[3.19.y-ckt stable] Patch "s390/scm_blk: fix deadlock for requests != REQ_TYPE_FS" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

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

    s390/scm_blk: fix deadlock for requests != REQ_TYPE_FS

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt20.

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

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 1fba4b5ce46636b02f1946ae5b9d7db218750b51 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott at linux.vnet.ibm.com>
Date: Tue, 22 Mar 2016 19:00:55 +0100
Subject: s390/scm_blk: fix deadlock for requests != REQ_TYPE_FS

commit b707c65ae70e24c47a0ce4a7279224ce8f0ffb7f upstream.

When we refuse a non REQ_TYPE_FS request in the build request function
we already hold the queue lock. Thus we must not call blk_end_request_all
but __blk_end_request_all.

Reported-by: Peter Oberparleiter <oberpar at linux.vnet.ibm.com>
Fixes: de9587a ('s390/scm_blk: fix endless loop for requests != REQ_TYPE_FS')
Signed-off-by: Sebastian Ott <sebott at linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky at de.ibm.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/s390/block/scm_blk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
index 75d9896..e6f54d3 100644
--- a/drivers/s390/block/scm_blk.c
+++ b/drivers/s390/block/scm_blk.c
@@ -303,7 +303,7 @@ static void scm_blk_request(struct request_queue *rq)
 		if (req->cmd_type != REQ_TYPE_FS) {
 			blk_start_request(req);
 			blk_dump_rq_flags(req, KMSG_COMPONENT " bad request");
-			blk_end_request_all(req, -EIO);
+			__blk_end_request_all(req, -EIO);
 			continue;
 		}

--
2.7.4