Re: [PATCH 2/4] ublk: refactor recovery configuration flag helpers

[Ming Lei <ming.lei@redhat.com>]

On Mon, Jul 01, 2024 at 03:02:49PM -0600, Uday Shankar wrote:
> On Sun, Jun 30, 2024 at 09:56:36PM +0800, Ming Lei wrote:
> > I meant that the following one-line patch may address your issue:
> > 
> > 
> > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> > index 4e159948c912..a89240f4f7b0 100644
> > --- a/drivers/block/ublk_drv.c
> > +++ b/drivers/block/ublk_drv.c
> > @@ -1068,7 +1068,7 @@ static inline void __ublk_abort_rq(struct ublk_queue *ubq,
> >  		struct request *rq)
> >  {
> >  	/* We cannot process this rq so just requeue it. */
> > -	if (ublk_queue_can_use_recovery(ubq))
> > +	if (ublk_queue_can_use_recovery_reissue(ubq))
> >  		blk_mq_requeue_request(rq, false);
> >  	else
> >  		blk_mq_end_request(rq, BLK_STS_IOERR);
> 
> It does not work (ran the same test from my previous email, got the same
> results), and how could it? As I've already mentioned several times, the
> root of the issue is that when UBLK_F_USER_RECOVERY is set, the request
> queue remains quiesced when the server has exited. Quiescing the queue
> means that the block layer will not call the driver's queue_rq when I/Os
> are submitted. Instead the block layer will queue those I/Os internally,
> only submitting them to the driver when the queue is unquiesced, which,
> in the current ublk_drv, only happens when the device is recovered or
> deleted.
> 
> Having ublk_drv return errors to I/Os issued while there is no ublk
> server requires the queue to be unquiesced. My patchset actually does
> this (see patch 4/4).

Sorry for ignoring the fact that queue is kept as quiesced after ublk
server is crashed, and I will review patch 4 soon.


Thanks,
Ming