From: Bernd Schubert <bschubert@ddn.com> mainline inclusion from mainline-v6.10-rc2 commit c090c8abae4b6b77a1bee116aa6c385456ebef96 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/ICJPON Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- This adds support for fuse request completion through ring SQEs (FUSE_URING_CMD_COMMIT_AND_FETCH handling). After committing the ring entry it becomes available for new fuse requests. Handling of requests through the ring (SQE/CQE handling) is complete now. Fuse request data are copied through the mmaped ring buffer, there is no support for any zero copy yet. Signed-off-by: Bernd Schubert <bschubert@ddn.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # io_uring Reviewed-by: Luis Henriques <luis@igalia.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/fuse/dev_uring.c | 441 ++++++++++++++++++++++++++++++++++++++++++ fs/fuse/dev_uring_i.h | 12 ++ fs/fuse/fuse_i.h | 4 + 3 files changed, 457 insertions(+) diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c index f4793f03f62f..1bdc1b3ec471 100644 --- a/fs/fuse/dev_uring.c +++ b/fs/fuse/dev_uring.c @@ -25,6 +25,17 @@ bool fuse_uring_enabled(void) return enable_uring; } +static void fuse_uring_req_end(struct fuse_ring_ent *ent, struct fuse_req *req, + int error) +{ + ent->fuse_req = NULL; + if (error) + req->out.h.error = error; + + clear_bit(FR_SENT, &req->flags); + fuse_request_end(req); +} + void fuse_uring_destruct(struct fuse_conn *fc) { struct fuse_ring *ring = fc->ring; @@ -40,8 +51,11 @@ void fuse_uring_destruct(struct fuse_conn *fc) continue; WARN_ON(!list_empty(&queue->ent_avail_queue)); + WARN_ON(!list_empty(&queue->ent_w_req_queue)); WARN_ON(!list_empty(&queue->ent_commit_queue)); + WARN_ON(!list_empty(&queue->ent_in_userspace)); + kfree(queue->fpq.processing); kfree(queue); ring->queues[qid] = NULL; } @@ -100,20 +114,34 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring, { struct fuse_conn *fc = ring->fc; struct fuse_ring_queue *queue; + struct list_head *pq; queue = kzalloc(sizeof(*queue), GFP_KERNEL_ACCOUNT); if (!queue) return NULL; + pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); + if (!pq) { + kfree(queue); + return NULL; + } + queue->qid = qid; queue->ring = ring; spin_lock_init(&queue->lock); INIT_LIST_HEAD(&queue->ent_avail_queue); INIT_LIST_HEAD(&queue->ent_commit_queue); + INIT_LIST_HEAD(&queue->ent_w_req_queue); + INIT_LIST_HEAD(&queue->ent_in_userspace); + INIT_LIST_HEAD(&queue->fuse_req_queue); + + queue->fpq.processing = pq; + fuse_pqueue_init(&queue->fpq); spin_lock(&fc->lock); if (ring->queues[qid]) { spin_unlock(&fc->lock); + kfree(queue->fpq.processing); kfree(queue); return ring->queues[qid]; } @@ -127,6 +155,214 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring, return queue; } +/* + * Checks for errors and stores it into the request + */ +static int fuse_uring_out_header_has_err(struct fuse_out_header *oh, + struct fuse_req *req, + struct fuse_conn *fc) +{ + int err; + + err = -EINVAL; + if (oh->unique == 0) { + /* Not supported through io-uring yet */ + pr_warn_once("notify through fuse-io-uring not supported\n"); + goto err; + } + + if (oh->error <= -ERESTARTSYS || oh->error > 0) + goto err; + + if (oh->error) { + err = oh->error; + goto err; + } + + err = -ENOENT; + if ((oh->unique & ~FUSE_INT_REQ_BIT) != req->in.h.unique) { + pr_warn_ratelimited("unique mismatch, expected: %llu got %llu\n", + req->in.h.unique, + oh->unique & ~FUSE_INT_REQ_BIT); + goto err; + } + + /* + * Is it an interrupt reply ID? + * XXX: Not supported through fuse-io-uring yet, it should not even + * find