start adding the tag to iov_iter

For now, just use the same thing we pass to ->direct_IO() - it's all
iovec-based at the moment.  Pass it explicitly to iov_iter_init() and
account for kvec vs. iovec in there, by the same kludge NFS ->direct_IO()
uses.

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

1 files changed, 15 insertions, 0 deletions

diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 2f762cc21080..e2c9a2db4350 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -220,3 +220,18 @@ unsigned long iov_iter_alignment(const struct iov_iter *i)
 	return res;
 }
 EXPORT_SYMBOL(iov_iter_alignment);
+
+void iov_iter_init(struct iov_iter *i, int direction,
+			const struct iovec *iov, unsigned long nr_segs,
+			size_t count)
+{
+	/* It will get better.  Eventually... */
+	if (segment_eq(get_fs(), KERNEL_DS))
+		direction |= REQ_KERNEL;
+	i->type = direction;
+	i->iov = iov;
+	i->nr_segs = nr_segs;
+	i->iov_offset = 0;
+	i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_init);