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| author | David Howells <dhowells@redhat.com> | 2018-10-20 01:57:56 +0200 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2018-10-24 01:41:07 +0200 |
| commit | 9ea9ce0427aab02a2fd88fc608267cf6952119f1 (patch) | |
| tree | cc25d73e227737862ccad90bc38919bd268c685b /include | |
| parent | iov_iter: Separate type from direction and use accessor functions (diff) | |
| download | linux-9ea9ce0427aab02a2fd88fc608267cf6952119f1.tar.xz linux-9ea9ce0427aab02a2fd88fc608267cf6952119f1.zip | |
iov_iter: Add I/O discard iterator
Add a new iterator, ITER_DISCARD, that can only be used in READ mode and
just discards any data copied to it.
This is useful in a network filesystem for discarding any unwanted data
sent by a server.
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/uio.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h index 3d8f1acc142c..55ce99ddb912 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -26,6 +26,7 @@ enum iter_type { ITER_KVEC = 2, ITER_BVEC = 4, ITER_PIPE = 8, + ITER_DISCARD = 16, }; struct iov_iter { @@ -72,6 +73,11 @@ static inline bool iov_iter_is_pipe(const struct iov_iter *i) return iov_iter_type(i) == ITER_PIPE; } +static inline bool iov_iter_is_discard(const struct iov_iter *i) +{ + return iov_iter_type(i) == ITER_DISCARD; +} + static inline unsigned char iov_iter_rw(const struct iov_iter *i) { return i->type & (READ | WRITE); @@ -220,6 +226,7 @@ void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_ unsigned long nr_segs, size_t count); void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe, size_t count); +void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count); ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start); ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, |