From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:25064 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751700Ab2HMMLF (ORCPT ); Mon, 13 Aug 2012 08:11:05 -0400 Date: Mon, 13 Aug 2012 08:10:54 -0400 From: Jeff Layton To: Stanislav Kinsbursky Cc: Trond.Myklebust@netapp.com, 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 Message-ID: <20120813081054.0ee39037@corrin.poochiereds.net> In-Reply-To: <20120813113731.9629.31906.stgit@localhost.localdomain> References: <20120813113731.9629.31906.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: 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