct io_poll_iocb *poll_one = poll; + struct io_poll_iocb *first = poll;

+ /* double add on the same waitqueue head, ignore */ + if (first->head == head) + return; /* already have a 2nd entry, fail a third attempt */ if (*poll_ptr) { + if ((*poll_ptr)->head == head) + return; pt->error = -EINVAL; return; } - /* double add on the same waitqueue head, ignore */ - if (poll->head == head) - return; + poll = kmalloc(sizeof(*poll), GFP_ATOMIC); if (!poll) { pt->error = -ENOMEM; return; } - io_init_poll_iocb(poll, poll_one->events, io_poll_double_wake); - refcount_inc(&req->refs); - poll->wait.private = req; + io_init_poll_iocb(poll, first->events, first->wait.func); *poll_ptr = poll; }

pt->nr_entries++; poll->head = head; + poll->wait.private = req;

if (poll->events & EPOLLEXCLUSIVE) add_wait_queue_exclusive(head, &poll->wait); @@ -5129,83 +5526,23 @@ static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, add_wait_queue(head, &poll->wait); }

-static void io_async_queue_proc(struct file *file, struct wait_queue_head *head, +static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, struct poll_table_struct *p) { struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); - struct async_poll *apoll = pt->req->apoll; - - __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll); -} - -static void io_async_task_func(struct callback_head *cb) -{ - struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work); - struct async_poll *apoll = req->apoll; - struct io_ring_ctx *ctx = req->ctx; - - trace_io_uring_task_run(req->ctx, req->opcode, req->user_data); - - if (io_poll_rewait(req, &apoll->poll)) { - spin_unlock_irq(&ctx->completion_lock); - percpu_ref_put(&ctx->refs); - return; - } - - /* If req is still hashed, it cannot have been canceled. Don't check. */ - if (hash_hashed(&req->hash_node)) - hash_del(&req->hash_node); - - io_poll_remove_double(req); - spin_unlock_irq(&ctx->completion_lock); - - if (!READ_ONCE(apoll->poll.canceled)) - __io_req_task_submit(req); - else - __io_req_task_cancel(req, -ECANCELED);

- percpu_ref_put(&ctx->refs); - kfree(apoll->double_poll); - kfree(apoll); -} - -static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync, - void *key) -{ - struct io_kiocb *req = wait->private; - struct io_poll_iocb *poll = &req->apoll->poll; - - trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data, - key_to_poll(key)); - - return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func); -} - -static void io_poll_req_insert(struct io_kiocb *req) -{ - struct io_ring_ctx *ctx = req->ctx; - struct hlist_head *list; - - list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)]; - hlist_add_head(&req->hash_node, list); + __io_queue_proc(&pt->req->poll, pt, head, + (struct io_poll_iocb **) &pt->req->async_data); }

-static __poll_t __io_arm_poll_handler(struct io_kiocb *req, - struct io_poll_iocb *poll, - struct io_poll_table *ipt, __poll_t mask, - wait_queue_func_t wake_func) - __acquires(&ctx->completion_lock) +static int __io_arm_poll_handler(struct io_kiocb *req, + struct io_poll_iocb *poll, + struct io_poll_table *ipt, __poll_t mask) { struct io_ring_ctx *ctx = req->ctx; - bool cancel = false; - - if (req->file->f_op->may_pollfree) { - spin_lock_irq(&ctx->completion_lock); - return -EOPNOTSUPP; - }

INIT_HLIST_NODE(&req->hash_node); - io_init_poll_iocb(poll, mask, wake_func); + io_init_poll_iocb(poll, mask, io_poll_wake); poll->file = req->file; poll->wait.private = req;

@@ -5214,169 +5551,138 @@ static __poll_t __io_arm_poll_handler(struct io_kiocb *req, ipt->error = 0; ipt->nr_entries = 0;

+ /* + * Take the ownership to delay any tw execution up until we're done + * with poll arming. see io_poll_get_ownership(). + */ + atomic_set(&req->poll_refs, 1); mask = vfs_poll(req->file, &ipt->pt) & poll->events; - if (unlikely(!ipt->nr_entries) && !ipt->error) - ipt->error = -EINVAL; - - spin_lock_irq(&ctx->completion_lock); - if (ipt->error) - io_poll_remove_double(req); - if (likely(poll->head)) { - spin_lock(&poll->head->lock); - if (unlikely(list_empty(&poll->wait.entry))) { - if (ipt->error) - cancel = true; + + if (mask && (poll->events & EPOLLONESHOT)) { + io_poll_remove_entries(req); + /* no one else has access to the req, forget about the ref */ + return mask; + } + if (!mask && unlikely(ipt->error || !ipt->nr_entries)) { + io_poll_remove_entries(req); + if (!ipt->error) + ipt->error = -EINVAL; + return 0; + } + + spin_lock(&ctx->completion_lock); + io_poll_req_insert(req); + spin_unlock(&ctx->completion_lock); + + if (mask) { + /* can't multishot if failed, just queue the event we've got */ + if (unlikely(ipt->error || !ipt->nr_entries)) { + poll->events |= EPOLLONESHOT; ipt->error = 0; - mask = 0; } - if (mask || ipt->error) - list_del_init(&poll->wait.entry); - else if (cancel) - WRITE_ONCE(poll->canceled, true); - else if (!poll->done) /* actually waiting for an event */ - io_poll_req_insert(req); - spin_unlock(&poll->head->lock); + __io_poll_execute(req, mask); + return 0; }

- return mask; + /* + * Try to release ownership. If we see a change of state, e.g. + * poll was waken up, queue up a tw, it'll deal with it. + */ + if (atomic_cmpxchg(&req->poll_refs, 1, 0) != 1) + __io_poll_execute(req, 0); + return 0; +} + +static void io_async_queue_proc(struct file *file, struct wait_queue_head *head, + struct poll_table_struct *p) +{ + struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); + struct async_poll *apoll = pt->req->apoll; + + __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll); }

-static bool io_arm_poll_handler(struct io_kiocb *req) +enum { + IO_APOLL_OK, + IO_APOLL_ABORTED, + IO_APOLL_READY +}; + +static int io_arm_poll_handler(struct io_kiocb *req) { const struct io_op_def *def = &io_op_defs[req->opcode]; struct io_ring_ctx *ctx = req->ctx; struct async_poll *apoll; struct io_poll_table ipt; - __poll_t mask, ret; - int rw; + __poll_t mask = EPOLLONESHOT | POLLERR | POLLPRI; + int ret;

if (!req->file || !file_can_poll(req->file)) - return false; + return IO_APOLL_ABORTED; if (req->flags & REQ_F_POLLED) - return false; - if (def->pollin) - rw = READ; - else if (def->pollout) - rw = WRITE; - else - return false; - /* if we can't nonblock try, then no point in arming a poll handler */ - if (!io_file_supports_async(req->file, rw)) - return false; + return IO_APOLL_ABORTED; + if (!def->pollin && !def->pollout) + return IO_APOLL_ABORTED; + + if (def->pollin) { + mask |= POLLIN | POLLRDNORM; + + /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */ + if ((req->opcode == IORING_OP_RECVMSG) && + (req->sr_msg.msg_flags & MSG_ERRQUEUE)) + mask &= ~POLLIN; + } else { + mask |= POLLOUT | POLLWRNORM; + }

apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC); if (unlikely(!apoll)) - return false; + return IO_APOLL_ABORTED; apoll->double_poll = NULL; - - req->flags |= REQ_F_POLLED; req->apoll = apoll; - - mask = 0; - if (def->pollin) - mask |= POLLIN | POLLRDNORM; - if (def->pollout) - mask |= POLLOUT | POLLWRNORM; - - /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */ - if ((req->opcode == IORING_OP_RECVMSG) && - (req->sr_msg.msg_flags & MSG_ERRQUEUE)) - mask &= ~POLLIN; - - mask |= POLLERR | POLLPRI; - + req->flags |= REQ_F_POLLED; ipt.pt._qproc = io_async_queue_proc;

- ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask, - io_async_wake); - if (ret || ipt.error) { - io_poll_remove_double(req); - spin_unlock_irq(&ctx->completion_lock); - kfree(apoll->double_poll); - kfree(apoll); - return false; - } - spin_unlock_irq(&ctx->completion_lock); - trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask, - apoll->poll.events); - return true; -} - -static bool __io_poll_remove_one(struct io_kiocb *req, - struct io_poll_iocb *poll) -{ - bool do_complete = false; - - spin_lock(&poll->head->lock); - WRITE_ONCE(poll->canceled, true); - if (!list_empty(&poll->wait.entry)) { - list_del_init(&poll->wait.entry); - do_complete = true; - } - spin_unlock(&poll->head->lock); - hash_del(&req->hash_node); - return do_complete; -} - -static bool io_poll_remove_one(struct io_kiocb *req) -{ - bool do_complete; - - io_poll_remove_double(req); - - if (req->opcode == IORING_OP_POLL_ADD) { - do_complete = __io_poll_remove_one(req, &req->poll); - } else { - struct async_poll *apoll = req->apoll; - - /* non-poll requests have submit ref still */ - do_complete = __io_poll_remove_one(req, &apoll->poll); - if (do_complete) { - io_put_req(req); - kfree(apoll->double_poll); - kfree(apoll); - } - } - - if (do_complete) { - io_cqring_fill_event(req, -ECANCELED); - io_commit_cqring(req->ctx); - req_set_fail_links(req); - io_put_req_deferred(req, 1); - } + ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask); + if (ret || ipt.error) + return ret ? IO_APOLL_READY : IO_APOLL_ABORTED;

- return do_complete; + trace_io_uring_poll_arm(ctx, req, req->opcode, req->user_data, + mask, apoll->poll.events); + return IO_APOLL_OK; }

/* * Returns true if we found and killed one or more poll requests */ static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk, - struct files_struct *files) + bool cancel_all) { struct hlist_node *tmp; struct io_kiocb *req; - int posted = 0, i; + bool found = false; + int i;

- spin_lock_irq(&ctx->completion_lock); + spin_lock(&ctx->completion_lock); for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { struct hlist_head *list;

list = &ctx->cancel_hash[i]; hlist_for_each_entry_safe(req, tmp, list, hash_node) { - if (io_match_task(req, tsk, files)) - posted += io_poll_remove_one(req); + if (io_match_task_safe(req, tsk, cancel_all)) { + hlist_del_init(&req->hash_node); + io_poll_cancel_req(req); + found = true; + } } } - spin_unlock_irq(&ctx->completion_lock); - - if (posted) - io_cqring_ev_posted(ctx); - - return posted != 0; + spin_unlock(&ctx->completion_lock); + return found; }

-static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr) +static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, __u64 sqe_addr, + bool poll_only) + __must_hold(&ctx->completion_lock) { struct hlist_head *list; struct io_kiocb *req; @@ -5385,107 +5691,161 @@ static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr) hlist_for_each_entry(req, list, hash_node) { if (sqe_addr != req->user_data) continue; - if (io_poll_remove_one(req)) - return 0; - return -EALREADY; + if (poll_only && req->opcode != IORING_OP_POLL_ADD) + continue; + return req; } - - return -ENOENT; + return NULL; }

-static int io_poll_remove_prep(struct io_kiocb *req, - const struct io_uring_sqe *sqe) +static bool io_poll_disarm(struct io_kiocb *req) + __must_hold(&ctx->completion_lock) { - if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) - return -EINVAL; - if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index || - sqe->poll_events) - return -EINVAL; - - req->poll.addr = READ_ONCE(sqe->addr); - return 0; + if (!io_poll_get_ownership(req)) + return false; + io_poll_remove_entries(req); + hash_del(&req->hash_node); + return true; }

-/* - * Find a running poll command that matches one specified in sqe->addr, - * and remove it if found. - */ -static int io_poll_remove(struct io_kiocb *req) +static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr, + bool poll_only) + __must_hold(&ctx->completion_lock) { - struct io_ring_ctx *ctx = req->ctx; - u64 addr; - int ret; + struct io_kiocb *req = io_poll_find(ctx, sqe_addr, poll_only);

- addr = req->poll.addr; - spin_lock_irq(&ctx->completion_lock); - ret = io_poll_cancel(ctx, addr); - spin_unlock_irq(&ctx->completion_lock); - - if (ret < 0) - req_set_fail_links(req); - io_req_complete(req, ret); + if (!req) + return -ENOENT; + io_poll_cancel_req(req); return 0; }

-static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, - void *key) +static __poll_t io_poll_parse_events(const struct io_uring_sqe *sqe, + unsigned int flags) { - struct io_kiocb *req = wait->private; - struct io_poll_iocb *poll = &req->poll; + u32 events;

- return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func); + events = READ_ONCE(sqe->poll32_events); +#ifdef __BIG_ENDIAN + events = swahw32(events); +#endif + if (!(flags & IORING_POLL_ADD_MULTI)) + events |= EPOLLONESHOT; + return demangle_poll(events) | (events & (EPOLLEXCLUSIVE|EPOLLONESHOT)); }

-static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, - struct poll_table_struct *p) +static int io_poll_update_prep(struct io_kiocb *req, + const struct io_uring_sqe *sqe) { - struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); + struct io_poll_update *upd = &req->poll_update; + u32 flags; + + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in) + return -EINVAL; + flags = READ_ONCE(sqe->len); + if (flags & ~(IORING_POLL_UPDATE_EVENTS | IORING_POLL_UPDATE_USER_DATA | + IORING_POLL_ADD_MULTI)) + return -EINVAL; + /* meaningless without update */ + if (flags == IORING_POLL_ADD_MULTI) + return -EINVAL; + + upd->old_user_data = READ_ONCE(sqe->addr); + upd->update_events = flags & IORING_POLL_UPDATE_EVENTS; + upd->update_user_data = flags & IORING_POLL_UPDATE_USER_DATA; + + upd->new_user_data = READ_ONCE(sqe->off); + if (!upd->update_user_data && upd->new_user_data) + return -EINVAL; + if (upd->update_events) + upd->events = io_poll_parse_events(sqe, flags); + else if (sqe->poll32_events) + return -EINVAL;

- __io_queue_proc(&pt->req->poll, pt, head, (struct io_poll_iocb **) &pt->req->async_data); + return 0; }

static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_poll_iocb *poll = &req->poll; - u32 events; + u32 flags;

if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; - if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index) + if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->addr) + return -EINVAL; + flags = READ_ONCE(sqe->len); + if (flags & ~IORING_POLL_ADD_MULTI) return -EINVAL;

- events = READ_ONCE(sqe->poll32_events); -#ifdef __BIG_ENDIAN - events = swahw32(events); -#endif - poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP | - (events & EPOLLEXCLUSIVE); + io_req_set_refcount(req); + poll->events = io_poll_parse_events(sqe, flags); return 0; }

-static int io_poll_add(struct io_kiocb *req) +static int io_poll_add(struct io_kiocb *req, unsigned int issue_flags) { struct io_poll_iocb *poll = &req->poll; - struct io_ring_ctx *ctx = req->ctx; struct io_poll_table ipt; - __poll_t mask; + int ret;

ipt.pt._qproc = io_poll_queue_proc;

- mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events, - io_poll_wake); + ret = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events); + if (!ret && ipt.error) + req_set_fail(req); + ret = ret ?: ipt.error; + if (ret) + __io_req_complete(req, issue_flags, ret, 0); + return 0; +}

- if (mask) { /* no async, we'd stolen it */ - ipt.error = 0; - io_poll_complete(req, mask, 0); +static int io_poll_update(struct io_kiocb *req, unsigned int issue_flags) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_kiocb *preq; + int ret2, ret = 0; + + spin_lock(&ctx->completion_lock); + preq = io_poll_find(ctx, req->poll_update.old_user_data, true); + if (!preq || !io_poll_disarm(preq)) { + spin_unlock(&ctx->completion_lock); + ret = preq ? -EALREADY : -ENOENT; + goto out; } - spin_unlock_irq(&ctx->completion_lock); + spin_unlock(&ctx->completion_lock);

- if (mask) { - io_cqring_ev_posted(ctx); - io_put_req(req); + if (req->poll_update.update_events || req->poll_update.update_user_data) { + /* only mask one event flags, keep behavior flags */ + if (req->poll_update.update_events) { + preq->poll.events &= ~0xffff; + preq->poll.events |= req->poll_update.events & 0xffff; + preq->poll.events |= IO_POLL_UNMASK; + } + if (req->poll_update.update_user_data) + preq->user_data = req->poll_update.new_user_data; + + ret2 = io_poll_add(preq, issue_flags); + /* successfully updated, don't complete poll request */ + if (!ret2) + goto out; } - return ipt.error; + req_set_fail(preq); + io_req_complete(preq, -ECANCELED); +out: + if (ret < 0) + req_set_fail(req); + /* complete update request, we're done with it */ + io_req_complete(req, ret); + return 0; +} + +static void io_req_task_timeout(struct io_kiocb *req, bool *locked) +{ + req_set_fail(req); + io_req_complete_post(req, -ETIME, 0); }

static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) @@ -5496,88 +5856,182 @@ static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) struct io_ring_ctx *ctx = req->ctx; unsigned long flags;

- spin_lock_irqsave(&ctx->completion_lock, flags); + spin_lock_irqsave(&ctx->timeout_lock, flags); list_del_init(&req->timeout.list); atomic_set(&req->ctx->cq_timeouts, atomic_read(&req->ctx->cq_timeouts) + 1); + spin_unlock_irqrestore(&ctx->timeout_lock, flags);

- io_cqring_fill_event(req, -ETIME); - io_commit_cqring(ctx); - spin_unlock_irqrestore(&ctx->completion_lock, flags); - - io_cqring_ev_posted(ctx); - req_set_fail_links(req); - io_put_req(req); + req->io_task_work.func = io_req_task_timeout; + io_req_task_work_add(req); return HRTIMER_NORESTART; }

-static int __io_timeout_cancel(struct io_kiocb *req) +static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx, + __u64 user_data) + __must_hold(&ctx->timeout_lock) { - struct io_timeout_data *io = req->async_data; - int ret; + struct io_timeout_data *io; + struct io_kiocb *req; + bool found = false;

- ret = hrtimer_try_to_cancel(&io->timer); - if (ret == -1) - return -EALREADY; + list_for_each_entry(req, &ctx->timeout_list, timeout.list) { + found = user_data == req->user_data; + if (found) + break; + } + if (!found) + return ERR_PTR(-ENOENT); + + io = req->async_data; + if (hrtimer_try_to_cancel(&io->timer) == -1) + return ERR_PTR(-EALREADY); list_del_init(&req->timeout.list); + return req; +} + +static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data) + __must_hold(&ctx->completion_lock) + __must_hold(&ctx->timeout_lock) +{ + struct io_kiocb *req = io_timeout_extract(ctx, user_data);

- req_set_fail_links(req); - io_cqring_fill_event(req, -ECANCELED); - io_put_req_deferred(req, 1); + if (IS_ERR(req)) + return PTR_ERR(req); + + req_set_fail(req); + io_fill_cqe_req(req, -ECANCELED, 0); + io_put_req_deferred(req); return 0; }

-static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data) +static clockid_t io_timeout_get_clock(struct io_timeout_data *data) +{ + switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) { + case IORING_TIMEOUT_BOOTTIME: + return CLOCK_BOOTTIME; + case IORING_TIMEOUT_REALTIME: + return CLOCK_REALTIME; + default: + /* can't happen, vetted at prep time */ + WARN_ON_ONCE(1); + fallthrough; + case 0: + return CLOCK_MONOTONIC; + } +} + +static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data, + struct timespec64 *ts, enum hrtimer_mode mode) + __must_hold(&ctx->timeout_lock) { + struct io_timeout_data *io; struct io_kiocb *req; - int ret = -ENOENT; + bool found = false;

- list_for_each_entry(req, &ctx->timeout_list, timeout.list) { - if (user_data == req->user_data) { - ret = 0; + list_for_each_entry(req, &ctx->ltimeout_list, timeout.list) { + found = user_data == req->user_data; + if (found) break; - } } + if (!found) + return -ENOENT;

- if (ret == -ENOENT) - return ret; + io = req->async_data; + if (hrtimer_try_to_cancel(&io->timer) == -1) + return -EALREADY; + hrtimer_init(&io->timer, io_timeout_get_clock(io), mode); + io->timer.function = io_link_timeout_fn; + hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode); + return 0; +}

- return __io_timeout_cancel(req); +static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data, + struct timespec64 *ts, enum hrtimer_mode mode) + __must_hold(&ctx->timeout_lock) +{ + struct io_kiocb *req = io_timeout_extract(ctx, user_data); + struct io_timeout_data *data; + + if (IS_ERR(req)) + return PTR_ERR(req); + + req->timeout.off = 0; /* noseq */ + data = req->async_data; + list_add_tail(&req->timeout.list, &ctx->timeout_list); + hrtimer_init(&data->timer, io_timeout_get_clock(data), mode); + data->timer.function = io_timeout_fn; + hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode); + return 0; }

static int io_timeout_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { + struct io_timeout_rem *tr = &req->timeout_rem; + if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) return -EINVAL; - if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->timeout_flags || - sqe->splice_fd_in) + if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->splice_fd_in) + return -EINVAL; + + tr->ltimeout = false; + tr->addr = READ_ONCE(sqe->addr); + tr->flags = READ_ONCE(sqe->timeout_flags); + if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) { + if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1) + return -EINVAL; + if (tr->flags & IORING_LINK_TIMEOUT_UPDATE) + tr->ltimeout = true; + if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS)) + return -EINVAL; + if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2))) + return -EFAULT; + } else if (tr->flags) { + /* timeout removal doesn't support flags */ return -EINVAL; + }

- req->timeout_rem.addr = READ_ONCE(sqe->addr); return 0; }

+static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags) +{ + return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS + : HRTIMER_MODE_REL; +} + /* * Remove or update an existing timeout command */ -static int io_timeout_remove(struct io_kiocb *req) +static int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags) { + struct io_timeout_rem *tr = &req->timeout_rem; struct io_ring_ctx *ctx = req->ctx; int ret;

- spin_lock_irq(&ctx->completion_lock); - ret = io_timeout_cancel(ctx, req->timeout_rem.addr); + if (!(req->timeout_rem.flags & IORING_TIMEOUT_UPDATE)) { + spin_lock(&ctx->completion_lock); + spin_lock_irq(&ctx->timeout_lock); + ret = io_timeout_cancel(ctx, tr->addr); + spin_unlock_irq(&ctx->timeout_lock); + spin_unlock(&ctx->completion_lock); + } else { + enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags); + + spin_lock_irq(&ctx->timeout_lock); + if (tr->ltimeout) + ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode); + else + ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode); + spin_unlock_irq(&ctx->timeout_lock); + }

- io_cqring_fill_event(req, ret); - io_commit_cqring(ctx); - spin_unlock_irq(&ctx->completion_lock); - io_cqring_ev_posted(ctx); if (ret < 0) - req_set_fail_links(req); - io_put_req(req); + req_set_fail(req); + io_req_complete_post(req, ret, 0); return 0; }

@@ -5596,38 +6050,52 @@ static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, if (off && is_timeout_link) return -EINVAL; flags = READ_ONCE(sqe->timeout_flags); - if (flags & ~IORING_TIMEOUT_ABS) + if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK)) + return -EINVAL; + /* more than one clock specified is invalid, obviously */ + if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1) return -EINVAL;

+ INIT_LIST_HEAD(&req->timeout.list); req->timeout.off = off; + if (unlikely(off && !req->ctx->off_timeout_used)) + req->ctx->off_timeout_used = true;

if (!req->async_data && io_alloc_async_data(req)) return -ENOMEM;

data = req->async_data; data->req = req; + data->flags = flags;

if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr))) return -EFAULT;

