Patch "scsi: megaraid_sas: Fix data integrity failure for JBOD (passthrough) devices" has been added to the 4.8-stable tree

PATCH [email protected] 1 participant 4 messages Nov 9, 2016 3 messages not in the archive

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Stable branch SCSI Megaraid SCSI/SAS drivers

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[email protected]

author maintainer Applied

2016-11-09 08:19 UTC #0 lore raw

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

scsi: megaraid_sas: Fix data integrity failure for JBOD (passthrough) devices

to the 4.8-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-megaraid_sas-fix-data-integrity-failure-for-jbod-passthrough-devices.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 1e793f6fc0db920400574211c48f9157a37e3945 Mon Sep 17 00:00:00 2001

From: Kashyap Desai <[email protected]>
Date: Fri, 21 Oct 2016 06:33:32 -0700
Subject: scsi: megaraid_sas: Fix data integrity failure for JBOD (passthrough) devices

From: Kashyap Desai <[email protected]>

commit 1e793f6fc0db920400574211c48f9157a37e3945 upstream.

Commit 02b01e010afe ("megaraid_sas: return sync cache call with success") modified the driver to successfully complete SYNCHRONIZE_CACHE commands without passing them to the controller. Disk drive caches are only explicitly managed by controller firmware when operating in RAID mode. So this commit effectively disabled writeback cache flushing for any drives used in JBOD mode, leading to data integrity failures.

[mkp: clarified patch description]

Fixes 02b01e010afeeb49328d35650d70721d2ca3fd59

Signed-off-by Kashyap Desai <[email protected]>

Signed-off-by Sumit Saxena <[email protected]>

Reviewed-by Tomas Henzl <[email protected]>

Reviewed-by Hannes Reinecke <[email protected]>

Reviewed-by Ewan D. Milne <[email protected]>

Signed-off-by Martin K. Petersen <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 drivers/scsi/megaraid/megaraid_sas_base.c |   13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

drivers/scsi/megaraid/megaraid_sas_base.c +5 -8

@@ -1713,16 +1713,13 @@ megasas_queue_command(struct Scsi_Host *
 		goto out_done;
 	}
 
-	switch (scmd->cmnd[0]) {
-	case SYNCHRONIZE_CACHE:
-		/*
-		 * FW takes care of flush cache on its own
-		 * No need to send it down
-		 */
+	/*
+	 * FW takes care of flush cache on its own for Virtual Disk.
+	 * No need to send it down for VD. For JBOD send SYNCHRONIZE_CACHE to FW.
+	 */
+	if ((scmd->cmnd[0] == SYNCHRONIZE_CACHE) && MEGASAS_IS_LOGICAL(scmd)) {
 		scmd->result = DID_OK << 16;
 		goto out_done;
-	default:
-		break;
 	}
 
 	return instance->instancet->build_and_issue_cmd(instance, scmd);

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/scsi-megaraid_sas-fix-data-integrity-failure-for-jbod-passthrough-devices.patch

Greg KH

author maintainer

2016-11-09 08:48 UTC #2 lore raw

In reply to a message not in the archive

Quoted 25 lines · Sumit Saxena

Quoted 11 lines
-----Original Message-----
From: [email protected] [mailto:[email protected]]
Sent: Wednesday, November 09, 2016 1:49 PM
To: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Cc: [email protected]; [email protected]
Subject: Patch "scsi: megaraid_sas: Fix data integrity failure for JBOD (passthrough) devices" has been added to the 4.8-stable tree
Quoted 3 lines
This is a note to let you know that I've just added the patch titled
scsi: megaraid_sas: Fix data integrity failure for JBOD (passthrough)
devices
Quoted 10 lines
to the 4.8-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-megaraid_sas-fix-data-integrity-failure-for-jbod-passthrough-
devices.patch
and it can be found in the queue-4.8 subdirectory.

Quoted 6 lines

Quoted 1 line
If you, or anyone else, feels it should not be added to the stable tree,
please let
Quoted 1 line
<[email protected]> know about it.
There will be follow up patch which I will be sending in sometime so follow patch needs to be applied along with this patch.

Does that mean that this patch on its own is broken?

confused,

greg k-h

Greg KH

author maintainer

2016-11-09 09:02 UTC #4 lore raw

In reply to a message not in the archive

Quoted 46 lines · Sumit Saxena

Quoted 8 lines
-----Original Message-----
From: Greg KH [mailto:[email protected]]
Sent: Wednesday, November 09, 2016 2:19 PM
To: Sumit Saxena
Cc: Kashyap Desai; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: Re: Patch "scsi: megaraid_sas: Fix data integrity failure for
JBOD
Quoted 37 lines
(passthrough) devices" has been added to the 4.8-stable tree
Quoted 34 lines · Sumit Saxena
Quoted 13 lines
-----Original Message-----
From: [email protected] [mailto:[email protected]]
Sent: Wednesday, November 09, 2016 1:49 PM
To: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Cc: [email protected]; [email protected]
Subject: Patch "scsi: megaraid_sas: Fix data integrity failure for JBOD
(passthrough) devices" has been added to the 4.8-stable tree
Quoted 4 lines
This is a note to let you know that I've just added the patch titled
scsi: megaraid_sas: Fix data integrity failure for JBOD
(passthrough)
devices
Quoted 5 lines
to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-
queue.git;a=summary
Quoted 8 lines
The filename of the patch is:
scsi-megaraid_sas-fix-data-integrity-failure-for-jbod-passthrough- devices.patch
and it can be found in the queue-4.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let
Quoted 1 line
<[email protected]> know about it.

Quoted 8 lines

Quoted 6 lines
Quoted 2 lines
There will be follow up patch which I will be sending in sometime so follow patch needs to be applied along with this patch.
Does that mean that this patch on its own is broken?
confused,
Yes this patch is broken and follow up patch will fix that. I am doing some testing with fix and will send it in sometime.

So should I drop this one from the stable trees until that one is merged?

thanks,

greg k-h

Greg KH

author maintainer

2016-11-09 10:08 UTC #6 lore raw

In reply to a message not in the archive

Quoted 15 lines · Kashyap Desai

Quoted 6 lines
Quoted 6 lines
Quoted 6 lines
please let
Quoted 4 lines
Quoted 1 line
<[email protected]> know about it.
There will be follow up patch which I will be sending in sometime so follow patch needs to be applied along with this patch.
Quoted 7 lines
Quoted 5 lines
Quoted 3 lines
Does that mean that this patch on its own is broken?
confused,
Yes this patch is broken and follow up patch will fix that. I am doing some testing with fix and will send it in sometime.
So should I drop this one from the stable trees until that one is
merged?

Quoted 7 lines

Greg - We are sending another patch which is small fix on top of this one. It is critical regression.
Not sure which will be a good .. To reject or hold current patch. Current patch is definitely a not good to keep without upcoming fix.
To avoid confusion, let's reject this patch and apply once full fix is available (by EOD).

Ok, I've dropped this from the stable queue, please let me know when the "fix" is in Linus's tree, so I can re-add this patch, and the fix patch (please let me know what the git ids are for both.)

thanks,

greg k-h