diff options
| -rw-r--r-- | fs/btrfs/ctree.c | 41 |
1 files changed, 18 insertions, 23 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 92775554d1cc..5f94414f3336 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2488,19 +2488,6 @@ done: return ret; } -static int key_search(struct extent_buffer *b, const struct btrfs_key *key, - int *prev_cmp, int *slot) -{ - if (*prev_cmp != 0) { - *prev_cmp = btrfs_bin_search(b, key, slot); - return *prev_cmp; - } - - *slot = 0; - - return 0; -} - int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, u64 iobjectid, u64 ioff, u8 key_type, struct btrfs_key *found_key) @@ -2770,9 +2757,23 @@ cow_done: } } - ret = key_search(b, key, &prev_cmp, &slot); - if (ret < 0) - goto done; + /* + * If btrfs_bin_search returns an exact match (prev_cmp == 0) + * we can safely assume the target key will always be in slot 0 + * on lower levels due to the invariants BTRFS' btree provides, + * namely that a btrfs_key_ptr entry always points to the + * lowest key in the child node, thus we can skip searching + * lower levels + */ + if (prev_cmp == 0) { + slot = 0; + ret = 0; + } else { + ret = btrfs_bin_search(b, key, &slot); + prev_cmp = ret; + if (ret < 0) + goto done; + } if (level == 0) { p->slots[level] = slot; @@ -2896,7 +2897,6 @@ int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, int level; int lowest_unlock = 1; u8 lowest_level = 0; - int prev_cmp = -1; lowest_level = p->lowest_level; WARN_ON(p->nodes[0] != NULL); @@ -2929,12 +2929,7 @@ again: */ btrfs_unlock_up_safe(p, level + 1); - /* - * Since we can unwind ebs we want to do a real search every - * time. - */ - prev_cmp = -1; - ret = key_search(b, key, &prev_cmp, &slot); + ret = btrfs_bin_search(b, key, &slot); if (ret < 0) goto done; |