inotify: use GFP_NOFS under potential memory pressure
inotify can have a watchs removed under filesystem reclaim.
=================================
[ INFO: inconsistent lock state ]
2.6.31-rc2 #16
---------------------------------
inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
khubd/217 [HC0[0]:SC0[0]:HE1:SE1] takes:
(iprune_mutex){+.+.?.}, at: [<c10ba899>] invalidate_inodes+0x20/0xe3
{IN-RECLAIM_FS-W} state was registered at:
[<c10536ab>] __lock_acquire+0x2c9/0xac4
[<c1053f45>] lock_acquire+0x9f/0xc2
[<c1308872>] __mutex_lock_common+0x2d/0x323
[<c1308c00>] mutex_lock_nested+0x2e/0x36
[<c10ba6ff>] shrink_icache_memory+0x38/0x1b2
[<c108bfb6>] shrink_slab+0xe2/0x13c
[<c108c3e1>] kswapd+0x3d1/0x55d
[<c10449b5>] kthread+0x66/0x6b
[<c1003fdf>] kernel_thread_helper+0x7/0x10
[<ffffffff>] 0xffffffff
Two things are needed to fix this. First we need a method to tell
fsnotify_create_event() to use GFP_NOFS and second we need to stop using
one global IN_IGNORED event and allocate them one at a time. This solves
current issues with multiple IN_IGNORED on a queue having tail drop
problems and simplifies the allocations since we don't have to worry about
two tasks opperating on the IGNORED event concurrently.
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 2b20feaf..5213685 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -153,7 +153,7 @@
return true;
break;
case (FSNOTIFY_EVENT_NONE):
- return true;
+ return false;
};
}
return false;
@@ -345,18 +345,19 @@
* @name the filename, if available
*/
struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, void *data,
- int data_type, const char *name, u32 cookie)
+ int data_type, const char *name, u32 cookie,
+ gfp_t gfp)
{
struct fsnotify_event *event;
- event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL);
+ event = kmem_cache_alloc(fsnotify_event_cachep, gfp);
if (!event)
return NULL;
initialize_event(event);
if (name) {
- event->file_name = kstrdup(name, GFP_KERNEL);
+ event->file_name = kstrdup(name, gfp);
if (!event->file_name) {
kmem_cache_free(fsnotify_event_cachep, event);
return NULL;