Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1209177

[RFC -v2 8/8] btrfs: use __GFP_NOFAIL in alloc_btrfs_bio

Show all headers | View raw

From: Michal Hocko <mhocko@suse.com>

alloc_btrfs_bio is relying on GFP_NOFS to allocate a bio but since "mm:
page_alloc: do not lock up GFP_NOFS allocations upon OOM" this is
allowed to fail which can lead to
[   37.928625] kernel BUG at fs/btrfs/extent_io.c:4045

This is clearly undesirable and the nofail behavior should be explicit
if the allocation failure cannot be tolerated.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 fs/btrfs/volumes.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 53af23f2c087..42b9949dd71d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4914,9 +4914,7 @@ static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes)
 		 * and the stripes
 		 */
 		sizeof(u64) * (total_stripes),
-		GFP_NOFS);
-	if (!bbio)
-		return NULL;
+		GFP_NOFS|__GFP_NOFAIL);
 
 	atomic_set(&bbio->error, 0);
 	atomic_set(&bbio->refs, 1);
-- 
2.5.0

-- 
Michal Hocko
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[RFC 8/8] btrfs: use __GFP_NOFAIL in alloc_btrfs_bio mhocko@kernel.org - 2015-08-05 12:00 +0200
  Re: [RFC 8/8] btrfs: use __GFP_NOFAIL in alloc_btrfs_bio David Sterba <dsterba@suse.com> - 2015-08-05 18:40 +0200
  [RFC -v2 8/8] btrfs: use __GFP_NOFAIL in alloc_btrfs_bio Michal Hocko <mhocko@kernel.org> - 2015-08-18 12:50 +0200

csiph-web