Re: libata SCSI page 0x83 query

[Jeff Garzik <jgarzik@pobox.com>]

Douglas Gilbert wrote:
> Douglas Gilbert wrote:
> 
>>Jeff Garzik wrote:
>>
>>
>>>Chris Paulson-Ellis wrote:
>>>
>>>
>>>
>>>>Hi,
>>>>
>>>>I have a problem with udev persistent device naming for SATA drives
>>>>that is caused by the libata implementation of the page 0x83 SCSI
>>>>device identifier query. See this thead from hotplug-devel:
>>>>
>>>>http://marc.theaimsgroup.com/?t=113518947900002&r=1&w=2
>>>>
>>>>I can work around the problem using /etc/scsi_id.config or udev rules
>>>>(see the thread), but here is a patch to fix the problem at source.
>>>>What do you think?
>>>>
>>>>Regards,
>>>>Chris.
>>>>
>>>>--- drivers/scsi/libata-scsi.c.orig     2005-12-22 23:23:55.000000000
>>>>+0000
>>>>+++ drivers/scsi/libata-scsi.c  2005-12-22 23:56:14.000000000 +0000
>>>>@@ -1532,16 +1532,13 @@
>>>>      return 0;
>>>>}
>>>>
>>>>-static const char *inq_83_str = "Linux ATA-SCSI simulator";
>>>>-
>>>>/**
>>>>*     ata_scsiop_inq_83 - Simulate INQUIRY EVPD page 83, device identity
>>>>*     @args: device IDENTIFY data / SCSI command of interest.
>>>>*     @rbuf: Response buffer, to which simulated SCSI cmd output is
>>>>sent.
>>>>*     @buflen: Response buffer length.
>>>>*
>>>>- *     Returns device identification.  Currently hardcoded to
>>>>- *     return "Linux ATA-SCSI simulator".
>>>>+ *     Returns ATA device serial number (as for page 80).
>>>>*
>>>>*     LOCKING:
>>>>*     spin_lock_irqsave(host_set lock)
>>>>@@ -1551,13 +1548,14 @@
>>>>                            unsigned int buflen)
>>>>{
>>>>      rbuf[1] = 0x83;                 /* this page code */
>>>>-       rbuf[3] = 4 + strlen(inq_83_str);       /* page len */
>>>>+       rbuf[3] = 4 + ATA_SERNO_LEN;    /* page len */
>>>>
>>>>      /* our one and only identification descriptor (vendor-specific) */
>>>>-       if (buflen > (strlen(inq_83_str) + 4 + 4 - 1)) {
>>>>+       if (buflen > (ATA_SERNO_LEN + 4 + 4 - 1)) {
>>>>              rbuf[4 + 0] = 2;        /* code set: ASCII */
>>>>-               rbuf[4 + 3] = strlen(inq_83_str);
>>>>-               memcpy(rbuf + 4 + 4, inq_83_str, strlen(inq_83_str));
>>>>+               rbuf[4 + 3] = ATA_SERNO_LEN;
>>>>+               ata_dev_id_string(args->id, (unsigned char *) rbuf + 4
>>>>+ 4,
>>>>+                                 ATA_ID_SERNO_OFS, ATA_SERNO_LEN);
>>>
>>>
>>>Douglas Gilbert has an improved patch along these lines...
> 
> 
> Oops, a minor documentation malfunction with that patch.
> Here is a second attempt ...
> 
> I assume that is a prompt to roll another version
> of that VPD patch, this time against lk 2.6.16-rc5
> as my git tree is unavailable.
> 
> Changelog:
>   - make existing libata VPD device identification page (0x83)
>     supply the ATA serial number in the libata "vendor
>     specific" designator (from Chris Paulson-Ellis)
>   - add a "t10 vendor id based" designator as defined in
>     SAT rev 08 (section 10.3.4.2.3) that supplies ATA
>     model and serial numbers
>   - make the libata VPD page 0x83 more extensible (for
>     adding more designators in the future).
>   - rename EVPD to VPD in various places. Enable Vital
>     Product Data (EVPD) is a bit in the INQUIRY cdb.
> 
> Signed-off-by: Douglas Gilbert <dougg@torque.net>

after further thought and a spec consult... applied.