Btrfs: btrfs_read_fs_root_no_name() returns ERR_PTRs

btrfs_read_fs_root_no_name() returns ERR_PTRs on error so I added a
check for that.  It's not clear to me if it can also return NULL
pointers or not so I left the original NULL pointer check as is.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 73895baf6e07..34f7c375567e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1985,6 +1985,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
         if (!fs_info->fs_root)
                 goto fail_trans_kthread;
+        if (IS_ERR(fs_info->fs_root)) {
+                err = PTR_ERR(fs_info->fs_root);
+                goto fail_trans_kthread;
+        }
 
         if (!(sb->s_flags & MS_RDONLY)) {
                 down_read(&fs_info->cleanup_work_sem);