ef0899410f
"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>