Revert "fs: btrfs: fix false negatives in ROOT_ITEM search"

Per Pierre this change shouldn't have been applied as it was superseded
by "fs: btrfs: fix btrfs_search_tree invalid results" which is also
applied now as 1627e5e5985d.

This reverts commit 633967f9818cb6a0e87ffa8cba33148a5bcc6edb.

Signed-off-by: Tom Rini <trini@konsulko.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index ca44a24..65c152a 100644 (file)
--- 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)