From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=/F/O=KD=vger.kernel.org=linux-kernel-owner@kernel.org>
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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 D6414ECDFB8
	for <linux-kernel@archiver.kernel.org>; Thu, 19 Jul 2018 21:45:27 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id 3988B2084C
	for <linux-kernel@archiver.kernel.org>; Thu, 19 Jul 2018 21:45:27 +0000 (UTC)
DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3988B2084C
Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ZenIV.linux.org.uk
Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1730776AbeGSWaY (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Thu, 19 Jul 2018 18:30:24 -0400
Received: from zeniv.linux.org.uk ([195.92.253.2]:44846 "EHLO
        ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1727721AbeGSWaY (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Thu, 19 Jul 2018 18:30:24 -0400
Received: from viro by ZenIV.linux.org.uk with local (Exim 4.87 #1 (Red Hat Linux))
        id 1fgGjg-00068r-1e; Thu, 19 Jul 2018 21:45:20 +0000
Date:   Thu, 19 Jul 2018 22:45:20 +0100
From:   Al Viro <viro@ZenIV.linux.org.uk>
To:     Miklos Szeredi <miklos@szeredi.hu>
Cc:     Miklos Szeredi <mszeredi@redhat.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 (v4.18 regression fix)] vfs: don't evict uninitialized
 inode
Message-ID: <20180719214519.GA23379@ZenIV.linux.org.uk>
References: <20180706204521.29654-1-mszeredi@redhat.com>
 <CAJfpeguFaaE8i+fAg3HhQm6MPcFzMciY3WLfQUPdnY4xnmC7kg@mail.gmail.com>
 <20180718121833.GR30522@ZenIV.linux.org.uk>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20180718121833.GR30522@ZenIV.linux.org.uk>
User-Agent: Mutt/1.9.1 (2017-09-22)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, Jul 18, 2018 at 01:18:33PM +0100, Al Viro wrote:

> BTW, why have you left generic_readlink() sitting around?  AFAICS,
> it could've been folded into the only remaining caller just as
> you've made it static in late 2016...  I'll fold it in;
> just curious what was the reason for not doing that back then...

BTW^2:
const char *vfs_get_link(struct dentry *dentry, struct delayed_call *done)
{
        const char *res = ERR_PTR(-EINVAL);
        struct inode *inode = d_inode(dentry);

        if (d_is_symlink(dentry)) {
                res = ERR_PTR(security_inode_readlink(dentry));
                if (!res)
                        res = inode->i_op->get_link(dentry, inode, done);
        }
        return res;
}
hits a method call that is not needed in the majority of cases.  Is there
any subtle reason why it shouldn't be

const char *vfs_get_link(struct dentry *dentry, struct delayed_call *done)
{
        const char *res = ERR_PTR(-EINVAL);
        struct inode *inode = d_inode(dentry);

        if (d_is_symlink(dentry)) {
                res = ERR_PTR(security_inode_readlink(dentry));
                if (!res)
			res = inode->i_link;
		if (!res)
                        res = inode->i_op->get_link(dentry, inode, done);
        }
        return res;
}
instead?