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

["Martin K. Petersen" <martin.petersen@oracle.com>]

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.

-- 
Martin K. Petersen	Oracle Linux Engineering