blk-mq: do not initialize req->special
Drivers can reach their private data easily using the blk_mq_rq_to_pdu
helper and don't need req->special. By not initializing it code can
be simplified nicely, and we also shave off a few more instructions from
the I/O path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 6d8a87f..c7d02bc9 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -112,7 +112,7 @@
static inline void virtblk_request_done(struct request *req)
{
- struct virtblk_req *vbr = req->special;
+ struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
int error = virtblk_result(vbr);
if (req->cmd_type == REQ_TYPE_BLOCK_PC) {
@@ -154,7 +154,7 @@
static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
{
struct virtio_blk *vblk = hctx->queue->queuedata;
- struct virtblk_req *vbr = req->special;
+ struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
unsigned long flags;
unsigned int num;
const bool last = (req->cmd_flags & REQ_END) != 0;
@@ -501,7 +501,7 @@
struct request *rq, unsigned int nr)
{
struct virtio_blk *vblk = data;
- struct virtblk_req *vbr = rq->special;
+ struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
sg_init_table(vbr->sg, vblk->sg_elems);
return 0;