On Fri, Jan 22, 2021 at 11:42:51PM +0100, David Disseldorp wrote:

On Wed, 20 Jan 2021 13:27:00 +0300, Dmitry Bogdanov wrote:

quoted

Now REPORT LUNS for software device servers always reports all luns
regardless of SELECT REPORT field.
Add handling of that field according to SPC-4:
* accept known values,
* reject unknown values.

We currently advertise SPC-3 VERSION compliance via standard INQUIRY
data, so I think we should either support SPC-3 SELECT REPORT values or
bump the VERSION field (SPC-4 behaviour is already scattered throughout
LIO).
Out of curiosity, do you know of any initiators which use this field?

Hi David,

SELECT REPORT field can be used for vVOL (LU conglomerate) discovery and
for well-known lun listing.

The field is used by VMware ESXi:
https://support.purestorage.com/Solutions/VMware_Platform_Guide/User_Guides_for_VMware_Solutions/Virtual_Volumes_User_Guide/vVols_User_Guide%3A_Protocol_Endpoints

"PEs greatly extend the number of vVols that can be connected to an ESXi
cluster; each PE can have up to 16,383 vVols per host bound to it
simultaneously. Moreover, a new binding does not require a complete I/O
rescan. Instead, ESXi issues a REPORT_LUNS SCSI command with SELECT
REPORT to the PE to which the sub-lun is bound. The PE returns a list of
sub-lun IDs for the vVols bound to that host. In large clusters,
REPORT_LUNS is significantly faster than a full I/O rescan because it is
more precisely targeted."

The post also confirms that:
https://sourceforge.net/p/scst/mailman/message/33030432/

A few more targets that support SELECT REPORT field below.

Sun/Oracle tape library:
https://docs.oracle.com/en/storage/tape-storage/storagetek-sl150-modular-tape-library/slorm/report-luns-a0h.html#GUID-4140F40D-BD9A-495C-9A86-8BD7E91C985C

IBM Flash Storage:
https://www.ibm.com/support/pages/sites/default/files/support/ssg/ssgdocs.nsf/0/95d7115d7eb428e485257f80005cc3a7/%24FILE/FlashSystem_840_SCSI_Interface_Manual_1.2.pdf

With regards to bumping TCM to SPC-4, are there any objections if we
submit a separate patch for that? Or resubmit a series with the patch?

Thanks,
Roman