From 3b1464434611c531e6c4ae488ee3206eadb58ef1 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Tue, 4 Feb 2025 06:32:03 +0800 Subject: [PATCH 1/5] fsnotify: use accessor to set FMODE_NONOTIFY_* ANBZ: #45492 commit 95101401bb50ae2cf9deee1bbf4d2b28d0dfdc26 upstream. The FMODE_NONOTIFY_* bits are a 2-bits mode. Open coding manipulation of those bits is risky. Use an accessor file_set_fsnotify_mode() to set the mode. Rename file_set_fsnotify_mode() => file_set_fsnotify_mode_from_watchers() to make way for the simple accessor name. Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/r/20250203223205.861346-2-amir73il@gmail.com Signed-off-by: Christian Brauner Assisted-by: PatchPilot Signed-off-by: Joseph Qi --- drivers/tty/pty.c | 2 +- fs/notify/fsnotify.c | 18 ++++++++++++------ fs/open.c | 7 ++++--- include/linux/fs.h | 7 ++++++- include/linux/fsnotify.h | 4 ++-- 5 files changed, 25 insertions(+), 13 deletions(-) diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index df08f13052ff..8bb1a01fef2a 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -798,7 +798,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) nonseekable_open(inode, filp); /* We refuse fsnotify events on ptmx, since it's a shared resource */ - filp->f_mode |= FMODE_NONOTIFY; + file_set_fsnotify_mode(filp, FMODE_NONOTIFY); retval = tty_alloc_file(filp); if (retval) diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 6621b9163e4e..c8a44bb42a08 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -652,7 +652,7 @@ EXPORT_SYMBOL_GPL(fsnotify); * Later, fsnotify permission hooks do not check if there are permission event * watches, but that there were permission event watches at open time. */ -void file_set_fsnotify_mode(struct file *file) +void file_set_fsnotify_mode_from_watchers(struct file *file) { struct dentry *dentry = file->f_path.dentry, *parent; struct super_block *sb = dentry->d_sb; @@ -669,7 +669,7 @@ void file_set_fsnotify_mode(struct file *file) */ if (likely(!fsnotify_sb_has_priority_watchers(sb, FSNOTIFY_PRIO_CONTENT))) { - file->f_mode |= FMODE_NONOTIFY_PERM; + file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM); return; } @@ -680,7 +680,7 @@ void file_set_fsnotify_mode(struct file *file) if ((!d_is_dir(dentry) && !d_is_reg(dentry)) || likely(!fsnotify_sb_has_priority_watchers(sb, FSNOTIFY_PRIO_PRE_CONTENT))) { - file->f_mode |= FMODE_NONOTIFY | FMODE_NONOTIFY_PERM; + file_set_fsnotify_mode(file, FMODE_NONOTIFY | FMODE_NONOTIFY_PERM); return; } @@ -690,19 +690,25 @@ void file_set_fsnotify_mode(struct file *file) */ mnt_mask = READ_ONCE(real_mount(file->f_path.mnt)->mnt_fsnotify_mask); if (unlikely(fsnotify_object_watched(d_inode(dentry), mnt_mask, - FSNOTIFY_PRE_CONTENT_EVENTS))) + FSNOTIFY_PRE_CONTENT_EVENTS))) { + /* Enable pre-content events */ + file_set_fsnotify_mode(file, 0); return; + } /* Is parent watching for pre-content events on this file? */ if (dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED) { parent = dget_parent(dentry); p_mask = fsnotify_inode_watches_children(d_inode(parent)); dput(parent); - if (p_mask & FSNOTIFY_PRE_CONTENT_EVENTS) + if (p_mask & FSNOTIFY_PRE_CONTENT_EVENTS) { + /* Enable pre-content events */ + file_set_fsnotify_mode(file, 0); return; + } } /* Nobody watching for pre-content events from this file */ - file->f_mode |= FMODE_NONOTIFY | FMODE_NONOTIFY_PERM; + file_set_fsnotify_mode(file, FMODE_NONOTIFY | FMODE_NONOTIFY_PERM); } #endif diff --git a/fs/open.c b/fs/open.c index 36d8034c69c2..3a757235354e 100644 --- a/fs/open.c +++ b/fs/open.c @@ -923,7 +923,8 @@ static int do_dentry_open(struct