kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-20 19:23:40 +00:00
Code Issues Releases Packages Activity
linux/fs/notify
History
Amir Goldstein f9a48bc3dd fsnotify: clear PARENT_WATCHED flags lazily 
[ Upstream commit 172e422ffe ]

In some setups directories can have many (usually negative) dentries.
Hence __fsnotify_update_child_dentry_flags() function can take a
significant amount of time. Since the bulk of this function happens
under inode->i_lock this causes a significant contention on the lock
when we remove the watch from the directory as the
__fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask()
races with __fsnotify_update_child_dentry_flags() calls from
__fsnotify_parent() happening on children. This can lead upto softlockup
reports reported by users.

Fix the problem by calling fsnotify_update_children_dentry_flags() to
set PARENT_WATCHED flags only when parent starts watching children.

When parent stops watching children, clear false positive PARENT_WATCHED
flags lazily in __fsnotify_parent() for each accessed child.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-09-12 11:07:41 +02:00
..
dnotify dnotify: use fsnotify group lock helpers 2024-04-10 16:19:03 +02:00
fanotify fanotify: Remove obsoleted fanotify_event_has_path() 2024-04-10 16:19:19 +02:00
inotify fs: inotify: Fix typo in inotify comment 2024-04-10 16:19:07 +02:00
fdinfo.c fanotify: prepare for setting event flags in ignore mask 2024-04-10 16:19:07 +02:00
fdinfo.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fsnotify.c fsnotify: clear PARENT_WATCHED flags lazily 2024-09-12 11:07:41 +02:00
fsnotify.h fsnotify: clear PARENT_WATCHED flags lazily 2024-09-12 11:07:41 +02:00
group.c fsnotify: create helpers for group mark_mutex lock 2024-04-10 16:19:03 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mark.c fsnotify: clear PARENT_WATCHED flags lazily 2024-09-12 11:07:41 +02:00
notification.c fsnotify: Pass group argument to free_event 2024-04-10 16:18:50 +02:00