1 files changed, 15 insertions, 11 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 6a062eebbd15..e8525fa72823 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1136,12 +1136,8 @@ static int cfq_dispatch_requests(struct request_queue *q, int force)
                 if (cfq_class_idle(cfqq))
                         max_dispatch = 1;
 
-                if (cfqq->dispatched >= max_dispatch) {
-                        if (cfqd->busy_queues > 1)
-                                break;
-                        if (cfqq->dispatched >= 4 * max_dispatch)
-                                break;
-                }
+                if (cfqq->dispatched >= max_dispatch && cfqd->busy_queues > 1)
+                        break;
 
                 if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq))
                         break;
@@ -1318,7 +1314,15 @@ static void cfq_exit_single_io_context(struct io_context *ioc,
                 unsigned long flags;
 
                 spin_lock_irqsave(q->queue_lock, flags);
-                __cfq_exit_single_io_context(cfqd, cic);
+
+                /*
+                 * Ensure we get a fresh copy of the ->key to prevent
+                 * race between exiting task and queue
+                 */
+                smp_read_barrier_depends();
+                if (cic->key)
+                        __cfq_exit_single_io_context(cfqd, cic);
+
                 spin_unlock_irqrestore(q->queue_lock, flags);
         }
 }
@@ -2160,7 +2164,7 @@ out_cont:
 static void cfq_shutdown_timer_wq(struct cfq_data *cfqd)
 {
         del_timer_sync(&cfqd->idle_slice_timer);
-        kblockd_flush_work(&cfqd->unplug_work);
+        cancel_work_sync(&cfqd->unplug_work);
 }
 
 static void cfq_put_async_queues(struct cfq_data *cfqd)
@@ -2178,7 +2182,7 @@ static void cfq_put_async_queues(struct cfq_data *cfqd)
                 cfq_put_queue(cfqd->async_idle_cfqq);
 }
 
-static void cfq_exit_queue(elevator_t *e)
+static void cfq_exit_queue(struct elevator_queue *e)
 {
         struct cfq_data *cfqd = e->elevator_data;
         struct request_queue *q = cfqd->queue;
@@ -2288,7 +2292,7 @@ cfq_var_store(unsigned int *var, const char *page, size_t count)
 }
 
 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV)                            \
-static ssize_t __FUNC(elevator_t *e, char *page)                        \
+static ssize_t __FUNC(struct elevator_queue *e, char *page)             \
 {                                                                       \
         struct cfq_data *cfqd = e->elevator_data;                       \
         unsigned int __data = __VAR;                                    \
@@ -2308,7 +2312,7 @@ SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
 #undef SHOW_FUNCTION
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)                 \
-static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)    \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
 {                                                                       \
         struct cfq_data *cfqd = e->elevator_data;                       \
         unsigned int __data;                                            \