[PATCH 4.4 45/67] quota: Check for register_shrinker() failure.

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>


[ Upstream commit 88bc0ede8d35edc969350852894dc864a2dc1859 ]

register_shrinker() might return -ENOMEM error since Linux 3.12.
Call panic() as with other failure checks in this function if
register_shrinker() failed.

Fixes: 1d3d4437eae1 ("vmscan: per-node deferred work")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jan Kara <jack@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Reviewed-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/quota/dquot.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2919,7 +2919,8 @@ static int __init dquot_init(void)
 	pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld,"
 		" %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order));
 
-	register_shrinker(&dqcache_shrinker);
+	if (register_shrinker(&dqcache_shrinker))
+		panic("Cannot register dquot shrinker");
 
 	return 0;
 }