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| author | Christoph Hellwig <hch@lst.de> | 2015-02-11 14:07:49 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-02-11 11:24:12 -0700 |
| commit | a0763b27bf24f028d8b049ad856b2ee031fb475d (patch) | |
| tree | 7fba607dd8e679b6ee787b0c5257d7461c1bd8f5 | |
| parent | 564e559f2baf6a868768d0cac286980b3cfd6e30 (diff) | |
| download | lwn-a0763b27bf24f028d8b049ad856b2ee031fb475d.tar.gz lwn-a0763b27bf24f028d8b049ad856b2ee031fb475d.zip | |
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 <hch@lst.de>
Fixes: ddad8dd0a162 ("block: use blk_rq_map_user_iov to implement blk_rq_map_user")
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | block/blk-map.c | 3 |
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() |