Commit 337c6f68 authored by Filipe Manana's avatar Filipe Manana Committed by Chris Mason

Btrfs: ensure btrfs_prev_leaf doesn't miss 1 item

We might have had an item with the previous key in the tree right
before we released our path. And after we released our path, that
item might have been pushed to the first slot (0) of the leaf we
were holding due to a tree balance. Alternatively, an item with the
previous key can exist as the only element of a leaf (big fat item).
Therefore account for these 2 cases, so that our callers (like
btrfs_previous_item) don't miss an existing item with a key matching
the previous key we computed above.
Signed-off-by: default avatarFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent f82a9901
...@@ -5097,7 +5097,17 @@ int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) ...@@ -5097,7 +5097,17 @@ int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
return ret; return ret;
btrfs_item_key(path->nodes[0], &found_key, 0); btrfs_item_key(path->nodes[0], &found_key, 0);
ret = comp_keys(&found_key, &key); ret = comp_keys(&found_key, &key);
if (ret < 0) /*
* We might have had an item with the previous key in the tree right
* before we released our path. And after we released our path, that
* item might have been pushed to the first slot (0) of the leaf we
* were holding due to a tree balance. Alternatively, an item with the
* previous key can exist as the only element of a leaf (big fat item).
* Therefore account for these 2 cases, so that our callers (like
* btrfs_previous_item) don't miss an existing item with a key matching
* the previous key we computed above.
*/
if (ret <= 0)
return 0; return 0;
return 1; return 1;
} }
......
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