bcache: check return value of register_shrinker

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>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 11c5503d31dc..81e8dc3dbe5e 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -807,7 +807,10 @@ 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;
 }