tree cf55d07e0c0aa962677a9657d800f9e44729d5c5
parent d4a774fdb92f37da91ebd827c3e507b542ab29b1
author Miklos Szeredi <mszeredi@redhat.com> 1471504244 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1480150492 +0100

fuse: fix fuse_write_end() if zero bytes were copied

commit 59c3b76cc61d1d676f965c192cc7969aa5cb2744 upstream.

If pos is at the beginning of a page and copied is zero then page is not
zeroed but is marked uptodate.

Fix by skipping everything except unlock/put of page if zero bytes were
copied.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 6b12c1b37e55 ("fuse: Implement write_begin/write_end callbacks")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>