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 40b01b9bbd.
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 <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
FUJITA Tomonori 2008-03-04 11:17:11 +01:00 • committed by Jens Axboe
commit 7a85f8896f
7 changed files with 13 additions and 18 deletions

View file

@ -19,7 +19,6 @@ int blk_rq_append_bio(struct request_queue *q, struct request *rq,
rq->biotail->bi_next = bio;
rq->biotail = bio;
rq->raw_data_len += bio->bi_size;
rq->data_len += bio->bi_size;
}
return 0;
@ -151,11 +150,8 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
*/
if (len & queue_dma_alignment(q)) {
unsigned int pad_len = (queue_dma_alignment(q) & ~len) + 1;
struct bio *bio = rq->biotail;
bio->bi_io_vec[bio->bi_vcnt - 1].bv_len += pad_len;
bio->bi_size += pad_len;
rq->data_len += pad_len;
rq->extra_len += pad_len;
}
rq->buffer = rq->data = NULL;