Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759921Ab3GSINS (ORCPT ); Fri, 19 Jul 2013 04:13:18 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:54008 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759433Ab3GSIND (ORCPT ); Fri, 19 Jul 2013 04:13:03 -0400 Date: Fri, 19 Jul 2013 09:12:58 +0100 From: Al Viro To: Andreas Dilger Cc: Nathan Rutman , Peng Tao , "Dilger, Andreas" , Linux Kernel Mailing List , "linux-fsdevel@vger.kernel.org" Subject: Re: [lustre mess] is mgc_fs_setup() reachable at all? Message-ID: <20130719081258.GE4165@ZenIV.linux.org.uk> References: <20130718090835.GZ4165@ZenIV.linux.org.uk> <5DD1CAAA-2008-47F9-B3B6-8D342B28D08C@xyratex.com> <20130718190703.GB4165@ZenIV.linux.org.uk> <3F4C226D-9D3B-46FA-9C8C-55268B2F904F@dilger.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3F4C226D-9D3B-46FA-9C8C-55268B2F904F@dilger.ca> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1820 Lines: 37 On Thu, Jul 18, 2013 at 02:57:11PM -0600, Andreas Dilger wrote: > > _THAT_ was going to be a remotely supplied data? I really hope I've > > misparsed what you said above... > > > > And that still leaves the question about the code path that could > > lead to execution of mgc_fs_setup(). > > The KEY_SET_FS is only used in the server code, not on the client. > The MGC code is shared between client and server to mount the > filesystem and fetch the cluster configuration from the management > server. In the case of a server mount, it also has to mount the > underlying block device, which isn't true on the client, so this > code is indeed unused. Wait a minute... So we have client side of things in staging, with parts shared with the server, which is *not* in tree at all? That sounds painful - any changes done to the client code either risk to break the server, or have the copies of the shared stuff diverge... I honestly have no idea about your plans wrt merging; are you going to put the server side of things there as well? Another thing: is your ll_statfs_internal() safe to call right up to the moment when client_common_put_super calls lprocfs_unregister_mountpoint? Because procfs IO *can* come right until the procfs entry removal; said removal will act as a barrier, so it won't leak past the return from remove_proc_entry(), but that's it. While we are at procfs side of thing, looks like you need exclusion between ll_..._seq_write() that clear/set bits in ->ll_flags; at least I haven't found anything that would prevent the races among those. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/