block: split scsi_request out of struct request

And require all drivers that want to support BLOCK_PC to allocate it
as the first thing of their private data.  To support this the legacy
IDE and BSG code is switched to set cmd_size on their queues to let
the block layer allocate the additional space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 0 insertions, 10 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 60dac10228fe..3d76e860f126 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -199,13 +199,7 @@ void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
         rq->special = NULL;
         /* tag was already set */
         rq->errors = 0;
-
-        rq->cmd = rq->__cmd;
-
         rq->extra_len = 0;
-        rq->sense_len = 0;
-        rq->resid_len = 0;
-        rq->sense = NULL;
 
         INIT_LIST_HEAD(&rq->timeout_list);
         rq->timeout = 0;
@@ -487,10 +481,6 @@ void blk_mq_start_request(struct request *rq)
 
         trace_block_rq_issue(q, rq);
 
-        rq->resid_len = blk_rq_bytes(rq);
-        if (unlikely(blk_bidi_rq(rq)))
-                rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq);
-
         if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) {
                 blk_stat_set_issue_time(&rq->issue_stat);
                 rq->rq_flags |= RQF_STATS;