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, 1 insertions, 1 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6fe67d1939c2..b72526c13ca0 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -216,8 +216,8 @@ struct request {
         unsigned int cmd_len;
         unsigned char cmd[BLK_MAX_CDB];
 
-        unsigned int raw_data_len;
         unsigned int data_len;
+        unsigned int extra_len; /* length of alignment and padding */
         unsigned int sense_len;
         void *data;
         void *sense;