[PATCH v2 10/10] nfsd: Ignore rpcbind errors on nfsd startup

[trondmy@kernel.org]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4 doesn't need rpcbind, so let's not refuse to start up just because
the rpcbind registration failed.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfsd/nfsctl.c               |  7 ++++++-
 fs/nfsd/nfsd.h                 |  1 +
 fs/nfsd/nfssvc.c               | 18 ++++++++++++++++--
 include/linux/sunrpc/svcsock.h |  5 +++--
 net/sunrpc/svcsock.c           | 14 ++++++++------
 5 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 51a49e0cfe37..da9760479acd 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -727,6 +727,7 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred
 	char *mesg = buf;
 	int fd, err;
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int flags = SVC_SOCK_DEFAULTS;
 
 	err = get_int(&mesg, &fd);
 	if (err != 0 || fd < 0)
@@ -741,7 +742,11 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred
 	if (err != 0)
 		return err;
 
-	err = svc_addsock(nn->nfsd_serv, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
+	if (!nfsd_rpcbind_error_is_fatal())
+		flags |= SVC_SOCK_RPCBIND_NOERR;
+
+	err = svc_addsock(nn->nfsd_serv, fd, buf, SIMPLE_TRANSACTION_LIMIT,
+			  flags, cred);
 	if (err < 0) {
 		nfsd_destroy(net);
 		return err;
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 498e5a489826..e0356d3ecf65 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -134,6 +134,7 @@ int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change);
 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change);
 void nfsd_reset_versions(struct nfsd_net *nn);
 int nfsd_create_serv(struct net *net);
+extern bool nfsd_rpcbind_error_is_fatal(void);
 
 extern int nfsd_max_blksize;
 
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 6815c70b06af..6f22c72f340d 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -289,17 +289,21 @@ static int nfsd_init_socks(struct net *net, const struct cred *cred)
 {
 	int error;
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int flags = SVC_SOCK_DEFAULTS;
 
 	if (!list_empty(&nn->nfsd_serv->sv_permsocks))
 		return 0;
 
+	if (!nfsd_rpcbind_error_is_fatal())
+		flags |= SVC_SOCK_RPCBIND_NOERR;
+
 	error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
-					SVC_SOCK_DEFAULTS, cred);
+				flags, cred);
 	if (error < 0)
 		return error;
 
 	error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
-					SVC_SOCK_DEFAULTS, cred);
+				flags, cred);
 	if (error < 0)
 		return error;
 
@@ -340,6 +344,16 @@ static void nfsd_shutdown_generic(void)
 	nfsd_file_cache_shutdown();
 }
 
+static bool nfsd_rpcbind_error_fatal = false;
+module_param(nfsd_rpcbind_error_fatal, bool, 0644);
+MODULE_PARM_DESC(nfsd_rpcbind_error_fatal,
+		 "rpcbind errors are fatal when starting nfsd.");
+
+bool nfsd_rpcbind_error_is_fatal(void)
+{
+	return nfsd_rpcbind_error_fatal;
+}
+
 /*
  * Allow admin to disable lockd. This would typically be used to allow (e.g.)
  * a userspace NLM server of some sort to be used.
diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index bcc555c7ae9c..f34c222cee9d 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -61,8 +61,8 @@ void		svc_drop(struct svc_rqst *);
 void		svc_sock_update_bufs(struct svc_serv *serv);
 bool		svc_alien_sock(struct net *net, int fd);
 int		svc_addsock(struct svc_serv *serv, const int fd,
-					char *name_return, const size_t len,
-					const struct cred *cred);
+			    char *name_return, const size_t len, int flags,
+			    const struct cred *cred);
 void		svc_init_xprt_sock(void);
 void		svc_cleanup_xprt_sock(void);
 struct svc_xprt *svc_sock_create(struct svc_serv *serv, int prot);
@@ -74,5 +74,6 @@ void		svc_sock_destroy(struct svc_xprt *);
 #define SVC_SOCK_DEFAULTS	(0U)
 #define SVC_SOCK_ANONYMOUS	(1U << 0)	/* don't register with pmap */
 #define SVC_SOCK_TEMPORARY	(1U << 1)	/* flag socket as temporary */
+#define SVC_SOCK_RPCBIND_NOERR	(1U << 2)	/* Ignore pmap errors */
 
 #endif /* SUNRPC_SVCSOCK_H */
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 478f857cdaed..7f5b12a50bf9 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1309,14 +1309,15 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
 	inet = sock->sk;
 
 	/* Register socket with portmapper */
-	if (pmap_register)
+	if (pmap_register) {
 		err = svc_register(serv, sock_net(sock->sk), inet->sk_family,
 				     inet->sk_protocol,
 				     ntohs(inet_sk(inet)->inet_sport));
 
-	if (err < 0) {
-		kfree(svsk);
-		return ERR_PTR(err);
+		if (err < 0 && !(flags & SVC_SOCK_RPCBIND_NOERR)) {
+			kfree(svsk);
+			return ERR_PTR(err);
+		}
 	}
 
 	svsk->sk_sock = sock;
@@ -1364,6 +1365,7 @@ EXPORT_SYMBOL_GPL(svc_alien_sock);
  * @fd: file descriptor of the new listener
  * @name_return: pointer to buffer to fill in with name of listener
  * @len: size of the buffer
+ * @flags: flags argument for svc_setup_socket()
  * @cred: credential
  *
  * Fills in socket name and returns positive length of name if successful.
@@ -1371,7 +1373,7 @@ EXPORT_SYMBOL_GPL(svc_alien_sock);
  * value.
  */
 int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
-		const size_t len, const struct cred *cred)
+		const size_t len, int flags, const struct cred *cred)
 {
 	int err = 0;
 	struct socket *so = sockfd_lookup(fd, &err);
@@ -1395,7 +1397,7 @@ int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
 	err = -ENOENT;
 	if (!try_module_get(THIS_MODULE))
 		goto out;
-	svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS);
+	svsk = svc_setup_socket(serv, so, flags);
 	if (IS_ERR(svsk)) {
 		module_put(THIS_MODULE);
 		err = PTR_ERR(svsk);
-- 
2.33.1