the request - should not happen. + */ + WARN_ON_ONCE(oh->unique & FUSE_INT_REQ_BIT); + + err = 0; +err: + return err; +} + +static int fuse_uring_copy_from_ring(struct fuse_ring *ring, + struct fuse_req *req, + struct fuse_ring_ent *ent) +{ + struct fuse_copy_state cs; + struct fuse_args *args = req->args; + struct iov_iter iter; + int err; + struct fuse_uring_ent_in_out ring_in_out; + + err = copy_from_user(&ring_in_out, &ent->headers->ring_ent_in_out, + sizeof(ring_in_out)); + if (err) + return -EFAULT; + + err = import_ubuf(ITER_SOURCE, ent->payload, ring->max_payload_sz, + &iter); + if (err) + return err; + + fuse_copy_init(&cs, 0, &iter); + cs.is_uring = 1; + cs.req = req; + + return fuse_copy_out_args(&cs, args, ring_in_out.payload_sz); +} + + /* + * Copy data from the req to the ring buffer + */ +static int fuse_uring_args_to_ring(struct fuse_ring *ring, struct fuse_req *req, + struct fuse_ring_ent *ent) +{ + struct fuse_copy_state cs; + struct fuse_args *args = req->args; + struct fuse_in_arg *in_args = args->in_args; + int num_args = args->in_numargs; + int err; + struct iov_iter iter; + struct fuse_uring_ent_in_out ent_in_out = { + .flags = 0, + .commit_id = req->in.h.unique, + }; + + err = import_ubuf(ITER_DEST, ent->payload, ring->max_payload_sz, &iter); + if (err) { + pr_info_ratelimited("fuse: Import of user buffer failed\n"); + return err; + } + + fuse_copy_init(&cs, 1, &iter); + cs.is_uring = 1; + cs.req = req; + + if (num_args > 0) { + /* + * Expectation is that the first argument is the per op header. + * Some op code have that as zero size. + */ + if (args->in_args[0].size > 0) { + err = copy_to_user(&ent->headers->op_in, in_args->value, + in_args->size); + if (err) { + pr_info_ratelimited( + "Copying the header failed.\n"); + return -EFAULT; + } + } + in_args++; + num_args--; + } + + /* copy the payload */ + err = fuse_copy_args(&cs, num_args, args->in_pages, + (struct fuse_arg *)in_args, 0); + if (err) { + pr_info_ratelimited("%s fuse_copy_args failed\n", __func__); + return err; + } + + ent_in_out.payload_sz = cs.ring.copied_sz; + err = copy_to_user(&ent->headers->ring_ent_in_out, &ent_in_out, + sizeof(ent_in_out)); + return err ? -EFAULT : 0; +} + +static int fuse_uring_copy_to_ring(struct fuse_ring_ent *ent, + struct fuse_req *req) +{ + struct fuse_ring_queue *queue = ent->queue; + struct fuse_ring *ring = queue->ring; + int err; + + err = -EIO; + if (WARN_ON(ent->state != FRRS_FUSE_REQ)) { + pr_err("qid=%d ring-req=%p invalid state %d on send\n", + queue->qid, ent, ent->state); + return err; + } + + err = -EINVAL; + if (WARN_ON(req->in.h.unique == 0)) + return err; + + /* copy the request */ + err = fuse_uring_args_to_ring(ring, req, ent); + if (unlikely(err)) { + pr_info_ratelimited("Copy to ring failed: %d\n", err); + return err; + } + + /* copy fuse_in_header */ + err = copy_to_user(&ent->headers->in_out, &req->in.h, + sizeof(req->in.h)); + if (err) { + err = -EFAULT; + return err; + } + + return 0; +} + +static int fuse_uring_prepare_send(struct fuse_ring_ent *ent, + struct fuse_req *req) +{ + int err; + + err = fuse_uring_copy_to_ring(ent, req); + if (!err) + set_bit(FR_SENT, &req->flags); + else + fuse_uring_req_end(ent, req, err); + + return err; +} + +/* + * Write data to the ring buffer and send the request to userspace, + * userspace will read it + * This is comparable with classical read(/dev/fuse) + */ +static int fuse_uring_send_next_to_ring(struct fuse_ring_ent *ent, + struct fuse_req *req, + unsigned int issue_flags) +{ + struct fuse_ring_queue *queue = ent->queue; + int err; + struct io_uring_cmd *cmd; + + err = fuse_uring_prepare_send(ent, req); + if (err) + return err; + + spin_lock(&queue->lock); + cmd = ent->cmd; + ent->cmd = NULL; + ent->state = FRRS_USERSPACE; + list_move(&ent->list, &queue->ent_in_userspace); + spin_unlock(&queue->lock); + + io_uring_cmd_done(cmd, 0, 0, issue_flags); + return 0; +} + /* * Make a ring entry available for fuse_req assignment */ @@ -138,6 +374,203 @@ static void fuse_uring_ent_avail(struct fuse_ring_ent *ent, ent->state = FRRS_AVAILABLE; } +/* Used to find the request on SQE commit */ +static void fuse_uring_add_to_pq(struct fuse_ring_ent *ent, + struct fuse_req *req) +{ + struct fuse_ring_queue *queue = ent->queue; + struct fuse_pqueue *fpq = &queue->fpq; + unsigned int hash; + + req->ring_entry = ent; + hash = fuse_req_hash(req->in.h.unique); + list_move_tail(&req->list, &fpq->processing[hash]); +} + +/* + * Assign a fuse queue entry to the given entry + */ +static void fuse_uring_add_req_to_ring_ent(struct fuse_ring_ent *ent, + struct fuse_req *req) +{ + struct fuse_ring_queue *queue = ent->queue; + struct fuse_conn *fc = req->fm->fc; + struct fuse_iqueue *fiq = &fc->iq; + + lockdep_assert_held(&queue->lock); + + if (WARN_ON_ONCE(ent->state != FRRS_AVAILABLE && + ent->state != FRRS_COMMIT)) { + pr_warn("%s qid=%d state=%d\n", __func__, ent->queue->qid, + ent->state); + } + + spin_lock(&fiq->lock); + clear_bit(FR_PENDING, &req->flags); + spin_unlock(&fiq->lock); + ent->fuse_req = req; + ent->state = FRRS_FUSE_REQ; + list_move(&ent->list, &queue->ent_w_req_queue); + fuse_uring_add_to_pq(ent, req); +} + +/* Fetch the next fuse request if available */ +static struct fuse_req *fuse_uring_ent_assign_req(struct fuse_ring_ent *ent) + __must_hold(&queue->lock) +{ + struct fuse_req *req; + struct fuse_ring_queue *queue = ent->queue; + struct list_head *req_queue = &queue->fuse_req_queue; + + lockdep_assert_held(&queue->lock); + + /* get and assign the next entry while it is still holding the lock */ + req = list_first_entry_or_null(req_queue, struct fuse_req, list); + if (req) + fuse_uring_add_req_to_ring_ent(ent, req); + + return req; +} + +/* + * Read data from the ring buffer, which user space has written to + * This is comparible with handling of classical write(/dev/fuse). + * Also make the ring request available again for new fuse requests. + */ +static void fuse_uring_commit(struct fuse_ring_ent *ent, struct fuse_req *req, + unsigned int issue_flags) +{ + struct fuse_ring *ring = ent->queue->ring; + struct fuse_conn *fc = ring->fc; + ssize_t err = 0; + + err = copy_from_user(&req->out.h, &ent->headers->in_out, + sizeof(req->out.h)); + if (err) { + req->out.h.error = -EFAULT; + goto out; + } + + err = fuse_uring_out_header_has_err(&req->out.h, req, fc); + if (err) { + /* req->out.h.error already set */ + goto out; + } + + err = fuse_uring_copy_from_ring(ring, req, ent); +out: + fuse_uring_req_end(ent, req, err); +} + +/* + * Get the next fuse req and send it + */ +static void fuse_uring_next_fuse_req(struct fuse_ring_ent *ent, + struct fuse_ring_queue *queue, + unsigned int issue_flags) +{ + int err; + struct fuse_req *req; + +retry: + spin_lock(&queue->lock); + fuse_uring_ent_avail(ent, queue); + req = fuse_uring_ent_assign_req(ent); + spin_unlock(&queue->lock); + + if (req) { + err = fuse_uring_send_next_to_ring(ent, req, issue_flags); + if (err) + goto retry; + } +} + +static int fuse_ring_ent_set_commit(struct fuse_ring_ent *ent) +{ + struct fuse_ring_queue *queue = ent->queue; + + lockdep_assert_held(&queue->lock); + + if (WARN_ON_ONCE(ent->state != FRRS_USERSPACE)) + return -EIO; + + ent->state = FRRS_COMMIT; + list_move(&ent->list, &queue->ent_commit_queue); + + return 0; +} + +/* FUSE_URING_CMD_COMMIT_AND_FETCH handler */ +static int fuse_uring_commit_fetch(struct io_uring_cmd *cmd, int issue_flags, + struct fuse_conn *fc) +{ + const struct fuse_uring_cmd_req *cmd_req = io_uring_sqe_cmd(cmd->sqe); + struct fuse_ring_ent *ent; + int err; + struct fuse_ring *ring = fc->ring; + struct fuse_ring_queue *queue; + uint64_t commit_id = READ_ONCE(cmd_req->commit_id); + unsigned int qid = READ_ONCE(cmd_req->qid); + struct fuse_pqueue *fpq; + struct fuse_req *req; + + err = -ENOTCONN; + if (!ring) + return err; + + if (qid >= ring->nr_queues) + return -EINVAL; + + queue = ring->queues[qid]; + if (!queue) + return err; + fpq = &queue->fpq; + + spin_lock(&queue->lock); + /* Find a request based on the unique ID of the fuse request + * This should get revised, as it needs a hash calculation and list + * search. And full struct fuse_pqueue is needed (memory overhead). + * As well as the link from req to ring_ent. + */ + req = fuse_request_find(fpq, commit_id); + err = -ENOENT; + if (!req) { + pr_info("qid=%d commit_id %llu not found\n", queue->qid, + commit_id); + spin_unlock(&queue->lock); + return err; + } + list_del_init(&req->list); + ent = req->ring_entry; + req->ring_entry = NULL; + + err = fuse_ring_ent_set_commit(ent); + if (err != 0) { + pr_info_ratelimited("qid=%d commit_id %llu state %d", + queue->qid, commit_id, ent->state); + spin_unlock(&queue->lock); + req->out.h.error = err; + clear_bit(FR_SENT, &req->flags); + fuse_request_end(req); + return err; + } + + ent->cmd = cmd; + spin_unlock(&queue->lock); + + /* without the queue lock, as other locks are taken */ + fuse_uring_commit(ent, req, issue_flags); + + /* + * Fetching the next request is absolutely required as queued + * fuse requests would otherwise not get processed - committing + * and fetching is done in one step vs legacy fuse, which has separated + * read (fetch request) and write (commit result). + */ + fuse_uring_next_fuse_req(ent, queue, issue_flags); + return 0; +} + /* * fuse_uring_req_fetch command handling */ @@ -319,6 +752,14 @@ int __maybe_unused fuse_uring_cmd(struct io_uring_cmd *cmd, return err; } break; + case FUSE_IO_URING_CMD_COMMIT_AND_FETCH: + err = fuse_uring_commit_fetch(cmd, issue_flags, fc); + if (err) { + pr_info_once("FUSE_IO_URING_COMMIT_AND_FETCH failed err=%d\n", + err); + return err; + } + break; default: return -EINVAL; } diff --git a/fs/fuse/dev_uring_i.h b/fs/fuse/dev_uring_i.h index ae1536355b36..44bf237f0d5a 100644 --- a/fs/fuse/dev_uring_i.h +++ b/fs/fuse/dev_uring_i.h @@ -20,6 +20,9 @@ enum fuse_ring_req_state { /* The ring entry is waiting for new fuse requests */ FRRS_AVAILABLE, + /* The ring entry got assigned a fuse req */ + FRRS_FUSE_REQ, + /* The ring entry is in or on the way to user space */ FRRS_USERSPACE, }; @@ -67,7 +70,16 @@ struct fuse_ring_queue { * entries in the process of being committed or in the process * to be sent to userspace */ + struct list_head ent_w_req_queue; struct list_head ent_commit_queue; + + /* entries in userspace */ + struct list_head ent_in_userspace; + + /* fuse requests waiting for an entry slot */ + struct list_head fuse_req_queue; + + struct fuse_pqueue fpq; }; /** diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 2ef87a94d547..88e1b1593bc1 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -449,6 +449,10 @@ struct fuse_req { /** fuse_mount this request belongs to */ struct fuse_mount *fm; + +#ifdef CONFIG_FUSE_IO_URING + void *ring_entry; +#endif }; struct fuse_iqueue; -- 2.39.2