ubuf += ret;
}
- /*
- * __blk_rq_map_user() copies the buffers if starting address
- * or length isn't aligned to dma_pad_mask. As the copied
- * buffer is always page aligned, we know that there's enough
- * room for padding. Extend the last bio and update
- * rq->data_len accordingly.
- *
- * On unmap, bio_uncopy_user() will use unmodified
- * bio_map_data pointed to by bio->bi_private.
- */
- if (len & q->dma_pad_mask) {
- unsigned int pad_len = (q->dma_pad_mask & ~len) + 1;
- struct bio *tail = rq->biotail;
-
- tail->bi_io_vec[tail->bi_vcnt - 1].bv_len += pad_len;
- tail->bi_size += pad_len;
-
- rq->extra_len += pad_len;
- }
+ if (!bio_flagged(bio, BIO_USER_MAPPED))
+ rq->cmd_flags |= REQ_COPY_USER;
rq->buffer = rq->data = NULL;
return 0;
return -EINVAL;
}
+ if (!bio_flagged(bio, BIO_USER_MAPPED))
+ rq->cmd_flags |= REQ_COPY_USER;
+
bio_get(bio);
blk_rq_bio_prep(q, rq, bio);
rq->buffer = rq->data = NULL;
* @kbuf: the kernel buffer
* @len: length of user data
* @gfp_mask: memory allocation flags
+ *
+ * Description:
+ * Data will be mapped directly if possible. Otherwise a bounce
+ * buffer is used.
*/
int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
unsigned int len, gfp_t gfp_mask)
{
+ unsigned long kaddr;
+ unsigned int alignment;
+ int reading = rq_data_dir(rq) == READ;
+ int do_copy = 0;
struct bio *bio;
if (len > (q->max_hw_sectors << 9))
if (!len || !kbuf)
return -EINVAL;
- bio = bio_map_kern(q, kbuf, len, gfp_mask);
+ kaddr = (unsigned long)kbuf;
+ alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+ do_copy = ((kaddr & alignment) || (len & alignment));
+
+ if (do_copy)
+ bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
+ else
+ bio = bio_map_kern(q, kbuf, len, gfp_mask);
+
if (IS_ERR(bio))
return PTR_ERR(bio);
if (rq_data_dir(rq) == WRITE)
bio->bi_rw |= (1 << BIO_RW);
+ if (do_copy)
+ rq->cmd_flags |= REQ_COPY_USER;
+
blk_rq_bio_prep(q, rq, bio);
blk_queue_bounce(q, &rq->bio);
rq->buffer = rq->data = NULL;