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: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 961e562c8a7a34b41a6a89d431cb191223625c8f..8b8d6a54140c28dbea5da0966189314715d8e676 100644 (file)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -397,7 +397,7 @@ 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,