Patch "scsi: add Synology to 1024 sector blacklist" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    scsi: add Synology to 1024 sector blacklist

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     scsi-add-synology-to-1024-sector-blacklist.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 9055082fb100cc66e20c048251d05159f5f2cfba Mon Sep 17 00:00:00 2001
From: Mike Christie <mchristi@redhat.com>
Date: Thu, 7 Jan 2016 16:34:05 -0600
Subject: scsi: add Synology to 1024 sector blacklist

From: Mike Christie <mchristi@redhat.com>

commit 9055082fb100cc66e20c048251d05159f5f2cfba upstream.

Another iscsi target that cannot handle large IOs, but does not tell us
a limit.

The Synology iSCSI targets report:

Block limits VPD page (SBC):
  Write same no zero (WSNZ): 0
  Maximum compare and write length: 0 blocks
  Optimal transfer length granularity: 0 blocks
  Maximum transfer length: 0 blocks
  Optimal transfer length: 0 blocks
  Maximum prefetch length: 0 blocks
  Maximum unmap LBA count: 0
  Maximum unmap block descriptor count: 0
  Optimal unmap granularity: 0
  Unmap granularity alignment valid: 0
  Unmap granularity alignment: 0
  Maximum write same length: 0x0 blocks

and the size of the command it can handle seems to depend on how much
memory it can allocate at the time. This results in IO errors when
handling large IOs. This patch just has us use the old 1024 default
sectors for this target by adding it to the scsi blacklist. We do not
have good contacs with this vendors, so I have not been able to try and
fix on their side.

I have posted this a long while back, but it was not merged. This
version just fixes it up for merge/patch failures in the original
version.

Reported-by: Ancoron Luciferis <ancoron.luciferis@googlemail.com>
Reported-by: Michael Meyers <steltek@tcnnet.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/scsi/scsi_devinfo.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -227,6 +227,7 @@ static struct {
 	{"Promise", "VTrak E610f", NULL, BLIST_SPARSELUN | BLIST_NO_RSOC},
 	{"Promise", "", NULL, BLIST_SPARSELUN},
 	{"QNAP", "iSCSI Storage", NULL, BLIST_MAX_1024},
+	{"SYNOLOGY", "iSCSI Storage", NULL, BLIST_MAX_1024},
 	{"QUANTUM", "XP34301", "1071", BLIST_NOTQ},
 	{"REGAL", "CDC-4X", NULL, BLIST_MAX5LUN | BLIST_SINGLELUN},
 	{"SanDisk", "ImageMate CF-SD1", NULL, BLIST_FORCELUN},


Patches currently in stable-queue which might be from mchristi@redhat.com are

queue-4.4/scsi-add-synology-to-1024-sector-blacklist.patch