file *f, f->f_sb_err = file_sample_sb_err(f); if (unlikely(f->f_flags & O_PATH)) { - f->f_mode = FMODE_PATH | FMODE_OPENED | FMODE_NONOTIFY; + f->f_mode = FMODE_PATH | FMODE_OPENED; + file_set_fsnotify_mode(f, FMODE_NONOTIFY); f->f_op = &empty_fops; return 0; } @@ -956,7 +957,7 @@ static int do_dentry_open(struct file *f, * If FMODE_NONOTIFY was already set for an fanotify fd, this doesn't * change anything. */ - file_set_fsnotify_mode(f); + file_set_fsnotify_mode_from_watchers(f); error = fsnotify_open_perm(f); if (error) goto cleanup_all; @@ -1142,7 +1143,7 @@ struct file *dentry_open_nonotify(const struct path *path, int flags, if (!IS_ERR(f)) { int error; - f->f_mode |= FMODE_NONOTIFY; + file_set_fsnotify_mode(f, FMODE_NONOTIFY); error = vfs_open(path, f); if (error) { fput(f); diff --git a/include/linux/fs.h b/include/linux/fs.h index 2e3c5aa79277..851d042a4b5b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -215,7 +215,6 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, #define FMODE_FSNOTIFY_HSM(mode) 0 #endif - /* * Attribute flags. These should be or-ed together to figure out what * has been changed! @@ -3069,6 +3068,12 @@ static inline void exe_file_allow_write_access(struct file *exe_file) allow_write_access(exe_file); } +static inline void file_set_fsnotify_mode(struct file *file, fmode_t mode) +{ + file->f_mode &= ~FMODE_FSNOTIFY_MASK; + file->f_mode |= mode; +} + static inline bool inode_is_open_for_write(const struct inode *inode) { return atomic_read(&inode->i_writecount) > 0; diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index ae4d57316499..83d3ac97f826 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -129,7 +129,7 @@ static inline int fsnotify_file(struct file *file, __u32 mask) #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS -void file_set_fsnotify_mode(struct file *file); +void file_set_fsnotify_mode_from_watchers(struct file *file); /* * fsnotify_file_area_perm - permission hook before access to file range @@ -228,7 +228,7 @@ static inline int fsnotify_open_perm(struct file *file) } #else -static inline void file_set_fsnotify_mode(struct file *file) +static inline void file_set_fsnotify_mode_from_watchers(struct file *file) { } -- Gitee From 94002281abb48ce322d3f9c101509a4ef0074e08 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Tue, 4 Feb 2025 06:32:04 +0800 Subject: [PATCH 2/5] fsnotify: disable notification by default for all pseudo files ANBZ: #45492 commit 2a42754b3104d78a2bc7a2ad8844427411c76ca6 upstream. Most pseudo files are not applicable for fsnotify events at all, let alone to the new pre-content events. Disable notifications to all files allocated with alloc_file_pseudo() and enable legacy inotify events for the specific cases of pipe and socket, which have known users of inotify events. Pre-content events are also kept disabled for sockets and pipes. Fixes: 20bf82a898b6 ("mm: don't allow huge faults for files with pre content watches") Reported-by: Alex Williamson Closes: https://lore.kernel.org/linux-fsdevel/20250131121703.1e4d00a7.alex.williamson@redhat.com/ Suggested-by: Linus Torvalds Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wi2pThSVY=zhO=ZKxViBj5QCRX-=AS2+rVknQgJnHXDFg@mail.gmail.com/ Tested-by: Alex Williamson Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/r/20250203223205.861346-3-amir73il@gmail.com Signed-off-by: Christian Brauner [Fixes conflicts, drop alloc_file_pseudo_noaccount() hunk] Assisted-by: PatchPilot Signed-off-by: Joseph Qi --- fs/file_table.c | 6 ++++++ fs/open.c | 4 ++-- fs/pipe.c | 6 ++++++ net/socket.c | 5 +++++ 4 