blk-mq: simplify the blk_mq_get_request calling convention

The bio argument is entirely unused, and the request_queue can be passed
through the alloc_data, given that it needs to be filled out for the
low-level tag allocation anyway.  Also rename the function to
__blk_mq_alloc_request as the switch between get and alloc in the call
chains is rather confusing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index f15722cbfac64374d645aa3f209db84986e1a852..74ebab41f7d2a8c03673b90e8577f7f07b453b56 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -332,10 +332,9 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
        return rq;
 }
 
-static struct request *blk_mq_get_request(struct request_queue *q,
-                                         struct bio *bio,
-                                         struct blk_mq_alloc_data *data)
+static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data)
 {
+       struct request_queue *q = data->q;
        struct elevator_queue *e = q->elevator;
        struct request *rq;
        unsigned int tag;
@@ -346,7 +345,6 @@ static struct request *blk_mq_get_request(struct request_queue *q,
        if (blk_queue_rq_alloc_time(q))
                alloc_time_ns = ktime_get_ns();
 
-       data->q = q;
        if (likely(!data->ctx)) {
                data->ctx = blk_mq_get_ctx(q);
                clear_ctx_on_error = true;
@@ -398,7 +396,11 @@ static struct request *blk_mq_get_request(struct request_queue *q,
 struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
                blk_mq_req_flags_t flags)
 {
-       struct blk_mq_alloc_data alloc_data = { .flags = flags, .cmd_flags = op };
+       struct blk_mq_alloc_data data = {
+               .q              = q,
+               .flags          = flags,
+               .cmd_flags      = op,
+       };
        struct request *rq;
        int ret;
 
@@ -406,7 +408,7 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
        if (ret)
                return ERR_PTR(ret);
 
-       rq = blk_mq_get_request(q, NULL, &alloc_data);
+       rq = __blk_mq_alloc_request(&data);
        if (!rq)
                goto out_queue_exit;
        rq->__data_len = 0;
@@ -422,7 +424,11 @@ EXPORT_SYMBOL(blk_mq_alloc_request);
 struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
        unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx)
 {
-       struct blk_mq_alloc_data alloc_data = { .flags = flags, .cmd_flags = op };
+       struct blk_mq_alloc_data data = {
+               .q              = q,
+               .flags          = flags,
+               .cmd_flags      = op,
+       };
        struct request *rq;
        unsigned int cpu;
        int ret;
@@ -448,14 +454,14 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
         * If not tell the caller that it should skip this queue.
         */
        ret = -EXDEV;
-       alloc_data.hctx = q->queue_hw_ctx[hctx_idx];
-       if (!blk_mq_hw_queue_mapped(alloc_data.hctx))
+       data.hctx = q->queue_hw_ctx[hctx_idx];
+       if (!blk_mq_hw_queue_mapped(data.hctx))
                goto out_queue_exit;
-       cpu = cpumask_first_and(alloc_data.hctx->cpumask, cpu_online_mask);
-       alloc_data.ctx = __blk_mq_get_ctx(q, cpu);
+       cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask);
+       data.ctx = __blk_mq_get_ctx(q, cpu);
 
        ret = -EWOULDBLOCK;
-       rq = blk_mq_get_request(q, NULL, &alloc_data);
+       rq = __blk_mq_alloc_request(&data);
        if (!rq)
                goto out_queue_exit;
        return rq;
@@ -2027,7 +2033,9 @@ blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 {
        const int is_sync = op_is_sync(bio->bi_opf);
        const int is_flush_fua = op_is_flush(bio->bi_opf);
-       struct blk_mq_alloc_data data = { .flags = 0};
+       struct blk_mq_alloc_data data = {
+               .q              = q,
+       };
        struct request *rq;
        struct blk_plug *plug;
        struct request *same_queue_rq = NULL;
@@ -2051,7 +2059,7 @@ blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
        rq_qos_throttle(q, bio);
 
        data.cmd_flags = bio->bi_opf;
-       rq = blk_mq_get_request(q, bio, &data);
+       rq = __blk_mq_alloc_request(&data);
        if (unlikely(!rq)) {
                rq_qos_cleanup(q, bio);
                if (bio->bi_opf & REQ_NOWAIT)