lkml.org 
[lkml]   [2014]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.10 75/85] s390/dasd: hold request queue sysfs lock when calling elevator_init()
Date
3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Heiko Carstens <heiko.carstens@de.ibm.com>

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@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>
Cc: Christian Borntraeger <christian@borntraeger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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;
}

/*



\
 
 \ /
  Last update: 2014-03-21 08:21    [W:0.360 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site