From: Joanne Koong <joannelkoong@gmail.com> mainline inclusion from mainline-v6.13-rc1 commit 2b3933b1e0a0a4b758fbc164bb31db0c113a7e2c category: feature bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC6CFR Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Introduce the capability to dynamically configure the max pages limit (FUSE_MAX_MAX_PAGES) through a sysctl. This allows system administrators to dynamically set the maximum number of pages that can be used for servicing requests in fuse. Previously, this is gated by FUSE_MAX_MAX_PAGES which is statically set to 256 pages. One result of this is that the buffer size for a write request is limited to 1 MiB on a 4k-page system. The default value for this sysctl is the original limit (256 pages). $ sysctl -a | grep max_pages_limit fs.fuse.max_pages_limit = 256 $ sysctl -n fs.fuse.max_pages_limit 256 $ echo 1024 | sudo tee /proc/sys/fs/fuse/max_pages_limit 1024 $ sysctl -n fs.fuse.max_pages_limit 1024 $ echo 65536 | sudo tee /proc/sys/fs/fuse/max_pages_limit tee: /proc/sys/fs/fuse/max_pages_limit: Invalid argument $ echo 0 | sudo tee /proc/sys/fs/fuse/max_pages_limit tee: /proc/sys/fs/fuse/max_pages_limit: Invalid argument $ echo 65535 | sudo tee /proc/sys/fs/fuse/max_pages_limit 65535 $ sysctl -n fs.fuse.max_pages_limit 65535 Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com> --- Documentation/admin-guide/sysctl/fs.rst | 10 +++++++ fs/fuse/Makefile | 1 + fs/fuse/fuse_i.h | 14 +++++++-- fs/fuse/inode.c | 11 ++++++- fs/fuse/ioctl.c | 4 ++- fs/fuse/sysctl.c | 40 +++++++++++++++++++++++++ 6 files changed, 75 insertions(+), 5 deletions(-) create mode 100644 fs/fuse/sysctl.c diff --git a/Documentation/admin-guide/sysctl/fs.rst b/Documentation/admin-guide/sysctl/fs.rst index a321b84eccaa..297228f9f299 100644 --- a/Documentation/admin-guide/sysctl/fs.rst +++ b/Documentation/admin-guide/sysctl/fs.rst @@ -330,5 +330,15 @@ This configuration option sets the maximum number of "watches" that are allowed for each user. Each "watch" costs roughly 90 bytes on a 32-bit kernel, and roughly 160 bytes on a 64-bit one. The current default value for ``max_user_watches`` is 4% of the available low memory, divided by the "watch" cost in bytes. + +5. /proc/sys/fs/fuse - Configuration options for FUSE filesystems +===================================================================== + +This directory contains the following configuration options for FUSE +filesystems: + +``/proc/sys/fs/fuse/max_pages_limit`` is a read/write file for +setting/getting the maximum number of pages that can be used for servicing +requests in FUSE. diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile index 6e0228c6d0cb..dabc852a7ff1 100644 --- a/fs/fuse/Makefile +++ b/fs/fuse/Makefile @@ -9,7 +9,8 @@ obj-$(CONFIG_VIRTIO_FS) += virtiofs.o fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o ioctl.o fuse-y += iomode.o fuse-$(CONFIG_FUSE_DAX) += dax.o fuse-$(CONFIG_FUSE_PASSTHROUGH) += passthrough.o +fuse-$(CONFIG_SYSCTL) += sysctl.o virtiofs-y := virtio_fs.o diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 7dd7471962b9..879111e1e9d4 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -34,13 +34,10 @@ #include <linux/kabi.h> /** Default max number of pages that can be used in a single read request */ #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32 -/** Maximum of max_pages received in init_out */ -#define FUSE_MAX_MAX_PAGES 256 - /** Maximum number of outstanding background requests */ #define FUSE_DEFAULT_MAX_BACKGROUND 12 /** Bias for fi->writectr, meaning new writepages must not be sent */ #define FUSE_NOWRITE INT_MIN @@ -49,10 +46,13 @@ #define FUSE_NAME_MAX 1024 /** Number of dentries for each connection in the control filesystem */ #define FUSE_CTL_NUM_DENTRIES 5 +/** Maximum of max_pages received in init_out */ +extern unsigned int fuse_max_pages_limit; + /** List of active connections */ extern struct list_head fuse_conn_list; /** Global mutex protecting fuse_conn_list and the control filesystem */ extern struct mutex fuse_mutex; @@ -1510,6 +1510,14 @@ ssize_t fuse_passthrough_splice_read(struct file *in, loff_t *ppos, ssize_t fuse_passthrough_splice_write(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags); ssize_t fuse_passthrough_mmap(struct file *file, struct vm_area_struct *vma); +#ifdef CONFIG_SYSCTL +extern int fuse_sysctl_register(void); +extern void fuse_sysctl_unregister(void); +#else +#define fuse_sysctl_register() (0) +#define fuse_sysctl_unregister() do { } while (0) +#endif /* CONFIG_SYSCTL */ + #endif /* _FS_FUSE_I_H */ diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 9caa80973a5c..0c95552179e5 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -33,10 +33,12 @@ static struct kmem_cache *fuse_inode_cachep; struct list_head fuse_conn_list; DEFINE_MUTEX(fuse_mutex); static int set_global_limit(const char *val, const struct kernel_param *kp); +unsigned int fuse_max_pages_limit = 256; + unsigned max_user_bgreq; module_param_call(max_user_bgreq, set_global_limit, param_get_uint, &max_user_bgreq, 0644); __MODULE_PARM_TYPE(max_user_bgreq, "uint"); MODULE_PARM_DESC(max_user_bgreq, @@ -947,11 +949,11 @@ void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm, atomic64_set(&fc->attr_version, 1); get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); fc->pid_ns = get_pid_ns(task_active_pid_ns(current)); fc->user_ns = get_user_ns(user_ns); fc->max_pages = FUSE_DEFAULT_MAX_PAGES_PER_REQ; - fc->max_pages_limit = FUSE_MAX_MAX_PAGES; + fc->max_pages_limit = fuse_max_pages_limit; if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) fuse_backing_files_init(fc); INIT_LIST_HEAD(&fc->mounts); @@ -2067,22 +2069,29 @@ static int __init fuse_fs_init(void) err = register_filesystem(&fuse_fs_type); if (err) goto out3; + err = fuse_sysctl_register(); + if (err) + goto out4; + return 0; + out4: + unregister_filesystem(&fuse_fs_type); out3: unregister_fuseblk(); out2: kmem_cache_destroy(fuse_inode_cachep); out: return err; } static void fuse_fs_cleanup(void) { + fuse_sysctl_unregister(); unregister_filesystem(&fuse_fs_type); unregister_fuseblk(); /* * Make sure all delayed rcu free inodes are flushed before we diff --git a/fs/fuse/ioctl.c b/fs/fuse/ioctl.c index 572ce8a82ceb..a6c8ee551635 100644 --- a/fs/fuse/ioctl.c +++ b/fs/fuse/ioctl.c @@ -8,10 +8,12 @@ #include <linux/uio.h> #include <linux/compat.h> #include <linux/fileattr.h> #include <linux/fsverity.h> +#define FUSE_VERITY_ENABLE_ARG_MAX_PAGES 256 + static ssize_t fuse_send_ioctl(struct fuse_mount *fm, struct fuse_args *args, struct fuse_ioctl_out *outarg) { ssize_t ret; @@ -138,11 +140,11 @@ static int fuse_setup_measure_verity(unsigned long arg, struct iovec *iov) static int fuse_setup_enable_verity(unsigned long arg, struct iovec *iov, unsigned int *in_iovs) { struct fsverity_enable_arg enable; struct fsverity_enable_arg __user *uarg = (void __user *)arg; - const __u32 max_buffer_len = FUSE_MAX_MAX_PAGES * PAGE_SIZE; + const __u32 max_buffer_len = FUSE_VERITY_ENABLE_ARG_MAX_PAGES * PAGE_SIZE; if (copy_from_user(&enable, uarg, sizeof(enable))) return -EFAULT; if (enable.salt_size > max_buffer_len || enable.sig_size > max_buffer_len) diff --git a/fs/fuse/sysctl.c b/fs/fuse/sysctl.c new file mode 100644 index 000000000000..b272bb333005 --- /dev/null +++ b/fs/fuse/sysctl.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/fuse/fuse_sysctl.c + * + * Sysctl interface to fuse parameters + */ +#include <linux/sysctl.h> + +#include "fuse_i.h" + +static struct ctl_table_header *fuse_table_header; + +/* Bound by fuse_init_out max_pages, which is a u16 */ +static unsigned int sysctl_fuse_max_pages_limit = 65535; + +static struct ctl_table fuse_sysctl_table[] = { + { + .procname = "max_pages_limit", + .data = &fuse_max_pages_limit, + .maxlen = sizeof(fuse_max_pages_limit), + .mode = 0644, + .proc_handler = proc_douintvec_minmax, + .extra1 = SYSCTL_ONE, + .extra2 = &sysctl_fuse_max_pages_limit, + }, +}; + +int fuse_sysctl_register(void) +{ + fuse_table_header = register_sysctl("fs/fuse", fuse_sysctl_table); + if (!fuse_table_header) + return -ENOMEM; + return 0; +} + +void fuse_sysctl_unregister(void) +{ + unregister_sysctl_table(fuse_table_header); + fuse_table_header = NULL; +} -- 2.34.3