block: add request->raw_data_len
[linux-2.6.git] / block / blk-map.c
index 955d75c..09f7fd0 100644 (file)
@@ -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);