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

[Alexey Kardashevskiy]

On 09/16/2014 10:10 PM, Paolo Bonzini wrote:
> Il 16/09/2014 14:02, Alexey Kardashevskiy ha scritto:
>> I am having problems when migrate a guest via libvirt like this:
>>
>> virsh migrate --live --persistent --undefinesource --copy-storage-all
>> --verbose --desturi qemu+ssh://legkvm/system --domain chig1
>>
>> The XML used to create the guest is at the end of this mail.
>>
>> I see NBD FLUSH command after the destination QEMU received EOF for
>> migration stream and this produces a crash in qcow2_co_flush_to_os() as
>> s->lock is false or s->l2_table_cache is NULL.
>>
> 
> Max, Kevin, could the fix be something like this?


btw this one did not help.


> 
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 0daf25c..e7459ea 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -1442,6 +1442,7 @@ static void qcow2_invalidate_cache(BlockDriverState 
> *bs, Error **errp)
>          memcpy(&aes_decrypt_key, &s->aes_decrypt_key, 
> sizeof(aes_decrypt_key));
>      }
>  
> +    qemu_co_mutex_lock(&s->lock);
>      qcow2_close(bs);
>  
>      bdrv_invalidate_cache(bs->file, &local_err);
> @@ -1455,6 +1456,7 @@ static void qcow2_invalidate_cache(BlockDriverState 
> *bs, Error **errp)
>  
>      ret = qcow2_open(bs, options, flags, &local_err);
>      QDECREF(options);
> +    qemu_co_mutex_unlock(&s->lock);
>      if (local_err) {
>          error_setg(errp, "Could not reopen qcow2 layer: %s",
>                     error_get_pretty(local_err));
> 
> On top of this, *_invalidate_cache needs to be marked as coroutine_fn.
> 
> Paolo
> 


-- 
Alexey