1 files changed, 53 insertions, 36 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index d716c9993a26..5e6877c37f73 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * linux/fs/lockd/host.c
  *
@@ -59,6 +60,7 @@ struct nlm_lookup_host_info {
 	const size_t		hostname_len;	/* it's length */
 	const int		noresvport;	/* use non-priv port */
 	struct net		*net;		/* network namespace to bind */
+	const struct cred	*cred;
 };
 
 /*
@@ -113,9 +115,8 @@ static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
 	unsigned long now = jiffies;
 
 	if (nsm != NULL)
-		atomic_inc(&nsm->sm_count);
+		refcount_inc(&nsm->sm_count);
 	else {
-		host = NULL;
 		nsm = nsm_get_handle(ni->net, ni->sap, ni->salen,
 					ni->hostname, ni->hostname_len);
 		if (unlikely(nsm == NULL)) {
@@ -150,7 +151,7 @@ static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
 	host->h_state      = 0;
 	host->h_nsmstate   = 0;
 	host->h_pidcount   = 0;
-	atomic_set(&host->h_count, 1);
+	refcount_set(&host->h_count, 1);
 	mutex_init(&host->h_mutex);
 	host->h_nextrebind = now + NLM_HOST_REBIND;
 	host->h_expires    = now + NLM_HOST_EXPIRE;
@@ -161,7 +162,8 @@ static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
 	host->h_nsmhandle  = nsm;
 	host->h_addrbuf    = nsm->sm_addrbuf;
 	host->net	   = ni->net;
-	strlcpy(host->nodename, utsname()->nodename, sizeof(host->nodename));
+	host->h_cred	   = get_cred(ni->cred);
+	strscpy(host->nodename, utsname()->nodename, sizeof(host->nodename));
 
 out:
 	return host;
@@ -187,6 +189,7 @@ static void nlm_destroy_host_locked(struct nlm_host *host)
 	clnt = host->h_rpcclnt;
 	if (clnt != NULL)
 		rpc_shutdown_client(clnt);
+	put_cred(host->h_cred);
 	kfree(host);
 
 	ln->nrhosts--;
@@ -201,6 +204,8 @@ static void nlm_destroy_host_locked(struct nlm_host *host)
  * @version: NLM protocol version
  * @hostname: '\0'-terminated hostname of server
  * @noresvport: 1 if non-privileged port should be used
+ * @net: pointer to net namespace
+ * @cred: pointer to cred
  *
  * Returns an nlm_host structure that matches the passed-in
  * [server address, transport protocol, NLM version, server hostname].
@@ -213,7 +218,8 @@ struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
 				     const u32 version,
 				     const char *hostname,
 				     int noresvport,
-				     struct net *net)
+				     struct net *net,
+				     const struct cred *cred)
 {
 	struct nlm_lookup_host_info ni = {
 		.server		= 0,
@@ -225,6 +231,7 @@ struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
 		.hostname_len	= strlen(hostname),
 		.noresvport	= noresvport,
 		.net		= net,
+		.cred		= cred,
 	};
 	struct hlist_head *chain;
 	struct nlm_host	*host;
@@ -289,12 +296,11 @@ void nlmclnt_release_host(struct nlm_host *host)
 
 	WARN_ON_ONCE(host->h_server);
 
-	if (atomic_dec_and_test(&host->h_count)) {
+	if (refcount_dec_and_mutex_lock(&host->h_count, &nlm_host_mutex)) {
 		WARN_ON_ONCE(!list_empty(&host->h_lockowners));
 		WARN_ON_ONCE(!list_empty(&host->h_granted));
 		WARN_ON_ONCE(!list_empty(&host->h_reclaim));
 
-		mutex_lock(&nlm_host_mutex);
 		nlm_destroy_host_locked(host);
 		mutex_unlock(&nlm_host_mutex);
 	}
@@ -340,7 +346,7 @@ struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 	};
 	struct lockd_net *ln = net_generic(net, lockd_net_id);
 
