new helper: iov_iter_kvec()

initialization of kvec-backed iov_iter

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 28ed2d9..c567655 100644 (file)
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -87,6 +87,8 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *);
 unsigned long iov_iter_alignment(const struct iov_iter *i);
 void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
                        unsigned long nr_segs, size_t count);
+void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *iov,
+                       unsigned long nr_segs, 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,

diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 1d2cdeb..88c052e 100644 (file)
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -479,6 +479,19 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i)
 }
 EXPORT_SYMBOL(iov_iter_single_seg_count);
 
+void iov_iter_kvec(struct iov_iter *i, int direction,
+                       const struct kvec *iov, unsigned long nr_segs,
+                       size_t count)
+{
+       BUG_ON(!(direction & ITER_KVEC));
+       i->type = direction;
+       i->kvec = (struct kvec *)iov;
+       i->nr_segs = nr_segs;
+       i->iov_offset = 0;
+       i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_kvec);
+
 unsigned long iov_iter_alignment(const struct iov_iter *i)
 {
        unsigned long res = 0;