mm: Add NR_WRITEBACK_TEMP counter

[linux-2.6-omap-h63xx.git] / block / elevator.c

diff --git a/block/elevator.c b/block/elevator.c
index bafbae0344d319e909e3e7add07467b1c0463a73..ac5310ef8270984e32799e0524917abf4246853a 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -69,7 +69,7 @@ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
 /*
  * can we safely merge with this request?
  */
-inline int elv_rq_merge_ok(struct request *rq, struct bio *bio)
+int elv_rq_merge_ok(struct request *rq, struct bio *bio)
 {
        if (!rq_mergeable(rq))
                return 0;
@@ -134,6 +134,21 @@ static struct elevator_type *elevator_get(const char *name)
        spin_lock(&elv_list_lock);
 
        e = elevator_find(name);
+       if (!e) {
+               char elv[ELV_NAME_MAX + strlen("-iosched")];
+
+               spin_unlock(&elv_list_lock);
+
+               if (!strcmp(name, "anticipatory"))
+                       sprintf(elv, "as-iosched");
+               else
+                       sprintf(elv, "%s-iosched", name);
+
+               request_module(elv);
+               spin_lock(&elv_list_lock);
+               e = elevator_find(name);
+       }
+
        if (e && !try_module_get(e->elevator_owner))
                e = NULL;
 
@@ -473,6 +488,9 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio)
                }
        }
 
+       if (blk_queue_nomerges(q))
+               return ELEVATOR_NO_MERGE;
+
        /*
         * See if our hash lookup can find a potential backmerge.
         */
@@ -1055,7 +1073,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
         */
        spin_lock_irq(q->queue_lock);
 
-       set_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+       queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
 
        elv_drain_elevator(q);
 
@@ -1089,7 +1107,10 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
         * finally exit old elevator and turn off BYPASS.
         */
        elevator_exit(old_elevator);
-       clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+       spin_lock_irq(q->queue_lock);
+       queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+       spin_unlock_irq(q->queue_lock);
+
        return 1;
 
 fail_register:
@@ -1100,7 +1121,11 @@ fail_register:
        elevator_exit(e);
        q->elevator = old_elevator;
        elv_register_queue(q);
-       clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+
+       spin_lock_irq(q->queue_lock);
+       queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+       spin_unlock_irq(q->queue_lock);
+
        return 0;
 }