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>

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 9ea85ae23c320b2dcb7409c97c3da3fa93a4fc12..a1de8ef63e56992c6e7eeb554c00dfc024111f94 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -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,