From patchwork Thu Feb 2 20:44:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 13126722 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 121D1C05027 for ; Thu, 2 Feb 2023 20:44:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233050AbjBBUov (ORCPT ); Thu, 2 Feb 2023 15:44:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232841AbjBBUof (ORCPT ); Thu, 2 Feb 2023 15:44:35 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6DAC76AB; Thu, 2 Feb 2023 12:44:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=74nszHLks+AFGqdfRGx6vNnWqXDqZ9xHI0qBKa9QcdI=; b=Bh63M/0nqGUZZvEkwrwA6JtjLg 6o8uQmpPAbwbDBcLTYskUV04rtjVxAbkRI8ywM/Cpg4QgkiduK6adIw3ab64Pf5IMVgLHdPjVDTBl aFg3fWxnpxmnDgfKBu03xsCHOnK4kcN7ZNcdNL6rFyRosOEDWxJ2OH3HyqGJPOB9okC+kK4RFv5JW x710OIFndtSvYOt8aghfbiSUMaoLwhFO3gM1DyXoahA8R0FHcoR780FR7VUl6VjqZywykxzxsTZsT z7NGee99rYn2z4rassj8Q+UR5edf87SIIhF/tDMjeQicVliVbhgeiEiraaTJYPSgPnMq8cG0Ud4/t ULWEZsfQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pNgRb-00Di7d-Ga; Thu, 02 Feb 2023 20:44:31 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-afs@lists.infradead.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Hugh Dickins , linux-kernel@vger.kernel.org, fstests@vger.kernel.org Subject: [PATCH 4/5] afs: Zero bytes after 'oldsize' if we're expanding the file Date: Thu, 2 Feb 2023 20:44:26 +0000 Message-Id: <20230202204428.3267832-5-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20230202204428.3267832-1-willy@infradead.org> References: <20230202204428.3267832-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org POSIX requires that "If the file size is increased, the extended area shall appear as if it were zero-filled". It is possible to use mmap to write past EOF and that data will become visible instead of zeroes. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: David Howells --- fs/afs/inode.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 6d3a3dbe4928..92e2ba7625de 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -854,6 +854,8 @@ static void afs_setattr_edit_file(struct afs_operation *op) if (size < i_size) truncate_pagecache(inode, size); + else + truncate_pagecache(inode, i_size); if (size != i_size) fscache_resize_cookie(afs_vnode_cache(vp->vnode), vp->scb.status.size);