block: optimize generic_unplug_device()

[firefly-linux-kernel-4.4.55.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index e447799256d6c0abeb460d61f10e15b6e80030e4..1b7dddf94f4f99769a715ffaaeb89e21d78ae72c 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -107,7 +107,7 @@ struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev)
 }
 EXPORT_SYMBOL(blk_get_backing_dev_info);
 
-void rq_init(struct request_queue *q, struct request *rq)
+void blk_rq_init(struct request_queue *q, struct request *rq)
 {
        memset(rq, 0, sizeof(*rq));
 
@@ -117,9 +117,11 @@ void rq_init(struct request_queue *q, struct request *rq)
        rq->sector = rq->hard_sector = (sector_t) -1;
        INIT_HLIST_NODE(&rq->hash);
        RB_CLEAR_NODE(&rq->rb_node);
+       rq->cmd = rq->__cmd;
        rq->tag = -1;
        rq->ref_count = 1;
 }
+EXPORT_SYMBOL(blk_rq_init);
 
 static void req_bio_endio(struct request *rq, struct bio *bio,
                          unsigned int nbytes, int error)
@@ -134,7 +136,7 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
 
                if (unlikely(nbytes > bio->bi_size)) {
                        printk(KERN_ERR "%s: want %u bytes done, %u left\n",
-                              __FUNCTION__, nbytes, bio->bi_size);
+                              __func__, nbytes, bio->bi_size);
                        nbytes = bio->bi_size;
                }
 
@@ -172,7 +174,7 @@ void blk_dump_rq_flags(struct request *rq, char *msg)
 
        if (blk_pc_request(rq)) {
                printk(KERN_INFO "  cdb: ");
-               for (bit = 0; bit < sizeof(rq->cmd); bit++)
+               for (bit = 0; bit < BLK_MAX_CDB; bit++)
                        printk("%02x ", rq->cmd[bit]);
                printk("\n");
        }
@@ -198,7 +200,8 @@ void blk_plug_device(struct request_queue *q)
        if (blk_queue_stopped(q))
                return;
 
-       if (!test_and_set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) {
+       if (!test_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) {
+               __set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags);
                mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
                blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG);
        }
@@ -213,9 +216,10 @@ int blk_remove_plug(struct request_queue *q)
 {
        WARN_ON(!irqs_disabled());
 
-       if (!test_and_clear_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags))
+       if (!test_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags))
                return 0;
 
+       queue_flag_clear(QUEUE_FLAG_PLUGGED, q);
        del_timer(&q->unplug_timer);
        return 1;
 }
@@ -249,9 +253,11 @@ EXPORT_SYMBOL(__generic_unplug_device);
  **/
 void generic_unplug_device(struct request_queue *q)
 {
-       spin_lock_irq(q->queue_lock);
-       __generic_unplug_device(q);
-       spin_unlock_irq(q->queue_lock);
+       if (blk_queue_plugged(q)) {
+               spin_lock_irq(q->queue_lock);
+               __generic_unplug_device(q);
+               spin_unlock_irq(q->queue_lock);
+       }
 }
 EXPORT_SYMBOL(generic_unplug_device);
 
@@ -311,15 +317,16 @@ void blk_start_queue(struct request_queue *q)
 {
        WARN_ON(!irqs_disabled());
 
-       clear_bit(QUEUE_FLAG_STOPPED, &q->queue_flags);
+       queue_flag_clear(QUEUE_FLAG_STOPPED, q);
 
        /*
         * one level of recursion is ok and is much faster than kicking
         * the unplug handling
         */
-       if (!test_and_set_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) {
+       if (!test_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) {
+               queue_flag_set(QUEUE_FLAG_REENTER, q);
                q->request_fn(q);
-               clear_bit(QUEUE_FLAG_REENTER, &q->queue_flags);
+               queue_flag_clear(QUEUE_FLAG_REENTER, q);
        } else {
                blk_plug_device(q);
                kblockd_schedule_work(&q->unplug_work);
@@ -344,7 +351,7 @@ EXPORT_SYMBOL(blk_start_queue);
 void blk_stop_queue(struct request_queue *q)
 {
        blk_remove_plug(q);
-       set_bit(QUEUE_FLAG_STOPPED, &q->queue_flags);
+       queue_flag_set(QUEUE_FLAG_STOPPED, q);
 }
 EXPORT_SYMBOL(blk_stop_queue);
 
@@ -373,11 +380,8 @@ EXPORT_SYMBOL(blk_sync_queue);
  * blk_run_queue - run a single device queue
  * @q: The queue to run
  */
-void blk_run_queue(struct request_queue *q)
+void __blk_run_queue(struct request_queue *q)
 {
-       unsigned long flags;
-
-       spin_lock_irqsave(q->queue_lock, flags);
        blk_remove_plug(q);
 
        /*
@@ -385,15 +389,28 @@ 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_and_set_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) {
+               if (!test_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) {
+                       queue_flag_set(QUEUE_FLAG_REENTER, q);
                        q->request_fn(q);
-                       clear_bit(QUEUE_FLAG_REENTER, &q->queue_flags);
+                       queue_flag_clear(QUEUE_FLAG_REENTER, q);
                } else {
                        blk_plug_device(q);
                        kblockd_schedule_work(&q->unplug_work);
                }
        }
+}
+EXPORT_SYMBOL(__blk_run_queue);
 
+/**
+ * blk_run_queue - run a single device queue
+ * @q: The queue to run
+ */
+void blk_run_queue(struct request_queue *q)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(q->queue_lock, flags);
+       __blk_run_queue(q);
        spin_unlock_irqrestore(q->queue_lock, flags);
 }
 EXPORT_SYMBOL(blk_run_queue);
@@ -406,7 +423,7 @@ void blk_put_queue(struct request_queue *q)
 void blk_cleanup_queue(struct request_queue *q)
 {
        mutex_lock(&q->sysfs_lock);
-       set_bit(QUEUE_FLAG_DEAD, &q->queue_flags);
+       queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
        mutex_unlock(&q->sysfs_lock);
 
        if (q->elevator)
@@ -585,7 +602,7 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask)
        if (!rq)
                return NULL;
 
-       rq_init(q, rq);
+       blk_rq_init(q, rq);
 
        /*
         * first three bits are identical in rq->cmd_flags and bio->bi_rw,
@@ -1551,8 +1568,7 @@ static int __end_that_request_first(struct request *req, int error,
                        if (unlikely(bio->bi_idx >= bio->bi_vcnt)) {
                                blk_dump_rq_flags(req, "__end_that");
                                printk(KERN_ERR "%s: bio idx %d >= vcnt %d\n",
-                                               __FUNCTION__, bio->bi_idx,
-                                               bio->bi_vcnt);
+                                      __func__, bio->bi_idx, bio->bi_vcnt);
                                break;
                        }