From: Josef Bacik <josef@toxicpanda.com> commit 315bf8ef914f31d51d084af950703aa1e09a728c upstream. While running my error injection script I hit a panic when we tried to clean up the fs_root when freeing the fs_root. This is because fs_info->fs_root == PTR_ERR(-EIO), which isn't great. Fix this by setting fs_info->fs_root = NULL; if we fail to read the root. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- fs/btrfs/disk-io.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index ea45112..24a04cd 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3153,6 +3153,7 @@ int open_ctree(struct super_block *sb, if (IS_ERR(fs_info->fs_root)) { err = PTR_ERR(fs_info->fs_root); btrfs_warn(fs_info, "failed to read fs tree: %d", err); + fs_info->fs_root = NULL; goto fail_qgroup; } -- 1.8.3