[PATCHv7 1/9] blk-mq-dma: create blk_map_iter type

[Keith Busch <kbusch@meta.com>]

From: Keith Busch <kbusch@kernel.org>

The req_iterator happens to have a similar fields to what the dma
iterator needs, but we're not necessarily iterating a request's
bi_io_vec. Create a new type that can be amended for additional future
use.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq-dma.c         | 4 ++--
 include/linux/blk-mq-dma.h | 7 ++++++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/block/blk-mq-dma.c b/block/blk-mq-dma.c
index ad283017caef2..51e7a0ff045f9 100644
--- a/block/blk-mq-dma.c
+++ b/block/blk-mq-dma.c
@@ -10,7 +10,7 @@ struct phys_vec {
 	u32		len;
 };
 
-static bool blk_map_iter_next(struct request *req, struct req_iterator *iter,
+static bool blk_map_iter_next(struct request *req, struct blk_map_iter *iter,
 			      struct phys_vec *vec)
 {
 	unsigned int max_size;
@@ -246,7 +246,7 @@ blk_next_sg(struct scatterlist **sg, struct scatterlist *sglist)
 int __blk_rq_map_sg(struct request *rq, struct scatterlist *sglist,
 		    struct scatterlist **last_sg)
 {
-	struct req_iterator iter = {
+	struct blk_map_iter iter = {
 		.bio	= rq->bio,
 	};
 	struct phys_vec vec;
diff --git a/include/linux/blk-mq-dma.h b/include/linux/blk-mq-dma.h
index c26a01aeae006..6a7e3828673d7 100644
--- a/include/linux/blk-mq-dma.h
+++ b/include/linux/blk-mq-dma.h
@@ -5,6 +5,11 @@
 #include <linux/blk-mq.h>
 #include <linux/pci-p2pdma.h>
 
+struct blk_map_iter {
+	struct bvec_iter		iter;
+	struct bio			*bio;
+};
+
 struct blk_dma_iter {
 	/* Output address range for this iteration */
 	dma_addr_t			addr;
@@ -14,7 +19,7 @@ struct blk_dma_iter {
 	blk_status_t			status;
 
 	/* Internal to blk_rq_dma_map_iter_* */
-	struct req_iterator		iter;
+	struct blk_map_iter		iter;
 	struct pci_p2pdma_map_state	p2pdma;
 };
 
-- 
2.47.3