diff mbox series

[v3,01/11] scsi: scsi_debug: Fix check for sdev queue full

Message ID 20230327074310.1862889-2-john.g.garry@oracle.com (mailing list archive)
State Accepted
Headers show
Series Fix shost command overloading issues | expand

Commit Message

John Garry March 27, 2023, 7:43 a.m. UTC
There is a report that the blktests scsi/004 test for "TASK SET FULL" (TSF)
now fails.

The condition upon we should issue this TSF is when the sdev queue is
full. The check for a full queue has an off-by-1 error. Previously we
would increment the number of requests in the queue after testing if the
queue would be full, i.e. test if one less than full. Since we now use
scsi_device_busy() to count the number of requests in the queue, this
would already account for the current request, so fix the test for queue
full accordingly.

Fixes: 151f0ec9ddb5 ("scsi: scsi_debug: Drop sdebug_dev_info.num_in_q")
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/oe-lkp/202303201334.18b30edc-oliver.sang@intel.com
Signed-off-by: John Garry <john.g.garry@oracle.com>
---
 drivers/scsi/scsi_debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Douglas Gilbert March 28, 2023, 11:35 p.m. UTC | #1
On 2023-03-27 03:43, John Garry wrote:
> There is a report that the blktests scsi/004 test for "TASK SET FULL" (TSF)
> now fails.
> 
> The condition upon we should issue this TSF is when the sdev queue is
> full. The check for a full queue has an off-by-1 error. Previously we
> would increment the number of requests in the queue after testing if the
> queue would be full, i.e. test if one less than full. Since we now use
> scsi_device_busy() to count the number of requests in the queue, this
> would already account for the current request, so fix the test for queue
> full accordingly.
> 
> Fixes: 151f0ec9ddb5 ("scsi: scsi_debug: Drop sdebug_dev_info.num_in_q")
> Reported-by: kernel test robot <oliver.sang@intel.com>
> Link: https://lore.kernel.org/oe-lkp/202303201334.18b30edc-oliver.sang@intel.com
> Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com

Thanks.

> ---
>   drivers/scsi/scsi_debug.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index 7ed117e78bd4..782515abca2c 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -5580,7 +5580,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
>   		int num_in_q = scsi_device_busy(sdp);
>   		int qdepth = cmnd->device->queue_depth;
>   
> -		if ((num_in_q == (qdepth - 1)) &&
> +		if ((num_in_q == qdepth) &&
>   		    (atomic_inc_return(&sdebug_a_tsf) >=
>   		     abs(sdebug_every_nth))) {
>   			atomic_set(&sdebug_a_tsf, 0);
Yi Zhang March 29, 2023, 4:20 a.m. UTC | #2
On Wed, Mar 29, 2023 at 7:37 AM Douglas Gilbert <dgilbert@interlog.com> wrote:
>
> On 2023-03-27 03:43, John Garry wrote:
> > There is a report that the blktests scsi/004 test for "TASK SET FULL" (TSF)
> > now fails.
> >
> > The condition upon we should issue this TSF is when the sdev queue is
> > full. The check for a full queue has an off-by-1 error. Previously we
> > would increment the number of requests in the queue after testing if the
> > queue would be full, i.e. test if one less than full. Since we now use
> > scsi_device_busy() to count the number of requests in the queue, this
> > would already account for the current request, so fix the test for queue
> > full accordingly.
> >
> > Fixes: 151f0ec9ddb5 ("scsi: scsi_debug: Drop sdebug_dev_info.num_in_q")
> > Reported-by: kernel test robot <oliver.sang@intel.com>
> > Link: https://lore.kernel.org/oe-lkp/202303201334.18b30edc-oliver.sang@intel.com
> > Signed-off-by: John Garry <john.g.garry@oracle.com>
> Acked-by: Douglas Gilbert <dgilbert@interlog.com

Confirmed the change fixed the blktests scsi/004 failure issue, feel
free to add:
Tested-by: Yi Zhang <yi.zhang@redhat.com>

>
> Thanks.
>
> > ---
> >   drivers/scsi/scsi_debug.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> > index 7ed117e78bd4..782515abca2c 100644
> > --- a/drivers/scsi/scsi_debug.c
> > +++ b/drivers/scsi/scsi_debug.c
> > @@ -5580,7 +5580,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
> >               int num_in_q = scsi_device_busy(sdp);
> >               int qdepth = cmnd->device->queue_depth;
> >
> > -             if ((num_in_q == (qdepth - 1)) &&
> > +             if ((num_in_q == qdepth) &&
> >                   (atomic_inc_return(&sdebug_a_tsf) >=
> >                    abs(sdebug_every_nth))) {
> >                       atomic_set(&sdebug_a_tsf, 0);
>
diff mbox series

Patch

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 7ed117e78bd4..782515abca2c 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -5580,7 +5580,7 @@  static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
 		int num_in_q = scsi_device_busy(sdp);
 		int qdepth = cmnd->device->queue_depth;
 
-		if ((num_in_q == (qdepth - 1)) &&
+		if ((num_in_q == qdepth) &&
 		    (atomic_inc_return(&sdebug_a_tsf) >=
 		     abs(sdebug_every_nth))) {
 			atomic_set(&sdebug_a_tsf, 0);