Re: [PATCH] SUNRPC: check current nsproxy before set of node nameon client creation

[Stanislav Kinsbursky]

Thanks, Jeff. Will fix.

13.08.2012 15:35, Jeff Layton ÐÐÑÐÑ:
> On Mon, 13 Aug 2012 15:21:56 +0400
> Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx> wrote:
>
> > When child reaper exits, it can destroy mount namespace it belong 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 <skinsbursky@xxxxxxxxxxxxx>
> > ---
> >   net/sunrpc/clnt.c |   14 ++++++++++++--
> >   1 files changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> > index 9a9676e..28ac940 100644
> > --- a/net/sunrpc/clnt.c
> > +++ b/net/sunrpc/clnt.c
> > @@ -279,6 +279,16 @@ void rpc_clients_notifier_unregister(void)
> >
> >   static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
>
> Don't you need to change the prototype of the function here too?
>
> >   {
> > +	const char *nodename;
> > +
> > +	/*
> > +	 * We have to protect against dying chilp reaper, which has released
>
> 	nit: "dying child reaper" ?
>
> > +	 * it's nsproxy already and is trying to destroy mount namespace.
>
> 	nit: "its"
>
> > +	 */
> > +	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);
> >
> > --
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--
Best regards,
Stanislav Kinsbursky
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