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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-09-02 16:20:19 +0900
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 08:56:11 +0200
commit818827669d85b84241696ffef2de485db46b0b5e (patch)
tree694d09728733e65d604bf3e1f13679db73fc1d9a /include/linux/bio.h
parent839e96afba87117befd39cf4e43f156edc8047a7 (diff)
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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.h1
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)))
/*