Despite supporting modern SCSI features some storage devices continue to
claim conformance to an older version of the SPC spec. This is done for
compatibility with legacy operating systems.

Linux by default will not attempt to read VPD pages on devices that
claim SPC-2 or older. Introduce a blacklist flag that can be used to
trigger VPD page inquiries on devices that are known to support them.
Reported-by: NKY Srinivasan <kys@microsoft.com>
Tested-by: NKY Srinivasan <kys@microsoft.com>
Reviewed-by: NKY Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Sequential scan for more than 256 LUNs is very fragile as
LUNs might not be numbered sequentially after that point.

SAM revisions later than SCSI-3 impose a structure on
LUNs larger than 256, making LUN numbers between 256
and 16384 illegal.
SCSI-3, however allows for plain 64-bit numbers with
no internal structure.

So restrict sequential LUN scan to 256 LUNs and add a
new blacklist flag 'BLIST_SCSI3LUN' to scan up to
max_lun devices.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NEwan Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Not all disks fill out the VPD pages correctly. Add a blacklist flag
that allows us ignore the SBC-3 VPD pages for a given device. The
BLIST_SKIP_VPD_PAGES flag triggers our existing skip_vpd_pages
scsi_device parameter to bypass VPD scanning.

Also blacklist the offending Seagate drive model.
Reported-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Hitachi Ultrastar 15K300 is quirky. Disable T10 PI (DIF).
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This is patch 3/3:
3. Implement the blacklist flag BLIST_ATTACH_PQ3 that makes the scsi
   scanning code register PQ3 devices and continues scanning; only sg
   will attach thanks to scsi_bus_match().
Signed-off-by: NKurt Garloff <garloff@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Original From: Ingo Flaschberger <if@xip.at>

To support the RA4100 array from Compaq.

This patch now correctly handles SCSI_UNKNOWN types with regard to
BLIST_REPORTLUNS2 (allow it) and cdb[1] LUN inclusion (don't).

It also allows a BLIST_MAX_512 flag to restrict the maximum transfer
length to 512 blocks (apparently this is an RA4100 problem).
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!