[PATCH 1/1] NFSD: don't start nfsd if sv_permsocks is empty

[Olga Kornievskaia <okorniev@redhat.com>]

Previously, while trying to create a server instance, if no
listening sockets were present then default parameter udp
and tcp listeners were created. It's unclear what purpose
was of starting these listeners were and how this could have
been triggered by the userland setup. This patch proposed
to ensure the reverse that we never end in a situation where
no listener sockets are created and we are trying to create
nfsd threads.

The problem it solves is: when nfs.conf only has tcp=n (and
nothing else for the choice of transports), nfsdctl would
still start the server and create udp and tcp listeners.

Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
---
 fs/nfsd/nfssvc.c | 28 +++++-----------------------
 1 file changed, 5 insertions(+), 23 deletions(-)

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 7057ddd7a0a8..40592b61b04b 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -249,27 +249,6 @@ int nfsd_nrthreads(struct net *net)
 	return rv;
 }
 
-static int nfsd_init_socks(struct net *net, const struct cred *cred)
-{
-	int error;
-	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
-
-	if (!list_empty(&nn->nfsd_serv->sv_permsocks))
-		return 0;
-
-	error = svc_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
-				SVC_SOCK_DEFAULTS, cred);
-	if (error < 0)
-		return error;
-
-	error = svc_xprt_create(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
-				SVC_SOCK_DEFAULTS, cred);
-	if (error < 0)
-		return error;
-
-	return 0;
-}
-
 static int nfsd_users = 0;
 
 static int nfsd_startup_generic(void)
@@ -377,9 +356,12 @@ static int nfsd_startup_net(struct net *net, const struct cred *cred)
 	ret = nfsd_startup_generic();
 	if (ret)
 		return ret;
-	ret = nfsd_init_socks(net, cred);
-	if (ret)
+
+	if (list_empty(&nn->nfsd_serv->sv_permsocks)) {
+		pr_warn("NFSD: not starting because no listening sockets found\n");
+		ret = -EIO;
 		goto out_socks;
+	}
 
 	if (nfsd_needs_lockd(nn) && !nn->lockd_up) {
 		ret = lockd_up(net, cred);
-- 
2.47.3