Messages in this thread | | | Date | Thu, 06 Jun 2013 10:42:16 +0200 | From | Hannes Reinecke <> | Subject | Re: [PATCH] [SCSI] scsilun_to_int should ignore the highest 2 bits |
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On 06/06/2013 10:18 AM, Jan Vesely wrote: > From: Jan Vesely <jvesely@redhat.com> > > The comment says the function does this but it does not. > Reported luns change from weirdly high numbers (like 16640) > to something saner (256), when using flat space addressing. > > CC: James Bottomley <JBottomley@Parallels.com> > CC: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Jan Vesely <jvesely@redhat.com> > --- > drivers/scsi/scsi_scan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c > index 3e58b22..38dc093 100644 > --- a/drivers/scsi/scsi_scan.c > +++ b/drivers/scsi/scsi_scan.c > @@ -1244,7 +1244,7 @@ int scsilun_to_int(struct scsi_lun *scsilun) > > lun = 0; > for (i = 0; i < sizeof(lun); i += 2) > - lun = lun | (((scsilun->scsi_lun[i] << 8) | > + lun = lun | ((((scsilun->scsi_lun[i] & 0x3f) << 8) | > scsilun->scsi_lun[i + 1]) << (i * 8)); > return lun; > } > Bzzt. It's not that simple.
For SCSI-3 _all_ numbers are valid, and doesn't know of any addressing scheme. It's only SPC-2 which introduced the addressing scheme. So at the very least you should be checking the scsi revision before attempting something like this.
But in general doing a sequential scan past 256 is criminally dangerous. Any array / device attempting to is in most cases misconfigured or does not have the correct BLIST flag set.
I know of some older Hitachi and EMC firmware which would pretend to be SCSI-2, but supporting more than 256 LUNs per host. Which, of course, it totally bonkers.
I'll be posting my 64-bit LUN patchset, that should fix this issue.
Cheers,
Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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