nfsd: Fix nfsd leaks sunrpc module references

Stefan Hajnoczi reports,
nfsd leaks 3 references to the sunrpc module here:

  # echo -n "asdf 1234" >/proc/fs/nfsd/portlist
  bash: echo: write error: Protocol not supported

Now stop nfsd and try unloading the kernel modules:

  # systemctl stop nfs-server
  # systemctl stop nfs
  # systemctl stop proc-fs-nfsd.mount
  # systemctl stop var-lib-nfs-rpc_pipefs.mount
  # rmmod nfsd
  # rmmod nfs_acl
  # rmmod lockd
  # rmmod auth_rpcgss
  # rmmod sunrpc
  rmmod: ERROR: Module sunrpc is in use
  # lsmod | grep rpc
  sunrpc                315392  3

It is caused by nfsd don't cleanup rpcb program for nfsd
when destroying svc service after creating xprt fail.

Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 3779a5fbeb424dafb6346aec30c5ceb7ec670538..45007acaf364686f58eb5242350e06a9e24e239c 100644 (file)
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -378,14 +378,13 @@ static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
         * write_ports can create the server without actually starting
         * any threads--if we get shut down before any threads are
         * started, then nfsd_last_thread will be run before any of this
-        * other initialization has been done.
+        * other initialization has been done except the rpcb information.
         */
+       svc_rpcb_cleanup(serv, net);
        if (!nn->nfsd_net_up)
                return;
-       nfsd_shutdown_net(net);
-
-       svc_rpcb_cleanup(serv, net);
 
+       nfsd_shutdown_net(net);
        printk(KERN_WARNING "nfsd: last server has exited, flushing export "
                            "cache\n");
        nfsd_export_flush(net);