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, URIBL_BLOCKED,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 B9236C35671 for ; Sun, 23 Feb 2020 01:16:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9786820702 for ; Sun, 23 Feb 2020 01:16:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727185AbgBWBQ5 (ORCPT ); Sat, 22 Feb 2020 20:16:57 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:50084 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727115AbgBWBQ5 (ORCPT ); Sat, 22 Feb 2020 20:16:57 -0500 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j5fst-00HDa1-GJ; Sun, 23 Feb 2020 01:16:42 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Linus Torvalds Subject: [RFC][PATCH v2 03/34] follow_automount(): get rid of dead^Wstillborn code Date: Sun, 23 Feb 2020 01:15:55 +0000 Message-Id: <20200223011626.4103706-3-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200223011626.4103706-1-viro@ZenIV.linux.org.uk> References: <20200223011154.GY23230@ZenIV.linux.org.uk> <20200223011626.4103706-1-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 1) no instances of ->d_automount() have ever made use of the "return ERR_PTR(-EISDIR) if you don't feel like mounting anything" - that's a rudiment of plans that got superseded before the thing went into the tree. Despite the comment in follow_automount(), autofs has never done that. 2) if there's no ->d_automount() in dentry_operations, filesystems should not set DCACHE_NEED_AUTOMOUNT in the first place. None have ever done so... Signed-off-by: Al Viro --- fs/namei.c | 28 +++------------------------- fs/namespace.c | 9 ++++++++- 2 files changed, 11 insertions(+), 26 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 626eddb33508..39dd56f5171f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1210,10 +1210,7 @@ EXPORT_SYMBOL(follow_up); */ static int follow_automount(struct path *path, struct nameidata *nd) { - struct vfsmount *mnt; - - if (!path->dentry->d_op || !path->dentry->d_op->d_automount) - return -EREMOTE; + struct dentry *dentry = path->dentry; /* We don't want to mount if someone's just doing a stat - * unless they're stat'ing a directory and appended a '/' to @@ -1228,33 +1225,14 @@ static int follow_automount(struct path *path, struct nameidata *nd) */ if (!(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY | LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) && - path->dentry->d_inode) + dentry->d_inode) return -EISDIR; nd->total_link_count++; if (nd->total_link_count >= 40) return -ELOOP; - mnt = path->dentry->d_op->d_automount(path); - if (IS_ERR(mnt)) { - /* - * The filesystem is allowed to return -EISDIR here to indicate - * it doesn't want to automount. For instance, autofs would do - * this so that its userspace daemon can mount on this dentry. - * - * However, we can only permit this if it's a terminal point in - * the path being looked up; if it wasn't then the remainder of - * the path is inaccessible and we should say so. - */ - if (PTR_ERR(mnt) == -EISDIR && (nd->flags & LOOKUP_PARENT)) - return -EREMOTE; - return PTR_ERR(mnt); - } - - if (!mnt) - return 0; - - return finish_automount(mnt, path); + return finish_automount(dentry->d_op->d_automount(path), path); } /* diff --git a/fs/namespace.c b/fs/namespace.c index 6228fd1ef94f..a9e556224945 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2824,9 +2824,16 @@ static int do_new_mount(struct path *path, const char *fstype, int sb_flags, int finish_automount(struct vfsmount *m, struct path *path) { struct dentry *dentry = path->dentry; - struct mount *mnt = real_mount(m); struct mountpoint *mp; + struct mount *mnt; int err; + + if (!m) + return 0; + if (IS_ERR(m)) + return PTR_ERR(m); + + mnt = real_mount(m); /* The new mount record should have at least 2 refs to prevent it being * expired before we get a chance to add it */ -- 2.11.0