files changed, 19 insertions(+), 2 deletions(-) diff --git a/fs/file_table.c b/fs/file_table.c index d4632ef96a1c..0553779d6aa3 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -384,7 +384,13 @@ struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt, if (IS_ERR(file)) { ihold(inode); path_put(&path); + return file; } + /* + * Disable all fsnotify events for pseudo files by default. + * They may be enabled by caller with file_set_fsnotify_mode(). + */ + file_set_fsnotify_mode(file, FMODE_NONOTIFY); return file; } EXPORT_SYMBOL(alloc_file_pseudo); diff --git a/fs/open.c b/fs/open.c index 3a757235354e..4c5b2b36f8a0 100644 --- a/fs/open.c +++ b/fs/open.c @@ -954,8 +954,8 @@ static int do_dentry_open(struct file *f, /* * Set FMODE_NONOTIFY_* bits according to existing permission watches. - * If FMODE_NONOTIFY was already set for an fanotify fd, this doesn't - * change anything. + * If FMODE_NONOTIFY mode was already set for an fanotify fd or for a + * pseudo file, this call will not change the mode. */ file_set_fsnotify_mode_from_watchers(f); error = fsnotify_open_perm(f); diff --git a/fs/pipe.c b/fs/pipe.c index ba4376341ddd..d4ccef4063ba 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -954,6 +954,12 @@ int create_pipe_files(struct file **res, int flags) res[1] = f; stream_open(inode, res[0]); stream_open(inode, res[1]); + /* + * Disable permission and pre-content events, but enable legacy + * inotify events for legacy users. + */ + file_set_fsnotify_mode(res[0], FMODE_NONOTIFY_PERM); + file_set_fsnotify_mode(res[1], FMODE_NONOTIFY_PERM); return 0; } diff --git a/net/socket.c b/net/socket.c index d977ac010b9e..0add654a50c2 100644 --- a/net/socket.c +++ b/net/socket.c @@ -478,6 +478,11 @@ struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname) sock->file = file; file->private_data = sock; stream_open(SOCK_INODE(sock), file); + /* + * Disable permission and pre-content events, but enable legacy + * inotify events for legacy users. + */ + file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM); return file; } EXPORT_SYMBOL(sock_alloc_file); -- Gitee From 6f3abd136c35ed3c555d3cd97d43c9d849dff7ca Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Mon, 3 Feb 2025 23:32:05 +0100 Subject: [PATCH 3/5] fsnotify: disable pre-content and permission events by default ANBZ: #45492 commit 711f9b8fbe4f4936302804e246e206f0829f628f upstream. After introducing pre-content events, we had a regression related to disabling huge faults on files that should never have pre-content events enabled. This happened because the default f_mode of allocated files (0) does not disable pre-content events. Pre-content events are disabled in file_set_fsnotify_mode_by_watchers() but internal files may not get to call this helper. Initialize f_mode to disable permission and pre-content events for all files and if needed they will be enabled for the callers of file_set_fsnotify_mode_by_watchers(). Fixes: 20bf82a898b6 ("mm: don't allow huge faults for files with pre content watches") Reported-by: Alex Williamson Closes: https://lore.kernel.org/linux-fsdevel/20250131121703.1e4d00a7.alex.williamson@redhat.com/ Tested-by: Alex Williamson Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/r/20250203223205.861346-4-amir73il@gmail.com Signed-off-by: Christian Brauner [Fixes conflicts] Assisted-by: PatchPilot Signed-off-by: Joseph Qi --- fs/file_table.