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| author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2008-09-02 16:20:19 +0900 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-10-09 08:56:11 +0200 |
| commit | 818827669d85b84241696ffef2de485db46b0b5e (patch) | |
| tree | 694d09728733e65d604bf3e1f13679db73fc1d9a /include/linux/bio.h | |
| parent | 839e96afba87117befd39cf4e43f156edc8047a7 (diff) | |
| download | lwn-818827669d85b84241696ffef2de485db46b0b5e.tar.gz lwn-818827669d85b84241696ffef2de485db46b0b5e.zip | |
block: make blk_rq_map_user take a NULL user-space buffer
This patch changes blk_rq_map_user to accept a NULL user-space buffer
with a READ command if rq_map_data is not NULL. Thus a caller can pass
page frames to lk_rq_map_user to just set up a request and bios with
page frames propely. bio_uncopy_user (called via blk_rq_unmap_user)
doesn't copy data to user space with such request.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/bio.h')
| -rw-r--r-- | include/linux/bio.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/bio.h b/include/linux/bio.h index bc386cd5e996..7af373f253dc 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -108,6 +108,7 @@ struct bio { #define BIO_USER_MAPPED 6 /* contains user pages */ #define BIO_EOPNOTSUPP 7 /* not supported */ #define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */ +#define BIO_NULL_MAPPED 9 /* contains invalid user pages */ #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) /* |