nfs_write_end(): fix handling of short copies

commit c0cf3ef5e0f47e385920450b245d22bead93e7ad upstream.

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.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 93e236429c5d785a1711d643d0b4676dfe4396cf..dc875cd0e11d52386c893ee83c1c71ff40f855ef 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -407,7 +407,7 @@ 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,