On Thu, 2012-07-12 at 15:43 +0200, Thomas Gleixner wrote: 

On Thu, 12 Jul 2012, Mike Galbraith wrote:

quoted

On Thu, 2012-07-12 at 15:31 +0200, Thomas Gleixner wrote: 

quoted

A quick check for memcpy finds that __btrfs_close_devices() does a
memcpy of btrfs_device structs w/o initializing the lock in the new
copy, but I have no idea whether that's the place we are looking for.

Cool, you found one, thanks!  I'm setting boobytraps.

Um, correction, box says I'm setting _buggy_ boobytraps :)

Tomorrow-man will test this and frob traps anew.

What kind of test setup do you have? i.e. raid, single disk ...

Yeah, megaraid sas.. x3550 M3.

-Mike