This is a note to let you know that I've just added the patch titled

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

to the 3.10-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     s390-dasd-hold-request-queue-sysfs-lock-when-calling-elevator_init.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From ef0899410ff630b2e75306da49996dbbfa318165 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <[email protected]>
Date: Thu, 31 Oct 2013 13:24:28 +0100
Subject: s390/dasd: hold request queue sysfs lock when calling elevator_init()

From: Heiko Carstens <[email protected]>

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 <[email protected]>
Cc: Jens Axboe <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 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;
 }
 
 /*


Patches currently in stable-queue which might be from [email protected] 
are

queue-3.10/s390-dasd-hold-request-queue-sysfs-lock-when-calling-elevator_init.patch
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