From: Mike Snitzer snitzer@kernel.org
commit 722d90822321497e2837cfc9000202e256e6b32f upstream.
issue_discard() passes GFP_NOWAIT to __blkdev_issue_discard() despite its code assuming bio_alloc() always succeeds.
Commit 3dba53a958a75 ("dm thin: use __blkdev_issue_discard for async discard support") clearly shows where things went bad:
Before commit 3dba53a958a75, dm-thin.c's open-coded __blkdev_issue_discard_async() properly handled using GFP_NOWAIT. Unfortunately __blkdev_issue_discard() doesn't and it was missed during review.
Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer snitzer@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/dm-thin.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -399,8 +399,7 @@ static int issue_discard(struct discard_ sector_t s = block_to_sectors(tc->pool, data_b); sector_t len = block_to_sectors(tc->pool, data_e - data_b);
- return __blkdev_issue_discard(tc->pool_dev->bdev, s, len, GFP_NOWAIT, - &op->bio); + return __blkdev_issue_discard(tc->pool_dev->bdev, s, len, GFP_NOIO, &op->bio); }
static void end_discard(struct discard_op *op, int r)