[RFC PATCH] fs: fsnotify: account fsnotify metadata to kmemcg

["Yang Shi" <yang.s@xxxxxxxxxxxxxxx>]

We observed some misbehaved user applications might consume significant
amount of fsnotify slabs silently. It'd better to account those slabs in
kmemcg so that we can get heads up before misbehaved applications use too
much memory silently.

Signed-off-by: Yang Shi <yang.s@xxxxxxxxxxxxxxx>
---
 fs/notify/dnotify/dnotify.c        | 4 ++--
 fs/notify/fanotify/fanotify_user.c | 6 +++---
 fs/notify/fsnotify.c               | 2 +-
 fs/notify/inotify/inotify_user.c   | 2 +-
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
index cba3283..3ec6233 100644
--- a/fs/notify/dnotify/dnotify.c
+++ b/fs/notify/dnotify/dnotify.c
@@ -379,8 +379,8 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
 
 static int __init dnotify_init(void)
 {
-	dnotify_struct_cache = KMEM_CACHE(dnotify_struct, SLAB_PANIC);
-	dnotify_mark_cache = KMEM_CACHE(dnotify_mark, SLAB_PANIC);
+	dnotify_struct_cache = KMEM_CACHE(dnotify_struct, SLAB_PANIC|SLAB_ACCOUNT);
+	dnotify_mark_cache = KMEM_CACHE(dnotify_mark, SLAB_PANIC|SLAB_ACCOUNT);
 
 	dnotify_group = fsnotify_alloc_group(&dnotify_fsnotify_ops);
 	if (IS_ERR(dnotify_group))
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 907a481..7d62dee 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -947,11 +947,11 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group,
  */
 static int __init fanotify_user_setup(void)
 {
-	fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC);
-	fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC);
+	fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC|SLAB_ACCOUNT);
+	fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC|SLAB_ACCOUNT);
 #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
 	fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event_info,
-						SLAB_PANIC);
+						SLAB_PANIC|SLAB_ACCOUNT);
 #endif
 
 	return 0;
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 0c4583b..82620ac 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -386,7 +386,7 @@ static __init int fsnotify_init(void)
 		panic("initializing fsnotify_mark_srcu");
 
 	fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector,
-						    SLAB_PANIC);
+						    SLAB_PANIC|SLAB_ACCOUNT);
 
 	return 0;
 }
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 7cc7d3f..57b32ff 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -785,7 +785,7 @@ static int __init inotify_user_setup(void)
 
 	BUG_ON(hweight32(ALL_INOTIFY_BITS) != 21);
 
-	inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC);
+	inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC|SLAB_ACCOUNT);
 
 	inotify_max_queued_events = 16384;
 	init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES] = 128;
-- 
1.8.3.1