copy_page_to_iter(): don't split high-order page in case of ITER_PIPE
... just shove it into one pipe_buffer.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 46ec078..4e3696d 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -706,30 +706,21 @@ static inline bool page_copy_sane(struct page *page, size_t offset, size_t n)
return false;
}
-static size_t __copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
- struct iov_iter *i)
-{
- if (unlikely(iov_iter_is_pipe(i))) {
- return copy_page_to_iter_pipe(page, offset, bytes, i);
- } else {
- void *kaddr = kmap_local_page(page);
- size_t wanted = _copy_to_iter(kaddr + offset, bytes, i);
- kunmap_local(kaddr);
- return wanted;
- }
-}
-
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
size_t res = 0;
if (unlikely(!page_copy_sane(page, offset, bytes)))
return 0;
+ if (unlikely(iov_iter_is_pipe(i)))
+ return copy_page_to_iter_pipe(page, offset, bytes, i);
page += offset / PAGE_SIZE; // first subpage
offset %= PAGE_SIZE;
while (1) {
- size_t n = __copy_page_to_iter(page, offset,
- min(bytes, (size_t)PAGE_SIZE - offset), i);
+ void *kaddr = kmap_local_page(page);
+ size_t n = min(bytes, (size_t)PAGE_SIZE - offset);
+ n = _copy_to_iter(kaddr + offset, n, i);
+ kunmap_local(kaddr);
res += n;
bytes -= n;
if (!bytes || !n)
