block: add a blk_plug_device_unlocked() that grabs the queue lock

[deliverable/linux.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index e0fb0bcc0c17dc240ebae88710608c1f1be3a574..4889eb86a39e883c040d53627c98e61a96cd0e26 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -205,14 +205,31 @@ void blk_plug_device(struct request_queue *q)
        if (blk_queue_stopped(q))
                return;
 
-       if (!test_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) {
-               __set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags);
+       if (!queue_flag_test_and_set(QUEUE_FLAG_PLUGGED, q)) {
                mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
                blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG);
        }
 }
 EXPORT_SYMBOL(blk_plug_device);
 
+/**
+ * blk_plug_device_unlocked - plug a device without queue lock held
+ * @q:    The &struct request_queue to plug
+ *
+ * Description:
+ *   Like @blk_plug_device(), but grabs the queue lock and disables
+ *   interrupts.
+ **/
+void blk_plug_device_unlocked(struct request_queue *q)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(q->queue_lock, flags);
+       blk_plug_device(q);
+       spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL(blk_plug_device_unlocked);
+
 /*
  * remove the queue from the plugged list, if present. called with
  * queue lock held and interrupts disabled.
@@ -221,10 +238,9 @@ int blk_remove_plug(struct request_queue *q)
 {
        WARN_ON(!irqs_disabled());
 
-       if (!test_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags))
+       if (!queue_flag_test_and_clear(QUEUE_FLAG_PLUGGED, q))
                return 0;
 
-       queue_flag_clear(QUEUE_FLAG_PLUGGED, q);
        del_timer(&q->unplug_timer);
        return 1;
 }
@@ -328,8 +344,7 @@ void blk_start_queue(struct request_queue *q)
         * one level of recursion is ok and is much faster than kicking
         * the unplug handling
         */
-       if (!test_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) {
-               queue_flag_set(QUEUE_FLAG_REENTER, q);
+       if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
                q->request_fn(q);
                queue_flag_clear(QUEUE_FLAG_REENTER, q);
        } else {
@@ -394,8 +409,7 @@ void __blk_run_queue(struct request_queue *q)
         * handling reinvoke the handler shortly if we already got there.
         */
        if (!elv_queue_empty(q)) {
-               if (!test_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) {
-                       queue_flag_set(QUEUE_FLAG_REENTER, q);
+               if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
                        q->request_fn(q);
                        queue_flag_clear(QUEUE_FLAG_REENTER, q);
                } else {
@@ -1046,15 +1060,9 @@ void blk_put_request(struct request *req)
        unsigned long flags;
        struct request_queue *q = req->q;
 
-       /*
-        * Gee, IDE calls in w/ NULL q.  Fix IDE and remove the
-        * following if (q) test.
-        */
-       if (q) {
-               spin_lock_irqsave(q->queue_lock, flags);
-               __blk_put_request(q, req);
-               spin_unlock_irqrestore(q->queue_lock, flags);
-       }
+       spin_lock_irqsave(q->queue_lock, flags);
+       __blk_put_request(q, req);
+       spin_unlock_irqrestore(q->queue_lock, flags);
 }
 EXPORT_SYMBOL(blk_put_request);
 
@@ -2052,7 +2060,7 @@ int __init blk_dev_init(void)
        for_each_possible_cpu(i)
                INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
 
-       open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL);
+       open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
        register_hotcpu_notifier(&blk_cpu_notifier);
 
        return 0;