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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 3B1C6C11D05 for ; Thu, 20 Feb 2020 11:14:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0DF78207FD for ; Thu, 20 Feb 2020 11:14:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582197291; bh=NGuLTwqRIowTiv67qF2Ws5o1JHHbOVRKWl2IuI/0+lk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=zbeICCh4hPE67gNA/yXTZqzeZO/XgDYesUvOSDnz7qhdAARE1g+wMPiZc0tWMPH94 TW37E0DbkOQeovhLj6Zc1dEMWhB83ATK7nk7UqF8HGiu4hOXuD9gWz+t6I9tf+p6rg JHDK6GdG6qdNLnuRlwS7pWso6EiBAnQ6pgSrvPB4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727298AbgBTLOs (ORCPT ); Thu, 20 Feb 2020 06:14:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:50284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726501AbgBTLOr (ORCPT ); Thu, 20 Feb 2020 06:14:47 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 63D91207FD; Thu, 20 Feb 2020 11:14:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582197285; bh=NGuLTwqRIowTiv67qF2Ws5o1JHHbOVRKWl2IuI/0+lk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Nb5h0Fn91B3r8V7cp16RJOaxvkgOzkcCLXlaqC1G7Zw6dDKaFM1y6nB+KalNjERYH HEQ2ADpe10DqFFwxvjiIbM/mnKhwVmlxfAw6BTywQ5gd5pnAwIx6qZn/PZZMmMxkdR ji3YFBO6gRPS96E42BY1ZfFmn7Hw27gaQXfe4FiI= Date: Thu, 20 Feb 2020 12:14:43 +0100 From: Greg Kroah-Hartman To: Christian Brauner Cc: "David S. Miller" , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, "Rafael J. Wysocki" , Pavel Machek , Jakub Kicinski , Eric Dumazet , Stephen Hemminger , linux-pm@vger.kernel.org Subject: Re: [PATCH net-next v3 2/9] sysfs: add sysfs_link_change_owner() Message-ID: <20200220111443.GD3374196@kroah.com> References: <20200218162943.2488012-1-christian.brauner@ubuntu.com> <20200218162943.2488012-3-christian.brauner@ubuntu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200218162943.2488012-3-christian.brauner@ubuntu.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Feb 18, 2020 at 05:29:36PM +0100, Christian Brauner wrote: > Add a helper to change the owner of a sysfs link. > This function will be used to correctly account for kobject ownership > changes, e.g. when moving network devices between network namespaces. > > Signed-off-by: Christian Brauner > --- > /* v2 */ > - Greg Kroah-Hartman : > - Add comment how ownership of sysfs object is changed. > > /* v3 */ > - Greg Kroah-Hartman : > - Add explicit uid/gid parameters. > --- > fs/sysfs/file.c | 40 ++++++++++++++++++++++++++++++++++++++++ > include/linux/sysfs.h | 10 ++++++++++ > 2 files changed, 50 insertions(+) > > diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c > index 32bb04b4d9d9..df5107d7b3fd 100644 > --- a/fs/sysfs/file.c > +++ b/fs/sysfs/file.c > @@ -570,6 +570,46 @@ static int internal_change_owner(struct kernfs_node *kn, struct kobject *kobj, > return kernfs_setattr(kn, &newattrs); > } > > +/** > + * sysfs_link_change_owner - change owner of a link. > + * @kobj: object of the kernfs_node the symlink is located in. > + * @targ: object of the kernfs_node the symlink points to. > + * @name: name of the link. > + * @kuid: new owner's kuid > + * @kgid: new owner's kgid > + */ > +int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ, > + const char *name, kuid_t kuid, kgid_t kgid) > +{ > + struct kernfs_node *parent, *kn = NULL; > + int error; > + > + if (!kobj) > + parent = sysfs_root_kn; > + else > + parent = kobj->sd; I don't understand this, why would (!kobj) ever be a valid situation? > + if (!targ->state_in_sysfs) > + return -EINVAL; Should you also check kobj->state_in_sysfs as well? thanks, greg k-h