- if (flags & IORING_TIMEOUT_ABS) - data->mode = HRTIMER_MODE_ABS; - else - data->mode = HRTIMER_MODE_REL; - INIT_LIST_HEAD(&req->timeout.list); - hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode); + data->mode = io_translate_timeout_mode(flags); + hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode); + + if (is_timeout_link) { + struct io_submit_link *link = &req->ctx->submit_state.link; + + if (!link->head) + return -EINVAL; + if (link->last->opcode == IORING_OP_LINK_TIMEOUT) + return -EINVAL; + req->timeout.head = link->last; + link->last->flags |= REQ_F_ARM_LTIMEOUT; + } return 0; }

-static int io_timeout(struct io_kiocb *req) +static int io_timeout(struct io_kiocb *req, unsigned int issue_flags) { struct io_ring_ctx *ctx = req->ctx; struct io_timeout_data *data = req->async_data; struct list_head *entry; u32 tail, off = req->timeout.off;

- spin_lock_irq(&ctx->completion_lock); + spin_lock_irq(&ctx->timeout_lock);

/* * sqe->off holds how many events that need to occur for this @@ -5666,23 +6134,34 @@ static int io_timeout(struct io_kiocb *req) list_add(&req->timeout.list, entry); data->timer.function = io_timeout_fn; hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode); - spin_unlock_irq(&ctx->completion_lock); + spin_unlock_irq(&ctx->timeout_lock); return 0; }

+struct io_cancel_data { + struct io_ring_ctx *ctx; + u64 user_data; +}; + static bool io_cancel_cb(struct io_wq_work *work, void *data) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct io_cancel_data *cd = data;

- return req->user_data == (unsigned long) data; + return req->ctx == cd->ctx && req->user_data == cd->user_data; }

-static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr) +static int io_async_cancel_one(struct io_uring_task *tctx, u64 user_data, + struct io_ring_ctx *ctx) { + struct io_cancel_data data = { .ctx = ctx, .user_data = user_data, }; enum io_wq_cancel cancel_ret; int ret = 0;

- cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr, false); + if (!tctx || !tctx->io_wq) + return -ENOENT; + + cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, &data, false); switch (cancel_ret) { case IO_WQ_CANCEL_OK: ret = 0; @@ -5698,35 +6177,27 @@ static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr) return ret; }

-static void io_async_find_and_cancel(struct io_ring_ctx *ctx, - struct io_kiocb *req, __u64 sqe_addr, - int success_ret) +static int io_try_cancel_userdata(struct io_kiocb *req, u64 sqe_addr) { - unsigned long flags; + struct io_ring_ctx *ctx = req->ctx; int ret;

- ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr); - if (ret != -ENOENT) { - spin_lock_irqsave(&ctx->completion_lock, flags); - goto done; - } + WARN_ON_ONCE(!io_wq_current_is_worker() && req->task != current);

- spin_lock_irqsave(&ctx->completion_lock, flags); - ret = io_timeout_cancel(ctx, sqe_addr); + ret = io_async_cancel_one(req->task->io_uring, sqe_addr, ctx); if (ret != -ENOENT) - goto done; - ret = io_poll_cancel(ctx, sqe_addr); -done: - if (!ret) - ret = success_ret; - io_cqring_fill_event(req, ret); - io_commit_cqring(ctx); - spin_unlock_irqrestore(&ctx->completion_lock, flags); - io_cqring_ev_posted(ctx); + return ret;

- if (ret < 0) - req_set_fail_links(req); - io_put_req(req); + spin_lock(&ctx->completion_lock); + spin_lock_irq(&ctx->timeout_lock); + ret = io_timeout_cancel(ctx, sqe_addr); + spin_unlock_irq(&ctx->timeout_lock); + if (ret != -ENOENT) + goto out; + ret = io_poll_cancel(ctx, sqe_addr, false); +out: + spin_unlock(&ctx->completion_lock); + return ret; }

static int io_async_cancel_prep(struct io_kiocb *req, @@ -5744,52 +6215,72 @@ static int io_async_cancel_prep(struct io_kiocb *req, return 0; }

-static int io_async_cancel(struct io_kiocb *req) +static int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags) { struct io_ring_ctx *ctx = req->ctx; + u64 sqe_addr = req->cancel.addr; + struct io_tctx_node *node; + int ret; + + ret = io_try_cancel_userdata(req, sqe_addr); + if (ret != -ENOENT) + goto done; + + /* slow path, try all io-wq's */ + io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); + ret = -ENOENT; + list_for_each_entry(node, &ctx->tctx_list, ctx_node) { + struct io_uring_task *tctx = node->task->io_uring;

- io_async_find_and_cancel(ctx, req, req->cancel.addr, 0); + ret = io_async_cancel_one(tctx, req->cancel.addr, ctx); + if (ret != -ENOENT) + break; + } + io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); +done: + if (ret < 0) + req_set_fail(req); + io_req_complete_post(req, ret, 0); return 0; }

-static int io_files_update_prep(struct io_kiocb *req, +static int io_rsrc_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - if (unlikely(req->ctx->flags & IORING_SETUP_SQPOLL)) - return -EINVAL; if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) return -EINVAL; - if (sqe->ioprio || sqe->rw_flags) + if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in) return -EINVAL;

- req->files_update.offset = READ_ONCE(sqe->off); - req->files_update.nr_args = READ_ONCE(sqe->len); - if (!req->files_update.nr_args) + req->rsrc_update.offset = READ_ONCE(sqe->off); + req->rsrc_update.nr_args = READ_ONCE(sqe->len); + if (!req->rsrc_update.nr_args) return -EINVAL; - req->files_update.arg = READ_ONCE(sqe->addr); + req->rsrc_update.arg = READ_ONCE(sqe->addr); return 0; }

-static int io_files_update(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_files_update(struct io_kiocb *req, unsigned int issue_flags) { struct io_ring_ctx *ctx = req->ctx; - struct io_uring_files_update up; + struct io_uring_rsrc_update2 up; int ret;

- if (force_nonblock) - return -EAGAIN; - - up.offset = req->files_update.offset; - up.fds = req->files_update.arg; + up.offset = req->rsrc_update.offset; + up.data = req->rsrc_update.arg; + up.nr = 0; + up.tags = 0; + up.resv = 0; + up.resv2 = 0;

- mutex_lock(&ctx->uring_lock); - ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args); - mutex_unlock(&ctx->uring_lock); + io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); + ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE, + &up, req->rsrc_update.nr_args); + io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));

if (ret < 0) - req_set_fail_links(req); - __io_req_complete(req, ret, 0, cs); + req_set_fail(req); + __io_req_complete(req, issue_flags, ret, 0); return 0; }

@@ -5809,11 +6300,11 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) case IORING_OP_POLL_ADD: return io_poll_add_prep(req, sqe); case IORING_OP_POLL_REMOVE: - return io_poll_remove_prep(req, sqe); + return io_poll_update_prep(req, sqe); case IORING_OP_FSYNC: - return io_prep_fsync(req, sqe); + return io_fsync_prep(req, sqe); case IORING_OP_SYNC_FILE_RANGE: - return io_prep_sfr(req, sqe); + return io_sfr_prep(req, sqe); case IORING_OP_SENDMSG: case IORING_OP_SEND: return io_sendmsg_prep(req, sqe); @@ -5839,7 +6330,7 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) case IORING_OP_CLOSE: return io_close_prep(req, sqe); case IORING_OP_FILES_UPDATE: - return io_files_update_prep(req, sqe); + return io_rsrc_update_prep(req, sqe); case IORING_OP_STATX: return io_statx_prep(req, sqe); case IORING_OP_FADVISE: @@ -5858,100 +6349,131 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return io_remove_buffers_prep(req, sqe); case IORING_OP_TEE: return io_tee_prep(req, sqe); + case IORING_OP_SHUTDOWN: + return io_shutdown_prep(req, sqe); + case IORING_OP_RENAMEAT: + return io_renameat_prep(req, sqe); + case IORING_OP_UNLINKAT: + return io_unlinkat_prep(req, sqe); }

printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", req->opcode); - return-EINVAL; + return -EINVAL; }

-static int io_req_defer_prep(struct io_kiocb *req, - const struct io_uring_sqe *sqe) +static int io_req_prep_async(struct io_kiocb *req) { - if (!sqe) + if (!io_op_defs[req->opcode].needs_async_setup) return 0; + if (WARN_ON_ONCE(req->async_data)) + return -EFAULT; if (io_alloc_async_data(req)) return -EAGAIN; - return io_req_prep(req, sqe); + + switch (req->opcode) { + case IORING_OP_READV: + return io_rw_prep_async(req, READ); + case IORING_OP_WRITEV: + return io_rw_prep_async(req, WRITE); + case IORING_OP_SENDMSG: + return io_sendmsg_prep_async(req); + case IORING_OP_RECVMSG: + return io_recvmsg_prep_async(req); + case IORING_OP_CONNECT: + return io_connect_prep_async(req); + } + printk_once(KERN_WARNING "io_uring: prep_async() bad opcode %d\n", + req->opcode); + return -EFAULT; }

static u32 io_get_sequence(struct io_kiocb *req) { - struct io_kiocb *pos; - struct io_ring_ctx *ctx = req->ctx; - u32 total_submitted, nr_reqs = 1; + u32 seq = req->ctx->cached_sq_head;

- if (req->flags & REQ_F_LINK_HEAD) - list_for_each_entry(pos, &req->link_list, link_list) - nr_reqs++; - - total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped; - return total_submitted - nr_reqs; + /* need original cached_sq_head, but it was increased for each req */ + io_for_each_link(req, req) + seq--; + return seq; }

-static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static bool io_drain_req(struct io_kiocb *req) { + struct io_kiocb *pos; struct io_ring_ctx *ctx = req->ctx; struct io_defer_entry *de; int ret; u32 seq;

+ if (req->flags & REQ_F_FAIL) { + io_req_complete_fail_submit(req); + return true; + } + + /* + * If we need to drain a request in the middle of a link, drain the + * head request and the next request/link after the current link. + * Considering sequential execution of links, IOSQE_IO_DRAIN will be + * maintained for every request of our link. + */ + if (ctx->drain_next) { + req->flags |= REQ_F_IO_DRAIN; + ctx->drain_next = false; + } + /* not interested in head, start from the first linked */ + io_for_each_link(pos, req->link) { + if (pos->flags & REQ_F_IO_DRAIN) { + ctx->drain_next = true; + req->flags |= REQ_F_IO_DRAIN; + break; + } + } + /* Still need defer if there is pending req in defer list. */ + spin_lock(&ctx->completion_lock); if (likely(list_empty_careful(&ctx->defer_list) && - !(req->flags & REQ_F_IO_DRAIN))) - return 0; + !(req->flags & REQ_F_IO_DRAIN))) { + spin_unlock(&ctx->completion_lock); + ctx->drain_active = false; + return false; + } + spin_unlock(&ctx->completion_lock);

seq = io_get_sequence(req); /* Still a chance to pass the sequence check */ if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) - return 0; + return false;

- if (!req->async_data) { - ret = io_req_defer_prep(req, sqe); - if (ret) - return ret; - } + ret = io_req_prep_async(req); + if (ret) + goto fail; io_prep_async_link(req); de = kmalloc(sizeof(*de), GFP_KERNEL); - if (!de) - return -ENOMEM; + if (!de) { + ret = -ENOMEM; +fail: + io_req_complete_failed(req, ret); + return true; + }

- spin_lock_irq(&ctx->completion_lock); + spin_lock(&ctx->completion_lock); if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) { - spin_unlock_irq(&ctx->completion_lock); + spin_unlock(&ctx->completion_lock); kfree(de); - io_queue_async_work(req); - return -EIOCBQUEUED; + io_queue_async_work(req, NULL); + return true; }

trace_io_uring_defer(ctx, req, req->user_data); de->req = req; de->seq = seq; list_add_tail(&de->list, &ctx->defer_list); - spin_unlock_irq(&ctx->completion_lock); - return -EIOCBQUEUED; -} - -static void io_req_drop_files(struct io_kiocb *req) -{ - struct io_ring_ctx *ctx = req->ctx; - struct io_uring_task *tctx = req->task->io_uring; - unsigned long flags; - - if (req->work.flags & IO_WQ_WORK_FILES) { - put_files_struct(req->work.identity->files); - put_nsproxy(req->work.identity->nsproxy); - } - spin_lock_irqsave(&ctx->inflight_lock, flags); - list_del(&req->inflight_entry); - spin_unlock_irqrestore(&ctx->inflight_lock, flags); - req->flags &= ~REQ_F_INFLIGHT; - req->work.flags &= ~IO_WQ_WORK_FILES; - if (atomic_read(&tctx->in_idle)) - wake_up(&tctx->wait); + spin_unlock(&ctx->completion_lock); + return true; }

-static void __io_clean_op(struct io_kiocb *req) +static void io_clean_op(struct io_kiocb *req) { if (req->flags & REQ_F_BUFFER_SELECTED) { switch (req->opcode) { @@ -5965,7 +6487,6 @@ static void __io_clean_op(struct io_kiocb *req) kfree(req->sr_msg.kbuf); break; } - req->flags &= ~REQ_F_BUFFER_SELECTED; }

if (req->flags & REQ_F_NEED_CLEANUP) { @@ -5977,508 +6498,589 @@ static void __io_clean_op(struct io_kiocb *req) case IORING_OP_WRITE_FIXED: case IORING_OP_WRITE: { struct io_async_rw *io = req->async_data; - if (io->free_iovec) - kfree(io->free_iovec); + + kfree(io->free_iovec); break; } case IORING_OP_RECVMSG: case IORING_OP_SENDMSG: { struct io_async_msghdr *io = req->async_data; - if (io->iov != io->fast_iov) - kfree(io->iov); + + kfree(io->free_iov); break; } - case IORING_OP_SPLICE: - case IORING_OP_TEE: - io_put_file(req, req->splice.file_in, - (req->splice.flags & SPLICE_F_FD_IN_FIXED)); - break; case IORING_OP_OPENAT: case IORING_OP_OPENAT2: if (req->open.filename) putname(req->open.filename); break; + case IORING_OP_RENAMEAT: + putname(req->rename.oldpath); + putname(req->rename.newpath); + break; + case IORING_OP_UNLINKAT: + putname(req->unlink.filename); + break; } - req->flags &= ~REQ_F_NEED_CLEANUP; } + if ((req->flags & REQ_F_POLLED) && req->apoll) { + kfree(req->apoll->double_poll); + kfree(req->apoll); + req->apoll = NULL; + } + if (req->flags & REQ_F_INFLIGHT) { + struct io_uring_task *tctx = req->task->io_uring; + + atomic_dec(&tctx->inflight_tracked); + } + if (req->flags & REQ_F_CREDS) + put_cred(req->creds); + + req->flags &= ~IO_REQ_CLEAN_FLAGS; }

-static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock, - struct io_comp_state *cs) +static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) { struct io_ring_ctx *ctx = req->ctx; + const struct cred *creds = NULL; int ret;

+ if ((req->flags & REQ_F_CREDS) && req->creds != current_cred()) + creds = override_creds(req->creds); + switch (req->opcode) { case IORING_OP_NOP: - ret = io_nop(req, cs); + ret = io_nop(req, issue_flags); break; case IORING_OP_READV: case IORING_OP_READ_FIXED: case IORING_OP_READ: - ret = io_read(req, force_nonblock, cs); + ret = io_read(req, issue_flags); break; case IORING_OP_WRITEV: case IORING_OP_WRITE_FIXED: case IORING_OP_WRITE: - ret = io_write(req, force_nonblock, cs); + ret = io_write(req, issue_flags); break; case IORING_OP_FSYNC: - ret = io_fsync(req, force_nonblock); + ret = io_fsync(req, issue_flags); break; case IORING_OP_POLL_ADD: - ret = io_poll_add(req); + ret = io_poll_add(req, issue_flags); break; case IORING_OP_POLL_REMOVE: - ret = io_poll_remove(req); + ret = io_poll_update(req, issue_flags); break; case IORING_OP_SYNC_FILE_RANGE: - ret = io_sync_file_range(req, force_nonblock); + ret = io_sync_file_range(req, issue_flags); break; case IORING_OP_SENDMSG: - ret = io_sendmsg(req, force_nonblock, cs); + ret = io_sendmsg(req, issue_flags); break; case IORING_OP_SEND: - ret = io_send(req, force_nonblock, cs); + ret = io_send(req, issue_flags); break; case IORING_OP_RECVMSG: - ret = io_recvmsg(req, force_nonblock, cs); + ret = io_recvmsg(req, issue_flags); break; case IORING_OP_RECV: - ret = io_recv(req, force_nonblock, cs); + ret = io_recv(req, issue_flags); break; case IORING_OP_TIMEOUT: - ret = io_timeout(req); + ret = io_timeout(req, issue_flags); break; case IORING_OP_TIMEOUT_REMOVE: - ret = io_timeout_remove(req); + ret = io_timeout_remove(req, issue_flags); break; case IORING_OP_ACCEPT: - ret = io_accept(req, force_nonblock, cs); + ret = io_accept(req, issue_flags); break; case IORING_OP_CONNECT: - ret = io_connect(req, force_nonblock, cs); + ret = io_connect(req, issue_flags); break; case IORING_OP_ASYNC_CANCEL: - ret = io_async_cancel(req); + ret = io_async_cancel(req, issue_flags); break; case IORING_OP_FALLOCATE: - ret = io_fallocate(req, force_nonblock); + ret = io_fallocate(req, issue_flags); break; case IORING_OP_OPENAT: - ret = io_openat(req, force_nonblock); + ret = io_openat(req, issue_flags); break; case IORING_OP_CLOSE: - ret = io_close(req, force_nonblock, cs); + ret = io_close(req, issue_flags); break; case IORING_OP_FILES_UPDATE: - ret = io_files_update(req, force_nonblock, cs); + ret = io_files_update(req, issue_flags); break; case IORING_OP_STATX: - ret = io_statx(req, force_nonblock); + ret = io_statx(req, issue_flags); break; case IORING_OP_FADVISE: - ret = io_fadvise(req, force_nonblock); + ret = io_fadvise(req, issue_flags); break; case IORING_OP_MADVISE: - ret = io_madvise(req, force_nonblock); + ret = io_madvise(req, issue_flags); break; case IORING_OP_OPENAT2: - ret = io_openat2(req, force_nonblock); + ret = io_openat2(req, issue_flags); break; case IORING_OP_EPOLL_CTL: - ret = io_epoll_ctl(req, force_nonblock, cs); + ret = io_epoll_ctl(req, issue_flags); break; case IORING_OP_SPLICE: - ret = io_splice(req, force_nonblock); + ret = io_splice(req, issue_flags); break; case IORING_OP_PROVIDE_BUFFERS: - ret = io_provide_buffers(req, force_nonblock, cs); + ret = io_provide_buffers(req, issue_flags); break; case IORING_OP_REMOVE_BUFFERS: - ret = io_remove_buffers(req, force_nonblock, cs); + ret = io_remove_buffers(req, issue_flags); break; case IORING_OP_TEE: - ret = io_tee(req, force_nonblock); + ret = io_tee(req, issue_flags); + break; + case IORING_OP_SHUTDOWN: + ret = io_shutdown(req, issue_flags); + break; + case IORING_OP_RENAMEAT: + ret = io_renameat(req, issue_flags); + break; + case IORING_OP_UNLINKAT: + ret = io_unlinkat(req, issue_flags); break; default: ret = -EINVAL; break; }

+ if (creds) + revert_creds(creds); if (ret) return ret; - /* If the op doesn't have a file, we're not polling for it */ - if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) { - const bool in_async = io_wq_current_is_worker(); - - /* workqueue context doesn't hold uring_lock, grab it now */ - if (in_async) - mutex_lock(&ctx->uring_lock); - + if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) io_iopoll_req_issued(req);

- if (in_async) - mutex_unlock(&ctx->uring_lock); - } - return 0; }

-static struct io_wq_work *io_wq_submit_work(struct io_wq_work *work) +static struct io_wq_work *io_wq_free_work(struct io_wq_work *work) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + + req = io_put_req_find_next(req); + return req ? &req->work : NULL; +} + +static void io_wq_submit_work(struct io_wq_work *work) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); struct io_kiocb *timeout; int ret = 0;

+ /* one will be dropped by ->io_free_work() after returning to io-wq */ + if (!(req->flags & REQ_F_REFCOUNT)) + __io_req_set_refcount(req, 2); + else + req_ref_get(req); + timeout = io_prep_linked_timeout(req); if (timeout) io_queue_linked_timeout(timeout);

- /* if NO_CANCEL is set, we must still run the work */ - if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) == - IO_WQ_WORK_CANCEL) { + /* either cancelled or io-wq is dying, so don't touch tctx->iowq */ + if (work->flags & IO_WQ_WORK_CANCEL) ret = -ECANCELED; - }

if (!ret) { do { - ret = io_issue_sqe(req, false, NULL); + ret = io_issue_sqe(req, 0); /* * We can get EAGAIN for polled IO even though we're * forcing a sync submission from here, since we can't * wait for request slots on the block side. */ - if (ret != -EAGAIN) + if (ret != -EAGAIN || !(req->ctx->flags & IORING_SETUP_IOPOLL)) break; cond_resched(); } while (1); }

- if (ret) { - struct io_ring_ctx *lock_ctx = NULL; - - if (req->ctx->flags & IORING_SETUP_IOPOLL) - lock_ctx = req->ctx; - - /* - * io_iopoll_complete() does not hold completion_lock to - * complete polled io, so here for polled io, we can not call - * io_req_complete() directly, otherwise there maybe concurrent - * access to cqring, defer_list, etc, which is not safe. Given - * that io_iopoll_complete() is always called under uring_lock, - * so here for polled io, we also get uring_lock to complete - * it. - */ - if (lock_ctx) - mutex_lock(&lock_ctx->uring_lock); - - req_set_fail_links(req); - io_req_complete(req, ret); - - if (lock_ctx) - mutex_unlock(&lock_ctx->uring_lock); - } + /* avoid locking problems by failing it from a clean context */ + if (ret) + io_req_task_queue_fail(req, ret); +}

- return io_steal_work(req); +static inline struct io_fixed_file *io_fixed_file_slot(struct io_file_table *table, + unsigned i) +{ + return &table->files[i]; }

static inline struct file *io_file_from_index(struct io_ring_ctx *ctx, int index) { - struct fixed_file_table *table; + struct io_fixed_file *slot = io_fixed_file_slot(&ctx->file_table, index);

- table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT]; - return table->files[index & IORING_FILE_TABLE_MASK]; + return (struct file *) (slot->file_ptr & FFS_MASK); }

-static struct file *io_file_get(struct io_submit_state *state, - struct io_kiocb *req, int fd, bool fixed) +static void io_fixed_file_set(struct io_fixed_file *file_slot, struct file *file) +{ + unsigned long file_ptr = (unsigned long) file; + + if (__io_file_supports_nowait(file, READ)) + file_ptr |= FFS_ASYNC_READ; + if (__io_file_supports_nowait(file, WRITE)) + file_ptr |= FFS_ASYNC_WRITE; + if (S_ISREG(file_inode(file)->i_mode)) + file_ptr |= FFS_ISREG; + file_slot->file_ptr = file_ptr; +} + +static inline struct file *io_file_get_fixed(struct io_ring_ctx *ctx, + struct io_kiocb *req, int fd) { - struct io_ring_ctx *ctx = req->ctx; struct file *file; + unsigned long file_ptr;

