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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF5D3C3F2D1 for ; Sun, 1 Mar 2020 21:53:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D031246B4 for ; Sun, 1 Mar 2020 21:53:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727497AbgCAVxm (ORCPT ); Sun, 1 Mar 2020 16:53:42 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:41714 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727173AbgCAVwt (ORCPT ); Sun, 1 Mar 2020 16:52:49 -0500 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j8WVz-003fPz-Ew; Sun, 01 Mar 2020 21:52:47 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Linus Torvalds Subject: [RFC][PATCH v3 44/55] move put_link() into handle_dots() Date: Sun, 1 Mar 2020 21:52:29 +0000 Message-Id: <20200301215240.873899-44-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200301215240.873899-1-viro@ZenIV.linux.org.uk> References: <20200301215125.GA873525@ZenIV.linux.org.uk> <20200301215240.873899-1-viro@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro That closes a harmless irregularity in do_last() - if trailing symlink ends with . or .. we forget to drop it. Not a problem, since nameidata is about to be done with anyway, but let's keep it more regular. Signed-off-by: Al Viro --- fs/namei.c | 76 +++++++++++++++++++++++++++++++------------------------------- 1 file changed, 38 insertions(+), 38 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index be756aa32240..3f15b18af991 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1654,40 +1654,6 @@ static inline int may_lookup(struct nameidata *nd) return inode_permission(nd->inode, MAY_EXEC); } -static inline int handle_dots(struct nameidata *nd, int type) -{ - if (type == LAST_DOTDOT) { - int error = 0; - - if (!nd->root.mnt) { - error = set_root(nd); - if (error) - return error; - } - if (nd->flags & LOOKUP_RCU) - error = follow_dotdot_rcu(nd); - else - error = follow_dotdot(nd); - if (error) - return error; - - if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) { - /* - * If there was a racing rename or mount along our - * path, then we can't be sure that ".." hasn't jumped - * above nd->root (and so userspace should retry or use - * some fallback). - */ - smp_rmb(); - if (unlikely(__read_seqcount_retry(&mount_lock.seqcount, nd->m_seq))) - return -EAGAIN; - if (unlikely(__read_seqcount_retry(&rename_lock.seqcount, nd->r_seq))) - return -EAGAIN; - } - } - return 0; -} - enum {WALK_TRAILING = 1, WALK_MORE = 2, WALK_NOFOLLOW = 4}; static const char *pick_link(struct nameidata *nd, struct path *link, @@ -1819,6 +1785,42 @@ static const char *step_into(struct nameidata *nd, int flags, return pick_link(nd, &path, inode, seq, flags); } +static int handle_dots(struct nameidata *nd, int type, int flags) +{ + if (type == LAST_DOTDOT) { + int error = 0; + + if (!nd->root.mnt) { + error = set_root(nd); + if (error) + return error; + } + if (nd->flags & LOOKUP_RCU) + error = follow_dotdot_rcu(nd); + else + error = follow_dotdot(nd); + if (error) + return error; + + if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) { + /* + * If there was a racing rename or mount along our + * path, then we can't be sure that ".." hasn't jumped + * above nd->root (and so userspace should retry or use + * some fallback). + */ + smp_rmb(); + if (unlikely(__read_seqcount_retry(&mount_lock.seqcount, nd->m_seq))) + return -EAGAIN; + if (unlikely(__read_seqcount_retry(&rename_lock.seqcount, nd->r_seq))) + return -EAGAIN; + } + } + if (!(flags & WALK_MORE) && nd->depth) + put_link(nd); + return 0; +} + static const char *walk_component(struct nameidata *nd, int flags) { struct dentry *dentry; @@ -1831,9 +1833,7 @@ static const char *walk_component(struct nameidata *nd, int flags) * parent relationships. */ if (unlikely(nd->last_type != LAST_NORM)) { - err = handle_dots(nd, nd->last_type); - if (!(flags & WALK_MORE) && nd->depth) - put_link(nd); + err = handle_dots(nd, nd->last_type, flags); return ERR_PTR(err); } dentry = lookup_fast(nd, &inode, &seq); @@ -3142,7 +3142,7 @@ static const char *open_last_lookups(struct nameidata *nd, nd->flags |= op->intent; if (nd->last_type != LAST_NORM) { - error = handle_dots(nd, nd->last_type); + error = handle_dots(nd, nd->last_type, WALK_TRAILING); if (likely(!error)) error = complete_walk(nd); return ERR_PTR(error); -- 2.11.0