From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758485Ab2IGWcl (ORCPT ); Fri, 7 Sep 2012 18:32:41 -0400 Received: from mx2.netapp.com ([216.240.18.37]:29443 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757683Ab2IGWcj (ORCPT ); Fri, 7 Sep 2012 18:32:39 -0400 X-IronPort-AV: E=Sophos;i="4.80,388,1344236400"; d="scan'208";a="687036367" From: "Myklebust, Trond" To: Jeff Layton CC: Stanislav Kinsbursky , "bfields@fieldses.org" , "linux-nfs@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devel@openvz.org" Subject: Re: [PATCH v2] SUNRPC: check current nsproxy before set of node name on client creation Thread-Topic: [PATCH v2] SUNRPC: check current nsproxy before set of node name on client creation Thread-Index: AQHNeUylwnVjh2tbW02Id+IcJKD75ZeAFAKA Date: Fri, 7 Sep 2012 22:32:16 +0000 Message-ID: <4FA345DA4F4AE44899BD2B03EEEC2FA908F90888@SACEXCMBX04-PRD.hq.netapp.com> References: <20120813113731.9629.31906.stgit@localhost.localdomain> <20120813081054.0ee39037@corrin.poochiereds.net> In-Reply-To: <20120813081054.0ee39037@corrin.poochiereds.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.104.60.116] Content-Type: text/plain; charset="utf-8" Content-ID: <72A991EA8A7E2848989859B8CB96B816@tahoe.netapp.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id q87MWmKh009795 On Mon, 2012-08-13 at 08:10 -0400, Jeff Layton wrote: > On Mon, 13 Aug 2012 15:37:31 +0400 > Stanislav Kinsbursky wrote: > > > v2: > > 1) rpc_clnt_set_nodename() prototype updated. > > 2) fixed errors in comment. > > > > When child reaper exits, it can destroy mount namespace it belongs to, and if > > there are NFS mounts inside, then it will try to umount them. But in this > > point current->nsproxy is set to NULL and all namespaces will be destroyed one > > by one. I.e. we can't dereference current->nsproxy to obtain uts namespace. > > > > Signed-off-by: Stanislav Kinsbursky > > --- > > net/sunrpc/clnt.c | 16 +++++++++++++--- > > 1 files changed, 13 insertions(+), 3 deletions(-) > > > > diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c > > index 9a9676e..8fbcbc8 100644 > > --- a/net/sunrpc/clnt.c > > +++ b/net/sunrpc/clnt.c > > @@ -277,8 +277,18 @@ void rpc_clients_notifier_unregister(void) > > return rpc_pipefs_notifier_unregister(&rpc_clients_block); > > } > > > > -static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename) > > +static void rpc_clnt_set_nodename(struct rpc_clnt *clnt) > > { > > + const char *nodename; > > + > > + /* > > + * We have to protect against dying child reaper, which has released > > + * its nsproxy already and is trying to destroy mount namespace. > > + */ > > + if (current->nsproxy == NULL) > > + return; > > + > > + nodename = utsname()->nodename; > > clnt->cl_nodelen = strlen(nodename); > > if (clnt->cl_nodelen > UNX_MAXNODENAME) > > clnt->cl_nodelen = UNX_MAXNODENAME; > > @@ -365,7 +375,7 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, stru > > } > > > > /* save the nodename */ > > - rpc_clnt_set_nodename(clnt, utsname()->nodename); > > + rpc_clnt_set_nodename(clnt); > > rpc_register_client(clnt); > > return clnt; > > > > @@ -524,7 +534,7 @@ rpc_clone_client(struct rpc_clnt *clnt) > > err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name); > > if (err != 0) > > goto out_no_path; > > - rpc_clnt_set_nodename(new, utsname()->nodename); > > + rpc_clnt_set_nodename(new); > > if (new->cl_auth) > > atomic_inc(&new->cl_auth->au_count); > > atomic_inc(&clnt->cl_count); > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Acked-by: Jeff Layton OK, colour me confused (again). Why should a umount trigger an rpc_create() or rpc_clone_client()? -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@netapp.com www.netapp.com {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I