Re: scsi_get_lba breakage in 5.10 -- Re: Linux 5.10.206

From: Greg Kroah-Hartman
Date: Wed Jan 10 2024 - 04:15:53 EST


On Tue, Jan 09, 2024 at 08:55:52AM -0500, Martin K. Petersen wrote:
>
> Pavel,
>
> > This is bad idea. This changes return value, but without fixing
> > callers; there will be subtle bugs somewhere.
>
> I'm not sure why this particular change was backported since it was part
> of a larger cleanup of explicitly distinguishing between block layer
> sectors and device-specific LBAs. This was done to fix devices using PI
> with 4 KB blocks which would otherwise end up getting programmed with
> the wrong reference tag value.
>
> > At minimum, we need this:
> >
> > 87662a472a9d8980b26ba5803447df2c4981d467 scsi: iser: Use scsi_get_sector() instead of scsi_get_lba()
>
> I agree this would be appropriate. Otherwise we'll print the error being
> at the wrong sector in case of an error on a PI device with 4 KB blocks.
> However, the message is purely informative.
>
> > That will fix iser, but there's also:
> >
> > drivers/s390/scsi/zfcp_fsf.c: io->ref_tag_value = scsi_get_lba(scsi_cmnd) & 0xFFFFFFFF;
> > drivers/scsi/isci/request.c: tc->ref_tag_seed_gen = scsi_get_lba(scmd) & 0xffffffff;
> > drivers/scsi/isci/request.c: tc->ref_tag_seed_verify = scsi_get_lba(scmd) & 0xffffffff;
> > drivers/scsi/lpfc/lpfc_scsi.c: lba = scsi_get_lba(sc);
> > drivers/scsi/lpfc/lpfc_scsi.c: reftag = (uint32_t)scsi_get_lba(sc); /* Truncate LBA */
> > drivers/scsi/lpfc/lpfc_scsi.c: reftag = (uint32_t)scsi_get_lba(sc); /* Truncate LBA */
> > drivers/scsi/lpfc/lpfc_scsi.c: reftag = (uint32_t)scsi_get_lba(sc); /* Truncate LBA */
> > drivers/scsi/lpfc/lpfc_scsi.c: reftag = (uint32_t)scsi_get_lba(sc); /* Truncate LBA */
> > drivers/scsi/lpfc/lpfc_scsi.c: start_ref_tag = (uint32_t)scsi_get_lba(cmd); /* Truncate LBA */
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: failing_sector = scsi_get_lba(cmd);
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long long)scsi_get_lba(cmd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long long)scsi_get_lba(cmnd),
> > drivers/scsi/lpfc/lpfc_scsi.c: (unsigned long long)scsi_get_lba(cmnd),
> > drivers/scsi/qla2xxx/qla_iocb.c: (0xffffffff & scsi_get_lba(cmd)));
> > drivers/scsi/qla2xxx/qla_iocb.c: (0xffffffff & scsi_get_lba(cmd)));
> > drivers/scsi/qla2xxx/qla_iocb.c: (0xffffffff & scsi_get_lba(cmd)));
> > drivers/scsi/qla2xxx/qla_isr.c: cmd->cmnd[0], (u64)scsi_get_lba(cmd), a_ref_tag, e_ref_tag,
> > drivers/scsi/qla2xxx/qla_isr.c: sector_t lba_s = scsi_get_lba(cmd);
>
> Save for two cases in lpfc_queuecommand (which like the iser case will
> print the wrong sector number on error) all these look OK to me. Note
> that almost all callers of scsi_get_lba() actually intended to get the
> protocol LBA as the name indicates and not the block layer sector
> number.

Ick, this is going to get complex fast. How about I revert the whole
series, and then just add the one bugfix at the end, in a "fixed by
hand" version like I have here below. Would that be better overall?

Thanks,

greg k-h


diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 0c4bc42b55c2..3d3d139127ee 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1069,6 +1069,7 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,

scsi_log_send(scmd);
scmd->scsi_done = scsi_eh_done;
+ scmd->flags |= SCMD_LAST;

/*
* Lock sdev->state_mutex to avoid that scsi_device_quiesce() can
@@ -2361,6 +2362,7 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
scsi_init_command(dev, scmd);
scmd->request = rq;
scmd->cmnd = scsi_req(rq)->cmd;
+ scmd->flags |= SCMD_LAST;

scmd->scsi_done = scsi_reset_provider_done_command;
memset(&scmd->sdb, 0, sizeof(scmd->sdb));