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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--
Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
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