Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

[pandora-kernel.git] / block / elevator.c

diff --git a/block/elevator.c b/block/elevator.c
index 98259ed..fb81bcc 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -573,7 +573,7 @@ void elv_requeue_request(struct request_queue *q, struct request *rq)
        elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE);
 }
 
-static void elv_drain_elevator(struct request_queue *q)
+void elv_drain_elevator(struct request_queue *q)
 {
        static int printed;
        while (q->elevator->ops->elevator_dispatch_fn(q, 1))
@@ -587,6 +587,31 @@ static void elv_drain_elevator(struct request_queue *q)
        }
 }
 
+/*
+ * Call with queue lock held, interrupts disabled
+ */
+void elv_quisce_start(struct request_queue *q)
+{
+       queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
+
+       /*
+        * make sure we don't have any requests in flight
+        */
+       elv_drain_elevator(q);
+       while (q->rq.elvpriv) {
+               blk_start_queueing(q);
+               spin_unlock_irq(q->queue_lock);
+               msleep(10);
+               spin_lock_irq(q->queue_lock);
+               elv_drain_elevator(q);
+       }
+}
+
+void elv_quisce_end(struct request_queue *q)
+{
+       queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+}
+
 void elv_insert(struct request_queue *q, struct request *rq, int where)
 {
        struct list_head *pos;
@@ -677,7 +702,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
        }
 
        if (unplug_it && blk_queue_plugged(q)) {
-               int nrq = q->rq.count[READ] + q->rq.count[WRITE]
+               int nrq = q->rq.count[BLK_RW_SYNC] + q->rq.count[BLK_RW_ASYNC]
                        - q->in_flight;
 
                if (nrq >= q->unplug_thresh)
@@ -1101,18 +1126,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
         * Turn on BYPASS and drain all requests w/ elevator private data
         */
        spin_lock_irq(q->queue_lock);
-
-       queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
-
-       elv_drain_elevator(q);
-
-       while (q->rq.elvpriv) {
-               blk_start_queueing(q);
-               spin_unlock_irq(q->queue_lock);
-               msleep(10);
-               spin_lock_irq(q->queue_lock);
-               elv_drain_elevator(q);
-       }
+       elv_quisce_start(q);
 
        /*
         * Remember old elevator.
@@ -1136,7 +1150,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
         */
        elevator_exit(old_elevator);
        spin_lock_irq(q->queue_lock);
-       queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+       elv_quisce_end(q);
        spin_unlock_irq(q->queue_lock);
 
        blk_add_trace_msg(q, "elv switch: %s", e->elevator_type->elevator_name);