s390/dasd: hold request queue sysfs lock when calling elevator_init()

"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@hds.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Heiko Carstens 2013-10-31 13:24:28 +01:00 committed by Jens Axboe
parent b88fac630b
commit ef0899410f

View file

@ -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;
}
/*