Amir Goldstein f929416d5c fsnotify: fix wrong lockdep annotations ... [ Upstream commit 623af4f538b5df9b416e1b82f720af7371b4c771 ] Commit 6960b0d909 ("fsnotify: change locking order") changed some of the mark_mutex locks in direct reclaim path to use: mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); This change is explained: "...It uses nested locking to avoid deadlock in case we do the final iput() on an inode which still holds marks and thus would take the mutex again when calling fsnotify_inode_delete() in destroy_inode()." The problem is that the mutex_lock_nested() is not a nested lock at all. In fact, it has the opposite effect of preventing lockdep from warning about a very possible deadlock. Due to these wrong annotations, a deadlock that was introduced with nfsd filecache in kernel v5.4 went unnoticed in v5.4.y for over two years until it was reported recently by Khazhismel Kumykov, only to find out that the deadlock was already fixed in kernel v5.5. Fix the wrong lockdep annotations. Cc: Khazhismel Kumykov <khazhy@google.com> Fixes: 6960b0d909 ("fsnotify: change locking order") Link: https://lore.kernel.org/r/20220321112310.vpr7oxro2xkz5llh@quack3.lan/ Link: https://lore.kernel.org/r/20220422120327.3459282-4-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-06-09 10:21:03 +02:00
..
dnotify	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
fanotify	fanotify: Fix stale file descriptor in copy_event_to_user()	2022-02-05 12:37:56 +01:00
inotify	inotify: show inotify mask flags in proc fdinfo	2022-06-09 10:21:03 +02:00
fdinfo.c	inotify: show inotify mask flags in proc fdinfo	2022-06-09 10:21:03 +02:00
fdinfo.h
fsnotify.c	fsnotify: fix events reported to watching parent and child	2020-12-30 11:54:18 +01:00
fsnotify.h	fsnotify: move declaration of fsnotify_mark_connector_cachep to fsnotify.h	2019-10-17 10:31:12 +02:00
group.c	fsnotify: add mutex destroy	2020-05-13 17:14:20 +02:00
Kconfig	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
Makefile
mark.c	fsnotify: fix wrong lockdep annotations	2022-06-09 10:21:03 +02:00
notification.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18	2019-05-21 11:28:46 +02:00