Commit c7bc6319c59cc791743cf1b6e98f86be69444495
Committed by
Chris Mason
Chris Mason
1 parent
7e33fd993a
Exists in
ti-lsk-linux-4.1.y
and in
10 other branches
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>
Showing 1 changed file with 7 additions and 2 deletions Side-by-side Diff
fs/btrfs/extent_io.c
| ... | ... | @@ -595,9 +595,14 @@ |
| 595 | 595 | clear = 1; |
| 596 | 596 | again: |
| 597 | 597 | if (!prealloc && (mask & __GFP_WAIT)) { |
| 598 | + /* | |
| 599 | + * Don't care for allocation failure here because we might end | |
| 600 | + * up not needing the pre-allocated extent state at all, which | |
| 601 | + * is the case if we only have in the tree extent states that | |
| 602 | + * cover our input range and don't cover too any other range. | |
| 603 | + * If we end up needing a new extent state we allocate it later. | |
| 604 | + */ | |
| 598 | 605 | prealloc = alloc_extent_state(mask); |
| 599 | - if (!prealloc) | |
| 600 | - return -ENOMEM; | |
| 601 | 606 | } |
| 602 | 607 | |
| 603 | 608 | spin_lock(&tree->lock); |