cfq-iosched: fix race in cfq_set_request()

We need to hold the queue lock over the reference increment,
it's not atomic anymore.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 3202c7e87fb3..fb2141ec205c 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3675,12 +3675,11 @@ new_queue:
 
         cfqq->allocated[rw]++;
 
-        spin_unlock_irqrestore(q->queue_lock, flags);
-
         cfqq->ref++;
         rq->elevator_private[0] = cic;
         rq->elevator_private[1] = cfqq;
         rq->elevator_private[2] = cfq_ref_get_cfqg(cfqq->cfqg);
+        spin_unlock_irqrestore(q->queue_lock, flags);
         return 0;
 
 queue_fail: