From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tomoki Sekiyama , Jens Axboe , Heiko Carstens , Christian Borntraeger Subject: [PATCH 3.10 75/85] s390/dasd: hold request queue sysfs lock when calling elevator_init() Date: Thu, 20 Mar 2014 17:10:18 -0700 Message-Id: <20140321000609.441627130@linuxfoundation.org> In-Reply-To: <20140321000558.606667505@linuxfoundation.org> References: <20140321000558.606667505@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Heiko Carstens 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(-) --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2879,12 +2879,12 @@ static int dasd_alloc_queue(struct dasd_ 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; } /*