[PATCH 3.19.y-ckt 56/66] s390/scm_blk: fix deadlock for requests != REQ_TYPE_FS

From: Kamal Mostafa
Date: Tue Apr 26 2016 - 16:26:25 EST


3.19.8-ckt20 -stable review patch. If anyone has any objections, please let me know.

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

From: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxx>
Fixes: de9587a ('s390/scm_blk: fix endless loop for requests != REQ_TYPE_FS')
Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
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