From patchwork Fri Mar 13 23:53:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 11438109 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E7CFD921 for ; Fri, 13 Mar 2020 23:57:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D136A20637 for ; Fri, 13 Mar 2020 23:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727654AbgCMX5q (ORCPT ); Fri, 13 Mar 2020 19:57:46 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:50018 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727730AbgCMXyA (ORCPT ); Fri, 13 Mar 2020 19:54:00 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jCu7r-00B6a0-Jy; Fri, 13 Mar 2020 23:53:59 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Linus Torvalds Subject: [RFC][PATCH v4 19/69] merging pick_link() with get_link(), part 1 Date: Fri, 13 Mar 2020 23:53:07 +0000 Message-Id: <20200313235357.2646756-19-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200313235357.2646756-1-viro@ZenIV.linux.org.uk> References: <20200313235303.GP23230@ZenIV.linux.org.uk> <20200313235357.2646756-1-viro@ZenIV.linux.org.uk> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Al Viro Move restoring LOOKUP_PARENT and zeroing nd->stack.name[0] past the call of get_link() (nothing _currently_ uses them in there). That allows to moved the call of may_follow_link() into get_link() as well, since now the presence of LOOKUP_PARENT distinguishes the callers from each other (link_path_walk() has it, trailing_symlink() doesn't). Preparations for folding trailing_symlink() into callers (lookup_last() and do_last()) and changing the calling conventions of those. Next stage after that will have get_link() call migrate into walk_component(), then - into step_into(). It's tricky enough to warrant doing that in stages, unfortunately... Signed-off-by: Al Viro --- fs/namei.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index db55de1b580b..cd91fc970830 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1115,6 +1115,12 @@ const char *get_link(struct nameidata *nd) int error; const char *res; + if (!(nd->flags & LOOKUP_PARENT)) { + error = may_follow_link(nd); + if (unlikely(error)) + return ERR_PTR(error); + } + if (unlikely(nd->flags & LOOKUP_NO_SYMLINKS)) return ERR_PTR(-ELOOP); @@ -2329,13 +2335,9 @@ static const char *path_init(struct nameidata *nd, unsigned flags) static const char *trailing_symlink(struct nameidata *nd) { - const char *s; - int error = may_follow_link(nd); - if (unlikely(error)) - return ERR_PTR(error); + const char *s = get_link(nd); nd->flags |= LOOKUP_PARENT; nd->stack[0].name = NULL; - s = get_link(nd); return s ? s : ""; }