problem with ceph and btrfs patch: set journal_info in async trans commit worker

[Stefan Priebe - Profihost AG <s.priebe@profihost.ag>]

Hello list,

i wanted to try out ceph with latest vanilla kernel 3.7-rc5. I was 
seeing a massive performance degration. I see around 22x 
btrfs-endio-write processes every 10-20 seconds and they run a long time 
while consuming a massive amount of CPU.

So my performance of 23.000 iops drops to an up and down of 23.000 iops 
to 0 - avg is now 2500 iops instead of 23.000.

Git bisect shows me commit: e209db7ace281ca347b1ac699bf1fb222eac03fe 
"Btrfs: set journal_info in async trans commit worker" as the 
problematic patch.

When i revert this one everything is fine again.

Is this known?

Greets,
Stefan