- if (fixed) { - if (unlikely((unsigned int)fd >= ctx->nr_user_files)) - return NULL; - fd = array_index_nospec(fd, ctx->nr_user_files); - file = io_file_from_index(ctx, fd); - if (file) { - req->fixed_file_refs = &ctx->file_data->node->refs; - percpu_ref_get(req->fixed_file_refs); - } - } else { - trace_io_uring_file_get(ctx, fd); - file = __io_file_get(state, fd); - } + if (unlikely((unsigned int)fd >= ctx->nr_user_files)) + return NULL; + fd = array_index_nospec(fd, ctx->nr_user_files); + file_ptr = io_fixed_file_slot(&ctx->file_table, fd)->file_ptr; + file = (struct file *) (file_ptr & FFS_MASK); + file_ptr &= ~FFS_MASK; + /* mask in overlapping REQ_F and FFS bits */ + req->flags |= (file_ptr << REQ_F_NOWAIT_READ_BIT); + io_req_set_rsrc_node(req); + return file; +}

- if (file && file->f_op == &io_uring_fops && - !(req->flags & REQ_F_INFLIGHT)) { - io_req_init_async(req); - req->flags |= REQ_F_INFLIGHT; +static struct file *io_file_get_normal(struct io_ring_ctx *ctx, + struct io_kiocb *req, int fd) +{ + struct file *file = fget(fd);

- spin_lock_irq(&ctx->inflight_lock); - list_add(&req->inflight_entry, &ctx->inflight_list); - spin_unlock_irq(&ctx->inflight_lock); - } + trace_io_uring_file_get(ctx, fd);

+ /* we don't allow fixed io_uring files */ + if (file && unlikely(file->f_op == &io_uring_fops)) + io_req_track_inflight(req); return file; }

-static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req, - int fd) +static inline struct file *io_file_get(struct io_ring_ctx *ctx, + struct io_kiocb *req, int fd, bool fixed) { - bool fixed; + if (fixed) + return io_file_get_fixed(ctx, req, fd); + else + return io_file_get_normal(ctx, req, fd); +}

- fixed = (req->flags & REQ_F_FIXED_FILE) != 0; - if (unlikely(!fixed && io_async_submit(req->ctx))) - return -EBADF; +static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked) +{ + struct io_kiocb *prev = req->timeout.prev; + int ret = -ENOENT;

- req->file = io_file_get(state, req, fd, fixed); - if (req->file || io_op_defs[req->opcode].needs_file_no_error) - return 0; - return -EBADF; + if (prev) { + if (!(req->task->flags & PF_EXITING)) + ret = io_try_cancel_userdata(req, prev->user_data); + io_req_complete_post(req, ret ?: -ETIME, 0); + io_put_req(prev); + } else { + io_req_complete_post(req, -ETIME, 0); + } }

static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) { struct io_timeout_data *data = container_of(timer, struct io_timeout_data, timer); - struct io_kiocb *req = data->req; + struct io_kiocb *prev, *req = data->req; struct io_ring_ctx *ctx = req->ctx; - struct io_kiocb *prev = NULL; unsigned long flags;

- spin_lock_irqsave(&ctx->completion_lock, flags); + spin_lock_irqsave(&ctx->timeout_lock, flags); + prev = req->timeout.head; + req->timeout.head = NULL;

/* * We don't expect the list to be empty, that will only happen if we * race with the completion of the linked work. */ - if (!list_empty(&req->link_list)) { - prev = list_entry(req->link_list.prev, struct io_kiocb, - link_list); - list_del_init(&req->link_list); - if (!refcount_inc_not_zero(&prev->refs)) + if (prev) { + io_remove_next_linked(prev); + if (!req_ref_inc_not_zero(prev)) prev = NULL; } - list_del(&req->timeout.list); - spin_unlock_irqrestore(&ctx->completion_lock, flags); + req->timeout.prev = prev; + spin_unlock_irqrestore(&ctx->timeout_lock, flags);

- if (prev) { - io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME); - io_put_req_deferred(prev, 1); - } else { - io_cqring_add_event(req, -ETIME, 0); - io_put_req_deferred(req, 1); - } + req->io_task_work.func = io_req_task_link_timeout; + io_req_task_work_add(req); return HRTIMER_NORESTART; }

-static void __io_queue_linked_timeout(struct io_kiocb *req) +static void io_queue_linked_timeout(struct io_kiocb *req) { + struct io_ring_ctx *ctx = req->ctx; + + spin_lock_irq(&ctx->timeout_lock); /* - * If the list is now empty, then our linked request finished before - * we got a chance to setup the timer + * If the back reference is NULL, then our linked request finished + * before we got a chance to setup the timer */ - if (!list_empty(&req->link_list)) { + if (req->timeout.head) { struct io_timeout_data *data = req->async_data;

data->timer.function = io_link_timeout_fn; hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode); + list_add_tail(&req->timeout.list, &ctx->ltimeout_list); } -} - -static void io_queue_linked_timeout(struct io_kiocb *req) -{ - struct io_ring_ctx *ctx = req->ctx; - - spin_lock_irq(&ctx->completion_lock); - __io_queue_linked_timeout(req); - spin_unlock_irq(&ctx->completion_lock); - + spin_unlock_irq(&ctx->timeout_lock); /* drop submission reference */ io_put_req(req); }

-static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) -{ - struct io_kiocb *nxt; - - if (!(req->flags & REQ_F_LINK_HEAD)) - return NULL; - if (req->flags & REQ_F_LINK_TIMEOUT) - return NULL; - - nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, - link_list); - if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT) - return NULL; - - nxt->flags |= REQ_F_LTIMEOUT_ACTIVE; - req->flags |= REQ_F_LINK_TIMEOUT; - return nxt; -} - -static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs) +static void __io_queue_sqe(struct io_kiocb *req) + __must_hold(&req->ctx->uring_lock) { struct io_kiocb *linked_timeout; - const struct cred *old_creds = NULL; int ret;

-again: - linked_timeout = io_prep_linked_timeout(req); - - if ((req->flags & REQ_F_WORK_INITIALIZED) && - (req->work.flags & IO_WQ_WORK_CREDS) && - req->work.identity->creds != current_cred()) { - if (old_creds) - revert_creds(old_creds); - if (old_creds == req->work.identity->creds) - old_creds = NULL; /* restored original creds */ - else - old_creds = override_creds(req->work.identity->creds); - } - - ret = io_issue_sqe(req, true, cs); +issue_sqe: + ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER);

/* * We async punt it if the file wasn't marked NOWAIT, or if the file * doesn't support non-blocking read/write attempts */ - if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) { - if (!io_arm_poll_handler(req)) { + if (likely(!ret)) { + if (req->flags & REQ_F_COMPLETE_INLINE) { + struct io_ring_ctx *ctx = req->ctx; + struct io_submit_state *state = &ctx->submit_state; + + state->compl_reqs[state->compl_nr++] = req; + if (state->compl_nr == ARRAY_SIZE(state->compl_reqs)) + io_submit_flush_completions(ctx); + return; + } + + linked_timeout = io_prep_linked_timeout(req); + if (linked_timeout) + io_queue_linked_timeout(linked_timeout); + } else if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) { + linked_timeout = io_prep_linked_timeout(req); + + switch (io_arm_poll_handler(req)) { + case IO_APOLL_READY: + if (linked_timeout) + io_queue_linked_timeout(linked_timeout); + goto issue_sqe; + case IO_APOLL_ABORTED: /* * Queued up for async execution, worker will release * submit reference when the iocb is actually submitted. */ - io_queue_async_work(req); + io_queue_async_work(req, NULL); + break; }

if (linked_timeout) io_queue_linked_timeout(linked_timeout); - } else if (likely(!ret)) { - /* drop submission reference */ - req = io_put_req_find_next(req); - if (linked_timeout) - io_queue_linked_timeout(linked_timeout); - - if (req) { - if (!(req->flags & REQ_F_FORCE_ASYNC)) - goto again; - io_queue_async_work(req); - } } else { - /* un-prep timeout, so it'll be killed as any other linked */ - req->flags &= ~REQ_F_LINK_TIMEOUT; - req_set_fail_links(req); - io_put_req(req); - io_req_complete(req, ret); + io_req_complete_failed(req, ret); } - - if (old_creds) - revert_creds(old_creds); }

-static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, - struct io_comp_state *cs) +static inline void io_queue_sqe(struct io_kiocb *req) + __must_hold(&req->ctx->uring_lock) { - int ret; + if (unlikely(req->ctx->drain_active) && io_drain_req(req)) + return;

- ret = io_req_defer(req, sqe); - if (ret) { - if (ret != -EIOCBQUEUED) { -fail_req: - req_set_fail_links(req); - io_put_req(req); - io_req_complete(req, ret); - } - } else if (req->flags & REQ_F_FORCE_ASYNC) { - if (!req->async_data) { - ret = io_req_defer_prep(req, sqe); - if (unlikely(ret)) - goto fail_req; - } - io_queue_async_work(req); + if (likely(!(req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL)))) { + __io_queue_sqe(req); + } else if (req->flags & REQ_F_FAIL) { + io_req_complete_fail_submit(req); } else { - if (sqe) { - ret = io_req_prep(req, sqe); - if (unlikely(ret)) - goto fail_req; - } - __io_queue_sqe(req, cs); + int ret = io_req_prep_async(req); + + if (unlikely(ret)) + io_req_complete_failed(req, ret); + else + io_queue_async_work(req, NULL); } }

-static inline void io_queue_link_head(struct io_kiocb *req, - struct io_comp_state *cs) +/* + * Check SQE restrictions (opcode and flags). + * + * Returns 'true' if SQE is allowed, 'false' otherwise. + */ +static inline bool io_check_restriction(struct io_ring_ctx *ctx, + struct io_kiocb *req, + unsigned int sqe_flags) { - if (unlikely(req->flags & REQ_F_FAIL_LINK)) { - io_put_req(req); - io_req_complete(req, -ECANCELED); - } else - io_queue_sqe(req, NULL, cs); -} + if (likely(!ctx->restricted)) + return true;

-static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, - struct io_kiocb **link, struct io_comp_state *cs) -{ - struct io_ring_ctx *ctx = req->ctx; - int ret; + if (!test_bit(req->opcode, ctx->restrictions.sqe_op)) + return false;

- /* - * If we already have a head request, queue this one for async - * submittal once the head completes. If we don't have a head but - * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be - * submitted sync once the chain is complete. If none of those - * conditions are true (normal request), then just queue it. - */ - if (*link) { - struct io_kiocb *head = *link; + if ((sqe_flags & ctx->restrictions.sqe_flags_required) != + ctx->restrictions.sqe_flags_required) + return false;

- /* - * Taking sequential execution of a link, draining both sides - * of the link also fullfils IOSQE_IO_DRAIN semantics for all - * requests in the link. So, it drains the head and the - * next after the link request. The last one is done via - * drain_next flag to persist the effect across calls. - */ - if (req->flags & REQ_F_IO_DRAIN) { - head->flags |= REQ_F_IO_DRAIN; - ctx->drain_next = 1; - } - ret = io_req_defer_prep(req, sqe); - if (unlikely(ret)) { - /* fail even hard links since we don't submit */ - head->flags |= REQ_F_FAIL_LINK; - return ret; - } - trace_io_uring_link(ctx, req, head); - list_add_tail(&req->link_list, &head->link_list); + if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed | + ctx->restrictions.sqe_flags_required)) + return false;

- /* last request of a link, enqueue the link */ - if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) { - io_queue_link_head(head, cs); - *link = NULL; + return true; +} + +static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, + const struct io_uring_sqe *sqe) + __must_hold(&ctx->uring_lock) +{ + struct io_submit_state *state; + unsigned int sqe_flags; + int personality, ret = 0; + + /* req is partially pre-initialised, see io_preinit_req() */ + req->opcode = READ_ONCE(sqe->opcode); + /* same numerical values with corresponding REQ_F_*, safe to copy */ + req->flags = sqe_flags = READ_ONCE(sqe->flags); + req->user_data = READ_ONCE(sqe->user_data); + req->file = NULL; + req->fixed_rsrc_refs = NULL; + req->task = current; + + /* enforce forwards compatibility on users */ + if (unlikely(sqe_flags & ~SQE_VALID_FLAGS)) + return -EINVAL; + if (unlikely(req->opcode >= IORING_OP_LAST)) + return -EINVAL; + if (!io_check_restriction(ctx, req, sqe_flags)) + return -EACCES; + + if ((sqe_flags & IOSQE_BUFFER_SELECT) && + !io_op_defs[req->opcode].buffer_select) + return -EOPNOTSUPP; + if (unlikely(sqe_flags & IOSQE_IO_DRAIN)) + ctx->drain_active = true; + + personality = READ_ONCE(sqe->personality); + if (personality) { + req->creds = xa_load(&ctx->personalities, personality); + if (!req->creds) + return -EINVAL; + get_cred(req->creds); + req->flags |= REQ_F_CREDS; + } + state = &ctx->submit_state; + + /* + * Plug now if we have more than 1 IO left after this, and the target + * is potentially a read/write to block based storage. + */ + if (!state->plug_started && state->ios_left > 1 && + io_op_defs[req->opcode].plug) { + blk_start_plug(&state->plug); + state->plug_started = true; + } + + if (io_op_defs[req->opcode].needs_file) { + req->file = io_file_get(ctx, req, READ_ONCE(sqe->fd), + (sqe_flags & IOSQE_FIXED_FILE)); + if (unlikely(!req->file)) + ret = -EBADF; + } + + state->ios_left--; + return ret; +} + +static int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, + const struct io_uring_sqe *sqe) + __must_hold(&ctx->uring_lock) +{ + struct io_submit_link *link = &ctx->submit_state.link; + int ret; + + ret = io_init_req(ctx, req, sqe); + if (unlikely(ret)) { +fail_req: + /* fail even hard links since we don't submit */ + if (link->head) { + /* + * we can judge a link req is failed or cancelled by if + * REQ_F_FAIL is set, but the head is an exception since + * it may be set REQ_F_FAIL because of other req's failure + * so let's leverage req->result to distinguish if a head + * is set REQ_F_FAIL because of its failure or other req's + * failure so that we can set the correct ret code for it. + * init result here to avoid affecting the normal path. + */ + if (!(link->head->flags & REQ_F_FAIL)) + req_fail_link_node(link->head, -ECANCELED); + } else if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) { + /* + * the current req is a normal req, we should return + * error and thus break the submittion loop. + */ + io_req_complete_failed(req, ret); + return ret; } + req_fail_link_node(req, ret); } else { - if (unlikely(ctx->drain_next)) { - req->flags |= REQ_F_IO_DRAIN; - ctx->drain_next = 0; + ret = io_req_prep(req, sqe); + if (unlikely(ret)) + goto fail_req; + } + + /* don't need @sqe from now on */ + trace_io_uring_submit_sqe(ctx, req, req->opcode, req->user_data, + req->flags, true, + ctx->flags & IORING_SETUP_SQPOLL); + + /* + * If we already have a head request, queue this one for async + * submittal once the head completes. If we don't have a head but + * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be + * submitted sync once the chain is complete. If none of those + * conditions are true (normal request), then just queue it. + */ + if (link->head) { + struct io_kiocb *head = link->head; + + if (!(req->flags & REQ_F_FAIL)) { + ret = io_req_prep_async(req); + if (unlikely(ret)) { + req_fail_link_node(req, ret); + if (!(head->flags & REQ_F_FAIL)) + req_fail_link_node(head, -ECANCELED); + } } - if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) { - req->flags |= REQ_F_LINK_HEAD; - INIT_LIST_HEAD(&req->link_list); + trace_io_uring_link(ctx, req, head); + link->last->link = req; + link->last = req;

- ret = io_req_defer_prep(req, sqe); - if (unlikely(ret)) - req->flags |= REQ_F_FAIL_LINK; - *link = req; + /* last request of a link, enqueue the link */ + if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) { + link->head = NULL; + io_queue_sqe(head); + } + } else { + if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) { + link->head = req; + link->last = req; } else { - io_queue_sqe(req, sqe, cs); + io_queue_sqe(req); } }

@@ -6488,29 +7090,27 @@ static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, /* * Batched submission is done, ensure local IO is flushed out. */ -static void io_submit_state_end(struct io_submit_state *state) +static void io_submit_state_end(struct io_submit_state *state, + struct io_ring_ctx *ctx) { - if (!list_empty(&state->comp.list)) - io_submit_flush_completions(&state->comp); - blk_finish_plug(&state->plug); - io_state_file_put(state); - if (state->free_reqs) - kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs); + if (state->link.head) + io_queue_sqe(state->link.head); + if (state->compl_nr) + io_submit_flush_completions(ctx); + if (state->plug_started) + blk_finish_plug(&state->plug); }

/* * Start submission side cache. */ static void io_submit_state_start(struct io_submit_state *state, - struct io_ring_ctx *ctx, unsigned int max_ios) -{ - blk_start_plug(&state->plug); - state->comp.nr = 0; - INIT_LIST_HEAD(&state->comp.list); - state->comp.ctx = ctx; - state->free_reqs = 0; - state->file = NULL; + unsigned int max_ios) +{ + state->plug_started = false; state->ios_left = max_ios; + /* set only head, no need to init link_last in advance */ + state->link.head = NULL; }

static void io_commit_sqring(struct io_ring_ctx *ctx) @@ -6526,7 +7126,7 @@ static void io_commit_sqring(struct io_ring_ctx *ctx) }

/* - * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory + * Fetch an sqe, if one is available. Note this returns a pointer to memory * that is mapped by userspace. This means that care needs to be taken to * ensure that reads are stable, as we cannot rely on userspace always * being a good citizen. If members of the sqe are validated and then later @@ -6535,8 +7135,8 @@ static void io_commit_sqring(struct io_ring_ctx *ctx) */ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) { - u32 *sq_array = ctx->sq_array; - unsigned head; + unsigned head, mask = ctx->sq_entries - 1; + unsigned sq_idx = ctx->cached_sq_head++ & mask;

/* * The cached sq head (or cq tail) serves two purposes: @@ -6546,423 +7146,256 @@ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) * 2) allows the kernel side to track the head on its own, even * though the application is the one updating it. */ - head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]); + head = READ_ONCE(ctx->sq_array[sq_idx]); if (likely(head < ctx->sq_entries)) return &ctx->sq_sqes[head];

/* drop invalid entries */ - ctx->cached_sq_dropped++; - WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped); + ctx->cq_extra--; + WRITE_ONCE(ctx->rings->sq_dropped, + READ_ONCE(ctx->rings->sq_dropped) + 1); return NULL; }

-static inline void io_consume_sqe(struct io_ring_ctx *ctx) -{ - ctx->cached_sq_head++; -} - -/* - * Check SQE restrictions (opcode and flags). - * - * Returns 'true' if SQE is allowed, 'false' otherwise. - */ -static inline bool io_check_restriction(struct io_ring_ctx *ctx, - struct io_kiocb *req, - unsigned int sqe_flags) -{ - if (!ctx->restricted) - return true; - - if (!test_bit(req->opcode, ctx->restrictions.sqe_op)) - return false; - - if ((sqe_flags & ctx->restrictions.sqe_flags_required) != - ctx->restrictions.sqe_flags_required) - return false; - - if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed | - ctx->restrictions.sqe_flags_required)) - return false; - - return true; -} - -#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \ - IOSQE_IO_HARDLINK | IOSQE_ASYNC | \ - IOSQE_BUFFER_SELECT) - -static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, - const struct io_uring_sqe *sqe, - struct io_submit_state *state) -{ - unsigned int sqe_flags; - int id, ret; - - req->opcode = READ_ONCE(sqe->opcode); - req->user_data = READ_ONCE(sqe->user_data); - req->async_data = NULL; - req->file = NULL; - req->ctx = ctx; - req->flags = 0; - /* one is dropped after submission, the other at completion */ - refcount_set(&req->refs, 2); - req->task = current; - req->result = 0; - - if (unlikely(req->opcode >= IORING_OP_LAST)) - return -EINVAL; - - if (unlikely(io_sq_thread_acquire_mm(ctx, req))) - return -EFAULT; - - sqe_flags = READ_ONCE(sqe->flags); - /* enforce forwards compatibility on users */ - if (unlikely(sqe_flags & ~SQE_VALID_FLAGS)) - return -EINVAL; - - if (unlikely(!io_check_restriction(ctx, req, sqe_flags))) - return -EACCES; - - if ((sqe_flags & IOSQE_BUFFER_SELECT) && - !io_op_defs[req->opcode].buffer_select) - return -EOPNOTSUPP; - - id = READ_ONCE(sqe->personality); - if (id) { - struct io_identity *iod; - - iod = xa_load(&ctx->personalities, id); - if (unlikely(!iod)) - return -EINVAL; - refcount_inc(&iod->count); - - __io_req_init_async(req); - get_cred(iod->creds); - req->work.identity = iod; - req->work.flags |= IO_WQ_WORK_CREDS; - } - - /* same numerical values with corresponding REQ_F_*, safe to copy */ - req->flags |= sqe_flags; - - if (!io_op_defs[req->opcode].needs_file) - return 0; - - ret = io_req_set_file(state, req, READ_ONCE(sqe->fd)); - state->ios_left--; - return ret; -} - static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) + __must_hold(&ctx->uring_lock) { - struct io_submit_state state; - struct io_kiocb *link = NULL; - int i, submitted = 0; - - /* if we have a backlog and couldn't flush it all, return BUSY */ - if (test_bit(0, &ctx->sq_check_overflow)) { - if (!__io_cqring_overflow_flush(ctx, false, NULL, NULL)) - return -EBUSY; - } + int submitted = 0;

/* make sure SQ entry isn't read before tail */ nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx)); - if (!percpu_ref_tryget_many(&ctx->refs, nr)) return -EAGAIN; + io_get_task_refs(nr);

- percpu_counter_add(&current->io_uring->inflight, nr); - refcount_add(nr, &current->usage); - - io_submit_state_start(&state, ctx, nr); - - for (i = 0; i < nr; i++) { + io_submit_state_start(&ctx->submit_state, nr); + while (submitted < nr) { const struct io_uring_sqe *sqe; struct io_kiocb *req; - int err;

- sqe = io_get_sqe(ctx); - if (unlikely(!sqe)) { - io_consume_sqe(ctx); - break; - } - req = io_alloc_req(ctx, &state); + req = io_alloc_req(ctx); if (unlikely(!req)) { if (!submitted) submitted = -EAGAIN; break; } - io_consume_sqe(ctx); + sqe = io_get_sqe(ctx); + if (unlikely(!sqe)) { + list_add(&req->inflight_entry, &ctx->submit_state.free_list); + break; + } /* will complete beyond this point, count as submitted */ submitted++; - - err = io_init_req(ctx, req, sqe, &state); - if (unlikely(err)) { -fail_req: - io_put_req(req); - io_req_complete(req, err); + if (io_submit_sqe(ctx, req, sqe)) break; - } - - trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data, - true, io_async_submit(ctx)); - err = io_submit_sqe(req, sqe, &link, &state.comp); - if (err) - goto fail_req; }

if (unlikely(submitted != nr)) { int ref_used = (submitted == -EAGAIN) ? 0 : submitted; - struct io_uring_task *tctx = current->io_uring; int unused = nr - ref_used;

+ current->io_uring->cached_refs += unused; percpu_ref_put_many(&ctx->refs, unused); - percpu_counter_sub(&tctx->inflight, unused); - put_task_struct_many(current, unused); } - if (link) - io_queue_link_head(link, &state.comp); - io_submit_state_end(&state);

