btrfs: hold a ref on the root in btrfs_search_path_in_tree

We look up an arbitrary fs root, we need to hold a ref on it while we're
doing our search.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index b173bb6..9c8a994 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2328,6 +2328,12 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
        root = btrfs_get_fs_root(info, &key, true);
        if (IS_ERR(root)) {
                ret = PTR_ERR(root);
+               root = NULL;
+               goto out;
+       }
+       if (!btrfs_grab_fs_root(root)) {
+               ret = -ENOENT;
+               root = NULL;
                goto out;
        }
 
@@ -2378,6 +2384,7 @@ static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
        name[total_len] = '\0';
        ret = 0;
 out:
+       btrfs_put_fs_root(root);
        btrfs_free_path(path);
        return ret;
 }