From patchwork Mon May 11 18:06:45 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 6381231 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D897CBEEE1 for ; Mon, 11 May 2015 18:23:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1A4D320A4F for ; Mon, 11 May 2015 18:23:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3BC720A51 for ; Mon, 11 May 2015 18:23:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755016AbbEKSIZ (ORCPT ); Mon, 11 May 2015 14:08:25 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:46999 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754929AbbEKSIQ (ORCPT ); Mon, 11 May 2015 14:08:16 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.76 #1 (Red Hat Linux)) id 1Yrs7i-0001Ov-DZ; Mon, 11 May 2015 18:08:14 +0000 From: Al Viro To: Linus Torvalds Cc: Neil Brown , Christoph Hellwig , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v3 025/110] do_last: regularize the logics around following symlinks Date: Mon, 11 May 2015 19:06:45 +0100 Message-Id: <1431367690-5223-25-git-send-email-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <20150511180650.GA4147@ZenIV.linux.org.uk> References: <20150511180650.GA4147@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Al Viro With LOOKUP_FOLLOW we unlazy and return 1; without it we either fail with ELOOP or, for O_PATH opens, succeed. No need to mix those cases... Signed-off-by: Al Viro --- fs/namei.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 3e45233..54cbfe7 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3046,9 +3046,7 @@ retry_lookup: goto out; } finish_lookup: - /* we _can_ be in RCU mode here */ - if (should_follow_link(path->dentry, - !(open_flag & O_PATH) || (nd->flags & LOOKUP_FOLLOW))) { + if (should_follow_link(path->dentry, nd->flags & LOOKUP_FOLLOW)) { if (nd->flags & LOOKUP_RCU) { if (unlikely(nd->path.mnt != path->mnt || unlazy_walk(nd, path->dentry))) { @@ -3057,14 +3055,15 @@ finish_lookup: } } BUG_ON(inode != path->dentry->d_inode); - if (!(nd->flags & LOOKUP_FOLLOW)) { - path_put_conditional(path, nd); - path_put(&nd->path); - return -ELOOP; - } return 1; } + if (unlikely(d_is_symlink(path->dentry)) && !(open_flag & O_PATH)) { + path_to_nameidata(path, nd); + error = -ELOOP; + goto out; + } + if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) { path_to_nameidata(path, nd); } else {