to make sure I read everything right - xfs itself was hanging in recovery, and your oopses came from when you tried to sync with SysRq? And then it sounds like the only thing you did before
Two cases. Case 1: if system panicked (like the panics I sent ksymoops'd oopses of), Alt+SysRq+S will sync all discs until my 00:0a (/dev/sda10, /opt/data) and then send another panic (I also sent ks