NFS: add a sysfs link to the lockd rpc_client

After lockd is started, add a symlink for lockd's rpc_client under
NFS' superblock sysfs.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/lockd/clntlock.c

@@ -93,6 +93,12 @@ void nlmclnt_prepare_block(struct nlm_wait *block, struct nlm_host *host, struct
 	block->b_status = nlm_lck_blocked;
 }
 
+struct rpc_clnt *nlmclnt_rpc_clnt(struct nlm_host *host)
+{
+	return host->h_rpcclnt;
+}
+EXPORT_SYMBOL_GPL(nlmclnt_rpc_clnt);
+
 /*
  * Queue up a lock for blocking so that the GRANTED request can see it
  */

fs/nfs/client.c

@@ -599,6 +599,7 @@ static int nfs_start_lockd(struct nfs_server *server)
 
 	server->nlm_host = host;
 	server->destroy = nfs_destroy_server;
+	nfs_sysfs_link_rpc_client(server, nlmclnt_rpc_clnt(host), NULL);
 	return 0;
 }
 

include/linux/lockd/bind.h

@@ -20,6 +20,7 @@
 /* Dummy declarations */
 struct svc_rqst;
 struct rpc_task;
+struct rpc_clnt;
 
 /*
  * This is the set of functions for lockd->nfsd communication
@@ -56,6 +57,7 @@ struct nlmclnt_initdata {
 
 extern struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init);
 extern void	nlmclnt_done(struct nlm_host *host);
+extern struct rpc_clnt *nlmclnt_rpc_clnt(struct nlm_host *host);
 
 /*
  * NLM client operations provide a means to modify RPC processing of NLM