+ io_submit_state_end(&ctx->submit_state, ctx); /* Commit SQ ring head once we've consumed and submitted all SQEs */ io_commit_sqring(ctx);

return submitted; }

-static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx) +static inline bool io_sqd_events_pending(struct io_sq_data *sqd) { - /* Tell userspace we may need a wakeup call */ - spin_lock_irq(&ctx->completion_lock); - ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP; - spin_unlock_irq(&ctx->completion_lock); + return READ_ONCE(sqd->state); }

-static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx) +static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx) { - spin_lock_irq(&ctx->completion_lock); - ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; - spin_unlock_irq(&ctx->completion_lock); + /* Tell userspace we may need a wakeup call */ + spin_lock(&ctx->completion_lock); + WRITE_ONCE(ctx->rings->sq_flags, + ctx->rings->sq_flags | IORING_SQ_NEED_WAKEUP); + spin_unlock(&ctx->completion_lock); }

-static int io_sq_wake_function(struct wait_queue_entry *wqe, unsigned mode, - int sync, void *key) +static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx) { - struct io_ring_ctx *ctx = container_of(wqe, struct io_ring_ctx, sqo_wait_entry); - int ret; - - ret = autoremove_wake_function(wqe, mode, sync, key); - if (ret) { - unsigned long flags; - - spin_lock_irqsave(&ctx->completion_lock, flags); - ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; - spin_unlock_irqrestore(&ctx->completion_lock, flags); - } - return ret; + spin_lock(&ctx->completion_lock); + WRITE_ONCE(ctx->rings->sq_flags, + ctx->rings->sq_flags & ~IORING_SQ_NEED_WAKEUP); + spin_unlock(&ctx->completion_lock); }

-enum sq_ret { - SQT_IDLE = 1, - SQT_SPIN = 2, - SQT_DID_WORK = 4, -}; - -static enum sq_ret __io_sq_thread(struct io_ring_ctx *ctx, - unsigned long start_jiffies, bool cap_entries) +static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) { - unsigned long timeout = start_jiffies + ctx->sq_thread_idle; - struct io_sq_data *sqd = ctx->sq_data; unsigned int to_submit; int ret = 0;

-again: - if (!list_empty(&ctx->iopoll_list)) { - unsigned nr_events = 0; - - mutex_lock(&ctx->uring_lock); - if (!list_empty(&ctx->iopoll_list) && !need_resched()) - io_do_iopoll(ctx, &nr_events, 0); - mutex_unlock(&ctx->uring_lock); - } - to_submit = io_sqring_entries(ctx); + /* if we're handling multiple rings, cap submit size for fairness */ + if (cap_entries && to_submit > IORING_SQPOLL_CAP_ENTRIES_VALUE) + to_submit = IORING_SQPOLL_CAP_ENTRIES_VALUE;

- /* - * If submit got -EBUSY, flag us as needing the application - * to enter the kernel to reap and flush events. - */ - if (!to_submit || ret == -EBUSY || need_resched()) { - /* - * Drop cur_mm before scheduling, we can't hold it for - * long periods (or over schedule()). Do this before - * adding ourselves to the waitqueue, as the unuse/drop - * may sleep. - */ - io_sq_thread_drop_mm(); + if (!list_empty(&ctx->iopoll_list) || to_submit) { + unsigned nr_events = 0; + const struct cred *creds = NULL;

- /* - * We're polling. If we're within the defined idle - * period, then let us spin without work before going - * to sleep. The exception is if we got EBUSY doing - * more IO, we should wait for the application to - * reap events and wake us up. - */ - if (!list_empty(&ctx->iopoll_list) || need_resched() || - (!time_after(jiffies, timeout) && ret != -EBUSY && - !percpu_ref_is_dying(&ctx->refs))) - return SQT_SPIN; + if (ctx->sq_creds != current_cred()) + creds = override_creds(ctx->sq_creds);

- prepare_to_wait(&sqd->wait, &ctx->sqo_wait_entry, - TASK_INTERRUPTIBLE); + mutex_lock(&ctx->uring_lock); + if (!list_empty(&ctx->iopoll_list)) + io_do_iopoll(ctx, &nr_events, 0);

/* - * While doing polled IO, before going to sleep, we need - * to check if there are new reqs added to iopoll_list, - * it is because reqs may have been punted to io worker - * and will be added to iopoll_list later, hence check - * the iopoll_list again. + * Don't submit if refs are dying, good for io_uring_register(), + * but also it is relied upon by io_ring_exit_work() */ - if ((ctx->flags & IORING_SETUP_IOPOLL) && - !list_empty_careful(&ctx->iopoll_list)) { - finish_wait(&sqd->wait, &ctx->sqo_wait_entry); - goto again; - } + if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs)) && + !(ctx->flags & IORING_SETUP_R_DISABLED)) + ret = io_submit_sqes(ctx, to_submit); + mutex_unlock(&ctx->uring_lock);

- to_submit = io_sqring_entries(ctx); - if (!to_submit || ret == -EBUSY) - return SQT_IDLE; + if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait)) + wake_up(&ctx->sqo_sq_wait); + if (creds) + revert_creds(creds); }

- finish_wait(&sqd->wait, &ctx->sqo_wait_entry); - io_ring_clear_wakeup_flag(ctx); - - /* if we're handling multiple rings, cap submit size for fairness */ - if (cap_entries && to_submit > 8) - to_submit = 8; - - mutex_lock(&ctx->uring_lock); - if (likely(!percpu_ref_is_dying(&ctx->refs) && !ctx->sqo_dead)) - ret = io_submit_sqes(ctx, to_submit); - mutex_unlock(&ctx->uring_lock); + return ret; +}

- if (!io_sqring_full(ctx) && wq_has_sleeper(&ctx->sqo_sq_wait)) - wake_up(&ctx->sqo_sq_wait); +static void io_sqd_update_thread_idle(struct io_sq_data *sqd) +{ + struct io_ring_ctx *ctx; + unsigned sq_thread_idle = 0;

- return SQT_DID_WORK; + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + sq_thread_idle = max(sq_thread_idle, ctx->sq_thread_idle); + sqd->sq_thread_idle = sq_thread_idle; }

-static void io_sqd_init_new(struct io_sq_data *sqd) +static bool io_sqd_handle_event(struct io_sq_data *sqd) { - struct io_ring_ctx *ctx; + bool did_sig = false; + struct ksignal ksig;

- while (!list_empty(&sqd->ctx_new_list)) { - ctx = list_first_entry(&sqd->ctx_new_list, struct io_ring_ctx, sqd_list); - init_wait(&ctx->sqo_wait_entry); - ctx->sqo_wait_entry.func = io_sq_wake_function; - list_move_tail(&ctx->sqd_list, &sqd->ctx_list); - complete(&ctx->sq_thread_comp); + if (test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) || + signal_pending(current)) { + mutex_unlock(&sqd->lock); + if (signal_pending(current)) + did_sig = get_signal(&ksig); + cond_resched(); + mutex_lock(&sqd->lock); } + return did_sig || test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); }

static int io_sq_thread(void *data) { - struct cgroup_subsys_state *cur_css = NULL; - const struct cred *old_cred = NULL; struct io_sq_data *sqd = data; struct io_ring_ctx *ctx; - unsigned long start_jiffies; + unsigned long timeout = 0; + char buf[TASK_COMM_LEN]; + DEFINE_WAIT(wait);

- start_jiffies = jiffies; - while (!kthread_should_stop()) { - enum sq_ret ret = 0; - bool cap_entries; + snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid); + set_task_comm(current, buf);

- /* - * Any changes to the sqd lists are synchronized through the - * kthread parking. This synchronizes the thread vs users, - * the users are synchronized on the sqd->ctx_lock. - */ - if (kthread_should_park()) { - kthread_parkme(); - /* - * When sq thread is unparked, in case the previous park operation - * comes from io_put_sq_data(), which means that sq thread is going - * to be stopped, so here needs to have a check. - */ - if (kthread_should_stop()) + if (sqd->sq_cpu != -1) + set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu)); + else + set_cpus_allowed_ptr(current, cpu_online_mask); + current->flags |= PF_NO_SETAFFINITY; + + mutex_lock(&sqd->lock); + while (1) { + bool cap_entries, sqt_spin = false; + + if (io_sqd_events_pending(sqd) || signal_pending(current)) { + if (io_sqd_handle_event(sqd)) break; + timeout = jiffies + sqd->sq_thread_idle; }

- if (unlikely(!list_empty(&sqd->ctx_new_list))) - io_sqd_init_new(sqd); - cap_entries = !list_is_singular(&sqd->ctx_list); - list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { - if (current->cred != ctx->creds) { - if (old_cred) - revert_creds(old_cred); - old_cred = override_creds(ctx->creds); - } - io_sq_thread_associate_blkcg(ctx, &cur_css); -#ifdef CONFIG_AUDIT - current->loginuid = ctx->loginuid; - current->sessionid = ctx->sessionid; -#endif + int ret = __io_sq_thread(ctx, cap_entries);

- ret |= __io_sq_thread(ctx, start_jiffies, cap_entries); - - io_sq_thread_drop_mm(); + if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list))) + sqt_spin = true; } + if (io_run_task_work()) + sqt_spin = true;

- if (ret & SQT_SPIN) { - io_run_task_work(); - io_sq_thread_drop_mm(); + if (sqt_spin || !time_after(jiffies, timeout)) { cond_resched(); - } else if (ret == SQT_IDLE) { - if (kthread_should_park()) - continue; - list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + if (sqt_spin) + timeout = jiffies + sqd->sq_thread_idle; + continue; + } + + prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE); + if (!io_sqd_events_pending(sqd) && !current->task_works) { + bool needs_sched = true; + + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { io_ring_set_wakeup_flag(ctx); - schedule(); - start_jiffies = jiffies; + + if ((ctx->flags & IORING_SETUP_IOPOLL) && + !list_empty_careful(&ctx->iopoll_list)) { + needs_sched = false; + break; + } + if (io_sqring_entries(ctx)) { + needs_sched = false; + break; + } + } + + if (needs_sched) { + mutex_unlock(&sqd->lock); + schedule(); + mutex_lock(&sqd->lock); + } list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) io_ring_clear_wakeup_flag(ctx); } + + finish_wait(&sqd->wait, &wait); + timeout = jiffies + sqd->sq_thread_idle; }

+ io_uring_cancel_generic(true, sqd); + sqd->thread = NULL; + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + io_ring_set_wakeup_flag(ctx); io_run_task_work(); - io_sq_thread_drop_mm(); - - if (cur_css) - io_sq_thread_unassociate_blkcg(); - if (old_cred) - revert_creds(old_cred); - - kthread_parkme(); + mutex_unlock(&sqd->lock);

- return 0; + complete(&sqd->exited); + do_exit(0); }

struct io_wait_queue { struct wait_queue_entry wq; struct io_ring_ctx *ctx; - unsigned to_wait; + unsigned cq_tail; unsigned nr_timeouts; };

static inline bool io_should_wake(struct io_wait_queue *iowq) { struct io_ring_ctx *ctx = iowq->ctx; + int dist = ctx->cached_cq_tail - (int) iowq->cq_tail;

/* * Wake up if we have enough events, or if a timeout occurred since we * started waiting. For timeouts, we always want to return to userspace, * regardless of event count. */ - return io_cqring_events(ctx) >= iowq->to_wait || - atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; + return dist >= 0 || atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; }

static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode, @@ -6975,7 +7408,7 @@ static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode, * Cannot safely flush overflowed CQEs from here, ensure we wake up * the task, and the next invocation will do it. */ - if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->cq_check_overflow)) + if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->check_cq_overflow)) return autoremove_wake_function(curr, mode, wake_flags, key); return -1; } @@ -6986,43 +7419,60 @@ static int io_run_task_work_sig(void) return 1; if (!signal_pending(current)) return 0; - if (current->jobctl & JOBCTL_TASK_WORK) { - spin_lock_irq(&current->sighand->siglock); - current->jobctl &= ~JOBCTL_TASK_WORK; - recalc_sigpending(); - spin_unlock_irq(&current->sighand->siglock); - return 1; - } + if (test_thread_flag(TIF_NOTIFY_SIGNAL)) + return -ERESTARTSYS; return -EINTR; }

+/* when returns >0, the caller should retry */ +static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, + struct io_wait_queue *iowq, + ktime_t timeout) +{ + int ret; + + /* make sure we run task_work before checking for signals */ + ret = io_run_task_work_sig(); + if (ret || io_should_wake(iowq)) + return ret; + /* let the caller flush overflows, retry */ + if (test_bit(0, &ctx->check_cq_overflow)) + return 1; + + if (!schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS)) + return -ETIME; + return 1; +} + /* * Wait until events become available, if we don't already have some. The * application must reap them itself, as they reside on the shared cq ring. */ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, - const sigset_t __user *sig, size_t sigsz) -{ - struct io_wait_queue iowq = { - .wq = { - .private = current, - .func = io_wake_function, - .entry = LIST_HEAD_INIT(iowq.wq.entry), - }, - .ctx = ctx, - .to_wait = min_events, - }; + const sigset_t __user *sig, size_t sigsz, + struct __kernel_timespec __user *uts) +{ + struct io_wait_queue iowq; struct io_rings *rings = ctx->rings; - int ret = 0; + ktime_t timeout = KTIME_MAX; + int ret;

do { - io_cqring_overflow_flush(ctx, false, NULL, NULL); + io_cqring_overflow_flush(ctx); if (io_cqring_events(ctx) >= min_events) return 0; if (!io_run_task_work()) break; } while (1);

+ if (uts) { + struct timespec64 ts; + + if (get_timespec64(&ts, uts)) + return -EFAULT; + timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns()); + } + if (sig) { #ifdef CONFIG_COMPAT if (in_compat_syscall()) @@ -7036,33 +7486,267 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, return ret; }

+ init_waitqueue_func_entry(&iowq.wq, io_wake_function); + iowq.wq.private = current; + INIT_LIST_HEAD(&iowq.wq.entry); + iowq.ctx = ctx; iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts); + iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events; + trace_io_uring_cqring_wait(ctx, min_events); do { - io_cqring_overflow_flush(ctx, false, NULL, NULL); - prepare_to_wait_exclusive(&ctx->wait, &iowq.wq, + /* if we can't even flush overflow, don't wait for more */ + if (!io_cqring_overflow_flush(ctx)) { + ret = -EBUSY; + break; + } + prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq, TASK_INTERRUPTIBLE); - /* make sure we run task_work before checking for signals */ - ret = io_run_task_work_sig(); - if (ret > 0) { - finish_wait(&ctx->wait, &iowq.wq); - continue; + ret = io_cqring_wait_schedule(ctx, &iowq, timeout); + finish_wait(&ctx->cq_wait, &iowq.wq); + cond_resched(); + } while (ret > 0); + + restore_saved_sigmask_unless(ret == -EINTR); + + return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; +} + +static void io_free_page_table(void **table, size_t size) +{ + unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE); + + for (i = 0; i < nr_tables; i++) + kfree(table[i]); + kfree(table); +} + +static void **io_alloc_page_table(size_t size) +{ + unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE); + size_t init_size = size; + void **table; + + table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL_ACCOUNT); + if (!table) + return NULL; + + for (i = 0; i < nr_tables; i++) { + unsigned int this_size = min_t(size_t, size, PAGE_SIZE); + + table[i] = kzalloc(this_size, GFP_KERNEL_ACCOUNT); + if (!table[i]) { + io_free_page_table(table, init_size); + return NULL; } - else if (ret < 0) + size -= this_size; + } + return table; +} + +static void io_rsrc_node_destroy(struct io_rsrc_node *ref_node) +{ + percpu_ref_exit(&ref_node->refs); + kfree(ref_node); +} + +static void io_rsrc_node_ref_zero(struct percpu_ref *ref) +{ + struct io_rsrc_node *node = container_of(ref, struct io_rsrc_node, refs); + struct io_ring_ctx *ctx = node->rsrc_data->ctx; + unsigned long flags; + bool first_add = false; + unsigned long delay = HZ; + + spin_lock_irqsave(&ctx->rsrc_ref_lock, flags); + node->done = true; + + /* if we are mid-quiesce then do not delay */ + if (node->rsrc_data->quiesce) + delay = 0; + + while (!list_empty(&ctx->rsrc_ref_list)) { + node = list_first_entry(&ctx->rsrc_ref_list, + struct io_rsrc_node, node); + /* recycle ref nodes in order */ + if (!node->done) + break; + list_del(&node->node); + first_add |= llist_add(&node->llist, &ctx->rsrc_put_llist); + } + spin_unlock_irqrestore(&ctx->rsrc_ref_lock, flags); + + if (first_add) + mod_delayed_work(system_wq, &ctx->rsrc_put_work, delay); +} + +static struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx) +{ + struct io_rsrc_node *ref_node; + + ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL); + if (!ref_node) + return NULL; + + if (percpu_ref_init(&ref_node->refs, io_rsrc_node_ref_zero, + 0, GFP_KERNEL)) { + kfree(ref_node); + return NULL; + } + INIT_LIST_HEAD(&ref_node->node); + INIT_LIST_HEAD(&ref_node->rsrc_list); + ref_node->done = false; + return ref_node; +} + +static void io_rsrc_node_switch(struct io_ring_ctx *ctx, + struct io_rsrc_data *data_to_kill) +{ + WARN_ON_ONCE(!ctx->rsrc_backup_node); + WARN_ON_ONCE(data_to_kill && !ctx->rsrc_node); + + if (data_to_kill) { + struct io_rsrc_node *rsrc_node = ctx->rsrc_node; + + rsrc_node->rsrc_data = data_to_kill; + spin_lock_irq(&ctx->rsrc_ref_lock); + list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list); + spin_unlock_irq(&ctx->rsrc_ref_lock); + + atomic_inc(&data_to_kill->refs); + percpu_ref_kill(&rsrc_node->refs); + ctx->rsrc_node = NULL; + } + + if (!ctx->rsrc_node) { + ctx->rsrc_node = ctx->rsrc_backup_node; + ctx->rsrc_backup_node = NULL; + } +} + +static int io_rsrc_node_switch_start(struct io_ring_ctx *ctx) +{ + if (ctx->rsrc_backup_node) + return 0; + ctx->rsrc_backup_node = io_rsrc_node_alloc(ctx); + return ctx->rsrc_backup_node ? 0 : -ENOMEM; +} + +static int io_rsrc_ref_quiesce(struct io_rsrc_data *data, struct io_ring_ctx *ctx) +{ + int ret; + + /* As we may drop ->uring_lock, other task may have started quiesce */ + if (data->quiesce) + return -ENXIO; + + data->quiesce = true; + do { + ret = io_rsrc_node_switch_start(ctx); + if (ret) break; - if (io_should_wake(&iowq)) + io_rsrc_node_switch(ctx, data); + + /* kill initial ref, already quiesced if zero */ + if (atomic_dec_and_test(&data->refs)) break; - if (test_bit(0, &ctx->cq_check_overflow)) { - finish_wait(&ctx->wait, &iowq.wq); - continue; + mutex_unlock(&ctx->uring_lock); + flush_delayed_work(&ctx->rsrc_put_work); + ret = wait_for_completion_interruptible(&data->done); + if (!ret) { + mutex_lock(&ctx->uring_lock); + if (atomic_read(&data->refs) > 0) { + /* + * it has been revived by another thread while + * we were unlocked + */ + mutex_unlock(&ctx->uring_lock); + } else { + break; + } + } + + atomic_inc(&data->refs); + /* wait for all works potentially completing data->done */ + flush_delayed_work(&ctx->rsrc_put_work); + reinit_completion(&data->done); + + ret = io_run_task_work_sig(); + mutex_lock(&ctx->uring_lock); + } while (ret >= 0); + data->quiesce = false; + + return ret; +} + +static u64 *io_get_tag_slot(struct io_rsrc_data *data, unsigned int idx) +{ + unsigned int off = idx & IO_RSRC_TAG_TABLE_MASK; + unsigned int table_idx = idx >> IO_RSRC_TAG_TABLE_SHIFT; + + return &data->tags[table_idx][off]; +} + +static void io_rsrc_data_free(struct io_rsrc_data *data) +{ + size_t size = data->nr * sizeof(data->tags[0][0]); + + if (data->tags) + io_free_page_table((void **)data->tags, size); + kfree(data); +} + +static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, rsrc_put_fn *do_put, + u64 __user *utags, unsigned nr, + struct io_rsrc_data **pdata) +{ + struct io_rsrc_data *data; + int ret = -ENOMEM; + unsigned i; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + data->tags = (u64 **)io_alloc_page_table(nr * sizeof(data->tags[0][0])); + if (!data->tags) { + kfree(data); + return -ENOMEM; + } + + data->nr = nr; + data->ctx = ctx; + data->do_put = do_put; + if (utags) { + ret = -EFAULT; + for (i = 0; i < nr; i++) { + u64 *tag_slot = io_get_tag_slot(data, i); + + if (copy_from_user(tag_slot, &utags[i], + sizeof(*tag_slot))) + goto fail; } - schedule(); - } while (1); - finish_wait(&ctx->wait, &iowq.wq); + }

- restore_saved_sigmask_unless(ret == -EINTR); + atomic_set(&data->refs, 1); + init_completion(&data->done); + *pdata = data; + return 0; +fail: + io_rsrc_data_free(data); + return ret; +}

- return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; +static bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files) +{ + table->files = kvcalloc(nr_files, sizeof(table->files[0]), + GFP_KERNEL_ACCOUNT); + return !!table->files; +} + +static void io_free_file_tables(struct io_file_table *table) +{ + kvfree(table->files); + table->files = NULL; }

static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) @@ -7086,129 +7770,97 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) fput(file); } #endif + io_free_file_tables(&ctx->file_table); + io_rsrc_data_free(ctx->file_data); + ctx->file_data = NULL; + ctx->nr_user_files = 0; }

-static void io_file_ref_kill(struct percpu_ref *ref) +static int io_sqe_files_unregister(struct io_ring_ctx *ctx) { - struct fixed_file_data *data; + unsigned nr = ctx->nr_user_files; + int ret;

- data = container_of(ref, struct fixed_file_data, refs); - complete(&data->done); -} + if (!ctx->file_data) + return -ENXIO;

-static void io_sqe_files_set_node(struct fixed_file_data *file_data, - struct fixed_file_ref_node *ref_node) -{ - spin_lock_bh(&file_data->lock); - file_data->node = ref_node; - list_add_tail(&ref_node->node, &file_data->ref_list); - spin_unlock_bh(&file_data->lock); - percpu_ref_get(&file_data->refs); + /* + * Quiesce may unlock ->uring_lock, and while it's not held + * prevent new requests using the table. + */ + ctx->nr_user_files = 0; + ret = io_rsrc_ref_quiesce(ctx->file_data, ctx); + ctx->nr_user_files = nr; + if (!ret) + __io_sqe_files_unregister(ctx); + return ret; }

- -static void io_sqe_files_kill_node(struct fixed_file_data *data) +static void io_sq_thread_unpark(struct io_sq_data *sqd) + __releases(&sqd->lock) { - struct fixed_file_ref_node *ref_node = NULL; + WARN_ON_ONCE(sqd->thread == current);

- spin_lock_bh(&data->lock); - ref_node = data->node; - spin_unlock_bh(&data->lock); - if (ref_node) - percpu_ref_kill(&ref_node->refs); + /* + * Do the dance but not conditional clear_bit() because it'd race with + * other threads incrementing park_pending and setting the bit. + */ + clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); + if (atomic_dec_return(&sqd->park_pending)) + set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); + mutex_unlock(&sqd->lock); }

