blk-mq: get rid of confusing blk_map_ctx structure

We can just use struct blk_mq_alloc_data - it has a few more
members, but we allocate it further down the stack anyway. So
this cleans up the code, and reduces the stack overhead a bit.

Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index f3d27a6dee09dfa48dd7b78bc024f4a9809e8f88..d74a74a9f9efe931e5c443e2a709b6bd661ef97b 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1190,21 +1190,15 @@ insert_rq:
        }
 }
 
-struct blk_map_ctx {
-       struct blk_mq_hw_ctx *hctx;
-       struct blk_mq_ctx *ctx;
-};
-
 static struct request *blk_mq_map_request(struct request_queue *q,
                                          struct bio *bio,
-                                         struct blk_map_ctx *data)
+                                         struct blk_mq_alloc_data *data)
 {
        struct blk_mq_hw_ctx *hctx;
        struct blk_mq_ctx *ctx;
        struct request *rq;
        int op = bio_data_dir(bio);
        int op_flags = 0;
-       struct blk_mq_alloc_data alloc_data;
 
        blk_queue_enter_live(q);
        ctx = blk_mq_get_ctx(q);
@@ -1214,11 +1208,9 @@ static struct request *blk_mq_map_request(struct request_queue *q,
                op_flags |= REQ_SYNC;
 
        trace_block_getrq(q, bio, op);
-       blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx);
-       rq = __blk_mq_alloc_request(&alloc_data, op, op_flags);
+       blk_mq_set_alloc_data(data, q, 0, ctx, hctx);
+       rq = __blk_mq_alloc_request(data, op, op_flags);
 
-       data->hctx = alloc_data.hctx;
-       data->ctx = alloc_data.ctx;
        data->hctx->queued++;
        return rq;
 }
@@ -1267,7 +1259,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 {
        const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf);
        const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
-       struct blk_map_ctx data;
+       struct blk_mq_alloc_data data;
        struct request *rq;
        unsigned int request_count = 0;
        struct blk_plug *plug;
@@ -1363,7 +1355,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
        const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
        struct blk_plug *plug;
        unsigned int request_count = 0;
-       struct blk_map_ctx data;
+       struct blk_mq_alloc_data data;
        struct request *rq;
        blk_qc_t cookie;