block: avoid setting none scheduler if it's already none

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

diff --git a/block/blk-core.c b/block/blk-core.c
index b725d9e340c2768c123c84cedf5573dcc9c89a47..c5d5c8587770394dd4257882c3b1b72bed4f95c9 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -821,9 +821,8 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 
        while (true) {
                bool success = false;
-               int ret;
 
-               rcu_read_lock_sched();
+               rcu_read_lock();
                if (percpu_ref_tryget_live(&q->q_usage_counter)) {
                        /*
                         * The code that sets the PREEMPT_ONLY flag is
@@ -836,7 +835,7 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
                                percpu_ref_put(&q->q_usage_counter);
                        }
                }
-               rcu_read_unlock_sched();
+               rcu_read_unlock();
 
                if (success)
                        return 0;
@@ -853,14 +852,12 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
                 */
                smp_rmb();
 
-               ret = wait_event_interruptible(q->mq_freeze_wq,
-                               (atomic_read(&q->mq_freeze_depth) == 0 &&
-                                (preempt || !blk_queue_preempt_only(q))) ||
-                               blk_queue_dying(q));
+               wait_event(q->mq_freeze_wq,
+                          (atomic_read(&q->mq_freeze_depth) == 0 &&
+                           (preempt || !blk_queue_preempt_only(q))) ||
+                          blk_queue_dying(q));
                if (blk_queue_dying(q))
                        return -ENODEV;
-               if (ret)
-                       return ret;
        }
 }
 
@@ -3260,6 +3257,8 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 {
        if (bio_has_data(bio))
                rq->nr_phys_segments = bio_phys_segments(q, bio);
+       else if (bio_op(bio) == REQ_OP_DISCARD)
+               rq->nr_phys_segments = 1;
 
        rq->__data_len = bio->bi_iter.bi_size;
        rq->bio = rq->biotail = bio;
@@ -3343,6 +3342,10 @@ static void __blk_rq_prep_clone(struct request *dst, struct request *src)
        dst->cpu = src->cpu;
        dst->__sector = blk_rq_pos(src);
        dst->__data_len = blk_rq_bytes(src);
+       if (src->rq_flags & RQF_SPECIAL_PAYLOAD) {
+               dst->rq_flags |= RQF_SPECIAL_PAYLOAD;
+               dst->special_vec = src->special_vec;
+       }
        dst->nr_phys_segments = src->nr_phys_segments;
        dst->ioprio = src->ioprio;
        dst->extra_len = src->extra_len;