-static int io_file_ref_quiesce(struct fixed_file_data *data, - struct io_ring_ctx *ctx) +static void io_sq_thread_park(struct io_sq_data *sqd) + __acquires(&sqd->lock) { - int ret; - struct fixed_file_ref_node *backup_node; - - if (data->quiesce) - return -ENXIO; - - data->quiesce = true; - do { - backup_node = alloc_fixed_file_ref_node(ctx); - if (!backup_node) - break; - - io_sqe_files_kill_node(data); - percpu_ref_kill(&data->refs); - flush_delayed_work(&ctx->file_put_work); - - ret = wait_for_completion_interruptible(&data->done); - if (!ret) - break; - - percpu_ref_resurrect(&data->refs); - io_sqe_files_set_node(data, backup_node); - backup_node = NULL; - reinit_completion(&data->done); - mutex_unlock(&ctx->uring_lock); - ret = io_run_task_work_sig(); - mutex_lock(&ctx->uring_lock); - - if (ret < 0) - break; - backup_node = alloc_fixed_file_ref_node(ctx); - ret = -ENOMEM; - if (!backup_node) - break; - } while (1); - data->quiesce = false; + WARN_ON_ONCE(sqd->thread == current);

- if (backup_node) - destroy_fixed_file_ref_node(backup_node); - return ret; + atomic_inc(&sqd->park_pending); + set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); + mutex_lock(&sqd->lock); + if (sqd->thread) + wake_up_process(sqd->thread); }

-static int io_sqe_files_unregister(struct io_ring_ctx *ctx) +static void io_sq_thread_stop(struct io_sq_data *sqd) { - struct fixed_file_data *data = ctx->file_data; - unsigned nr_tables, i; - int ret; + WARN_ON_ONCE(sqd->thread == current); + WARN_ON_ONCE(test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state));

- /* - * percpu_ref_is_dying() is to stop parallel files unregister - * Since we possibly drop uring lock later in this function to - * run task work. - */ - if (!data || percpu_ref_is_dying(&data->refs)) - return -ENXIO; - ret = io_file_ref_quiesce(data, ctx); - if (ret) - return ret; - - __io_sqe_files_unregister(ctx); - nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE); - for (i = 0; i < nr_tables; i++) - kfree(data->table[i].files); - kfree(data->table); - percpu_ref_exit(&data->refs); - kfree(data); - ctx->file_data = NULL; - ctx->nr_user_files = 0; - return 0; + set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); + mutex_lock(&sqd->lock); + if (sqd->thread) + wake_up_process(sqd->thread); + mutex_unlock(&sqd->lock); + wait_for_completion(&sqd->exited); }

static void io_put_sq_data(struct io_sq_data *sqd) { if (refcount_dec_and_test(&sqd->refs)) { - /* - * The park is a bit of a work-around, without it we get - * warning spews on shutdown with SQPOLL set and affinity - * set to a single CPU. - */ - if (sqd->thread) { - kthread_park(sqd->thread); - kthread_stop(sqd->thread); - } + WARN_ON_ONCE(atomic_read(&sqd->park_pending));

+ io_sq_thread_stop(sqd); kfree(sqd); } }

+static void io_sq_thread_finish(struct io_ring_ctx *ctx) +{ + struct io_sq_data *sqd = ctx->sq_data; + + if (sqd) { + io_sq_thread_park(sqd); + list_del_init(&ctx->sqd_list); + io_sqd_update_thread_idle(sqd); + io_sq_thread_unpark(sqd); + + io_put_sq_data(sqd); + ctx->sq_data = NULL; + } +} + static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p) { struct io_ring_ctx *ctx_attach; @@ -7229,92 +7881,46 @@ static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p) fdput(f); return ERR_PTR(-EINVAL); } + if (sqd->task_tgid != current->tgid) { + fdput(f); + return ERR_PTR(-EPERM); + }

refcount_inc(&sqd->refs); fdput(f); return sqd; }

-static struct io_sq_data *io_get_sq_data(struct io_uring_params *p) +static struct io_sq_data *io_get_sq_data(struct io_uring_params *p, + bool *attached) { struct io_sq_data *sqd;

- if (p->flags & IORING_SETUP_ATTACH_WQ) - return io_attach_sq_data(p); + *attached = false; + if (p->flags & IORING_SETUP_ATTACH_WQ) { + sqd = io_attach_sq_data(p); + if (!IS_ERR(sqd)) { + *attached = true; + return sqd; + } + /* fall through for EPERM case, setup new sqd/task */ + if (PTR_ERR(sqd) != -EPERM) + return sqd; + }

sqd = kzalloc(sizeof(*sqd), GFP_KERNEL); if (!sqd) return ERR_PTR(-ENOMEM);

+ atomic_set(&sqd->park_pending, 0); refcount_set(&sqd->refs, 1); INIT_LIST_HEAD(&sqd->ctx_list); - INIT_LIST_HEAD(&sqd->ctx_new_list); - mutex_init(&sqd->ctx_lock); mutex_init(&sqd->lock); init_waitqueue_head(&sqd->wait); + init_completion(&sqd->exited); return sqd; }

-static void io_sq_thread_unpark(struct io_sq_data *sqd) - __releases(&sqd->lock) -{ - if (!sqd->thread) - return; - kthread_unpark(sqd->thread); - mutex_unlock(&sqd->lock); -} - -static void io_sq_thread_park(struct io_sq_data *sqd) - __acquires(&sqd->lock) -{ - if (!sqd->thread) - return; - mutex_lock(&sqd->lock); - kthread_park(sqd->thread); -} - -static void io_sq_thread_stop(struct io_ring_ctx *ctx) -{ - struct io_sq_data *sqd = ctx->sq_data; - - if (sqd) { - if (sqd->thread) { - /* - * We may arrive here from the error branch in - * io_sq_offload_create() where the kthread is created - * without being waked up, thus wake it up now to make - * sure the wait will complete. - */ - wake_up_process(sqd->thread); - wait_for_completion(&ctx->sq_thread_comp); - - io_sq_thread_park(sqd); - } - - mutex_lock(&sqd->ctx_lock); - list_del(&ctx->sqd_list); - mutex_unlock(&sqd->ctx_lock); - - if (sqd->thread) { - finish_wait(&sqd->wait, &ctx->sqo_wait_entry); - io_sq_thread_unpark(sqd); - } - - io_put_sq_data(sqd); - ctx->sq_data = NULL; - } -} - -static void io_finish_async(struct io_ring_ctx *ctx) -{ - io_sq_thread_stop(ctx); - - if (ctx->io_wq) { - io_wq_destroy(ctx->io_wq); - ctx->io_wq = NULL; - } -} - #if defined(CONFIG_UNIX) /* * Ensure the UNIX gc is aware of our file set, so we are certain that @@ -7342,7 +7948,7 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) skb->scm_io_uring = 1;

nr_files = 0; - fpl->user = get_uid(ctx->user); + fpl->user = get_uid(current_user()); for (i = 0; i < nr; i++) { struct file *file = io_file_from_index(ctx, i + offset);

@@ -7418,35 +8024,9 @@ static int io_sqe_files_scm(struct io_ring_ctx *ctx) } #endif

-static int io_sqe_alloc_file_tables(struct fixed_file_data *file_data, - unsigned nr_tables, unsigned nr_files) -{ - int i; - - for (i = 0; i < nr_tables; i++) { - struct fixed_file_table *table = &file_data->table[i]; - unsigned this_files; - - this_files = min(nr_files, IORING_MAX_FILES_TABLE); - table->files = kcalloc(this_files, sizeof(struct file *), - GFP_KERNEL_ACCOUNT); - if (!table->files) - break; - nr_files -= this_files; - } - - if (i == nr_tables) - return 0; - - for (i = 0; i < nr_tables; i++) { - struct fixed_file_table *table = &file_data->table[i]; - kfree(table->files); - } - return 1; -} - -static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file) +static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc) { + struct file *file = prsrc->file; #if defined(CONFIG_UNIX) struct sock *sock = ctx->ring_sock->sk; struct sk_buff_head list, *head = &sock->sk_receive_queue; @@ -7507,117 +8087,61 @@ static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file) #endif }

-struct io_file_put { - struct list_head list; - struct file *file; -}; - -static void __io_file_put_work(struct fixed_file_ref_node *ref_node) +static void __io_rsrc_put_work(struct io_rsrc_node *ref_node) { - struct fixed_file_data *file_data = ref_node->file_data; - struct io_ring_ctx *ctx = file_data->ctx; - struct io_file_put *pfile, *tmp; + struct io_rsrc_data *rsrc_data = ref_node->rsrc_data; + struct io_ring_ctx *ctx = rsrc_data->ctx; + struct io_rsrc_put *prsrc, *tmp; + + list_for_each_entry_safe(prsrc, tmp, &ref_node->rsrc_list, list) { + list_del(&prsrc->list); + + if (prsrc->tag) { + bool lock_ring = ctx->flags & IORING_SETUP_IOPOLL;

- list_for_each_entry_safe(pfile, tmp, &ref_node->file_list, list) { - list_del(&pfile->list); - io_ring_file_put(ctx, pfile->file); - kfree(pfile); + io_ring_submit_lock(ctx, lock_ring); + spin_lock(&ctx->completion_lock); + io_fill_cqe_aux(ctx, prsrc->tag, 0, 0); + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock); + io_cqring_ev_posted(ctx); + io_ring_submit_unlock(ctx, lock_ring); + } + + rsrc_data->do_put(ctx, prsrc); + kfree(prsrc); }

- percpu_ref_exit(&ref_node->refs); - kfree(ref_node); - percpu_ref_put(&file_data->refs); + io_rsrc_node_destroy(ref_node); + if (atomic_dec_and_test(&rsrc_data->refs)) + complete(&rsrc_data->done); }

-static void io_file_put_work(struct work_struct *work) +static void io_rsrc_put_work(struct work_struct *work) { struct io_ring_ctx *ctx; struct llist_node *node;

- ctx = container_of(work, struct io_ring_ctx, file_put_work.work); - node = llist_del_all(&ctx->file_put_llist); + ctx = container_of(work, struct io_ring_ctx, rsrc_put_work.work); + node = llist_del_all(&ctx->rsrc_put_llist);

while (node) { - struct fixed_file_ref_node *ref_node; + struct io_rsrc_node *ref_node; struct llist_node *next = node->next;

- ref_node = llist_entry(node, struct fixed_file_ref_node, llist); - __io_file_put_work(ref_node); + ref_node = llist_entry(node, struct io_rsrc_node, llist); + __io_rsrc_put_work(ref_node); node = next; } }

-static void io_file_data_ref_zero(struct percpu_ref *ref) -{ - struct fixed_file_ref_node *ref_node; - struct fixed_file_data *data; - struct io_ring_ctx *ctx; - bool first_add = false; - int delay = HZ; - - ref_node = container_of(ref, struct fixed_file_ref_node, refs); - data = ref_node->file_data; - ctx = data->ctx; - - spin_lock_bh(&data->lock); - ref_node->done = true; - - while (!list_empty(&data->ref_list)) { - ref_node = list_first_entry(&data->ref_list, - struct fixed_file_ref_node, node); - /* recycle ref nodes in order */ - if (!ref_node->done) - break; - list_del(&ref_node->node); - first_add |= llist_add(&ref_node->llist, &ctx->file_put_llist); - } - spin_unlock_bh(&data->lock); - - if (percpu_ref_is_dying(&data->refs)) - delay = 0; - - if (!delay) - mod_delayed_work(system_wq, &ctx->file_put_work, 0); - else if (first_add) - queue_delayed_work(system_wq, &ctx->file_put_work, delay); -} - -static struct fixed_file_ref_node *alloc_fixed_file_ref_node( - struct io_ring_ctx *ctx) -{ - struct fixed_file_ref_node *ref_node; - - ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL); - if (!ref_node) - return NULL; - - if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero, - 0, GFP_KERNEL)) { - kfree(ref_node); - return NULL; - } - INIT_LIST_HEAD(&ref_node->node); - INIT_LIST_HEAD(&ref_node->file_list); - ref_node->file_data = ctx->file_data; - ref_node->done = false; - return ref_node; -} - -static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node) -{ - percpu_ref_exit(&ref_node->refs); - kfree(ref_node); -} - static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, - unsigned nr_args) + unsigned nr_args, u64 __user *tags) { __s32 __user *fds = (__s32 __user *) arg; - unsigned nr_tables, i; struct file *file; - int fd, ret = -ENOMEM; - struct fixed_file_ref_node *ref_node; - struct fixed_file_data *file_data; + int fd, ret; + unsigned i;

if (ctx->file_data) return -EBUSY; @@ -7627,44 +8151,34 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, return -EMFILE; if (nr_args > rlimit(RLIMIT_NOFILE)) return -EMFILE; + ret = io_rsrc_node_switch_start(ctx); + if (ret) + return ret; + ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args, + &ctx->file_data); + if (ret) + return ret;

- file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL_ACCOUNT); - if (!file_data) - return -ENOMEM; - file_data->ctx = ctx; - init_completion(&file_data->done); - INIT_LIST_HEAD(&file_data->ref_list); - spin_lock_init(&file_data->lock); - - nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE); - file_data->table = kcalloc(nr_tables, sizeof(*file_data->table), - GFP_KERNEL_ACCOUNT); - if (!file_data->table) - goto out_free; - - if (percpu_ref_init(&file_data->refs, io_file_ref_kill, - PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) + ret = -ENOMEM; + if (!io_alloc_file_tables(&ctx->file_table, nr_args)) goto out_free;

- if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args)) - goto out_ref; - ctx->file_data = file_data; - for (i = 0; i < nr_args; i++, ctx->nr_user_files++) { - struct fixed_file_table *table; - unsigned index; - if (copy_from_user(&fd, &fds[i], sizeof(fd))) { ret = -EFAULT; goto out_fput; } /* allow sparse sets */ - if (fd == -1) + if (fd == -1) { + ret = -EINVAL; + if (unlikely(*io_get_tag_slot(ctx->file_data, i))) + goto out_fput; continue; + }

file = fget(fd); ret = -EBADF; - if (!file) + if (unlikely(!file)) goto out_fput;

/* @@ -7678,24 +8192,16 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, fput(file); goto out_fput; } - table = &file_data->table[i >> IORING_FILE_TABLE_SHIFT]; - index = i & IORING_FILE_TABLE_MASK; - table->files[index] = file; + io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file); }

ret = io_sqe_files_scm(ctx); if (ret) { - io_sqe_files_unregister(ctx); + __io_sqe_files_unregister(ctx); return ret; }

- ref_node = alloc_fixed_file_ref_node(ctx); - if (!ref_node) { - io_sqe_files_unregister(ctx); - return -ENOMEM; - } - - io_sqe_files_set_node(file_data, ref_node); + io_rsrc_node_switch(ctx, NULL); return ret; out_fput: for (i = 0; i < ctx->nr_user_files; i++) { @@ -7703,14 +8209,10 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, if (file) fput(file); } - for (i = 0; i < nr_tables; i++) - kfree(file_data->table[i].files); + io_free_file_tables(&ctx->file_table); ctx->nr_user_files = 0; -out_ref: - percpu_ref_exit(&file_data->refs); out_free: - kfree(file_data->table); - kfree(file_data); + io_rsrc_data_free(ctx->file_data); ctx->file_data = NULL; return ret; } @@ -7745,76 +8247,172 @@ static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file, skb = NULL; } } - spin_unlock_irq(&head->lock); + spin_unlock_irq(&head->lock); + + if (skb) { + fput(file); + return 0; + } + + return __io_sqe_files_scm(ctx, 1, index); +#else + return 0; +#endif +} + +static int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx, + struct io_rsrc_node *node, void *rsrc) +{ + u64 *tag_slot = io_get_tag_slot(data, idx); + struct io_rsrc_put *prsrc; + + prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL); + if (!prsrc) + return -ENOMEM; + + prsrc->tag = *tag_slot; + *tag_slot = 0; + prsrc->rsrc = rsrc; + list_add(&prsrc->list, &node->rsrc_list); + return 0; +} + +static int io_install_fixed_file(struct io_kiocb *req, struct file *file, + unsigned int issue_flags, u32 slot_index) +{ + struct io_ring_ctx *ctx = req->ctx; + bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; + bool needs_switch = false; + struct io_fixed_file *file_slot; + int ret = -EBADF; + + io_ring_submit_lock(ctx, !force_nonblock); + if (file->f_op == &io_uring_fops) + goto err; + ret = -ENXIO; + if (!ctx->file_data) + goto err; + ret = -EINVAL; + if (slot_index >= ctx->nr_user_files) + goto err; + + slot_index = array_index_nospec(slot_index, ctx->nr_user_files); + file_slot = io_fixed_file_slot(&ctx->file_table, slot_index); + + if (file_slot->file_ptr) { + struct file *old_file; + + ret = io_rsrc_node_switch_start(ctx); + if (ret) + goto err; + + old_file = (struct file *)(file_slot->file_ptr & FFS_MASK); + ret = io_queue_rsrc_removal(ctx->file_data, slot_index, + ctx->rsrc_node, old_file); + if (ret) + goto err; + file_slot->file_ptr = 0; + needs_switch = true; + } + + *io_get_tag_slot(ctx->file_data, slot_index) = 0; + io_fixed_file_set(file_slot, file); + ret = io_sqe_file_register(ctx, file, slot_index); + if (ret) { + file_slot->file_ptr = 0; + goto err; + }

- if (skb) { + ret = 0; +err: + if (needs_switch) + io_rsrc_node_switch(ctx, ctx->file_data); + io_ring_submit_unlock(ctx, !force_nonblock); + if (ret) fput(file); - return 0; - } - - return __io_sqe_files_scm(ctx, 1, index); -#else - return 0; -#endif + return ret; }

-static int io_queue_file_removal(struct fixed_file_data *data, - struct file *file) +static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags) { - struct io_file_put *pfile; - struct fixed_file_ref_node *ref_node = data->node; + unsigned int offset = req->close.file_slot - 1; + struct io_ring_ctx *ctx = req->ctx; + struct io_fixed_file *file_slot; + struct file *file; + int ret;

- pfile = kzalloc(sizeof(*pfile), GFP_KERNEL); - if (!pfile) - return -ENOMEM; + io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); + ret = -ENXIO; + if (unlikely(!ctx->file_data)) + goto out; + ret = -EINVAL; + if (offset >= ctx->nr_user_files) + goto out; + ret = io_rsrc_node_switch_start(ctx); + if (ret) + goto out; + + offset = array_index_nospec(offset, ctx->nr_user_files); + file_slot = io_fixed_file_slot(&ctx->file_table, offset); + ret = -EBADF; + if (!file_slot->file_ptr) + goto out;

- pfile->file = file; - list_add(&pfile->list, &ref_node->file_list); + file = (struct file *)(file_slot->file_ptr & FFS_MASK); + ret = io_queue_rsrc_removal(ctx->file_data, offset, ctx->rsrc_node, file); + if (ret) + goto out;

- return 0; + file_slot->file_ptr = 0; + io_rsrc_node_switch(ctx, ctx->file_data); + ret = 0; +out: + io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK)); + return ret; }

static int __io_sqe_files_update(struct io_ring_ctx *ctx, - struct io_uring_files_update *up, + struct io_uring_rsrc_update2 *up, unsigned nr_args) { - struct fixed_file_data *data = ctx->file_data; - struct fixed_file_ref_node *ref_node; + u64 __user *tags = u64_to_user_ptr(up->tags); + __s32 __user *fds = u64_to_user_ptr(up->data); + struct io_rsrc_data *data = ctx->file_data; + struct io_fixed_file *file_slot; struct file *file; - __s32 __user *fds; - int fd, i, err; - __u32 done; + int fd, i, err = 0; + unsigned int done; bool needs_switch = false;

- if (check_add_overflow(up->offset, nr_args, &done)) - return -EOVERFLOW; - if (done > ctx->nr_user_files) + if (!ctx->file_data) + return -ENXIO; + if (up->offset + nr_args > ctx->nr_user_files) return -EINVAL;

- ref_node = alloc_fixed_file_ref_node(ctx); - if (!ref_node) - return -ENOMEM; - - done = 0; - fds = u64_to_user_ptr(up->fds); - while (nr_args) { - struct fixed_file_table *table; - unsigned index; + for (done = 0; done < nr_args; done++) { + u64 tag = 0;

- err = 0; - if (copy_from_user(&fd, &fds[done], sizeof(fd))) { + if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) || + copy_from_user(&fd, &fds[done], sizeof(fd))) { err = -EFAULT; break; } - i = array_index_nospec(up->offset, ctx->nr_user_files); - table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT]; - index = i & IORING_FILE_TABLE_MASK; - if (table->files[index]) { - file = table->files[index]; - err = io_queue_file_removal(data, file); + if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) { + err = -EINVAL; + break; + } + if (fd == IORING_REGISTER_FILES_SKIP) + continue; + + i = array_index_nospec(up->offset + done, ctx->nr_user_files); + file_slot = io_fixed_file_slot(&ctx->file_table, i); + + if (file_slot->file_ptr) { + file = (struct file *)(file_slot->file_ptr & FFS_MASK); + err = io_queue_rsrc_removal(data, i, ctx->rsrc_node, file); if (err) break; - table->files[index] = NULL; + file_slot->file_ptr = 0; needs_switch = true; } if (fd != -1) { @@ -7836,106 +8434,61 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx, err = -EBADF; break; } - table->files[index] = file; + *io_get_tag_slot(data, i) = tag; + io_fixed_file_set(file_slot, file); err = io_sqe_file_register(ctx, file, i); if (err) { - table->files[index] = NULL; + file_slot->file_ptr = 0; fput(file); break; } } - nr_args--; - done++; - up->offset++; }

- if (needs_switch) { - percpu_ref_kill(&data->node->refs); - io_sqe_files_set_node(data, ref_node); - } else - destroy_fixed_file_ref_node(ref_node); - + if (needs_switch) + io_rsrc_node_switch(ctx, data); return done ? done : err; }

-static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg, - unsigned nr_args) -{ - struct io_uring_files_update up; - - if (!ctx->file_data) - return -ENXIO; - if (!nr_args) - return -EINVAL; - if (copy_from_user(&up, arg, sizeof(up))) - return -EFAULT; - if (up.resv) - return -EINVAL; - - return __io_sqe_files_update(ctx, &up, nr_args); -} - -static void io_free_work(struct io_wq_work *work) -{ - struct io_kiocb *req = container_of(work, struct io_kiocb, work); - - /* Consider that io_steal_work() relies on this ref */ - io_put_req(req); -} - -static int io_init_wq_offload(struct io_ring_ctx *ctx, - struct io_uring_params *p) +static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx, + struct task_struct *task) { + struct io_wq_hash *hash; struct io_wq_data data; - struct fd f; - struct io_ring_ctx *ctx_attach; unsigned int concurrency; - int ret = 0; - - data.user = ctx->user; - data.free_work = io_free_work; - data.do_work = io_wq_submit_work;

- if (!(p->flags & IORING_SETUP_ATTACH_WQ)) { - /* Do QD, or 4 * CPUS, whatever is smallest */ - concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); - - ctx->io_wq = io_wq_create(concurrency, &data); - if (IS_ERR(ctx->io_wq)) { - ret = PTR_ERR(ctx->io_wq); - ctx->io_wq = NULL; + mutex_lock(&ctx->uring_lock); + hash = ctx->hash_map; + if (!hash) { + hash = kzalloc(sizeof(*hash), GFP_KERNEL); + if (!hash) { + mutex_unlock(&ctx->uring_lock); + return ERR_PTR(-ENOMEM); } - return ret; + refcount_set(&hash->refs, 1); + init_waitqueue_head(&hash->wait); + ctx->hash_map = hash; } + mutex_unlock(&ctx->uring_lock);

