[3.13.y.z extended stable] Patch "scsi: handle flush errors properly" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    scsi: handle flush errors properly

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 1918a05d9621d9659783dfaf7b009f873e835d53 Mon Sep 17 00:00:00 2001
From: James Bottomley <JBottomley at Parallels.com>
Date: Thu, 3 Jul 2014 19:17:34 +0200
Subject: scsi: handle flush errors properly

commit 89fb4cd1f717a871ef79fa7debbe840e3225cd54 upstream.

Flush commands don't transfer data and thus need to be special cased
in the I/O completion handler so that we can propagate errors to
the block layer and filesystem.

Signed-off-by: James Bottomley <JBottomley at Parallels.com>
Reported-by: Steven Haber <steven at qumulo.com>
Tested-by: Steven Haber <steven at qumulo.com>
Reviewed-by: Martin K. Petersen <martin.petersen at oracle.com>
Signed-off-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/scsi/scsi_lib.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 62ec84b..64e487a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -831,6 +831,14 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 			scsi_next_command(cmd);
 			return;
 		}
+	} else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) {
+		/*
+		 * Certain non BLOCK_PC requests are commands that don't
+		 * actually transfer anything (FLUSH), so cannot use
+		 * good_bytes != blk_rq_bytes(req) as the signal for an error.
+		 * This sets the error explicitly for the problem case.
+		 */
+		error = __scsi_error_from_host_byte(cmd, result);
 	}

 	/* no bidi support for !REQ_TYPE_BLOCK_PC yet */
--
1.9.1