On Thu, 2 Mar 2017 14:25:14 +0100 Hannes Reinecke <hare@xxxxxxx> wrote: > On 03/02/2017 02:40 AM, Stephen Hemminger wrote: > > On Thu, 2 Mar 2017 01:56:15 +0100 > > Christoph Hellwig <hch@xxxxxx> wrote: > > > >> On Thu, Mar 02, 2017 at 01:01:35AM +0100, Christoph Hellwig wrote: > >>> On Wed, Mar 01, 2017 at 07:54:12AM -0800, Stephen Hemminger wrote: > >>>>> http://git.infradead.org/users/hch/block.git/commitdiff/148cff67b401e2229c076c0ea418712654be77e4 > >>>> > >>>> It appears that is already in the code I am testing in linux-next... > >>> > >>> It's in -next now, but it wasn't at the time you reported the bug. > >>> > >>> And it would sortof explain the bug if the INQUIRY data is correct > >>> in the scatterlist, but we ignore it, given that scsi_probe_lun > >>> ignores the result based on sense data. > >>> > >>> Can you check what happens with the horrible hack below: > >> > >> Strike that - we're checking result later, so this can't be the case. > >> > >> Now the other interesting thing is the memset in __scsi_exectute, > >> which looks very suspicious. Try the following please: > >> > >> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > >> index 3e32dc954c3c..22f4fb550561 100644 > >> --- a/drivers/scsi/scsi_lib.c > >> +++ b/drivers/scsi/scsi_lib.c > >> @@ -253,7 +253,8 @@ static int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, > >> * and prevent security leaks by zeroing out the excess data. > >> */ > >> if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen)) > >> - memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len); > >> +// memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len); > >> + printk_ratelimited("%s: got resid %d\n", __func__, rq->resid_len); > >> > >> if (resid) > >> *resid = rq->resid_len; > > > > > > Still fails but does print resid on some of the later INQUIRY commands (not the initial one). > > > Can you test what happens if you blank out the storvsc_drv workaround: > > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c > index 585e54f..c36f42d 100644 > --- a/drivers/scsi/storvsc_drv.c > +++ b/drivers/scsi/storvsc_drv.c > @@ -1060,13 +1060,13 @@ static void storvsc_on_io_completion(struct > storvsc_device *stor_device, > * We do this so we can distinguish truly fatal failues > * (srb status == 0x4) and off-line the device in that case. > */ > - > +#if 0 > if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) || > (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) { > vstor_packet->vm_srb.scsi_status = 0; > vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS; > } > - > +#endif > > /* Copy over the status...etc */ > stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status; > > It might thappen that we're fail to interpret the 'Device not present' > status correctly (which will happen for non-connected DVDs) causing the > SCSI stack to make incorrect decisions later on. > > Cheers, > > Hannes Makes no difference, that was one of the first things I tried (and just tried again).
