Re: [Qemu-devel] [PATCH] migration: Fix race of image locking between src and dst

[Peter Maydell]

On 19 June 2017 at 16:26, Juan Quintela <address@hidden> wrote:
> Fam Zheng <address@hidden> wrote:
>> Previously, dst side will immediately try to lock the write byte upon
>> receiving QEMU_VM_EOF, but at src side, bdrv_inactivate_all() is only
>> done after sending it. If the src host is under load, dst may fail to
>> acquire the lock due to racing with the src unlocking it.
>>
>> Fix this by hoisting the bdrv_inactivate_all() operation before
>> QEMU_VM_EOF.
>>
>> N.B. A further improvement could possibly be done to cleanly handover
>> locks between src and dst, so that there is no window where a third QEMU
>> could steal the locks and prevent src and dst from running.
>>
>> Reported-by: Peter Maydell <address@hidden>
>> Signed-off-by: Fam Zheng <address@hidden>
>
> Reviewed-by: Juan Quintela <address@hidden>

Applied to master, thanks all.

-- PMM