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| author | Filipe Manana | 2014-11-03 15:12:57 +0100 |
|---|---|---|
| committer | Chris Mason | 2014-11-21 02:20:06 +0100 |
| commit | c7bc6319c59cc791743cf1b6e98f86be69444495 (patch) | |
| tree | ab6180b41c0dab292280b217fe88e3c24fbcf531 /fs/btrfs/extent_io.c | |
| parent | Btrfs: don't take the chunk_mutex/dev_list mutex in statfs V2 (diff) | |
| download | kernel-qcow2-linux-c7bc6319c59cc791743cf1b6e98f86be69444495.tar.gz kernel-qcow2-linux-c7bc6319c59cc791743cf1b6e98f86be69444495.tar.xz kernel-qcow2-linux-c7bc6319c59cc791743cf1b6e98f86be69444495.zip | |
Btrfs: avoid premature -ENOMEM in clear_extent_bit()
We try to allocate an extent state structure before acquiring the extent
state tree's spinlock as we might need a new one later and therefore avoid
doing later an atomic allocation while holding the tree's spinlock. However
we returned -ENOMEM if that initial non-atomic allocation failed, which is
a bit excessive since we might end up not needing the pre-allocated extent
state at all - for the case where the tree doesn't have any extent states
that cover the input range and cover too any other range. Therefore don't
return -ENOMEM if that pre-allocation fails.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/extent_io.c')
| -rw-r--r-- | fs/btrfs/extent_io.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 654ed3de0054..4ebabd237153 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -595,9 +595,14 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, clear = 1; again: if (!prealloc && (mask & __GFP_WAIT)) { + /* + * Don't care for allocation failure here because we might end + * up not needing the pre-allocated extent state at all, which + * is the case if we only have in the tree extent states that + * cover our input range and don't cover too any other range. + * If we end up needing a new extent state we allocate it later. + */ prealloc = alloc_extent_state(mask); - if (!prealloc) - return -ENOMEM; } spin_lock(&tree->lock); |