On 01/12/2009 01:18, Neil Brown wrote:

On Mon, 30 Nov 2009 15:00:24 +0100
Arkadiusz Miskiewicz [off-list ref] wrote:

[...]

quoted

[2500705.083965] BUG: unable to handle kernel NULL pointer
dereference at
(null) [2500705.090142] IP: [<ffffffffa001387a>]
bitmap_daemon_work+0x20a/0x500

That is bad.  I think I can see what is happening.  I suspect that this
is a fairly hard race to hit - you must been unlucky:-(

I had an oops removing a bitmap a wee while ago, and I mentioned it on 
this list, but I couldn't post a backtrace. I guess I was unlucky too 
but I'm delighted to hear luck's not going to be an issue in the future :-)

Cheers,

John.