null_blk: remove legacy IO path

We're planning on removing this code completely, kill the old
path.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 093b614d652445a337db00ea8beaded767073415..0b302d707095fb1384c9ac848ed775cfb4d10313 100644 (file)
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -616,10 +616,6 @@ static void end_cmd(struct nullb_cmd *cmd)
        case NULL_Q_MQ:
                blk_mq_end_request(cmd->rq, cmd->error);
                return;
-       case NULL_Q_RQ:
-               INIT_LIST_HEAD(&cmd->rq->queuelist);
-               blk_end_request_all(cmd->rq, cmd->error);
-               break;
        case NULL_Q_BIO:
                cmd->bio->bi_status = cmd->error;
                bio_endio(cmd->bio);
@@ -627,15 +623,6 @@ static void end_cmd(struct nullb_cmd *cmd)
        }
 
        free_cmd(cmd);
-
-       /* Restart queue if needed, as we are freeing a tag */
-       if (queue_mode == NULL_Q_RQ && blk_queue_stopped(q)) {
-               unsigned long flags;
-
-               spin_lock_irqsave(q->queue_lock, flags);
-               blk_start_queue_async(q);
-               spin_unlock_irqrestore(q->queue_lock, flags);
-       }
 }
 
 static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
@@ -1136,25 +1123,14 @@ static void null_stop_queue(struct nullb *nullb)
 
        if (nullb->dev->queue_mode == NULL_Q_MQ)
                blk_mq_stop_hw_queues(q);
-       else {
-               spin_lock_irq(q->queue_lock);
-               blk_stop_queue(q);
-               spin_unlock_irq(q->queue_lock);
-       }
 }
 
 static void null_restart_queue_async(struct nullb *nullb)
 {
        struct request_queue *q = nullb->q;
-       unsigned long flags;
 
        if (nullb->dev->queue_mode == NULL_Q_MQ)
                blk_mq_start_stopped_hw_queues(q, true);
-       else {
-               spin_lock_irqsave(q->queue_lock, flags);
-               blk_start_queue_async(q);
-               spin_unlock_irqrestore(q->queue_lock, flags);
-       }
 }
 
 static bool cmd_report_zone(struct nullb *nullb, struct nullb_cmd *cmd)
@@ -1197,17 +1173,8 @@ static blk_status_t null_handle_cmd(struct nullb_cmd *cmd)
                        /* race with timer */
                        if (atomic_long_read(&nullb->cur_bytes) > 0)
                                null_restart_queue_async(nullb);
-                       if (dev->queue_mode == NULL_Q_RQ) {
-                               struct request_queue *q = nullb->q;
-
-                               spin_lock_irq(q->queue_lock);
-                               rq->rq_flags |= RQF_DONTPREP;
-                               blk_requeue_request(q, rq);
-                               spin_unlock_irq(q->queue_lock);
-                               return BLK_STS_OK;
-                       } else
-                               /* requeue request */
-                               return BLK_STS_DEV_RESOURCE;
+                       /* requeue request */
+                       return BLK_STS_DEV_RESOURCE;
                }
        }
 
@@ -1278,9 +1245,6 @@ out:
                case NULL_Q_MQ:
                        blk_mq_complete_request(cmd->rq);
                        break;
-               case NULL_Q_RQ:
-                       blk_complete_request(cmd->rq);
-                       break;
                case NULL_Q_BIO:
                        /*
                         * XXX: no proper submitting cpu information available.
@@ -1349,30 +1313,6 @@ static blk_qc_t null_queue_bio(struct request_queue *q, struct bio *bio)
        return BLK_QC_T_NONE;
 }
 
-static enum blk_eh_timer_return null_rq_timed_out_fn(struct request *rq)
-{
-       pr_info("null: rq %p timed out\n", rq);
-       __blk_complete_request(rq);
-       return BLK_EH_DONE;
-}
-
-static int null_rq_prep_fn(struct request_queue *q, struct request *req)
-{
-       struct nullb *nullb = q->queuedata;
-       struct nullb_queue *nq = nullb_to_queue(nullb);
-       struct nullb_cmd *cmd;
-
-       cmd = alloc_cmd(nq, 0);
-       if (cmd) {
-               cmd->rq = req;
-               req->special = cmd;
-               return BLKPREP_OK;
-       }
-       blk_stop_queue(q);
-
-       return BLKPREP_DEFER;
-}
-
 static bool should_timeout_request(struct request *rq)
 {
 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
@@ -1391,27 +1331,6 @@ static bool should_requeue_request(struct request *rq)
        return false;
 }
 
-static void null_request_fn(struct request_queue *q)
-{
-       struct request *rq;
-
-       while ((rq = blk_fetch_request(q)) != NULL) {
-               struct nullb_cmd *cmd = rq->special;
-
-               /* just ignore the request */
-               if (should_timeout_request(rq))
-                       continue;
-               if (should_requeue_request(rq)) {
-                       blk_requeue_request(q, rq);
-                       continue;
-               }
-
-               spin_unlock_irq(q->queue_lock);
-               null_handle_cmd(cmd);
-               spin_lock_irq(q->queue_lock);
-       }
-}
-
 static enum blk_eh_timer_return null_timeout_rq(struct request *rq, bool res)
 {
        pr_info("null: rq %p timed out\n", rq);
@@ -1766,24 +1685,6 @@ static int null_add_dev(struct nullb_device *dev)
                rv = init_driver_queues(nullb);
                if (rv)
                        goto out_cleanup_blk_queue;
-       } else {
-               nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock,
-                                               dev->home_node);
-               if (!nullb->q) {
-                       rv = -ENOMEM;
-                       goto out_cleanup_queues;
-               }
-
-               if (!null_setup_fault())
-                       goto out_cleanup_blk_queue;
-
-               blk_queue_prep_rq(nullb->q, null_rq_prep_fn);
-               blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
-               blk_queue_rq_timed_out(nullb->q, null_rq_timed_out_fn);
-               nullb->q->rq_timeout = 5 * HZ;
-               rv = init_driver_queues(nullb);
-               if (rv)
-                       goto out_cleanup_blk_queue;
        }
 
        if (dev->mbps) {
@@ -1865,6 +1766,10 @@ static int __init null_init(void)
                return -EINVAL;
        }
 
+       if (g_queue_mode == NULL_Q_RQ) {
+               pr_err("null_blk: legacy IO path no longer available\n");
+               return -EINVAL;
+       }
        if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) {
                if (g_submit_queues != nr_online_nodes) {
                        pr_warn("null_blk: submit_queues param is set to %u.\n",