block: restore the meaning of rq->data_len to the true data length

The meaning of rq->data_len was changed to the length of an allocated
buffer from the true data length. It breaks SG_IO friends and
bsg. This patch restores the meaning of rq->data_len to the true data
length and adds rq->extra_len to store an extended length (due to
drain buffer and padding).

This patch also removes the code to update bio in blk_rq_map_user
introduced by the commit 40b01b9bbdf51ae543a04744283bf2d56c4a6afa.
The commit adjusts bio according to memory alignment
(queue_dma_alignment). However, memory alignment is NOT padding
alignment. This adjustment also breaks SG_IO friends and bsg. Padding
alignment needs to be fixed in a proper way (by a separate patch).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>

1 files changed, 4 insertions, 4 deletions

diff --git a/block/bsg.c b/block/bsg.c
index 7f3c09549e4b..8917c5174dc2 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -437,14 +437,14 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
         }
 
         if (rq->next_rq) {
-                hdr->dout_resid = rq->raw_data_len;
-                hdr->din_resid = rq->next_rq->raw_data_len;
+                hdr->dout_resid = rq->data_len;
+                hdr->din_resid = rq->next_rq->data_len;
                 blk_rq_unmap_user(bidi_bio);
                 blk_put_request(rq->next_rq);
         } else if (rq_data_dir(rq) == READ)
-                hdr->din_resid = rq->raw_data_len;
+                hdr->din_resid = rq->data_len;
         else
-                hdr->dout_resid = rq->raw_data_len;
+                hdr->dout_resid = rq->data_len;
 
         /*
          * If the request generated a negative error number, return it