nfs_write_end(): fix handling of short copies

What matters when deciding if we should make a page uptodate is
not how much we _wanted_ to copy, but how much we actually have
copied.  As it is, on architectures that do not zero tail on
short copy we can leave uninitialized data in page marked uptodate.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-09-05 21:42:32 -04:00
parent e5517c2a5a
commit c0cf3ef5e0

View File

@ -374,7 +374,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
*/
if (!PageUptodate(page)) {
unsigned pglen = nfs_page_length(page);
unsigned end = offset + len;
unsigned end = offset + copied;
if (pglen == 0) {
zero_user_segments(page, 0, offset,