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

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 <[email protected]> know about it.

From: Mike Christie <[email protected]>
Date: Thu, 7 Jan 2016 16:34:05 -0600
Subject: scsi: add Synology to 1024 sector blacklist

From: Mike Christie <[email protected]>

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.

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

@@ -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 [email protected] are

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