Jeff Layton 13d34ac6e5 Revert "fsnotify: destroy marks with call_srcu instead of dedicated thread" ... This reverts commit c510eff6be ("fsnotify: destroy marks with call_srcu instead of dedicated thread"). Eryu reported that he was seeing some OOM kills kick in when running a testcase that adds and removes inotify marks on a file in a tight loop. The above commit changed the code to use call_srcu to clean up the marks. While that does (in principle) work, the srcu callback job is limited to cleaning up entries in small batches and only once per jiffy. It's easily possible to overwhelm that machinery with too many call_srcu callbacks, and Eryu's reproduer did just that. There's also another potential problem with using call_srcu here. While you can obviously sleep while holding the srcu_read_lock, the callbacks run under local_bh_disable, so you can't sleep there. It's possible when putting the last reference to the fsnotify_mark that we'll end up putting a chain of references including the fsnotify_group, uid, and associated keys. While I don't see any obvious ways that that could occurs, it's probably still best to avoid using call_srcu here after all. This patch reverts the above patch. A later patch will take a different approach to eliminated the dedicated thread here. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Reported-by: Eryu Guan <guaneryu@gmail.com> Tested-by: Eryu Guan <guaneryu@gmail.com> Cc: Jan Kara <jack@suse.com> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-02-18 16:23:24 -08:00
..
dnotify	fsnotify: get rid of fsnotify_destroy_mark_locked()	2015-09-04 16:54:41 -07:00
fanotify	fsnotify: get rid of fsnotify_destroy_mark_locked()	2015-09-04 16:54:41 -07:00
inotify	inotify: actually check for invalid bits in sys_inotify_add_watch()	2015-11-05 19:34:48 -08:00
fdinfo.c	inotify: hide internal kernel bits from fdinfo	2015-11-05 19:34:48 -08:00
fdinfo.h	fs: Convert show_fdinfo functions to void	2014-11-05 14:13:23 -05:00
fsnotify.c	fsnotify: remove mark->free_list	2015-09-04 16:54:41 -07:00
fsnotify.h	fsnotify: remove mark->free_list	2015-09-04 16:54:41 -07:00
group.c	fs/notify/group.c: make fsnotify_final_destroy_group() static	2014-10-09 22:25:45 -04:00
inode_mark.c	fs/notify/inode_mark.c: use list_next_entry in fsnotify_unmount_inodes	2016-01-14 16:00:49 -08:00
Kconfig	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
Makefile
mark.c	Revert "fsnotify: destroy marks with call_srcu instead of dedicated thread"	2016-02-18 16:23:24 -08:00
notification.c
vfsmount_mark.c	fsnotify: remove mark->free_list	2015-09-04 16:54:41 -07:00