The regression is introduced to btrfs in linux v4.4 and it refuses to
create new files after log replay by returning -EEXIST.
Although the problem is on btrfs only, there is no btrfs stuff in terms
of test, so this makes it generic.
The kernel fix is
Btrfs: fix unexpected -EEXIST when creating new inode
[Eryu: add _require_metadata_journaling rule and 'log' 'metadata' group]
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>