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/file_table.c b/fs/file_table.c index 0553779d6aa3..b64c1678eb5c 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -202,6 +202,11 @@ static int init_file(struct file *f, int flags, const struct cred *cred) f->f_mode = OPEN_FMODE(flags); /* f->f_version: 0 */ + /* + * Disable permission and pre-content events for all files by default. + * They may be enabled later by file_set_fsnotify_mode_from_watchers(). + */ + file_set_fsnotify_mode(f, FMODE_NONOTIFY_PERM); return 0; } -- Gitee From 1f207f616be4e720c0270793d3ca2eb427bb9302 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Tue, 8 Jul 2025 22:36:40 +0800 Subject: [PATCH 4/5] fsnotify: merge file_set_fsnotify_mode_from_watchers() with open perm hook ANBZ: #45492 commit 08da98e1b2f76cdbacf84b9affaa75960dbce515 upstream. Create helper fsnotify_open_perm_and_set_mode() that moves the fsnotify_open_perm() hook into file_set_fsnotify_mode_from_watchers(). This will allow some more optimizations. Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Link: https://patch.msgid.link/20250708143641.418603-2-amir73il@gmail.com Assisted-by: PatchPilot Signed-off-by: Joseph Qi --- fs/file_table.c | 2 +- fs/notify/fsnotify.c | 22 +++++++++++++--------- fs/open.c | 6 +++--- include/linux/fsnotify.h | 8 +++----- 4 files changed, 20 insertions(+), 18 deletions(-) diff --git a/fs/file_table.c b/fs/file_table.c index b64c1678eb5c..7b06bbe71494 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -204,7 +204,7 @@ static int init_file(struct file *f, int flags, const struct cred *cred) /* * Disable permission and pre-content events for all files by default. - * They may be enabled later by file_set_fsnotify_mode_from_watchers(). + * They may be enabled later by fsnotify_open_perm_and_set_mode(). */ file_set_fsnotify_mode(f, FMODE_NONOTIFY_PERM); return 0; diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index c8a44bb42a08..9a1bbc578183 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -647,12 +647,12 @@ EXPORT_SYMBOL_GPL(fsnotify); #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS /* - * At open time we check fsnotify_sb_has_priority_watchers() and set the - * FMODE_NONOTIFY_ mode bits accordignly. + * At open time we check fsnotify_sb_has_priority_watchers(), call the open perm + * hook and set the FMODE_NONOTIFY_ mode bits accordignly. * Later, fsnotify permission hooks do not check if there are permission event * watches, but that there were permission event watches at open time. */ -void file_set_fsnotify_mode_from_watchers(struct file *file) +int fsnotify_open_perm_and_set_mode(struct file *file) { struct dentry *dentry = file->f_path.dentry, *parent; struct super_block *sb = dentry->d_sb; @@ -660,7 +660,7 @@ void file_set_fsnotify_mode_from_watchers(struct file *file) /* Is it a file opened by fanotify? */ if (FMODE_FSNOTIFY_NONE(file->f_mode)) - return; + return 0; /* * Permission events is a super set of pre-content events, so if there @@ -670,7 +670,7 @@ void file_set_fsnotify_mode_from_watchers(struct file *file) if (likely(!fsnotify_sb_has_priority_watchers(sb, FSNOTIFY_PRIO_CONTENT))) { file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM); - return; + return 0; } /* @@ -680,8 +680,9 @@ void file_set_fsnotify_mode_from_watchers(struct file *file) if ((!d_is_dir(dentry) && !d_is_reg(dentry)) || likely(!fsnotify_sb_has_priority_watchers(sb, FSNOTIFY_PRIO_PRE_CONTENT))) { - file_set_fsnotify_mode(file, FMODE_NONOTIFY | FMODE_NONOTIFY_PERM); - return; + file_set_fsnotify_mode(file, FMODE_NONOTIFY | + FMODE_NONOTIFY_PERM); + goto open_perm; } /* @@ -693,7 +694,7 @@ void file_set_fsnotify_mode_from_watchers(struct file *file) FSNOTIFY_PRE_CONTENT_EVENTS))) { /* Enable pre-content events */ file_set_fsnotify_mode(file, 