- f = fdget(p->wq_fd); - if (!f.file) - return -EBADF; - - if (f.file->f_op != &io_uring_fops) { - ret = -EINVAL; - goto out_fput; - } + data.hash = hash; + data.task = task; + data.free_work = io_wq_free_work; + data.do_work = io_wq_submit_work;

- ctx_attach = f.file->private_data; - /* @io_wq is protected by holding the fd */ - if (!io_wq_get(ctx_attach->io_wq, &data)) { - ret = -EINVAL; - goto out_fput; - } + /* Do QD, or 4 * CPUS, whatever is smallest */ + concurrency = min(ctx->sq_entries, 4 * num_online_cpus());

- ctx->io_wq = ctx_attach->io_wq; -out_fput: - fdput(f); - return ret; + return io_wq_create(concurrency, &data); }

-static int io_uring_alloc_task_context(struct task_struct *task) +static int io_uring_alloc_task_context(struct task_struct *task, + struct io_ring_ctx *ctx) { struct io_uring_task *tctx; int ret;

- tctx = kmalloc(sizeof(*tctx), GFP_KERNEL); + tctx = kzalloc(sizeof(*tctx), GFP_KERNEL); if (unlikely(!tctx)) return -ENOMEM;

@@ -7945,14 +8498,22 @@ static int io_uring_alloc_task_context(struct task_struct *task) return ret; }

+ tctx->io_wq = io_init_wq_offload(ctx, task); + if (IS_ERR(tctx->io_wq)) { + ret = PTR_ERR(tctx->io_wq); + percpu_counter_destroy(&tctx->inflight); + kfree(tctx); + return ret; + } + xa_init(&tctx->xa); init_waitqueue_head(&tctx->wait); - tctx->last = NULL; atomic_set(&tctx->in_idle, 0); - tctx->sqpoll = false; - io_init_identity(&tctx->__identity); - tctx->identity = &tctx->__identity; + atomic_set(&tctx->inflight_tracked, 0); task->io_uring = tctx; + spin_lock_init(&tctx->task_lock); + INIT_WQ_LIST(&tctx->task_list); + init_task_work(&tctx->task_work, tctx_task_work); return 0; }

@@ -7961,9 +8522,9 @@ void __io_uring_free(struct task_struct *tsk) struct io_uring_task *tctx = tsk->io_uring;

WARN_ON_ONCE(!xa_empty(&tctx->xa)); - WARN_ON_ONCE(refcount_read(&tctx->identity->count) != 1); - if (tctx->identity != &tctx->__identity) - kfree(tctx->identity); + WARN_ON_ONCE(tctx->io_wq); + WARN_ON_ONCE(tctx->cached_refs); + percpu_counter_destroy(&tctx->inflight); kfree(tctx); tsk->io_uring = NULL; @@ -7974,54 +8535,71 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, { int ret;

+ /* Retain compatibility with failing for an invalid attach attempt */ + if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) == + IORING_SETUP_ATTACH_WQ) { + struct fd f; + + f = fdget(p->wq_fd); + if (!f.file) + return -ENXIO; + if (f.file->f_op != &io_uring_fops) { + fdput(f); + return -EINVAL; + } + fdput(f); + } if (ctx->flags & IORING_SETUP_SQPOLL) { + struct task_struct *tsk; struct io_sq_data *sqd; + bool attached;

- ret = -EPERM; - if (!capable(CAP_SYS_ADMIN)) - goto err; - - sqd = io_get_sq_data(p); + sqd = io_get_sq_data(p, &attached); if (IS_ERR(sqd)) { ret = PTR_ERR(sqd); goto err; }

+ ctx->sq_creds = get_current_cred(); ctx->sq_data = sqd; - io_sq_thread_park(sqd); - mutex_lock(&sqd->ctx_lock); - list_add(&ctx->sqd_list, &sqd->ctx_new_list); - mutex_unlock(&sqd->ctx_lock); - io_sq_thread_unpark(sqd); - ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle); if (!ctx->sq_thread_idle) ctx->sq_thread_idle = HZ;

- if (sqd->thread) - goto done; + io_sq_thread_park(sqd); + list_add(&ctx->sqd_list, &sqd->ctx_list); + io_sqd_update_thread_idle(sqd); + /* don't attach to a dying SQPOLL thread, would be racy */ + ret = (attached && !sqd->thread) ? -ENXIO : 0; + io_sq_thread_unpark(sqd); + + if (ret < 0) + goto err; + if (attached) + return 0;

if (p->flags & IORING_SETUP_SQ_AFF) { int cpu = p->sq_thread_cpu;

ret = -EINVAL; - if (cpu >= nr_cpu_ids) - goto err; - if (!cpu_online(cpu)) - goto err; - - sqd->thread = kthread_create_on_cpu(io_sq_thread, sqd, - cpu, "io_uring-sq"); + if (cpu >= nr_cpu_ids || !cpu_online(cpu)) + goto err_sqpoll; + sqd->sq_cpu = cpu; } else { - sqd->thread = kthread_create(io_sq_thread, sqd, - "io_uring-sq"); + sqd->sq_cpu = -1; } - if (IS_ERR(sqd->thread)) { - ret = PTR_ERR(sqd->thread); - sqd->thread = NULL; - goto err; + + sqd->task_pid = current->pid; + sqd->task_tgid = current->tgid; + tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE); + if (IS_ERR(tsk)) { + ret = PTR_ERR(tsk); + goto err_sqpoll; } - ret = io_uring_alloc_task_context(sqd->thread); + + sqd->thread = tsk; + ret = io_uring_alloc_task_context(tsk, ctx); + wake_up_new_task(tsk); if (ret) goto err; } else if (p->flags & IORING_SETUP_SQ_AFF) { @@ -8030,26 +8608,14 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, goto err; }

-done: - ret = io_init_wq_offload(ctx, p); - if (ret) - goto err; - return 0; +err_sqpoll: + complete(&ctx->sq_data->exited); err: - io_finish_async(ctx); + io_sq_thread_finish(ctx); return ret; }

-static void io_sq_offload_start(struct io_ring_ctx *ctx) -{ - struct io_sq_data *sqd = ctx->sq_data; - - ctx->flags &= ~IORING_SETUP_R_DISABLED; - if ((ctx->flags & IORING_SETUP_SQPOLL) && sqd && sqd->thread) - wake_up_process(sqd->thread); -} - static inline void __io_unaccount_mem(struct user_struct *user, unsigned long nr_pages) { @@ -8075,37 +8641,27 @@ static inline int __io_account_mem(struct user_struct *user, return 0; }

-static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages, - enum io_mem_account acct) +static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) { - if (ctx->limit_mem) + if (ctx->user) __io_unaccount_mem(ctx->user, nr_pages);

- if (ctx->mm_account) { - if (acct == ACCT_LOCKED) - ctx->mm_account->locked_vm -= nr_pages; - else if (acct == ACCT_PINNED) - atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm); - } + if (ctx->mm_account) + atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm); }

-static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages, - enum io_mem_account acct) +static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) { int ret;

- if (ctx->limit_mem) { + if (ctx->user) { ret = __io_account_mem(ctx->user, nr_pages); if (ret) return ret; }

- if (ctx->mm_account) { - if (acct == ACCT_LOCKED) - ctx->mm_account->locked_vm += nr_pages; - else if (acct == ACCT_PINNED) - atomic64_add(nr_pages, &ctx->mm_account->pinned_vm); - } + if (ctx->mm_account) + atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);

return 0; } @@ -8124,10 +8680,9 @@ static void io_mem_free(void *ptr)

static void *io_mem_alloc(size_t size) { - gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP | - __GFP_NORETRY; + gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP;

- return (void *) __get_free_pages(gfp_flags, get_order(size)); + return (void *) __get_free_pages(gfp, get_order(size)); }

static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries, @@ -8159,41 +8714,58 @@ static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries, return off; }

-static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries) +static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slot) { - size_t pages; - - pages = (size_t)1 << get_order( - rings_size(sq_entries, cq_entries, NULL)); - pages += (size_t)1 << get_order( - array_size(sizeof(struct io_uring_sqe), sq_entries)); + struct io_mapped_ubuf *imu = *slot; + unsigned int i;

- return pages; + if (imu != ctx->dummy_ubuf) { + for (i = 0; i < imu->nr_bvecs; i++) + unpin_user_page(imu->bvec[i].bv_page); + if (imu->acct_pages) + io_unaccount_mem(ctx, imu->acct_pages); + kvfree(imu); + } + *slot = NULL; }

-static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx) +static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc) { - int i, j; + io_buffer_unmap(ctx, &prsrc->buf); + prsrc->buf = NULL; +}

- if (!ctx->user_bufs) - return -ENXIO; +static void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx) +{ + unsigned int i;

- for (i = 0; i < ctx->nr_user_bufs; i++) { - struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; + for (i = 0; i < ctx->nr_user_bufs; i++) + io_buffer_unmap(ctx, &ctx->user_bufs[i]); + kfree(ctx->user_bufs); + io_rsrc_data_free(ctx->buf_data); + ctx->user_bufs = NULL; + ctx->buf_data = NULL; + ctx->nr_user_bufs = 0; +}

- for (j = 0; j < imu->nr_bvecs; j++) - unpin_user_page(imu->bvec[j].bv_page); +static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) +{ + unsigned nr = ctx->nr_user_bufs; + int ret;

- if (imu->acct_pages) - io_unaccount_mem(ctx, imu->acct_pages, ACCT_PINNED); - kvfree(imu->bvec); - imu->nr_bvecs = 0; - } + if (!ctx->buf_data) + return -ENXIO;

- kfree(ctx->user_bufs); - ctx->user_bufs = NULL; + /* + * Quiesce may unlock ->uring_lock, and while it's not held + * prevent new requests using the table. + */ ctx->nr_user_bufs = 0; - return 0; + ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx); + ctx->nr_user_bufs = nr; + if (!ret) + __io_sqe_buffers_unregister(ctx); + return ret; }

static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, @@ -8245,7 +8817,7 @@ static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,

/* check previously registered pages */ for (i = 0; i < ctx->nr_user_bufs; i++) { - struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; + struct io_mapped_ubuf *imu = ctx->user_bufs[i];

for (j = 0; j < imu->nr_bvecs; j++) { if (!PageCompound(imu->bvec[j].bv_page)) @@ -8264,6 +8836,7 @@ static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages, { int i, ret;

+ imu->acct_pages = 0; for (i = 0; i < nr_pages; i++) { if (!PageCompound(pages[i])) { imu->acct_pages++; @@ -8283,147 +8856,252 @@ static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages, if (!imu->acct_pages) return 0;

- ret = io_account_mem(ctx, imu->acct_pages, ACCT_PINNED); + ret = io_account_mem(ctx, imu->acct_pages); if (ret) imu->acct_pages = 0; return ret; }

-static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, - unsigned nr_args) +static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, + struct io_mapped_ubuf **pimu, + struct page **last_hpage) { + struct io_mapped_ubuf *imu = NULL; struct vm_area_struct **vmas = NULL; struct page **pages = NULL; + unsigned long off, start, end, ubuf; + size_t size; + int ret, pret, nr_pages, i; + + if (!iov->iov_base) { + *pimu = ctx->dummy_ubuf; + return 0; + } + + ubuf = (unsigned long) iov->iov_base; + end = (ubuf + iov->iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; + start = ubuf >> PAGE_SHIFT; + nr_pages = end - start; + + *pimu = NULL; + ret = -ENOMEM; + + pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL); + if (!pages) + goto done; + + vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *), + GFP_KERNEL); + if (!vmas) + goto done; + + imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL); + if (!imu) + goto done; + + ret = 0; + mmap_read_lock(current->mm); + pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM, + pages, vmas); + if (pret == nr_pages) { + /* don't support file backed memory */ + for (i = 0; i < nr_pages; i++) { + struct vm_area_struct *vma = vmas[i]; + + if (vma_is_shmem(vma)) + continue; + if (vma->vm_file && + !is_file_hugepages(vma->vm_file)) { + ret = -EOPNOTSUPP; + break; + } + } + } else { + ret = pret < 0 ? pret : -EFAULT; + } + mmap_read_unlock(current->mm); + if (ret) { + /* + * if we did partial map, or found file backed vmas, + * release any pages we did get + */ + if (pret > 0) + unpin_user_pages(pages, pret); + goto done; + } + + ret = io_buffer_account_pin(ctx, pages, pret, imu, last_hpage); + if (ret) { + unpin_user_pages(pages, pret); + goto done; + } + + off = ubuf & ~PAGE_MASK; + size = iov->iov_len; + for (i = 0; i < nr_pages; i++) { + size_t vec_len; + + vec_len = min_t(size_t, size, PAGE_SIZE - off); + imu->bvec[i].bv_page = pages[i]; + imu->bvec[i].bv_len = vec_len; + imu->bvec[i].bv_offset = off; + off = 0; + size -= vec_len; + } + /* store original address for later verification */ + imu->ubuf = ubuf; + imu->ubuf_end = ubuf + iov->iov_len; + imu->nr_bvecs = nr_pages; + *pimu = imu; + ret = 0; +done: + if (ret) + kvfree(imu); + kvfree(pages); + kvfree(vmas); + return ret; +} + +static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args) +{ + ctx->user_bufs = kcalloc(nr_args, sizeof(*ctx->user_bufs), GFP_KERNEL); + return ctx->user_bufs ? 0 : -ENOMEM; +} + +static int io_buffer_validate(struct iovec *iov) +{ + unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1); + + /* + * Don't impose further limits on the size and buffer + * constraints here, we'll -EINVAL later when IO is + * submitted if they are wrong. + */ + if (!iov->iov_base) + return iov->iov_len ? -EFAULT : 0; + if (!iov->iov_len) + return -EFAULT; + + /* arbitrary limit, but we need something */ + if (iov->iov_len > SZ_1G) + return -EFAULT; + + if (check_add_overflow((unsigned long)iov->iov_base, acct_len, &tmp)) + return -EOVERFLOW; + + return 0; +} + +static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, + unsigned int nr_args, u64 __user *tags) +{ struct page *last_hpage = NULL; - int i, j, got_pages = 0; - int ret = -EINVAL; + struct io_rsrc_data *data; + int i, ret; + struct iovec iov;

if (ctx->user_bufs) return -EBUSY; - if (!nr_args || nr_args > UIO_MAXIOV) + if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS) return -EINVAL; + ret = io_rsrc_node_switch_start(ctx); + if (ret) + return ret; + ret = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data); + if (ret) + return ret; + ret = io_buffers_map_alloc(ctx, nr_args); + if (ret) { + io_rsrc_data_free(data); + return ret; + }

- ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf), - GFP_KERNEL); - if (!ctx->user_bufs) - return -ENOMEM; - - for (i = 0; i < nr_args; i++) { - struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; - unsigned long off, start, end, ubuf; - int pret, nr_pages; - struct iovec iov; - size_t size; - + for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) { ret = io_copy_iov(ctx, &iov, arg, i); if (ret) - goto err; + break; + ret = io_buffer_validate(&iov); + if (ret) + break; + if (!iov.iov_base && *io_get_tag_slot(data, i)) { + ret = -EINVAL; + break; + }

- /* - * Don't impose further limits on the size and buffer - * constraints here, we'll -EINVAL later when IO is - * submitted if they are wrong. - */ - ret = -EFAULT; - if (!iov.iov_base || !iov.iov_len) - goto err; + ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i], + &last_hpage); + if (ret) + break; + }

- /* arbitrary limit, but we need something */ - if (iov.iov_len > SZ_1G) - goto err; + WARN_ON_ONCE(ctx->buf_data);

- ubuf = (unsigned long) iov.iov_base; - end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; - start = ubuf >> PAGE_SHIFT; - nr_pages = end - start; + ctx->buf_data = data; + if (ret) + __io_sqe_buffers_unregister(ctx); + else + io_rsrc_node_switch(ctx, NULL); + return ret; +}

- ret = 0; - if (!pages || nr_pages > got_pages) { - kvfree(vmas); - kvfree(pages); - pages = kvmalloc_array(nr_pages, sizeof(struct page *), - GFP_KERNEL); - vmas = kvmalloc_array(nr_pages, - sizeof(struct vm_area_struct *), - GFP_KERNEL); - if (!pages || !vmas) { - ret = -ENOMEM; - goto err; - } - got_pages = nr_pages; - } +static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, + struct io_uring_rsrc_update2 *up, + unsigned int nr_args) +{ + u64 __user *tags = u64_to_user_ptr(up->tags); + struct iovec iov, __user *iovs = u64_to_user_ptr(up->data); + struct page *last_hpage = NULL; + bool needs_switch = false; + __u32 done; + int i, err; + + if (!ctx->buf_data) + return -ENXIO; + if (up->offset + nr_args > ctx->nr_user_bufs) + return -EINVAL;

- imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec), - GFP_KERNEL); - ret = -ENOMEM; - if (!imu->bvec) - goto err; + for (done = 0; done < nr_args; done++) { + struct io_mapped_ubuf *imu; + int offset = up->offset + done; + u64 tag = 0;

- ret = 0; - mmap_read_lock(current->mm); - pret = pin_user_pages(ubuf, nr_pages, - FOLL_WRITE | FOLL_LONGTERM, - pages, vmas); - if (pret == nr_pages) { - /* don't support file backed memory */ - for (j = 0; j < nr_pages; j++) { - struct vm_area_struct *vma = vmas[j]; - - if (vma->vm_file && - !is_file_hugepages(vma->vm_file)) { - ret = -EOPNOTSUPP; - break; - } - } - } else { - ret = pret < 0 ? pret : -EFAULT; - } - mmap_read_unlock(current->mm); - if (ret) { - /* - * if we did partial map, or found file backed vmas, - * release any pages we did get - */ - if (pret > 0) - unpin_user_pages(pages, pret); - kvfree(imu->bvec); - goto err; + err = io_copy_iov(ctx, &iov, iovs, done); + if (err) + break; + if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) { + err = -EFAULT; + break; } - - ret = io_buffer_account_pin(ctx, pages, pret, imu, &last_hpage); - if (ret) { - unpin_user_pages(pages, pret); - kvfree(imu->bvec); - goto err; + err = io_buffer_validate(&iov); + if (err) + break; + if (!iov.iov_base && tag) { + err = -EINVAL; + break; } + err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage); + if (err) + break;

- off = ubuf & ~PAGE_MASK; - size = iov.iov_len; - for (j = 0; j < nr_pages; j++) { - size_t vec_len; - - vec_len = min_t(size_t, size, PAGE_SIZE - off); - imu->bvec[j].bv_page = pages[j]; - imu->bvec[j].bv_len = vec_len; - imu->bvec[j].bv_offset = off; - off = 0; - size -= vec_len; + i = array_index_nospec(offset, ctx->nr_user_bufs); + if (ctx->user_bufs[i] != ctx->dummy_ubuf) { + err = io_queue_rsrc_removal(ctx->buf_data, i, + ctx->rsrc_node, ctx->user_bufs[i]); + if (unlikely(err)) { + io_buffer_unmap(ctx, &imu); + break; + } + ctx->user_bufs[i] = NULL; + needs_switch = true; } - /* store original address for later verification */ - imu->ubuf = ubuf; - imu->len = iov.iov_len; - imu->nr_bvecs = nr_pages;

- ctx->nr_user_bufs++; + ctx->user_bufs[i] = imu; + *io_get_tag_slot(ctx->buf_data, offset) = tag; } - kvfree(pages); - kvfree(vmas); - return 0; -err: - kvfree(pages); - kvfree(vmas); - io_sqe_buffer_unregister(ctx); - return ret; + + if (needs_switch) + io_rsrc_node_switch(ctx, ctx->buf_data); + return done ? done : err; }

static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg) @@ -8440,6 +9118,7 @@ static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg) ctx->cq_ev_fd = eventfd_ctx_fdget(fd); if (IS_ERR(ctx->cq_ev_fd)) { int ret = PTR_ERR(ctx->cq_ev_fd); + ctx->cq_ev_fd = NULL; return ret; } @@ -8467,26 +9146,68 @@ static void io_destroy_buffers(struct io_ring_ctx *ctx) __io_remove_buffers(ctx, buf, index, -1U); }

-static void io_ring_ctx_free(struct io_ring_ctx *ctx) +static void io_req_cache_free(struct list_head *list) { - io_finish_async(ctx); - io_sqe_buffer_unregister(ctx); + struct io_kiocb *req, *nxt;

- if (ctx->sqo_task) { - put_task_struct(ctx->sqo_task); - ctx->sqo_task = NULL; + list_for_each_entry_safe(req, nxt, list, inflight_entry) { + list_del(&req->inflight_entry); + kmem_cache_free(req_cachep, req); } +}

-#ifdef CONFIG_BLK_CGROUP - if (ctx->sqo_blkcg_css) - css_put(ctx->sqo_blkcg_css); -#endif +static void io_req_caches_free(struct io_ring_ctx *ctx) +{ + struct io_submit_state *state = &ctx->submit_state; + + mutex_lock(&ctx->uring_lock); + + if (state->free_reqs) { + kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs); + state->free_reqs = 0; + } + + io_flush_cached_locked_reqs(ctx, state); + io_req_cache_free(&state->free_list); + mutex_unlock(&ctx->uring_lock); +} + +static void io_wait_rsrc_data(struct io_rsrc_data *data) +{ + if (data && !atomic_dec_and_test(&data->refs)) + wait_for_completion(&data->done); +} + +static void io_ring_ctx_free(struct io_ring_ctx *ctx) +{ + io_sq_thread_finish(ctx); + + /* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */ + io_wait_rsrc_data(ctx->buf_data); + io_wait_rsrc_data(ctx->file_data);

mutex_lock(&ctx->uring_lock); - io_sqe_files_unregister(ctx); + if (ctx->buf_data) + __io_sqe_buffers_unregister(ctx); + if (ctx->file_data) + __io_sqe_files_unregister(ctx); + if (ctx->rings) + __io_cqring_overflow_flush(ctx, true); mutex_unlock(&ctx->uring_lock); io_eventfd_unregister(ctx); io_destroy_buffers(ctx); + if (ctx->sq_creds) + put_cred(ctx->sq_creds); + + /* there are no registered resources left, nobody uses it */ + if (ctx->rsrc_node) + io_rsrc_node_destroy(ctx->rsrc_node); + if (ctx->rsrc_backup_node) + io_rsrc_node_destroy(ctx->rsrc_backup_node); + flush_delayed_work(&ctx->rsrc_put_work); + + WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list)); + WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));

#if defined(CONFIG_UNIX) if (ctx->ring_sock) { @@ -8494,6 +9215,7 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) sock_release(ctx->ring_sock); } #endif + WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));

if (ctx->mm_account) { mmdrop(ctx->mm_account); @@ -8505,9 +9227,11 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)

percpu_ref_exit(&ctx->refs); free_uid(ctx->user); - put_cred(ctx->creds); + io_req_caches_free(ctx); + if (ctx->hash_map) + io_wq_put_hash(ctx->hash_map); kfree(ctx->cancel_hash); - kmem_cache_free(req_cachep, ctx->fallback_req); + kfree(ctx->dummy_ubuf); kfree(ctx); }

@@ -8516,7 +9240,7 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait) struct io_ring_ctx *ctx = file->private_data; __poll_t mask = 0;

