Commit 5168489a authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: hold a ref on the root in get_subvol_name_from_objectid 



We lookup the name of a subvol which means we'll cross into different
roots.  Hold a ref while we're doing the look ups in the fs_root we're
searching.

Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 6f9a3da5

fs/btrfs/super.c

+10 −1
Original line number Diff line number Diff line
@@ -1028,7 +1028,7 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 
					   u64 subvol_objectid)

{

	struct btrfs_root *root = fs_info->tree_root;

	struct btrfs_root *fs_root;

	struct btrfs_root *fs_root = NULL;

	struct btrfs_root_ref *root_ref;

	struct btrfs_inode_ref *inode_ref;

	struct btrfs_key key;
@@ -1099,6 +1099,12 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 
		fs_root = btrfs_get_fs_root(fs_info, &key, true);

		if (IS_ERR(fs_root)) {

			ret = PTR_ERR(fs_root);

			fs_root = NULL;

			goto err;

		}

		if (!btrfs_grab_fs_root(fs_root)) {

			ret = -ENOENT;

			fs_root = NULL;

			goto err;

		}
@@ -1143,6 +1149,8 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 
			ptr[0] = '/';

			btrfs_release_path(path);

		}

		btrfs_put_fs_root(fs_root);

		fs_root = NULL;

	}



	btrfs_free_path(path);
@@ -1155,6 +1163,7 @@ static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 
	return name;



err:

	btrfs_put_fs_root(fs_root);

	btrfs_free_path(path);

	kfree(name);

	return ERR_PTR(ret);