From: Michal Hocko Date: Wed, 19 Aug 2015 12:17:41 +0000 (+0200) Subject: btrfs: use __GFP_NOFAIL in alloc_btrfs_bio X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=277fb5fc177dc4674ef6151a7697f5396bbdff11;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git btrfs: use __GFP_NOFAIL in alloc_btrfs_bio alloc_btrfs_bio relies on GFP_NOFS allocation when committing the transaction but this allocation context is rather weak wrt. reclaim capabilities. The page allocator currently tries hard to not fail these allocations if they are small (<=PAGE_ALLOC_COSTLY_ORDER) but it can still fail if the _current_ process is the OOM killer victim. Moreover there is an attempt to move away from the default no-fail behavior and allow these allocation to fail more eagerly. This would lead to: [ 37.928625] kernel BUG at fs/btrfs/extent_io.c:4045 which is clearly undesirable and the nofail behavior should be explicit if the allocation failure cannot be tolerated. Signed-off-by: Michal Hocko Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 7c84a8122c37..53a38075911e 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5082,9 +5082,7 @@ 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);