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-rw-r--r--fs/btrfs/ctree.h44
1 files changed, 6 insertions, 38 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index ca44a2404d..65c152a52f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -292,52 +292,20 @@ btrfs_search_tree_key_type(const struct btrfs_root *root, u64 objectid,
{
struct btrfs_key key, *res;
- /*
- * In some cases (e.g. tree roots), we need to look for a given
- * objectid and type without knowing the offset value (3rd element of a
- * btrfs tree node key). We can rely on the fact that btrfs_search_tree
- * returns the first element with key >= search_key, and then perform
- * our own comparison between the returned element and the search key.
- *
- * It is tempting to use a search key with offset 0 to perform this
- * "fuzzy search". This would return the first item with the (objectid,
- * type) we're looking for. However, using offset 0 has the wrong
- * behavior when the wanted item is the first in a leaf: since our
- * search key will be lower than the wanted item, the recursive search
- * will explore the wrong branch of the tree.
- *
- * Instead, use the largest possible offset (-1). The result of this
- * search will either be:
- * 1. An element with the (objectid, type) we're looking for, if it
- * has offset -1 or if it is the last element in its leaf.
- * 2. The first element *after* an element with the (objectid, type)
- */
key.objectid = objectid;
key.type = type;
- key.offset = -1;
+ key.offset = 0;
if (btrfs_search_tree(root, &key, path))
return NULL;
- /*
- * Compare with the previous element first -- this is the likely case
- * since the result of the search is only what we want if it had offset
- * == -1 or if it was last in its leaf.
- */
- if (path->slots[0] > 0) {
- path->slots[0]--;
- res = btrfs_path_leaf_key(path);
- if (!btrfs_comp_keys_type(&key, res))
- return res;
- path->slots[0]++;
- }
-
res = btrfs_path_leaf_key(path);
- if (!btrfs_comp_keys_type(&key, res))
- return res;
+ if (btrfs_comp_keys_type(&key, res)) {
+ btrfs_free_path(path);
+ return NULL;
+ }
- btrfs_free_path(path);
- return NULL;
+ return res;
}
static inline u32 btrfs_path_item_size(struct btrfs_path *p)