new helper: iov_iter_bvec()

similar to iov_iter_kvec(), for ITER_BVEC ones

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

diff --git a/fs/splice.c b/fs/splice.c
index 75c6058..7c7176f 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1006,11 +1006,8 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
                }
 
                /* ... iov_iter */
-               from.type = ITER_BVEC | WRITE;
-               from.bvec = array;
-               from.nr_segs = n;
-               from.count = sd.total_len - left;
-               from.iov_offset = 0;
+               iov_iter_bvec(&from, ITER_BVEC | WRITE, array, n,
+                             sd.total_len - left);
 
                /* ... and iocb */
                init_sync_kiocb(&kiocb, out);

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 1c5e453..b447402 100644 (file)
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -88,7 +88,9 @@ 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,
+void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec,
+                       unsigned long nr_segs, size_t count);
+void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec,
                        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);

diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index a1599ca..8277320 100644 (file)
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -501,18 +501,31 @@ 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,
+                       const struct kvec *kvec, unsigned long nr_segs,
                        size_t count)
 {
        BUG_ON(!(direction & ITER_KVEC));
        i->type = direction;
-       i->kvec = (struct kvec *)iov;
+       i->kvec = kvec;
        i->nr_segs = nr_segs;
        i->iov_offset = 0;
        i->count = count;
 }
 EXPORT_SYMBOL(iov_iter_kvec);
 
+void iov_iter_bvec(struct iov_iter *i, int direction,
+                       const struct bio_vec *bvec, unsigned long nr_segs,
+                       size_t count)
+{
+       BUG_ON(!(direction & ITER_BVEC));
+       i->type = direction;
+       i->bvec = bvec;
+       i->nr_segs = nr_segs;
+       i->iov_offset = 0;
+       i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_bvec);
+
 unsigned long iov_iter_alignment(const struct iov_iter *i)
 {
        unsigned long res = 0;

diff --git a/mm/page_io.c b/mm/page_io.c
index 955db8b..e604580 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -269,14 +269,9 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
                        .bv_len  = PAGE_SIZE,
                        .bv_offset = 0
                };
-               struct iov_iter from = {
-                       .type = ITER_BVEC | WRITE,
-                       .count = PAGE_SIZE,
-                       .iov_offset = 0,
-                       .nr_segs = 1,
-               };
-               from.bvec = &bv;        /* older gcc versions are broken */
+               struct iov_iter from;
 
+               iov_iter_bvec(&from, ITER_BVEC | WRITE, &bv, 1, PAGE_SIZE);
                init_sync_kiocb(&kiocb, swap_file);
                kiocb.ki_pos = page_file_offset(page);
                kiocb.ki_nbytes = PAGE_SIZE;