[patch added to the 3.12 stable tree] s390/dasd: hold request queue sysfs lock when calling elevator_init()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit ef0899410ff630b2e75306da49996dbbfa318165 upstream.

"elevator: Fix a race in elevator switching and md device initialization"
changed the semantics of elevator_init() in a way that now enforces to hold
the corresponding request queue's sysfs_lock when calling elevator_init()
to fix a race.
The patch did not convert the s390 dasd device driver which is the only
device driver which also calls elevator_init(). So add the missing locking.

Cc: Tomoki Sekiyama <tomoki.sekiyama@xxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/s390/block/dasd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 451bf99582ff..846d5c6609d8 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2978,12 +2978,12 @@ static int dasd_alloc_queue(struct dasd_block *block)
 
 	elevator_exit(block->request_queue->elevator);
 	block->request_queue->elevator = NULL;
+	mutex_lock(&block->request_queue->sysfs_lock);
 	rc = elevator_init(block->request_queue, "deadline");
-	if (rc) {
+	if (rc)
 		blk_cleanup_queue(block->request_queue);
-		return rc;
-	}
-	return 0;
+	mutex_unlock(&block->request_queue->sysfs_lock);
+	return rc;
 }
 
 /*
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]