0); - return; + goto open_perm; } /* Is parent watching for pre-content events on this file? */ @@ -704,11 +705,14 @@ void file_set_fsnotify_mode_from_watchers(struct file *file) if (p_mask & FSNOTIFY_PRE_CONTENT_EVENTS) { /* Enable pre-content events */ file_set_fsnotify_mode(file, 0); - return; + goto open_perm; } } /* Nobody watching for pre-content events from this file */ file_set_fsnotify_mode(file, FMODE_NONOTIFY | FMODE_NONOTIFY_PERM); + +open_perm: + return fsnotify_open_perm(file); } #endif diff --git a/fs/open.c b/fs/open.c index 4c5b2b36f8a0..08cc707f4305 100644 --- a/fs/open.c +++ b/fs/open.c @@ -953,12 +953,12 @@ static int do_dentry_open(struct file *f, goto cleanup_all; /* - * Set FMODE_NONOTIFY_* bits according to existing permission watches. + * Call fsnotify open permission hook and set FMODE_NONOTIFY_* bits + * according to existing permission watches. * If FMODE_NONOTIFY mode was already set for an fanotify fd or for a * pseudo file, this call will not change the mode. */ - file_set_fsnotify_mode_from_watchers(f); - error = fsnotify_open_perm(f); + error = fsnotify_open_perm_and_set_mode(f); if (error) goto cleanup_all; diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 83d3ac97f826..9f691d45abd1 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -129,7 +129,7 @@ static inline int fsnotify_file(struct file *file, __u32 mask) #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS -void file_set_fsnotify_mode_from_watchers(struct file *file); +int fsnotify_open_perm_and_set_mode(struct file *file); /* * fsnotify_file_area_perm - permission hook before access to file range @@ -215,9 +215,6 @@ static inline int fsnotify_open_perm(struct file *file) { int ret; - if (likely(!FMODE_FSNOTIFY_PERM(file->f_mode))) - return 0; - if (file->f_flags & __FMODE_EXEC) { ret = fsnotify_path(&file->f_path, FS_OPEN_EXEC_PERM); if (ret) @@ -228,8 +225,9 @@ static inline int fsnotify_open_perm(struct file *file) } #else -static inline void file_set_fsnotify_mode_from_watchers(struct file *file) +static inline int fsnotify_open_perm_and_set_mode(struct file *file) { + return 0; } static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, -- Gitee From 4fe19f13fd3a3a4ba87241cd4e06bc9e91ee6b38 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Tue, 8 Jul 2025 22:36:41 +0800 Subject: [PATCH 5/5] fsnotify: optimize FMODE_NONOTIFY_PERM for the common cases ANBZ: #45492 commit 0d4c4d4ea443babab6ec1a79f481260963fc969a upstream. The most unlikely watched permission event is FAN_ACCESS_PERM, because at the time that it was introduced there were no evictable ignore mark, so subscribing to FAN_ACCESS_PERM would have incured a very high overhead. Yet, when we set the fmode to FMODE_NOTIFY_HSM(), we never skip trying to send FAN_ACCESS_PERM, which is almost always a waste of cycles. We got to this logic because of bundling FAN_OPEN*_PERM and FAN_ACCESS_PERM in the same category and because FAN_OPEN_PERM is a commonly used event. By open coding fsnotify_open_perm() in fsnotify_open_perm_and_set_mode(), we no longer need to regard FAN_OPEN*_PERM when calculating fmode. This leaves the case of having pre-content events and not having any other permission event in the object masks a more likely case than the other way around. Rework the fmode macros and code so that their meaning now refers only to hooks on an already open file: - FMODE_NOTIFY_NONE() skip all events - FMODE_NOTIFY_ACCESS_PERM() send all permission events including FAN_ACCESS_PERM - FMODE_NOTIFY_HSM() send pre-content permission events Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Link: https://patch.msgid.link/20250708143641.418603-3-amir73il@gmail.com Assisted-by: PatchPilot Signed-off-by: Joseph Qi --- fs/notify/fsnotify.c | 75 ++++++++++++++++++++++++---------------- include/linux/fs.h | 12 +++---- include/linux/fsnotify.h | 27 ++------------- 3 files changed, 53 insertions(+), 61 deletions(-) diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 9a1bbc578183..b7a8d0b91a7d 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -192,8 +192,8 @@ static bool fsnotify_event_needs_parent(struct inode *inode, __u32 mnt_mask, } /* Are there any inode/mount/sb objects that watch for these events? */ -static inline bool fsnotify_object_watched(struct inode *inode, __u32 mnt_mask, - __u32 mask) +static inline __u32 fsnotify_object_watched(struct inode *inode, __u32 mnt_mask, + __u32 mask) { __u32 marks_mask = inode->i_fsnotify_mask | mnt_mask | inode->i_sb->s_fsnotify_mask; @@ -656,7 +656,7 @@ int fsnotify_open_perm_and_set_mode(struct file *file) { struct dentry *dentry = file->f_path.dentry, *parent; struct super_block *sb = dentry->d_sb; - __u32 mnt_mask, p_mask; + __u32 mnt_mask, p_mask = 0; /* Is it a file opened by fanotify? */ if (FMODE_FSNOTIFY_NONE(file->f_mode)) @@ -674,45 +674,60 @@ int fsnotify_open_perm_and_set_mode(struct file *file) } /* - * If there are permission event watchers but no pre-content event - * watchers, set FMODE_NONOTIFY | FMODE_NONOTIFY_PERM to indicate that. + * OK, there are some permission event watchers. Check if anybody is + * watching for permission events on *this* file. */ - if ((!d_is_dir(dentry) && !d_is_reg(dentry)) || - likely(!fsnotify_sb_has_priority_watchers(sb, - FSNOTIFY_PRIO_PRE_CONTENT))) { - file_set_fsnotify_mode(file, FMODE_NONOTIFY | - FMODE_NONOTIFY_PERM); - goto open_perm; + mnt_mask = READ_ONCE(real_mount(file->f_path.mnt)->mnt_fsnotify_mask); + p_mask = fsnotify_object_watched(d_inode(dentry), mnt_mask, + ALL_FSNOTIFY_PERM_EVENTS); + if (dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED) { + parent = dget_parent(dentry); + p_mask |= fsnotify_inode_watches_children(d_inode(parent)); + dput(parent); } /* - * OK, there are some pre-content watchers. Check if anybody is - * watching for pre-content events on *this* file. + * Legacy FAN_ACCESS_PERM events have very high performance overhead, + * so unlikely to be used in the wild. If they are used there will be + * no optimizations at all. */ - mnt_mask = READ_ONCE(real_mount(file->f_path.mnt)->mnt_fsnotify_mask); - if (unlikely(fsnotify_object_watched(d_inode(dentry), mnt_mask, - FSNOTIFY_PRE_CONTENT_EVENTS))) { - /* Enable pre-content events */ + if (unlikely(p_mask & FS_ACCESS_PERM)) { + /* Enable all permission and pre-content events */ file_set_fsnotify_mode(file, 0); goto open_perm; } - /* Is parent watching for pre-content events on this file? */ - if (dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED) { - parent = dget_parent(dentry); - p_mask = fsnotify_inode_watches_children(d_inode(parent)); - dput(parent); - if (p_mask & FSNOTIFY_PRE_CONTENT_EVENTS) { - /* Enable pre-content events */ - file_set_fsnotify_mode(file, 0); - goto open_perm; - } + /* + * Pre-content events are only supported on regular files. + * If there are pre-content event watchers and no permission access + * watchers, set FMODE_NONOTIFY | FMODE_NONOTIFY_PERM to indicate that. + * That is the common case with HSM service. + */ + if (d_is_reg(dentry) && (p_mask & FSNOTIFY_PRE_CONTENT_EVENTS)) { + file_set_fsnotify_mode(file, FMODE_NONOTIFY | + FMODE_NONOTIFY_PERM); + goto open_perm; } - /* Nobody watching