- poll_wait(file, &ctx->cq_wait, wait); + poll_wait(file, &ctx->poll_wait, wait); /* * synchronizes with barrier from wq_has_sleeper call in * io_commit_cqring @@ -8538,38 +9262,63 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait) * Users may get EPOLLIN meanwhile seeing nothing in cqring, this * pushs them to do the flush. */ - if (io_cqring_events(ctx) || test_bit(0, &ctx->cq_check_overflow)) + if (io_cqring_events(ctx) || test_bit(0, &ctx->check_cq_overflow)) mask |= EPOLLIN | EPOLLRDNORM;

return mask; }

-static int io_uring_fasync(int fd, struct file *file, int on) -{ - struct io_ring_ctx *ctx = file->private_data; - - return fasync_helper(fd, file, on, &ctx->cq_fasync); -} - static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) { - struct io_identity *iod; + const struct cred *creds;

- iod = xa_erase(&ctx->personalities, id); - if (iod) { - put_cred(iod->creds); - if (refcount_dec_and_test(&iod->count)) - kfree(iod); + creds = xa_erase(&ctx->personalities, id); + if (creds) { + put_cred(creds); return 0; }

return -EINVAL; }

+struct io_tctx_exit { + struct callback_head task_work; + struct completion completion; + struct io_ring_ctx *ctx; +}; + +static void io_tctx_exit_cb(struct callback_head *cb) +{ + struct io_uring_task *tctx = current->io_uring; + struct io_tctx_exit *work; + + work = container_of(cb, struct io_tctx_exit, task_work); + /* + * When @in_idle, we're in cancellation and it's racy to remove the + * node. It'll be removed by the end of cancellation, just ignore it. + * tctx can be NULL if the queueing of this task_work raced with + * work cancelation off the exec path. + */ + if (tctx && !atomic_read(&tctx->in_idle)) + io_uring_del_tctx_node((unsigned long)work->ctx); + complete(&work->completion); +} + +static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data) +{ + struct io_kiocb *req = container_of(work, struct io_kiocb, work); + + return req->ctx == data; +} + static void io_ring_exit_work(struct work_struct *work) { - struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, - exit_work); + struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work); + unsigned long timeout = jiffies + HZ * 60 * 5; + unsigned long interval = HZ / 20; + struct io_tctx_exit exit; + struct io_tctx_node *node; + int ret;

/* * If we're doing polled IO and end up having requests being @@ -8578,53 +9327,100 @@ static void io_ring_exit_work(struct work_struct *work) * as nobody else will be looking for them. */ do { - io_iopoll_try_reap_events(ctx); - } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20)); + io_uring_try_cancel_requests(ctx, NULL, true); + if (ctx->sq_data) { + struct io_sq_data *sqd = ctx->sq_data; + struct task_struct *tsk; + + io_sq_thread_park(sqd); + tsk = sqd->thread; + if (tsk && tsk->io_uring && tsk->io_uring->io_wq) + io_wq_cancel_cb(tsk->io_uring->io_wq, + io_cancel_ctx_cb, ctx, true); + io_sq_thread_unpark(sqd); + } + + if (WARN_ON_ONCE(time_after(jiffies, timeout))) { + /* there is little hope left, don't run it too often */ + interval = HZ * 60; + } + } while (!wait_for_completion_timeout(&ctx->ref_comp, interval)); + + init_completion(&exit.completion); + init_task_work(&exit.task_work, io_tctx_exit_cb); + exit.ctx = ctx; + /* + * Some may use context even when all refs and requests have been put, + * and they are free to do so while still holding uring_lock or + * completion_lock, see io_req_task_submit(). Apart from other work, + * this lock/unlock section also waits them to finish. + */ + mutex_lock(&ctx->uring_lock); + while (!list_empty(&ctx->tctx_list)) { + WARN_ON_ONCE(time_after(jiffies, timeout)); + + node = list_first_entry(&ctx->tctx_list, struct io_tctx_node, + ctx_node); + /* don't spin on a single task if cancellation failed */ + list_rotate_left(&ctx->tctx_list); + ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL); + if (WARN_ON_ONCE(ret)) + continue; + wake_up_process(node->task); + + mutex_unlock(&ctx->uring_lock); + wait_for_completion(&exit.completion); + mutex_lock(&ctx->uring_lock); + } + mutex_unlock(&ctx->uring_lock); + spin_lock(&ctx->completion_lock); + spin_unlock(&ctx->completion_lock); + io_ring_ctx_free(ctx); }

-static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data) +/* Returns true if we found and killed one or more timeouts */ +static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk, + bool cancel_all) { - struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct io_kiocb *req, *tmp; + int canceled = 0;

- return req->ctx == data; + spin_lock(&ctx->completion_lock); + spin_lock_irq(&ctx->timeout_lock); + list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) { + if (io_match_task(req, tsk, cancel_all)) { + io_kill_timeout(req, -ECANCELED); + canceled++; + } + } + spin_unlock_irq(&ctx->timeout_lock); + if (canceled != 0) + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock); + if (canceled != 0) + io_cqring_ev_posted(ctx); + return canceled != 0; }

static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) { unsigned long index; - struct io_identify *iod; + struct creds *creds;

mutex_lock(&ctx->uring_lock); percpu_ref_kill(&ctx->refs); - /* if force is set, the ring is going away. always drop after that */ - - if (WARN_ON_ONCE((ctx->flags & IORING_SETUP_SQPOLL) && !ctx->sqo_dead)) - ctx->sqo_dead = 1; - - ctx->cq_overflow_flushed = 1; if (ctx->rings) - __io_cqring_overflow_flush(ctx, true, NULL, NULL); + __io_cqring_overflow_flush(ctx, true); + xa_for_each(&ctx->personalities, index, creds) + io_unregister_personality(ctx, index); mutex_unlock(&ctx->uring_lock);

- io_kill_timeouts(ctx, NULL, NULL); - io_poll_remove_all(ctx, NULL, NULL); - - if (ctx->io_wq) - io_wq_cancel_cb(ctx->io_wq, io_cancel_ctx_cb, ctx, true); + io_kill_timeouts(ctx, NULL, true); + io_poll_remove_all(ctx, NULL, true);

/* if we failed setting up the ctx, we might not have any rings */ io_iopoll_try_reap_events(ctx); - xa_for_each(&ctx->personalities, index, iod) - io_unregister_personality(ctx, index); - - /* - * Do this upfront, so we won't have a grace period where the ring - * is closed but resources aren't reaped yet. This can cause - * spurious failure in setting up a new ring. - */ - io_unaccount_mem(ctx, ring_pages(ctx->sq_entries, ctx->cq_entries), - ACCT_LOCKED);

INIT_WORK(&ctx->exit_work, io_ring_exit_work); /* @@ -8647,352 +9443,290 @@ static int io_uring_release(struct inode *inode, struct file *file)

struct io_task_cancel { struct task_struct *task; - struct files_struct *files; + bool all; };

static bool io_cancel_task_cb(struct io_wq_work *work, void *data) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); struct io_task_cancel *cancel = data; - bool ret; - - if (cancel->files && (req->flags & REQ_F_LINK_TIMEOUT)) { - unsigned long flags; - struct io_ring_ctx *ctx = req->ctx;

- /* protect against races with linked timeouts */ - spin_lock_irqsave(&ctx->completion_lock, flags); - ret = io_match_task(req, cancel->task, cancel->files); - spin_unlock_irqrestore(&ctx->completion_lock, flags); - } else { - ret = io_match_task(req, cancel->task, cancel->files); - } - return ret; + return io_match_task_safe(req, cancel->task, cancel->all); }

-static void io_cancel_defer_files(struct io_ring_ctx *ctx, - struct task_struct *task, - struct files_struct *files) +static bool io_cancel_defer_files(struct io_ring_ctx *ctx, + struct task_struct *task, bool cancel_all) { - struct io_defer_entry *de = NULL; + struct io_defer_entry *de; LIST_HEAD(list);

- spin_lock_irq(&ctx->completion_lock); + spin_lock(&ctx->completion_lock); list_for_each_entry_reverse(de, &ctx->defer_list, list) { - if (io_match_task(de->req, task, files)) { + if (io_match_task_safe(de->req, task, cancel_all)) { list_cut_position(&list, &ctx->defer_list, &de->list); break; } } - spin_unlock_irq(&ctx->completion_lock); + spin_unlock(&ctx->completion_lock); + if (list_empty(&list)) + return false;

while (!list_empty(&list)) { de = list_first_entry(&list, struct io_defer_entry, list); list_del_init(&de->list); - req_set_fail_links(de->req); - io_put_req(de->req); - io_req_complete(de->req, -ECANCELED); + io_req_complete_failed(de->req, -ECANCELED); kfree(de); } + return true; }

-static int io_uring_count_inflight(struct io_ring_ctx *ctx, - struct task_struct *task, - struct files_struct *files) -{ - struct io_kiocb *req; - int cnt = 0; - - spin_lock_irq(&ctx->inflight_lock); - list_for_each_entry(req, &ctx->inflight_list, inflight_entry) - cnt += io_match_task(req, task, files); - spin_unlock_irq(&ctx->inflight_lock); - return cnt; -} - -static void io_uring_cancel_files(struct io_ring_ctx *ctx, - struct task_struct *task, - struct files_struct *files) +static bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx) { - while (!list_empty_careful(&ctx->inflight_list)) { - struct io_task_cancel cancel = { .task = task, .files = files }; - DEFINE_WAIT(wait); - int inflight; - - inflight = io_uring_count_inflight(ctx, task, files); - if (!inflight) - break; + struct io_tctx_node *node; + enum io_wq_cancel cret; + bool ret = false;

- io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true); - io_poll_remove_all(ctx, task, files); - io_kill_timeouts(ctx, task, files); - /* cancellations _may_ trigger task work */ - io_run_task_work(); + mutex_lock(&ctx->uring_lock); + list_for_each_entry(node, &ctx->tctx_list, ctx_node) { + struct io_uring_task *tctx = node->task->io_uring;

- prepare_to_wait(&task->io_uring->wait, &wait, - TASK_UNINTERRUPTIBLE); - if (inflight == io_uring_count_inflight(ctx, task, files)) - schedule(); - finish_wait(&task->io_uring->wait, &wait); + /* + * io_wq will stay alive while we hold uring_lock, because it's + * killed after ctx nodes, which requires to take the lock. + */ + if (!tctx || !tctx->io_wq) + continue; + cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true); + ret |= (cret != IO_WQ_CANCEL_NOTFOUND); } + mutex_unlock(&ctx->uring_lock); + + return ret; }

-static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx, - struct task_struct *task) +static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, + struct task_struct *task, + bool cancel_all) { + struct io_task_cancel cancel = { .task = task, .all = cancel_all, }; + struct io_uring_task *tctx = task ? task->io_uring : NULL; + while (1) { - struct io_task_cancel cancel = { .task = task, .files = NULL, }; enum io_wq_cancel cret; bool ret = false;

- cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true); - if (cret != IO_WQ_CANCEL_NOTFOUND) - ret = true; + if (!task) { + ret |= io_uring_try_cancel_iowq(ctx); + } else if (tctx && tctx->io_wq) { + /* + * Cancels requests of all rings, not only @ctx, but + * it's fine as the task is in exit/exec. + */ + cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb, + &cancel, true); + ret |= (cret != IO_WQ_CANCEL_NOTFOUND); + }

/* SQPOLL thread does its own polling */ - if (!(ctx->flags & IORING_SETUP_SQPOLL)) { + if ((!(ctx->flags & IORING_SETUP_SQPOLL) && cancel_all) || + (ctx->sq_data && ctx->sq_data->thread == current)) { while (!list_empty_careful(&ctx->iopoll_list)) { io_iopoll_try_reap_events(ctx); ret = true; } }

- ret |= io_poll_remove_all(ctx, task, NULL); - ret |= io_kill_timeouts(ctx, task, NULL); + ret |= io_cancel_defer_files(ctx, task, cancel_all); + ret |= io_poll_remove_all(ctx, task, cancel_all); + ret |= io_kill_timeouts(ctx, task, cancel_all); + if (task) + ret |= io_run_task_work(); if (!ret) break; - io_run_task_work(); cond_resched(); } }

-static void io_disable_sqo_submit(struct io_ring_ctx *ctx) -{ - mutex_lock(&ctx->uring_lock); - ctx->sqo_dead = 1; - if (ctx->flags & IORING_SETUP_R_DISABLED) - io_sq_offload_start(ctx); - mutex_unlock(&ctx->uring_lock); - - /* make sure callers enter the ring to get error */ - if (ctx->rings) - io_ring_set_wakeup_flag(ctx); -} - -/* - * We need to iteratively cancel requests, in case a request has dependent - * hard links. These persist even for failure of cancelations, hence keep - * looping until none are found. - */ -static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, - struct files_struct *files) -{ - struct task_struct *task = current; - - if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { - io_disable_sqo_submit(ctx); - task = ctx->sq_data->thread; - atomic_inc(&task->io_uring->in_idle); - io_sq_thread_park(ctx->sq_data); - } - - io_cancel_defer_files(ctx, task, files); - io_cqring_overflow_flush(ctx, true, task, files); - - if (!files) - __io_uring_cancel_task_requests(ctx, task); - else - io_uring_cancel_files(ctx, task, files); - - if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { - atomic_dec(&task->io_uring->in_idle); - io_sq_thread_unpark(ctx->sq_data); - } -} - -/* - * Note that this task has used io_uring. We use it for cancelation purposes. - */ -static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file) +static int __io_uring_add_tctx_node(struct io_ring_ctx *ctx) { struct io_uring_task *tctx = current->io_uring; + struct io_tctx_node *node; int ret;

if (unlikely(!tctx)) { - ret = io_uring_alloc_task_context(current); + ret = io_uring_alloc_task_context(current, ctx); if (unlikely(ret)) return ret; + tctx = current->io_uring; - } - if (tctx->last != file) { - void *old = xa_load(&tctx->xa, (unsigned long)file); + if (ctx->iowq_limits_set) { + unsigned int limits[2] = { ctx->iowq_limits[0], + ctx->iowq_limits[1], };

- if (!old) { - get_file(file); - ret = xa_err(xa_store(&tctx->xa, (unsigned long)file, - file, GFP_KERNEL)); - if (ret) { - fput(file); + ret = io_wq_max_workers(tctx->io_wq, limits); + if (ret) return ret; - } } - tctx->last = file; } + if (!xa_load(&tctx->xa, (unsigned long)ctx)) { + node = kmalloc(sizeof(*node), GFP_KERNEL); + if (!node) + return -ENOMEM; + node->ctx = ctx; + node->task = current;

- /* - * This is race safe in that the task itself is doing this, hence it - * cannot be going through the exit/cancel paths at the same time. - * This cannot be modified while exit/cancel is running. - */ - if (!tctx->sqpoll && (ctx->flags & IORING_SETUP_SQPOLL)) - tctx->sqpoll = true; + ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx, + node, GFP_KERNEL)); + if (ret) { + kfree(node); + return ret; + }

+ mutex_lock(&ctx->uring_lock); + list_add(&node->ctx_node, &ctx->tctx_list); + mutex_unlock(&ctx->uring_lock); + } + tctx->last = ctx; return 0; }

/* - * Remove this io_uring_file -> task mapping. + * Note that this task has used io_uring. We use it for cancelation purposes. */ -static void io_uring_del_task_file(struct file *file) +static inline int io_uring_add_tctx_node(struct io_ring_ctx *ctx) { struct io_uring_task *tctx = current->io_uring;

- if (tctx->last == file) - tctx->last = NULL; - file = xa_erase(&tctx->xa, (unsigned long)file); - if (file) - fput(file); + if (likely(tctx && tctx->last == ctx)) + return 0; + return __io_uring_add_tctx_node(ctx); }

-static void io_uring_remove_task_files(struct io_uring_task *tctx) +/* + * Remove this io_uring_file -> task mapping. + */ +static void io_uring_del_tctx_node(unsigned long index) { - struct file *file; - unsigned long index; + struct io_uring_task *tctx = current->io_uring; + struct io_tctx_node *node;

- xa_for_each(&tctx->xa, index, file) - io_uring_del_task_file(file); -} + if (!tctx) + return; + node = xa_erase(&tctx->xa, index); + if (!node) + return;

-void __io_uring_files_cancel(struct files_struct *files) -{ - struct io_uring_task *tctx = current->io_uring; - struct file *file; - unsigned long index; + WARN_ON_ONCE(current != node->task); + WARN_ON_ONCE(list_empty(&node->ctx_node));

- /* make sure overflow events are dropped */ - atomic_inc(&tctx->in_idle); - xa_for_each(&tctx->xa, index, file) - io_uring_cancel_task_requests(file->private_data, files); - atomic_dec(&tctx->in_idle); + mutex_lock(&node->ctx->uring_lock); + list_del(&node->ctx_node); + mutex_unlock(&node->ctx->uring_lock);

- if (files) - io_uring_remove_task_files(tctx); + if (tctx->last == node->ctx) + tctx->last = NULL; + kfree(node); }

-static s64 tctx_inflight(struct io_uring_task *tctx) +static void io_uring_clean_tctx(struct io_uring_task *tctx) { + struct io_wq *wq = tctx->io_wq; + struct io_tctx_node *node; unsigned long index; - struct file *file; - s64 inflight; - - inflight = percpu_counter_sum(&tctx->inflight); - if (!tctx->sqpoll) - return inflight;

- /* - * If we have SQPOLL rings, then we need to iterate and find them, and - * add the pending count for those. - */ - xa_for_each(&tctx->xa, index, file) { - struct io_ring_ctx *ctx = file->private_data; - - if (ctx->flags & IORING_SETUP_SQPOLL) { - struct io_uring_task *__tctx = ctx->sqo_task->io_uring; - - inflight += percpu_counter_sum(&__tctx->inflight); - } + xa_for_each(&tctx->xa, index, node) { + io_uring_del_tctx_node(index); + cond_resched(); + } + if (wq) { + /* + * Must be after io_uring_del_task_file() (removes nodes under + * uring_lock) to avoid race with io_uring_try_cancel_iowq(). + */ + io_wq_put_and_exit(wq); + tctx->io_wq = NULL; } +}

- return inflight; +static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked) +{ + if (tracked) + return atomic_read(&tctx->inflight_tracked); + return percpu_counter_sum(&tctx->inflight); }

/* - * Find any io_uring fd that this task has registered or done IO on, and cancel - * requests. + * Find any io_uring ctx that this task has registered or done IO on, and cancel + * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation. */ -void __io_uring_task_cancel(void) +static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd) { struct io_uring_task *tctx = current->io_uring; - DEFINE_WAIT(wait); + struct io_ring_ctx *ctx; s64 inflight; + DEFINE_WAIT(wait);

- /* make sure overflow events are dropped */ - atomic_inc(&tctx->in_idle); + WARN_ON_ONCE(sqd && sqd->thread != current);

- /* trigger io_disable_sqo_submit() */ - if (tctx->sqpoll) - __io_uring_files_cancel(NULL); + if (!current->io_uring) + return; + if (tctx->io_wq) + io_wq_exit_start(tctx->io_wq);

+ atomic_inc(&tctx->in_idle); do { + io_uring_drop_tctx_refs(current); /* read completions before cancelations */ - inflight = tctx_inflight(tctx); + inflight = tctx_inflight(tctx, !cancel_all); if (!inflight) break; - __io_uring_files_cancel(NULL); - - prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE); - - /* - * If we've seen completions, retry without waiting. This - * avoids a race where a completion comes in before we did - * prepare_to_wait(). - */ - if (inflight == tctx_inflight(tctx)) - schedule(); - finish_wait(&tctx->wait, &wait); - } while (1); - - atomic_dec(&tctx->in_idle); - - io_uring_remove_task_files(tctx); -} - -static int io_uring_flush(struct file *file, void *data) -{ - struct io_uring_task *tctx = current->io_uring; - struct io_ring_ctx *ctx = file->private_data; - - if (fatal_signal_pending(current) || (current->flags & PF_EXITING)) - io_uring_cancel_task_requests(ctx, NULL);

- if (!tctx) - return 0; + if (!sqd) { + struct io_tctx_node *node; + unsigned long index;

- /* we should have cancelled and erased it before PF_EXITING */ - WARN_ON_ONCE((current->flags & PF_EXITING) && - xa_load(&tctx->xa, (unsigned long)file)); + xa_for_each(&tctx->xa, index, node) { + /* sqpoll task will cancel all its requests */ + if (node->ctx->sq_data) + continue; + io_uring_try_cancel_requests(node->ctx, current, + cancel_all); + } + } else { + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + io_uring_try_cancel_requests(ctx, current, + cancel_all); + }

- /* - * fput() is pending, will be 2 if the only other ref is our potential - * task file note. If the task is exiting, drop regardless of count. - */ - if (atomic_long_read(&file->f_count) != 2) - return 0; + prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE); + io_run_task_work(); + io_uring_drop_tctx_refs(current);

- if (ctx->flags & IORING_SETUP_SQPOLL) { - /* there is only one file note, which is owned by sqo_task */ - WARN_ON_ONCE(ctx->sqo_task != current && - xa_load(&tctx->xa, (unsigned long)file)); - /* sqo_dead check is for when this happens after cancellation */ - WARN_ON_ONCE(ctx->sqo_task == current && !ctx->sqo_dead && - !xa_load(&tctx->xa, (unsigned long)file)); + /* + * If we've seen completions, retry without waiting. This + * avoids a race where a completion comes in before we did + * prepare_to_wait(). + */ + if (inflight == tctx_inflight(tctx, !cancel_all)) + schedule(); + finish_wait(&tctx->wait, &wait); + } while (1);

- io_disable_sqo_submit(ctx); + io_uring_clean_tctx(tctx); + if (cancel_all) { + /* + * We shouldn't run task_works after cancel, so just leave + * ->in_idle set for normal exit. + */ + atomic_dec(&tctx->in_idle); + /* for exec all current's requests should be gone, kill tctx */ + __io_uring_free(current); } +}

- if (!(ctx->flags & IORING_SETUP_SQPOLL) || ctx->sqo_task == current) - io_uring_del_task_file(file); - return 0; +void __io_uring_cancel(bool cancel_all) +{ + io_uring_cancel_generic(cancel_all, NULL); }

static void *io_uring_validate_mmap_request(struct file *file, @@ -9067,60 +9801,84 @@ static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,

static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx) { - int ret = 0; DEFINE_WAIT(wait);

do { if (!io_sqring_full(ctx)) break; - prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE);

- if (unlikely(ctx->sqo_dead)) { - ret = -EOWNERDEAD; - break; - } - if (!io_sqring_full(ctx)) break; - schedule(); } while (!signal_pending(current));

finish_wait(&ctx->sqo_sq_wait, &wait); - return ret; + return 0; +} + +static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz, + struct __kernel_timespec __user **ts, + const sigset_t __user **sig) +{ + struct io_uring_getevents_arg arg; + + /* + * If EXT_ARG isn't set, then we have no timespec and the argp pointer + * is just a pointer to the sigset_t. + */ + if (!(flags & IORING_ENTER_EXT_ARG)) { + *sig = (const sigset_t __user *) argp; + *ts = NULL; + return 0; + } + + /* + * EXT_ARG is set - ensure we agree on the size of it and copy in our + * timespec and sigset_t pointers if good. + */ + if (*argsz != sizeof(arg)) + return -EINVAL; + if (copy_from_user(&arg, argp, sizeof(arg))) + return -EFAULT; + if (arg.pad) + return -EINVAL; + *sig = u64_to_user_ptr(arg.sigmask); + *argsz = arg.sigmask_sz; + *ts = u64_to_user_ptr(arg.ts); + return 0; }

SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, - u32, min_complete, u32, flags, const sigset_t __user *, sig, - size_t, sigsz) + u32, min_complete, u32, flags, const void __user *, argp, + size_t, argsz) { struct io_ring_ctx *ctx; - long ret = -EBADF; int submitted = 0; struct fd f; + long ret;

io_run_task_work();

