From patchwork Thu Feb 2 20:44:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 1736635 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org (client-ip=2404:9400:2221:ea00::3; helo=gandalf.ozlabs.org; envelope-from=srs0=pwo0=56=vger.kernel.org=linux-ext4-owner@ozlabs.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=Cnpe1akX; dkim-atps=neutral Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4P79l14nP8z23qv for ; Fri, 3 Feb 2023 07:44:45 +1100 (AEDT) Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4P79kz56QHz4xyj for ; Fri, 3 Feb 2023 07:44:43 +1100 (AEDT) Received: by gandalf.ozlabs.org (Postfix) id 4P79kx6CMSz4xyy; Fri, 3 Feb 2023 07:44:41 +1100 (AEDT) Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: gandalf.ozlabs.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: gandalf.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Authentication-Results: gandalf.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=Cnpe1akX; dkim-atps=neutral Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4P79kx67lFz4xyt for ; Fri, 3 Feb 2023 07:44:41 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232957AbjBBUoj (ORCPT ); Thu, 2 Feb 2023 15:44:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232067AbjBBUof (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 C74C48A58; 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=CHTViCFku/KBgg0p6DZbUUb80eMrbMHO+BwTMmLL/c8=; b=Cnpe1akXRcTjrbOFxM+9HrW+ur d1lfcvyzmUOAlYVR9x6xYmCbrq53KnUEe+yqtSAHOPbH7OHm0rewQg2RMYzAmtBFcYZE4oSeqLxMi eCHHJ8dFrq4kz9d/JcMQzW5XpXnfBUje4e46WGl4WZgLZJBy7/sDkudm3R/iXLIpz5Vh7F5wllJ7I OUkIXT5U0OkITUYHT6Dd+ODvKs5q3qcDfvn3fcX5d53emCWIimY8ED0Y5esijwiT7AN7seZkhU+G+ eFufWstFTegm87OA4SkZuEQOD6F1ZgjDbt9nNJNndVfqGOf533nK3ibsN/iH0hY3EkdfhgfQTwKHm GPQu7rFA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pNgRa-00Di7O-Ue; 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 2/5] ext4: Zero bytes after 'oldsize' if we're expanding the file Date: Thu, 2 Feb 2023 20:44:24 +0000 Message-Id: <20230202204428.3267832-3-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 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-ext4@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) --- fs/ext4/inode.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 9d9f414f99fe..14e3fa99f733 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5604,6 +5604,7 @@ int ext4_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, if (!shrink) { pagecache_isize_extended(inode, oldsize, inode->i_size); + truncate_pagecache(inode, oldsize); } else if (ext4_should_journal_data(inode)) { ext4_wait_for_tail_page_commit(inode); }