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block: handle the null_mapped flag correctly in blk_rq_map_user_iov

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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>
This commit is contained in:
Christoph Hellwig 2015-02-11 14:07:49 +01:00 committed by Jens Axboe
parent 564e559f2b
commit a0763b27bf
1 changed files with 3 additions and 0 deletions
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3
block/blk-map.c
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@ -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()