From mboxrd@z Thu Jan 1 00:00:00 1970 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 28190C4167B for ; Tue, 5 Dec 2023 02:25:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376532AbjLECZd (ORCPT ); Mon, 4 Dec 2023 21:25:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376315AbjLECYf (ORCPT ); Mon, 4 Dec 2023 21:24:35 -0500 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [IPv6:2a03:a000:7:0:5054:ff:fe1c:15ff]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 945B319B; Mon, 4 Dec 2023 18:24:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=T08sUyzdKaybfEkZCNae4ocOGsjYgJj1qnspFJtuRWw=; b=sG2R03ekVwwAxoq11TFm7JYoNF LBzgdyhR0BPn4bSp+rm5Q/rwH6wBDh9Zb7Wp/GjnViZelURXwrV68kMLIGNyVSns+QMr5M4qRfqH+ cc/j/YX5S0Ps/6k/c7cUuaFYkv647kmCb3Al9Zn+2BcQzeSP0Vo9Q0VQ8q7UBdlMn5UdNVZudqKT5 JnTEmRlOVHn412hWtQWUkWCPPtTHUbDZHo31J8muxpz1ttkwaBZHvgUIx12SuvabvGWGyqocb1AvN skzKt4RgIbOTs6oKoMD2oAAYwFC98RfyhHXYvH6If2i3IKTXulQkYt+U682n5Y1tBFhb12eXQIKm2 RHf3LYMA==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1rAL6h-00792A-2A; Tue, 05 Dec 2023 02:24:19 +0000 From: Al Viro To: linux-arch@vger.kernel.org Cc: gus Gusenleitner Klaus , Al Viro , Thomas Gleixner , lkml , Ingo Molnar , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "x86@kernel.org" , "David S. Miller" , "dsahern@kernel.org" , "kuba@kernel.org" , Paolo Abeni , Eric Dumazet Subject: [PATCH v2 4/9] ext2: Avoid reading renamed directory if parent does not change Date: Tue, 5 Dec 2023 02:23:58 +0000 Message-Id: <20231205022418.1703007-7-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231205022418.1703007-1-viro@zeniv.linux.org.uk> References: <20231205022100.GB1674809@ZenIV> <20231205022418.1703007-1-viro@zeniv.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Kara The VFS will not be locking moved directory if its parent does not change. Change ext2 rename code to avoid reading renamed directory if its parent does not change. Although it is currently harmless it is a bad practice to read directory contents without inode->i_rwsem. Signed-off-by: Jan Kara Signed-off-by: Al Viro --- fs/ext2/namei.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c index 65f702b1da5b..8346ab9534c1 100644 --- a/fs/ext2/namei.c +++ b/fs/ext2/namei.c @@ -325,6 +325,7 @@ static int ext2_rename (struct mnt_idmap * idmap, struct ext2_dir_entry_2 * dir_de = NULL; struct folio * old_folio; struct ext2_dir_entry_2 * old_de; + bool old_is_dir = S_ISDIR(old_inode->i_mode); int err; if (flags & ~RENAME_NOREPLACE) @@ -342,7 +343,7 @@ static int ext2_rename (struct mnt_idmap * idmap, if (IS_ERR(old_de)) return PTR_ERR(old_de); - if (S_ISDIR(old_inode->i_mode)) { + if (old_is_dir && old_dir != new_dir) { err = -EIO; dir_de = ext2_dotdot(old_inode, &dir_folio); if (!dir_de) @@ -354,7 +355,7 @@ static int ext2_rename (struct mnt_idmap * idmap, struct ext2_dir_entry_2 *new_de; err = -ENOTEMPTY; - if (dir_de && !ext2_empty_dir (new_inode)) + if (old_is_dir && !ext2_empty_dir(new_inode)) goto out_dir; new_de = ext2_find_entry(new_dir, &new_dentry->d_name, @@ -368,14 +369,14 @@ static int ext2_rename (struct mnt_idmap * idmap, if (err) goto out_dir; inode_set_ctime_current(new_inode); - if (dir_de) + if (old_is_dir) drop_nlink(new_inode); inode_dec_link_count(new_inode); } else { err = ext2_add_link(new_dentry, old_inode); if (err) goto out_dir; - if (dir_de) + if (old_is_dir) inode_inc_link_count(new_dir); } @@ -387,7 +388,7 @@ static int ext2_rename (struct mnt_idmap * idmap, mark_inode_dirty(old_inode); err = ext2_delete_entry(old_de, old_folio); - if (!err && dir_de) { + if (!err && old_is_dir) { if (old_dir != new_dir) err = ext2_set_link(old_inode, dir_de, dir_folio, new_dir, false); -- 2.39.2