for pre-content events from this file */ - file_set_fsnotify_mode(file, FMODE_NONOTIFY | FMODE_NONOTIFY_PERM); + + /* Nobody watching permission and pre-content events on this file */ + file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM); open_perm: - return fsnotify_open_perm(file); + /* + * Send open perm events depending on object masks and regardless of + * FMODE_NONOTIFY_PERM. + */ + if (file->f_flags & __FMODE_EXEC && p_mask & FS_OPEN_EXEC_PERM) { + int ret = fsnotify_path(&file->f_path, FS_OPEN_EXEC_PERM); + + if (ret) + return ret; + } + + if (p_mask & FS_OPEN_PERM) + return fsnotify_path(&file->f_path, FS_OPEN_PERM); + + return 0; } #endif diff --git a/include/linux/fs.h b/include/linux/fs.h index 851d042a4b5b..6a12417faf96 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -192,12 +192,12 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, /* * The two FMODE_NONOTIFY* define which fsnotify events should not be generated - * for a file. These are the possible values of (f->f_mode & - * FMODE_FSNOTIFY_MASK) and their meaning: + * for an open file. These are the possible values of + * (f->f_mode & FMODE_FSNOTIFY_MASK) and their meaning: * * FMODE_NONOTIFY - suppress all (incl. non-permission) events. * FMODE_NONOTIFY_PERM - suppress permission (incl. pre-content) events. - * FMODE_NONOTIFY | FMODE_NONOTIFY_PERM - suppress only pre-content events. + * FMODE_NONOTIFY | FMODE_NONOTIFY_PERM - suppress only FAN_ACCESS_PERM. */ #define FMODE_FSNOTIFY_MASK \ (FMODE_NONOTIFY | FMODE_NONOTIFY_PERM) @@ -205,13 +205,13 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, #define FMODE_FSNOTIFY_NONE(mode) \ ((mode & FMODE_FSNOTIFY_MASK) == FMODE_NONOTIFY) #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS -#define FMODE_FSNOTIFY_PERM(mode) \ +#define FMODE_FSNOTIFY_HSM(mode) \ ((mode & FMODE_FSNOTIFY_MASK) == 0 || \ (mode & FMODE_FSNOTIFY_MASK) == (FMODE_NONOTIFY | FMODE_NONOTIFY_PERM)) -#define FMODE_FSNOTIFY_HSM(mode) \ +#define FMODE_FSNOTIFY_ACCESS_PERM(mode) \ ((mode & FMODE_FSNOTIFY_MASK) == 0) #else -#define FMODE_FSNOTIFY_PERM(mode) 0 +#define FMODE_FSNOTIFY_ACCESS_PERM(mode) 0 #define FMODE_FSNOTIFY_HSM(mode) 0 #endif diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index 9f691d45abd1..6e8084f8ef27 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -147,9 +147,6 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, if (!(perm_mask & (MAY_READ | MAY_WRITE | MAY_ACCESS))) return 0; - if (likely(!FMODE_FSNOTIFY_PERM(file->f_mode))) - return 0; - /* * read()/write() and other types of access generate pre-content events. */ @@ -160,7 +157,8 @@ static inline int fsnotify_file_area_perm(struct file *file, int perm_mask, return ret; } - if (!(perm_mask & MAY_READ)) + if (!(perm_mask & MAY_READ) || + likely(!FMODE_FSNOTIFY_ACCESS_PERM(file->f_mode))) return 0; /* @@ -208,22 +206,6 @@ static inline int fsnotify_file_perm(struct file *file, int perm_mask) return fsnotify_file_area_perm(file, perm_mask, NULL, 0); } -/* - * fsnotify_open_perm - permission hook before file open - */ -static inline int fsnotify_open_perm(struct file *file) -{ - int ret; - - if (file->f_flags & __FMODE_EXEC) { - ret = fsnotify_path(&file->f_path, FS_OPEN_EXEC_PERM); - if (ret) - return ret; - } - - return fsnotify_path(&file->f_path, FS_OPEN_PERM); -} - #else static inline int fsnotify_open_perm_and_set_mode(struct file *file) { @@ -251,11 +233,6 @@ static inline int fsnotify_file_perm(struct file *file, int perm_mask) { return 0; } - -static inline int fsnotify_open_perm(struct file *file) -{ - return 0; -} #endif /* -- Gitee