From 367e04e0f2c6730824dc59ba53d16eafec317b6a Mon Sep 17 00:00:00 2001 From: Zach Brown Date: Fri, 14 Jun 2013 15:54:14 -0500 Subject: [PATCH] iov_iter: let callers extract iovecs and bio_vecs direct IO treats memory from user iovecs and memory from arrays of kernel pages very differently. User memory is pinned and worked with in batches while kernel pages are always pinned and don't require additional processing. Rather than try and provide an abstraction that includes these different behaviours we let direct IO extract the memory structs and hand them to the existing code. Signed-off-by: Dave Kleikamp Cc: Zach Brown --- include/linux/fs.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/include/linux/fs.h b/include/linux/fs.h index a89bcb9573a6..322d5854bb73 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -371,6 +371,17 @@ static inline void iov_iter_init_bvec(struct iov_iter *i, iov_iter_advance(i, written); } + +static inline int iov_iter_has_bvec(struct iov_iter *i) +{ + return i->ops == &ii_bvec_ops; +} + +static inline struct bio_vec *iov_iter_bvec(struct iov_iter *i) +{ + BUG_ON(!iov_iter_has_bvec(i)); + return (struct bio_vec *)i->data; +} #endif extern struct iov_iter_ops ii_iovec_ops; @@ -388,8 +399,14 @@ static inline void iov_iter_init(struct iov_iter *i, iov_iter_advance(i, written); } +static inline int iov_iter_has_iovec(struct iov_iter *i) +{ + return i->ops == &ii_iovec_ops; +} + static inline struct iovec *iov_iter_iovec(struct iov_iter *i) { + BUG_ON(!iov_iter_has_iovec(i)); return (struct iovec *)i->data; } -- 2.39.5