Re: [PATCH] ide: Explicitly poll for BHs on cancel

[Hanna Reitz <hreitz@redhat.com>]

On 19.01.22 12:11, Paolo Bonzini wrote:
> On 1/5/22 12:13, Hanna Reitz wrote:
>> - assert(s->bus->dma->aiocb == NULL);
>> +
>> +        /*
>> +         * Wait for potentially still-scheduled BHs, like 
>> ide_trim_bh_cb()
>> +         * (blk_drain() will only poll if there are in-flight 
>> requests on the
>> +         * BlockBackend, which there may not necessarily be, e.g. 
>> when the
>> +         * guest has issued a zero-length TRIM request)
>> +         */
>> +        while (s->bus->dma->aiocb) {
>> +            bool progress = aio_poll(qemu_get_aio_context(), true);
>> +            assert(progress);
>> +        }
>
>
> I think the right way to do this is to do  blk_inc_in_flight before 
> scheduling the bottom half and blk_dec_in_flight in the BH callback. 
> See virtio_blk_dma_restart_cb for an example.

Oh, yes, that sounds better.  Thanks!

Hanna