On Nov 20, 2021 / 07:34, Damien Le Moal wrote:
> On 11/19/21 19:22, Shin'ichiro Kawasaki wrote:
> > When reset write pointer is requested to scsi_debug devices with zoned
> > model, positions of write pointers are reset, but the data in the target
> > zones are not cleared. Read to the zones returns data written before the
> > reset write pointer. This unexpected left data is confusing and does not
> > allow using scsi_debug for stale page cache test of the BLKRESETZONE
> > ioctl. Hence, zero clear the target zones at reset write pointer.
> >
> > Fixes: f0d1cf9378bd ("scsi: scsi_debug: Add ZBC zone commands")
> > Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
> > ---
> > drivers/scsi/scsi_debug.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> > index 1d0278da9041..6d1f1a4a6724 100644
> > --- a/drivers/scsi/scsi_debug.c
> > +++ b/drivers/scsi/scsi_debug.c
> > @@ -4653,6 +4653,7 @@ static void zbc_rwp_zone(struct sdebug_dev_info *devip,
> > struct sdeb_zone_state *zsp)
> > {
> > enum sdebug_z_cond zc;
> > + struct sdeb_store_info *sip = devip2sip(devip, false);
> >
> > if (zbc_zone_is_conv(zsp))
> > return;
> > @@ -4667,6 +4668,9 @@ static void zbc_rwp_zone(struct sdebug_dev_info *devip,
> > zsp->z_non_seq_resource = false;
> > zsp->z_wp = zsp->z_start;
> > zsp->z_cond = ZC1_EMPTY;
> > +
> > + memset(sip->storep + zsp->z_start * sdebug_sector_size, 0,
> > + devip->zsize * sdebug_sector_size);
>
> May be do this only if the zone is *not* already empty ? Resetting an
> empty zone is not an error, and in that case there will be no need for
> the memset(). This will avoid a lot of memset() when this function is
> called from zbc_rwp_all() to handle an all zone reset operation.
That sounds a good idea. Also, we can reduce the number of bytes to zero clear
by limiting the clear target between z->start and z->wp. Will post v2 with that
change.
>
> > }
> >
> > static void zbc_rwp_all(struct sdebug_dev_info *devip)
> >
>
>
> --
> Damien Le Moal
> Western Digital Research
--
Best Regards,
Shin'ichiro Kawasaki
