block: drop barrier ordering by queue draining

[mirror_ubuntu-bionic-kernel.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index f8d37a8e2c55b4e9c82ab337fc8de4da431602b9..d316662682c8bbe926ad39b326641f7d5d6c32f5 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -520,6 +520,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
        init_timer(&q->unplug_timer);
        setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
        INIT_LIST_HEAD(&q->timeout_list);
+       INIT_LIST_HEAD(&q->pending_barriers);
        INIT_WORK(&q->unplug_work, blk_unplug_work);
 
        kobject_init(&q->kobj, &blk_queue_ktype);
@@ -1185,6 +1186,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
        const bool sync = (bio->bi_rw & REQ_SYNC);
        const bool unplug = (bio->bi_rw & REQ_UNPLUG);
        const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
+       int where = ELEVATOR_INSERT_SORT;
        int rw_flags;
 
        /* REQ_HARDBARRIER is no more */
@@ -1203,7 +1205,12 @@ static int __make_request(struct request_queue *q, struct bio *bio)
 
        spin_lock_irq(q->queue_lock);
 
-       if (unlikely((bio->bi_rw & REQ_HARDBARRIER)) || elv_queue_empty(q))
+       if (bio->bi_rw & REQ_HARDBARRIER) {
+               where = ELEVATOR_INSERT_FRONT;
+               goto get_rq;
+       }
+
+       if (elv_queue_empty(q))
                goto get_rq;
 
        el_ret = elv_merge(q, &req, bio);
@@ -1303,7 +1310,7 @@ get_rq:
 
        /* insert the request into the elevator */
        drive_stat_acct(req, 1);
-       __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
+       __elv_add_request(q, req, where, 0);
 out:
        if (unplug || !queue_should_plug(q))
                __generic_unplug_device(q);