diff options
authorChristoph Hellwig <>2015-02-11 14:07:49 +0100
committerJens Axboe <>2015-02-11 11:24:12 -0700
commita0763b27bf24f028d8b049ad856b2ee031fb475d (patch)
parent564e559f2baf6a868768d0cac286980b3cfd6e30 (diff)
block: handle the null_mapped flag correctly in blk_rq_map_user_iov
The tape drivers (and the sg driver in a special case that doesn't matter here) use the null_mapped flag to tell blk_rq_map_user to not copy around any data into or out of the bounce buffers. blk_rq_map_user_iov never got that treatment, which didn't matter until I refactored blk_rq_map_user to be implemented in terms of blk_rq_map_user_iov. Signed-off-by: Christoph Hellwig <> Fixes: ddad8dd0a162 ("block: use blk_rq_map_user_iov to implement blk_rq_map_user") Signed-off-by: Jens Axboe <>
1 files changed, 3 insertions, 0 deletions
diff --git a/block/blk-map.c b/block/blk-map.c
index 0f22911f17dc..b8d2725324a6 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -93,6 +93,9 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
if (IS_ERR(bio))
return PTR_ERR(bio);
+ if (map_data && map_data->null_mapped)
+ bio->bi_flags |= (1 << BIO_NULL_MAPPED);
if (bio->bi_iter.bi_size != iter->count) {
* Grab an extra reference to this bio, as bio_unmap_user()