diff options
Diffstat (limited to 'block/blk-map.c')
| -rw-r--r-- | block/blk-map.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/block/blk-map.c b/block/blk-map.c index 955d75c1a58f..09f7fd0bcb73 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -19,6 +19,7 @@ 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; @@ -139,10 +140,29 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq, ubuf += ret; } + /* + * __blk_rq_map_user() copies the buffers if starting address + * or length isn't aligned. 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 & 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->buffer = rq->data = NULL; return 0; unmap_rq: blk_rq_unmap_user(bio); + rq->bio = NULL; return ret; } EXPORT_SYMBOL(blk_rq_map_user); |