- if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP | - IORING_ENTER_SQ_WAIT)) + if (unlikely(flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP | + IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG))) return -EINVAL;

f = fdget(fd); - if (!f.file) + if (unlikely(!f.file)) return -EBADF;

ret = -EOPNOTSUPP; - if (f.file->f_op != &io_uring_fops) + if (unlikely(f.file->f_op != &io_uring_fops)) goto out_fput;

ret = -ENXIO; ctx = f.file->private_data; - if (!percpu_ref_tryget(&ctx->refs)) + if (unlikely(!percpu_ref_tryget(&ctx->refs))) goto out_fput;

ret = -EBADFD; - if (ctx->flags & IORING_SETUP_R_DISABLED) + if (unlikely(ctx->flags & IORING_SETUP_R_DISABLED)) goto out;

/* @@ -9130,9 +9888,9 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, */ ret = 0; if (ctx->flags & IORING_SETUP_SQPOLL) { - io_cqring_overflow_flush(ctx, false, NULL, NULL); + io_cqring_overflow_flush(ctx);

- if (unlikely(ctx->sqo_dead)) { + if (unlikely(ctx->sq_data->thread == NULL)) { ret = -EOWNERDEAD; goto out; } @@ -9145,7 +9903,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, } submitted = to_submit; } else if (to_submit) { - ret = io_uring_add_task_file(ctx, f.file); + ret = io_uring_add_tctx_node(ctx); if (unlikely(ret)) goto out; mutex_lock(&ctx->uring_lock); @@ -9156,6 +9914,13 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, goto out; } if (flags & IORING_ENTER_GETEVENTS) { + const sigset_t __user *sig; + struct __kernel_timespec __user *ts; + + ret = io_get_ext_arg(flags, argp, &argsz, &ts, &sig); + if (unlikely(ret)) + goto out; + min_complete = min(min_complete, ctx->cq_entries);

/* @@ -9168,7 +9933,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, !(ctx->flags & IORING_SETUP_SQPOLL)) { ret = io_iopoll_check(ctx, min_complete); } else { - ret = io_cqring_wait(ctx, min_complete, sig, sigsz); + ret = io_cqring_wait(ctx, min_complete, sig, argsz, ts); } }

@@ -9181,9 +9946,8 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,

#ifdef CONFIG_PROC_FS static int io_uring_show_cred(struct seq_file *m, unsigned int id, - const struct io_identity *iod) + const struct cred *cred) { - const struct cred *cred = iod->creds; struct user_namespace *uns = seq_user_ns(m); struct group_info *gi; kernel_cap_t cap; @@ -9227,18 +9991,18 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) */ has_lock = mutex_trylock(&ctx->uring_lock);

- if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) + if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) { sq = ctx->sq_data; + if (!sq->thread) + sq = NULL; + }

seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1); seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1); seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files); for (i = 0; has_lock && i < ctx->nr_user_files; i++) { - struct fixed_file_table *table; - struct file *f; + struct file *f = io_file_from_index(ctx, i);

- table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT]; - f = table->files[i & IORING_FILE_TABLE_MASK]; if (f) seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname); else @@ -9246,21 +10010,21 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) } seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs); for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) { - struct io_mapped_ubuf *buf = &ctx->user_bufs[i]; + struct io_mapped_ubuf *buf = ctx->user_bufs[i]; + unsigned int len = buf->ubuf_end - buf->ubuf;

- seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, - (unsigned int) buf->len); + seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len); } if (has_lock && !xa_empty(&ctx->personalities)) { unsigned long index; - const struct io_identity *iod; + const struct cred *cred;

seq_printf(m, "Personalities:\n"); - xa_for_each(&ctx->personalities, index, iod) - io_uring_show_cred(m, index, iod); + xa_for_each(&ctx->personalities, index, cred) + io_uring_show_cred(m, index, cred); } seq_printf(m, "PollList:\n"); - spin_lock_irq(&ctx->completion_lock); + spin_lock(&ctx->completion_lock); for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { struct hlist_head *list = &ctx->cancel_hash[i]; struct io_kiocb *req; @@ -9269,7 +10033,7 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) seq_printf(m, " op=%d, task_works=%d\n", req->opcode, req->task->task_works != NULL); } - spin_unlock_irq(&ctx->completion_lock); + spin_unlock(&ctx->completion_lock); if (has_lock) mutex_unlock(&ctx->uring_lock); } @@ -9287,14 +10051,12 @@ static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)

static const struct file_operations io_uring_fops = { .release = io_uring_release, - .flush = io_uring_flush, .mmap = io_uring_mmap, #ifndef CONFIG_MMU .get_unmapped_area = io_uring_nommu_get_unmapped_area, .mmap_capabilities = io_uring_nommu_mmap_capabilities, #endif .poll = io_uring_poll, - .fasync = io_uring_fasync, #ifdef CONFIG_PROC_FS .show_fdinfo = io_uring_show_fdinfo, #endif @@ -9324,8 +10086,6 @@ static int io_allocate_scq_urings(struct io_ring_ctx *ctx, rings->cq_ring_mask = p->cq_entries - 1; rings->sq_ring_entries = p->sq_entries; rings->cq_ring_entries = p->cq_entries; - ctx->sq_mask = rings->sq_ring_mask; - ctx->cq_mask = rings->cq_ring_mask;

size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); if (size == SIZE_MAX) { @@ -9352,7 +10112,7 @@ static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file) if (fd < 0) return fd;

- ret = io_uring_add_task_file(ctx, file); + ret = io_uring_add_tctx_node(ctx); if (ret) { put_unused_fd(fd); return ret; @@ -9395,10 +10155,8 @@ static struct file *io_uring_get_file(struct io_ring_ctx *ctx) static int io_uring_create(unsigned entries, struct io_uring_params *p, struct io_uring_params __user *params) { - struct user_struct *user = NULL; struct io_ring_ctx *ctx; struct file *file; - bool limit_mem; int ret;

if (!entries) @@ -9438,34 +10196,12 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, p->cq_entries = 2 * p->sq_entries; }

- user = get_uid(current_user()); - limit_mem = !capable(CAP_IPC_LOCK); - - if (limit_mem) { - ret = __io_account_mem(user, - ring_pages(p->sq_entries, p->cq_entries)); - if (ret) { - free_uid(user); - return ret; - } - } - ctx = io_ring_ctx_alloc(p); - if (!ctx) { - if (limit_mem) - __io_unaccount_mem(user, ring_pages(p->sq_entries, - p->cq_entries)); - free_uid(user); + if (!ctx) return -ENOMEM; - } ctx->compat = in_compat_syscall(); - ctx->user = user; - ctx->creds = get_current_cred(); -#ifdef CONFIG_AUDIT - ctx->loginuid = current->loginuid; - ctx->sessionid = current->sessionid; -#endif - ctx->sqo_task = get_task_struct(current); + if (!capable(CAP_IPC_LOCK)) + ctx->user = get_uid(current_user());

/* * This is just grabbed for accounting purposes. When a process exits, @@ -9476,35 +10212,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, mmgrab(current->mm); ctx->mm_account = current->mm;

-#ifdef CONFIG_BLK_CGROUP - /* - * The sq thread will belong to the original cgroup it was inited in. - * If the cgroup goes offline (e.g. disabling the io controller), then - * issued bios will be associated with the closest cgroup later in the - * block layer. - */ - rcu_read_lock(); - ctx->sqo_blkcg_css = blkcg_css(); - ret = css_tryget_online(ctx->sqo_blkcg_css); - rcu_read_unlock(); - if (!ret) { - /* don't init against a dying cgroup, have the user try again */ - ctx->sqo_blkcg_css = NULL; - ret = -ENODEV; - goto err; - } -#endif - - /* - * Account memory _before_ installing the file descriptor. Once - * the descriptor is installed, it can get closed at any time. Also - * do this before hitting the general error path, as ring freeing - * will un-account as well. - */ - io_account_mem(ctx, ring_pages(p->sq_entries, p->cq_entries), - ACCT_LOCKED); - ctx->limit_mem = limit_mem; - ret = io_allocate_scq_urings(ctx, p); if (ret) goto err; @@ -9512,9 +10219,11 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, ret = io_sq_offload_create(ctx, p); if (ret) goto err; - - if (!(p->flags & IORING_SETUP_R_DISABLED)) - io_sq_offload_start(ctx); + /* always set a rsrc node */ + ret = io_rsrc_node_switch_start(ctx); + if (ret) + goto err; + io_rsrc_node_switch(ctx, NULL);

memset(&p->sq_off, 0, sizeof(p->sq_off)); p->sq_off.head = offsetof(struct io_rings, sq.head); @@ -9537,7 +10246,9 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP | IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS | IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL | - IORING_FEAT_POLL_32BITS; + IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED | + IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS | + IORING_FEAT_RSRC_TAGS;

if (copy_to_user(params, p, sizeof(*p))) { ret = -EFAULT; @@ -9556,7 +10267,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, */ ret = io_uring_install_fd(ctx, file); if (ret < 0) { - io_disable_sqo_submit(ctx); /* fput will clean it up */ fput(file); return ret; @@ -9565,7 +10275,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); return ret; err: - io_disable_sqo_submit(ctx); io_ring_ctx_wait_and_kill(ctx); return ret; } @@ -9643,22 +10352,16 @@ static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)

static int io_register_personality(struct io_ring_ctx *ctx) { - struct io_identity *iod; + const struct cred *creds; u32 id; int ret;

- iod = kmalloc(sizeof(*iod), GFP_KERNEL); - if (unlikely(!iod)) - return -ENOMEM; - - io_init_identity(iod); - iod->creds = get_current_cred(); + creds = get_current_cred();

- ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)iod, + ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds, XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL); if (ret < 0) { - put_cred(iod->creds); - kfree(iod); + put_cred(creds); return ret; } return id; @@ -9742,24 +10445,273 @@ static int io_register_enable_rings(struct io_ring_ctx *ctx) if (ctx->restrictions.registered) ctx->restricted = 1;

- io_sq_offload_start(ctx); + ctx->flags &= ~IORING_SETUP_R_DISABLED; + if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait)) + wake_up(&ctx->sq_data->wait); + return 0; +} + +static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type, + struct io_uring_rsrc_update2 *up, + unsigned nr_args) +{ + __u32 tmp; + int err; + + if (check_add_overflow(up->offset, nr_args, &tmp)) + return -EOVERFLOW; + err = io_rsrc_node_switch_start(ctx); + if (err) + return err; + + switch (type) { + case IORING_RSRC_FILE: + return __io_sqe_files_update(ctx, up, nr_args); + case IORING_RSRC_BUFFER: + return __io_sqe_buffers_update(ctx, up, nr_args); + } + return -EINVAL; +} + +static int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg, + unsigned nr_args) +{ + struct io_uring_rsrc_update2 up; + + if (!nr_args) + return -EINVAL; + memset(&up, 0, sizeof(up)); + if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update))) + return -EFAULT; + if (up.resv || up.resv2) + return -EINVAL; + return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args); +} + +static int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg, + unsigned size, unsigned type) +{ + struct io_uring_rsrc_update2 up; + + if (size != sizeof(up)) + return -EINVAL; + if (copy_from_user(&up, arg, sizeof(up))) + return -EFAULT; + if (!up.nr || up.resv || up.resv2) + return -EINVAL; + return __io_register_rsrc_update(ctx, type, &up, up.nr); +} + +static int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg, + unsigned int size, unsigned int type) +{ + struct io_uring_rsrc_register rr; + + /* keep it extendible */ + if (size != sizeof(rr)) + return -EINVAL; + + memset(&rr, 0, sizeof(rr)); + if (copy_from_user(&rr, arg, size)) + return -EFAULT; + if (!rr.nr || rr.resv || rr.resv2) + return -EINVAL; + + switch (type) { + case IORING_RSRC_FILE: + return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data), + rr.nr, u64_to_user_ptr(rr.tags)); + case IORING_RSRC_BUFFER: + return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data), + rr.nr, u64_to_user_ptr(rr.tags)); + } + return -EINVAL; +} + +static int io_register_iowq_aff(struct io_ring_ctx *ctx, void __user *arg, + unsigned len) +{ + struct io_uring_task *tctx = current->io_uring; + cpumask_var_t new_mask; + int ret; + + if (!tctx || !tctx->io_wq) + return -EINVAL; + + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) + return -ENOMEM; + + cpumask_clear(new_mask); + if (len > cpumask_size()) + len = cpumask_size(); + +#ifdef CONFIG_COMPAT + if (in_compat_syscall()) { + ret = compat_get_bitmap(cpumask_bits(new_mask), + (const compat_ulong_t __user *)arg, + len * 8 /* CHAR_BIT */); + } else { + ret = copy_from_user(new_mask, arg, len); + } +#else + ret = copy_from_user(new_mask, arg, len); +#endif + + if (ret) { + free_cpumask_var(new_mask); + return -EFAULT; + } + + ret = io_wq_cpu_affinity(tctx->io_wq, new_mask); + free_cpumask_var(new_mask); + return ret; +} + +static int io_unregister_iowq_aff(struct io_ring_ctx *ctx) +{ + struct io_uring_task *tctx = current->io_uring; + + if (!tctx || !tctx->io_wq) + return -EINVAL; + + return io_wq_cpu_affinity(tctx->io_wq, NULL); +} + +static int io_register_iowq_max_workers(struct io_ring_ctx *ctx, + void __user *arg) + __must_hold(&ctx->uring_lock) +{ + struct io_tctx_node *node; + struct io_uring_task *tctx = NULL; + struct io_sq_data *sqd = NULL; + __u32 new_count[2]; + int i, ret; + + if (copy_from_user(new_count, arg, sizeof(new_count))) + return -EFAULT; + for (i = 0; i < ARRAY_SIZE(new_count); i++) + if (new_count[i] > INT_MAX) + return -EINVAL; + + if (ctx->flags & IORING_SETUP_SQPOLL) { + sqd = ctx->sq_data; + if (sqd) { + /* + * Observe the correct sqd->lock -> ctx->uring_lock + * ordering. Fine to drop uring_lock here, we hold + * a ref to the ctx. + */ + refcount_inc(&sqd->refs); + mutex_unlock(&ctx->uring_lock); + mutex_lock(&sqd->lock); + mutex_lock(&ctx->uring_lock); + if (sqd->thread) + tctx = sqd->thread->io_uring; + } + } else { + tctx = current->io_uring; + } + + BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits)); + + for (i = 0; i < ARRAY_SIZE(new_count); i++) + if (new_count[i]) + ctx->iowq_limits[i] = new_count[i]; + ctx->iowq_limits_set = true; + + ret = -EINVAL; + if (tctx && tctx->io_wq) { + ret = io_wq_max_workers(tctx->io_wq, new_count); + if (ret) + goto err; + } else { + memset(new_count, 0, sizeof(new_count)); + } + + if (sqd) { + mutex_unlock(&sqd->lock); + io_put_sq_data(sqd); + } + + if (copy_to_user(arg, new_count, sizeof(new_count))) + return -EFAULT; + + /* that's it for SQPOLL, only the SQPOLL task creates requests */ + if (sqd) + return 0; + + /* now propagate the restriction to all registered users */ + list_for_each_entry(node, &ctx->tctx_list, ctx_node) { + struct io_uring_task *tctx = node->task->io_uring; + + if (WARN_ON_ONCE(!tctx->io_wq)) + continue; + + for (i = 0; i < ARRAY_SIZE(new_count); i++) + new_count[i] = ctx->iowq_limits[i]; + /* ignore errors, it always returns zero anyway */ + (void)io_wq_max_workers(tctx->io_wq, new_count); + } return 0; +err: + if (sqd) { + mutex_unlock(&sqd->lock); + io_put_sq_data(sqd); + } + return ret; }

static bool io_register_op_must_quiesce(int op) { switch (op) { + case IORING_REGISTER_BUFFERS: + case IORING_UNREGISTER_BUFFERS: + case IORING_REGISTER_FILES: case IORING_UNREGISTER_FILES: case IORING_REGISTER_FILES_UPDATE: case IORING_REGISTER_PROBE: case IORING_REGISTER_PERSONALITY: case IORING_UNREGISTER_PERSONALITY: + case IORING_REGISTER_FILES2: + case IORING_REGISTER_FILES_UPDATE2: + case IORING_REGISTER_BUFFERS2: + case IORING_REGISTER_BUFFERS_UPDATE: + case IORING_REGISTER_IOWQ_AFF: + case IORING_UNREGISTER_IOWQ_AFF: + case IORING_REGISTER_IOWQ_MAX_WORKERS: return false; default: return true; } }

+static int io_ctx_quiesce(struct io_ring_ctx *ctx) +{ + long ret; + + percpu_ref_kill(&ctx->refs); + + /* + * Drop uring mutex before waiting for references to exit. If another + * thread is currently inside io_uring_enter() it might need to grab the + * uring_lock to make progress. If we hold it here across the drain + * wait, then we can deadlock. It's safe to drop the mutex here, since + * no new references will come in after we've killed the percpu ref. + */ + mutex_unlock(&ctx->uring_lock); + do { + ret = wait_for_completion_interruptible(&ctx->ref_comp); + if (!ret) + break; + ret = io_run_task_work_sig(); + } while (ret >= 0); + mutex_lock(&ctx->uring_lock); + + if (ret) + io_refs_resurrect(&ctx->refs, &ctx->ref_comp); + return ret; +} + static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, void __user *arg, unsigned nr_args) __releases(ctx->uring_lock) @@ -9775,58 +10727,32 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, if (percpu_ref_is_dying(&ctx->refs)) return -ENXIO;

- if (io_register_op_must_quiesce(opcode)) { - percpu_ref_kill(&ctx->refs); - - /* - * Drop uring mutex before waiting for references to exit. If - * another thread is currently inside io_uring_enter() it might - * need to grab the uring_lock to make progress. If we hold it - * here across the drain wait, then we can deadlock. It's safe - * to drop the mutex here, since no new references will come in - * after we've killed the percpu ref. - */ - mutex_unlock(&ctx->uring_lock); - do { - ret = wait_for_completion_interruptible(&ctx->ref_comp); - if (!ret) - break; - ret = io_run_task_work_sig(); - if (ret < 0) - break; - } while (1); - mutex_lock(&ctx->uring_lock); - - if (ret) { - io_refs_resurrect(&ctx->refs, &ctx->ref_comp); - return ret; - } - } - if (ctx->restricted) { - if (opcode >= IORING_REGISTER_LAST) { - ret = -EINVAL; - goto out; - } + if (opcode >= IORING_REGISTER_LAST) + return -EINVAL; + opcode = array_index_nospec(opcode, IORING_REGISTER_LAST); + if (!test_bit(opcode, ctx->restrictions.register_op)) + return -EACCES; + }

- if (!test_bit(opcode, ctx->restrictions.register_op)) { - ret = -EACCES; - goto out; - } + if (io_register_op_must_quiesce(opcode)) { + ret = io_ctx_quiesce(ctx); + if (ret) + return ret; }

switch (opcode) { case IORING_REGISTER_BUFFERS: - ret = io_sqe_buffer_register(ctx, arg, nr_args); + ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL); break; case IORING_UNREGISTER_BUFFERS: ret = -EINVAL; if (arg || nr_args) break; - ret = io_sqe_buffer_unregister(ctx); + ret = io_sqe_buffers_unregister(ctx); break; case IORING_REGISTER_FILES: - ret = io_sqe_files_register(ctx, arg, nr_args); + ret = io_sqe_files_register(ctx, arg, nr_args, NULL); break; case IORING_UNREGISTER_FILES: ret = -EINVAL; @@ -9835,7 +10761,7 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, ret = io_sqe_files_unregister(ctx); break; case IORING_REGISTER_FILES_UPDATE: - ret = io_sqe_files_update(ctx, arg, nr_args); + ret = io_register_files_update(ctx, arg, nr_args); break; case IORING_REGISTER_EVENTFD: case IORING_REGISTER_EVENTFD_ASYNC: @@ -9883,12 +10809,43 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, case IORING_REGISTER_RESTRICTIONS: ret = io_register_restrictions(ctx, arg, nr_args); break; + case IORING_REGISTER_FILES2: + ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE); + break; + case IORING_REGISTER_FILES_UPDATE2: + ret = io_register_rsrc_update(ctx, arg, nr_args, + IORING_RSRC_FILE); + break; + case IORING_REGISTER_BUFFERS2: + ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER); + break; + case IORING_REGISTER_BUFFERS_UPDATE: + ret = io_register_rsrc_update(ctx, arg, nr_args, + IORING_RSRC_BUFFER); + break; + case IORING_REGISTER_IOWQ_AFF: + ret = -EINVAL; + if (!arg || !nr_args) + break; + ret = io_register_iowq_aff(ctx, arg, nr_args); + break; + case IORING_UNREGISTER_IOWQ_AFF: + ret = -EINVAL; + if (arg || nr_args) + break; + ret = io_unregister_iowq_aff(ctx); + break; + case IORING_REGISTER_IOWQ_MAX_WORKERS: + ret = -EINVAL; + if (!arg || nr_args != 2) + break; + ret = io_register_iowq_max_workers(ctx, arg); + break; default: ret = -EINVAL; break; }

-out: if (io_register_op_must_quiesce(opcode)) { /* bring the ctx back to life */ percpu_ref_reinit(&ctx->refs); @@ -9914,6 +10871,8 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,

ctx = f.file->private_data;

+ io_run_task_work(); + mutex_lock(&ctx->uring_lock); ret = __io_uring_register(ctx, opcode, arg, nr_args); mutex_unlock(&ctx->uring_lock); @@ -9960,12 +10919,27 @@ static int __init io_uring_init(void) BUILD_BUG_SQE_ELEM(28, __u32, splice_flags); BUILD_BUG_SQE_ELEM(32, __u64, user_data); BUILD_BUG_SQE_ELEM(40, __u16, buf_index); + BUILD_BUG_SQE_ELEM(40, __u16, buf_group); BUILD_BUG_SQE_ELEM(42, __u16, personality); BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in); + BUILD_BUG_SQE_ELEM(44, __u32, file_index); + + BUILD_BUG_ON(sizeof(struct io_uring_files_update) != + sizeof(struct io_uring_rsrc_update)); + BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) > + sizeof(struct io_uring_rsrc_update2)); + + /* ->buf_index is u16 */ + BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16)); + + /* should fit into one byte */ + BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));

BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST); - BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int)); - req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC); + BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof(int)); + + req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC | + SLAB_ACCOUNT); return 0; }; __initcall(io_uring_init); diff --git a/kernel/exit.c b/kernel/exit.c index d612cb5b5943..26a81ea63156 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -764,7 +764,7 @@ void __noreturn do_exit(long code) schedule(); }

- io_uring_files_cancel(tsk->files); + io_uring_files_cancel(); exit_signals(tsk); /* sets PF_EXITING */

/* sync mm's RSS info before statistics gathering */ diff --git a/kernel/fork.c b/kernel/fork.c index 6e836b048662..0e141623a95d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -950,6 +950,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) tsk->splice_pipe = NULL; tsk->task_frag.page = NULL; tsk->wake_q.next = NULL; + tsk->pf_io_worker = NULL;

account_kernel_stack(tsk, 1);

diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 62d14fba4ca6..a2ea3b0ab334 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -21,7 +21,7 @@ #include <asm/tlb.h>

#include "../workqueue_internal.h" -#include "../../fs/io-wq.h" +#include "../../io_uring/io-wq.h" #include "../smpboot.h"

#include "pelt.h"