If xfs_repair doesn't work, and like it won't if it didn't by now, there's one last thing you can try, and you need to do that to run a file recovery util anyway, rebuild the disk as is, then run xfs_repair on the sd device (xfs_repair -v /dev/sdx1), the result will likely be the same but it's just to rule out any md driver issues, there have been a couple of times where it did make a difference.