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Tejun Heo 0b764b2ea1 kernfs: don't depend on d_find_any_alias() when generating notifications ... [ Upstream commit df6a58c5c5 ] kernfs_notify_workfn() sends out file modified events for the scheduled kernfs_nodes. Because the modifications aren't from userland, it doesn't have the matching file struct at hand and can't use fsnotify_modify(). Instead, it looked up the inode and then used d_find_any_alias() to find the dentry and used fsnotify_parent() and fsnotify() directly to generate notifications. The assumption was that the relevant dentries would have been pinned if there are listeners, which isn't true as inotify doesn't pin dentries at all and watching the parent doesn't pin the child dentries even for dnotify. This led to, for example, inotify watchers not getting notifications if the system is under memory pressure and the matching dentries got reclaimed. It can also be triggered through /proc/sys/vm/drop_caches or a remount attempt which involves shrinking dcache. fsnotify_parent() only uses the dentry to access the parent inode, which kernfs can do easily. Update kernfs_notify_workfn() so that it uses fsnotify() directly for both the parent and target inodes without going through d_find_any_alias(). While at it, supply the target file name to fsnotify() from kernfs_node->name. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Fixes: d911d98748 ("kernfs: make kernfs_notify() trigger inotify events too") Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Eric Paris <eparis@parisplace.org> Cc: stable@vger.kernel.org # v3.16+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>		History 2016-09-15 18:54:06 -04:00
..
dir.c	vfs: Remove unnecessary calls of check_submounts_and_drop	2014-10-09 02:38:56 -04:00
file.c	kernfs: don't depend on d_find_any_alias() when generating notifications	2016-09-15 18:54:06 -04:00
inode.c	kernfs: protect lazy kernfs_iattrs allocation with mutex	2014-04-16 11:54:40 -07:00
Kconfig	kernfs: add CONFIG_KERNFS	2014-02-07 16:08:57 -08:00
kernfs-internal.h	kernfs: implement kernfs_root->supers list	2014-04-25 11:43:31 -07:00
Makefile	sysfs, kernfs: add skeletons for kernfs	2013-11-27 13:28:24 -08:00
mount.c	kernfs: introduce kernfs_pin_sb()	2014-06-30 10:16:25 -04:00
symlink.c	kernfs: remove kernfs_addrm_cxt	2014-02-07 15:42:40 -08:00