iov_iter.c: get rid of bvec_copy_page_{to,from}_iter()

Just have copy_page_{to,from}_iter() fall back to kmap_atomic +
copy_{to,from}_iter() + kunmap_atomic() in ITER_BVEC case.  As
the matter of fact, that's what we want to do for any iov_iter
kind that isn't blocking - e.g. ITER_KVEC will also go that way
once we recognize it on iov_iter.c primitives level

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 39ad713..17b7144 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -486,44 +486,6 @@
 	return wanted;
 }
 
-static size_t copy_page_to_iter_bvec(struct page *page, size_t offset,
-					size_t bytes, struct iov_iter *i)
-{
-	void *kaddr = kmap_atomic(page);
-	size_t wanted = copy_to_iter_bvec(kaddr + offset, bytes, i);
-	kunmap_atomic(kaddr);
-	return wanted;
-}
-
-static size_t copy_page_from_iter_bvec(struct page *page, size_t offset,
-					size_t bytes, struct iov_iter *i)
-{
-	void *kaddr = kmap_atomic(page);
-	size_t wanted = copy_from_iter_bvec(kaddr + offset, bytes, i);
-	kunmap_atomic(kaddr);
-	return wanted;
-}
-
-size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
-			 struct iov_iter *i)
-{
-	if (i->type & ITER_BVEC)
-		return copy_page_to_iter_bvec(page, offset, bytes, i);
-	else
-		return copy_page_to_iter_iovec(page, offset, bytes, i);
-}
-EXPORT_SYMBOL(copy_page_to_iter);
-
-size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
-			 struct iov_iter *i)
-{
-	if (i->type & ITER_BVEC)
-		return copy_page_from_iter_bvec(page, offset, bytes, i);
-	else
-		return copy_page_from_iter_iovec(page, offset, bytes, i);
-}
-EXPORT_SYMBOL(copy_page_from_iter);
-
 size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
 	if (i->type & ITER_BVEC)
@@ -542,6 +504,32 @@
 }
 EXPORT_SYMBOL(copy_from_iter);
 
+size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
+			 struct iov_iter *i)
+{
+	if (i->type & (ITER_BVEC|ITER_KVEC)) {
+		void *kaddr = kmap_atomic(page);
+		size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
+		kunmap_atomic(kaddr);
+		return wanted;
+	} else
+		return copy_page_to_iter_iovec(page, offset, bytes, i);
+}
+EXPORT_SYMBOL(copy_page_to_iter);
+
+size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
+			 struct iov_iter *i)
+{
+	if (i->type & ITER_BVEC) {
+		void *kaddr = kmap_atomic(page);
+		size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
+		kunmap_atomic(kaddr);
+		return wanted;
+	} else
+		return copy_page_from_iter_iovec(page, offset, bytes, i);
+}
+EXPORT_SYMBOL(copy_page_from_iter);
+
 size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
 {
 	if (unlikely(bytes > i->count))