From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Tue, 22 Mar 2016 18:00:55 +0000 (+0100)
Subject: s390/scm_blk: fix deadlock for requests != REQ_TYPE_FS
X-Git-Tag: v3.16.36~103
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=74599272b052bf13a9520d634224b862deaf4d24;p=thirdparty%2Fkernel%2Fstable.git

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@linux.vnet.ibm.com>
Fixes: de9587a ('s390/scm_blk: fix endless loop for requests != REQ_TYPE_FS')
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
index 76bed1743db1c..bc1ea58040d73 100644
--- a/drivers/s390/block/scm_blk.c
+++ b/drivers/s390/block/scm_blk.c
@@ -210,7 +210,7 @@ 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;
 		}