Re: [Qemu-devel] migration: qemu-coroutine-lock.c:141: qemu_co_mutex_unlock: Assertion `mutex->locked == 1' failed

[Alexey Kardashevskiy]

On 09/18/2014 01:07 AM, Stefan Hajnoczi wrote:
> On Wed, Sep 17, 2014 at 2:44 PM, Alexey Kardashevskiy <address@hidden> wrote:
>> On 09/17/2014 07:25 PM, Paolo Bonzini wrote:
>> btw any better idea of a hack to try? Testers are pushing me - they want to
>> upgrade the broken setup and I am blocking them :) Thanks!
> 
> Paolo's qemu_co_mutex_lock(&s->lock) idea in qcow2_invalidate_cache()
> is good.  Have you tried that patch?


Yes, did not help.

> 
> I haven't checked the qcow2 code whether that works properly across
> bdrv_close() (is the lock freed?) but in principle that's how you
> protect against concurrent I/O.

I thought we have to avoid qemu_coroutine_yield() in this particular case.
I fail to see how the locks may help if we still do yeild. But the whole
thing is already way behind of my understanding :) For example - how many
BlockDriverState things are layered here? NBD -> QCOW2 -> RAW?



-- 
Alexey