From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
commit a506abc7b644d71966a75337d5a534f531b3cdc4 upstream.
we need to advance the iterator...
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/iov_iter.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -906,9 +906,12 @@ size_t copy_page_to_iter(struct page *pa
size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
kunmap_atomic(kaddr);
return wanted;
- } else if (unlikely(iov_iter_is_discard(i)))
+ } else if (unlikely(iov_iter_is_discard(i))) {
+ if (unlikely(i->count < bytes))
+ bytes = i->count;
+ i->count -= bytes;
return bytes;
- else if (likely(!iov_iter_is_pipe(i)))
+ } else if (likely(!iov_iter_is_pipe(i)))
return copy_page_to_iter_iovec(page, offset, bytes, i);
else
return copy_page_to_iter_pipe(page, offset, bytes, i);
