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Diffstat (limited to 'block/elevator.c')
-rw-r--r--block/elevator.c44
1 files changed, 29 insertions, 15 deletions
diff --git a/block/elevator.c b/block/elevator.c
index 98259eda0ef6..fb81bcc14a8c 100644
--- 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);