[PATCH AUTOSEL for 3.18 04/16] bcache: check return value of register_shrinker

[Sasha Levin <Alexander.Levin@microsoft.com>]

From: Michael Lyle <mlyle@lyle.org>

[ Upstream commit 6c4ca1e36cdc1a0a7a84797804b87920ccbebf51 ]

register_shrinker is now __must_check, so check it to kill a warning.
Caller of bch_btree_cache_alloc in super.c appropriately checks return
value so this is fully plumbed through.

This V2 fixes checkpatch warnings and improves the commit description,
as I was too hasty getting the previous version out.

Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Vojtech Pavlik <vojtech@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/md/bcache/btree.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 43829d9493f7..e53ce5e2a28a 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -808,7 +808,10 @@ int bch_btree_cache_alloc(struct cache_set *c)
 	c->shrink.scan_objects = bch_mca_scan;
 	c->shrink.seeks = 4;
 	c->shrink.batch = c->btree_pages * 2;
-	register_shrinker(&c->shrink);
+
+	if (register_shrinker(&c->shrink))
+		pr_warn("bcache: %s: could not register shrinker",
+				__func__);
 
 	return 0;
 }
-- 
2.11.0