Btrfs: fix the inode ref searches done by btrfs_search_path_in_tree (8ad6fcab) · Commits · 戴 / test

This is used by the inode lookup ioctl to follow all the backrefs up to the subvol root. But the search being done would sometimes land one past the last item in the leaf instead of finding the backref. This changes the search to look for the highest possible backref and hop back one item. It also fixes a leaked path on failure to find the root. Signed-off-by:

Chris Mason <chris.mason@oracle.com>

fs/btrfs/ioctl.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -1147,12 +1147,13 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
		root = btrfs_read_fs_root_no_name(info, &key);
		if (IS_ERR(root)) {
		printk(KERN_ERR "could not find root %llu\n", tree_id);
		return -ENOENT;
		ret = -ENOENT;
		goto out;
		}

		key.objectid = dirid;
		key.type = BTRFS_INODE_REF_KEY;
		key.offset = 0;
		key.offset = (u64)-1;

		while(1) {
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		@@ -1161,6 +1162,8 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,

		l = path->nodes[0];
		slot = path->slots[0];
		if (ret > 0 && slot > 0)
		slot--;
		btrfs_item_key_to_cpu(l, &key, slot);

		if (ret > 0 && (key.objectid != dirid \|\|
		@@ -1184,7 +1187,7 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,

		btrfs_release_path(root, path);
		key.objectid = key.offset;
		key.offset = 0;
		key.offset = (u64)-1;
		dirid = key.objectid;

		}

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