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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 8675FC11F66 for ; Mon, 12 Jul 2021 14:03:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64E0E610E6 for ; Mon, 12 Jul 2021 14:03:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231734AbhGLOFz (ORCPT ); Mon, 12 Jul 2021 10:05:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:41632 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230181AbhGLOFy (ORCPT ); Mon, 12 Jul 2021 10:05:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626098586; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=6QZTkpToWndbC/JY1O8MzhhwkItgB1oCt3LUvlhk+js=; b=NbB31piU9rOSePeduFeIQGvFXqcotfXDHwagXe2Icf4/S4MDF7/vBs7cIbSYnmmys1aFUg 5B9loNMyP/jlUMxyO/OjZknhYg0S52Nu+mqp2OkBbnJ+eDcClVeS01Y65s1ZLB4zIk0N9p uMuTC9OxIPp/9SEVNDma3JRSA1C65j4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-18-9z529XwbMaij_RCHZvvi3A-1; Mon, 12 Jul 2021 10:03:02 -0400 X-MC-Unique: 9z529XwbMaij_RCHZvvi3A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 99D93101F7C4; Mon, 12 Jul 2021 14:03:00 +0000 (UTC) Received: from horse.redhat.com (ovpn-114-176.rdu2.redhat.com [10.10.114.176]) by smtp.corp.redhat.com (Postfix) with ESMTP id C6C005DF56; Mon, 12 Jul 2021 14:02:47 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 5751522054F; Mon, 12 Jul 2021 10:02:47 -0400 (EDT) Date: Mon, 12 Jul 2021 10:02:47 -0400 From: Vivek Goyal To: Bruce Fields Cc: Casey Schaufler , Christian Brauner , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, virtio-fs@redhat.com, dwalsh@redhat.com, dgilbert@redhat.com, casey.schaufler@intel.com, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, tytso@mit.edu, miklos@szeredi.hu, gscrivan@redhat.com, jack@suse.cz, Christoph Hellwig Subject: Re: [PATCH v2 1/1] xattr: Allow user.* xattr on symlink and special files Message-ID: <20210712140247.GA486376@redhat.com> References: <20210708175738.360757-1-vgoyal@redhat.com> <20210708175738.360757-2-vgoyal@redhat.com> <20210709091915.2bd4snyfjndexw2b@wittgenstein> <20210709152737.GA398382@redhat.com> <710d1c6f-d477-384f-0cc1-8914258f1fb1@schaufler-ca.com> <20210709175947.GB398382@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Jul 09, 2021 at 04:10:16PM -0400, Bruce Fields wrote: > On Fri, Jul 9, 2021 at 1:59 PM Vivek Goyal wrote: > > nfs seems to have some issues. > > I'm not sure what the expected behavior is for nfs. All I have for > now is some generic troubleshooting ideas, sorry: > > > - I can set user.foo xattr on symlink and query it back using xattr name. > > > > getfattr -h -n user.foo foo-link.txt > > > > But when I try to dump all xattrs on this file, user.foo is being > > filtered out it looks like. Not sure why. > > Logging into the server and seeing what's set there could help confirm > whether it's the client or server that's at fault. (Or watching the > traffic in wireshark; there are GET/SET/LISTXATTR ops that should be > easy to spot.) > > > - I can't set "user.foo" xattr on a device node on nfs and I get > > "Permission denied". I am assuming nfs server is returning this. > > Wireshark should tell you whether it's the server or client doing that. > > The RFC is https://datatracker.ietf.org/doc/html/rfc8276, and I don't > see any explicit statement about what the server should do in the case > of symlinks or device nodes, but I do see "Any regular file or > directory may have a set of extended attributes", so that was clearly > the assumption. Also, NFS4ERR_WRONG_TYPE is listed as a possible > error return for the xattr ops. But on a quick skim I don't see any > explicit checks in the nfsd code, so I *think* it's just relying on > the vfs for any file type checks. Hi Bruce, Thanks for the response. I am just trying to do set a user.foo xattr on a device node on nfs. setfattr -n "user.foo" -v "bar" /mnt/nfs/test-dev and I get -EACCESS. I put some printk() statements and EACCESS is being returned from here. nfs4_xattr_set_nfs4_user() { if (!nfs_access_get_cached(inode, current_cred(), &cache, true)) { if (!(cache.mask & NFS_ACCESS_XAWRITE)) { return -EACCES; } } } Value of cache.mask=0xd at the time of error. Thanks Vivek