Merge remote-tracking branch 'block/for-next'

[karo-tx-linux.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index 18e92a6645e24741b786bc35f14b9d06f1355569..89eec79658702a7e53712bc52178dae25bddcc22 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -554,22 +554,23 @@ void blk_cleanup_queue(struct request_queue *q)
         * Drain all requests queued before DYING marking. Set DEAD flag to
         * prevent that q->request_fn() gets invoked after draining finished.
         */
-       if (q->mq_ops) {
-               blk_mq_freeze_queue(q);
-               spin_lock_irq(lock);
-       } else {
-               spin_lock_irq(lock);
+       blk_freeze_queue(q);
+       spin_lock_irq(lock);
+       if (!q->mq_ops)
                __blk_drain_queue(q, true);
-       }
        queue_flag_set(QUEUE_FLAG_DEAD, q);
        spin_unlock_irq(lock);
 
+       /* for synchronous bio-based driver finish in-flight integrity i/o */
+       blk_flush_integrity();
+
        /* @q won't process any more request, flush async actions */
        del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
        blk_sync_queue(q);
 
        if (q->mq_ops)
                blk_mq_free_queue(q);
+       percpu_ref_exit(&q->q_usage_counter);
 
        spin_lock_irq(lock);
        if (q->queue_lock != &q->__queue_lock)
@@ -629,6 +630,40 @@ struct request_queue *blk_alloc_queue(gfp_t gfp_mask)
 }
 EXPORT_SYMBOL(blk_alloc_queue);
 
+int blk_queue_enter(struct request_queue *q, gfp_t gfp)
+{
+       while (true) {
+               int ret;
+
+               if (percpu_ref_tryget_live(&q->q_usage_counter))
+                       return 0;
+
+               if (!(gfp & __GFP_WAIT))
+                       return -EBUSY;
+
+               ret = wait_event_interruptible(q->mq_freeze_wq,
+                               !atomic_read(&q->mq_freeze_depth) ||
+                               blk_queue_dying(q));
+               if (blk_queue_dying(q))
+                       return -ENODEV;
+               if (ret)
+                       return ret;
+       }
+}
+
+void blk_queue_exit(struct request_queue *q)
+{
+       percpu_ref_put(&q->q_usage_counter);
+}
+
+static void blk_queue_usage_counter_release(struct percpu_ref *ref)
+{
+       struct request_queue *q =
+               container_of(ref, struct request_queue, q_usage_counter);
+
+       wake_up_all(&q->mq_freeze_wq);
+}
+
 struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 {
        struct request_queue *q;
@@ -690,11 +725,22 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 
        init_waitqueue_head(&q->mq_freeze_wq);
 
-       if (blkcg_init_queue(q))
+       /*
+        * Init percpu_ref in atomic mode so that it's faster to shutdown.
+        * See blk_register_queue() for details.
+        */
+       if (percpu_ref_init(&q->q_usage_counter,
+                               blk_queue_usage_counter_release,
+                               PERCPU_REF_INIT_ATOMIC, GFP_KERNEL))
                goto fail_bdi;
 
+       if (blkcg_init_queue(q))
+               goto fail_ref;
+
        return q;
 
+fail_ref:
+       percpu_ref_exit(&q->q_usage_counter);
 fail_bdi:
        bdi_destroy(&q->backing_dev_info);
 fail_split:
@@ -1594,6 +1640,30 @@ out:
        return ret;
 }
 
+unsigned int blk_plug_queued_count(struct request_queue *q)
+{
+       struct blk_plug *plug;
+       struct request *rq;
+       struct list_head *plug_list;
+       unsigned int ret = 0;
+
+       plug = current->plug;
+       if (!plug)
+               goto out;
+
+       if (q->mq_ops)
+               plug_list = &plug->mq_list;
+       else
+               plug_list = &plug->list;
+
+       list_for_each_entry(rq, plug_list, queuelist) {
+               if (rq->q == q)
+                       ret++;
+       }
+out:
+       return ret;
+}
+
 void init_request_from_bio(struct request *req, struct bio *bio)
 {
        req->cmd_type = REQ_TYPE_FS;
@@ -1641,9 +1711,11 @@ static void blk_queue_bio(struct request_queue *q, struct bio *bio)
         * Check if we can merge with the plugged list before grabbing
         * any locks.
         */
-       if (!blk_queue_nomerges(q) &&
-           blk_attempt_plug_merge(q, bio, &request_count, NULL))
-               return;
+       if (!blk_queue_nomerges(q)) {
+               if (blk_attempt_plug_merge(q, bio, &request_count, NULL))
+                       return;
+       } else
+               request_count = blk_plug_queued_count(q);
 
        spin_lock_irq(q->queue_lock);
 
@@ -1966,9 +2038,19 @@ void generic_make_request(struct bio *bio)
        do {
                struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 
-               q->make_request_fn(q, bio);
+               if (likely(blk_queue_enter(q, __GFP_WAIT) == 0)) {
+
+                       q->make_request_fn(q, bio);
+
+                       blk_queue_exit(q);
 
-               bio = bio_list_pop(current->bio_list);
+                       bio = bio_list_pop(current->bio_list);
+               } else {
+                       struct bio *bio_next = bio_list_pop(current->bio_list);
+
+                       bio_io_error(bio);
+                       bio = bio_next;
+               }
        } while (bio);
        current->bio_list = NULL; /* deactivate */
 }