From ed93fb01a3991ced713a37bc844ed2f2abef8ea8 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 31 Oct 2013 13:24:28 +0100 Subject: [PATCH] s390/dasd: hold request queue sysfs lock when calling elevator_init() 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 Cc: Jens Axboe Signed-off-by: Heiko Carstens Signed-off-by: Jens Axboe Cc: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman --- 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 d72a9216ee2e..e91ec8cd9b09 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2879,12 +2879,12 @@ 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; } /* -- 2.34.1