bcache: Fix a shrinker deadlock

commit a698e08c82 upstream.

GFP_NOIO means we could be getting called recursively - mca_alloc() ->
mca_data_alloc() - definitely can't use mutex_lock(bucket_lock) then.
Whoops.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kent Overstreet
2013-09-23 23:17:34 -07:00
committed by Greg Kroah-Hartman
parent ff1a51b9bf
commit 7866bece34

View File

@@ -633,7 +633,7 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
return mca_can_free(c) * c->btree_pages;
/* Return -1 if we can't do anything right now */
if (sc->gfp_mask & __GFP_WAIT)
if (sc->gfp_mask & __GFP_IO)
mutex_lock(&c->bucket_lock);
else if (!mutex_trylock(&c->bucket_lock))
return -1;