nfs_write_end(): fix handling of short copies

[ Upstream commit c0cf3ef5e0f47e385920450b245d22bead93e7ad ]

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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 8b8d83a526ce2366ae974a87761c9c62c22da7f5..ddf5f9fd719fd3b131efe592e452b49311ea0cfc 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -414,7 +414,7 @@ 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,