-	dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
+	dprintk("lockd: %s(host='%.*s', vers=%u, proto=%s)\n", __func__,
 			(int)hostname_len, hostname, rqstp->rq_vers,
 			(rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
 
@@ -387,6 +393,8 @@ struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 	ln->nrhosts++;
 	nrhosts++;
 
+	refcount_inc(&host->h_count);
+
 	dprintk("lockd: %s created host %s (%s)\n",
 		__func__, host->h_name, host->h_addrbuf);
 
@@ -409,7 +417,7 @@ void nlmsvc_release_host(struct nlm_host *host)
 	dprintk("lockd: release server host %s\n", host->h_name);
 
 	WARN_ON_ONCE(!host->h_server);
-	atomic_dec(&host->h_count);
+	refcount_dec(&host->h_count);
 }
 
 /*
@@ -430,14 +438,9 @@ nlm_bind_host(struct nlm_host *host)
 	 * RPC rebind is required
 	 */
 	if ((clnt = host->h_rpcclnt) != NULL) {
-		if (time_after_eq(jiffies, host->h_nextrebind)) {
-			rpc_force_rebind(clnt);
-			host->h_nextrebind = jiffies + NLM_HOST_REBIND;
-			dprintk("lockd: next rebind in %lu jiffies\n",
-					host->h_nextrebind - jiffies);
-		}
+		nlm_rebind_host(host);
 	} else {
-		unsigned long increment = nlmsvc_timeout;
+		unsigned long increment = nlm_timeout * HZ;
 		struct rpc_timeout timeparms = {
 			.to_initval	= increment,
 			.to_increment	= increment,
@@ -455,7 +458,9 @@ nlm_bind_host(struct nlm_host *host)
 			.version	= host->h_version,
 			.authflavor	= RPC_AUTH_UNIX,
 			.flags		= (RPC_CLNT_CREATE_NOPING |
-					   RPC_CLNT_CREATE_AUTOBIND),
+					   RPC_CLNT_CREATE_AUTOBIND |
+					   RPC_CLNT_CREATE_REUSEPORT),
+			.cred		= host->h_cred,
 		};
 
 		/*
@@ -483,13 +488,20 @@ nlm_bind_host(struct nlm_host *host)
 	return clnt;
 }
 
-/*
- * Force a portmap lookup of the remote lockd port
+/**
+ * nlm_rebind_host - If needed, force a portmap lookup of the peer's lockd port
+ * @host: NLM host handle for peer
+ *
+ * This is not needed when using a connection-oriented protocol, such as TCP.
+ * The existing autobind mechanism is sufficient to force a rebind when
+ * required, e.g. on connection state transitions.
  */
 void
 nlm_rebind_host(struct nlm_host *host)
 {
-	dprintk("lockd: rebind host %s\n", host->h_name);
+	if (host->h_proto != IPPROTO_UDP)
+		return;
+
 	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
 		rpc_force_rebind(host->h_rpcclnt);
 		host->h_nextrebind = jiffies + NLM_HOST_REBIND;
@@ -503,7 +515,7 @@ struct nlm_host * nlm_get_host(struct nlm_host *host)
 {
 	if (host) {
 		dprintk("lockd: get host %s\n", host->h_name);
-		atomic_inc(&host->h_count);
+		refcount_inc(&host->h_count);
 		host->h_expires = jiffies + NLM_HOST_EXPIRE;
 	}
 	return host;
@@ -577,8 +589,10 @@ static void nlm_complain_hosts(struct net *net)
 
 		if (ln->nrhosts == 0)
 			return;
-		printk(KERN_WARNING "lockd: couldn't shutdown host module for net %p!\n", net);
-		dprintk("lockd: %lu hosts left in net %p:\n", ln->nrhosts, net);
+		pr_warn("lockd: couldn't shutdown host module for net %x!\n",
+			net->ns.inum);
+		dprintk("lockd: %lu hosts left in net %x:\n", ln->nrhosts,
+			net->ns.inum);
 	} else {
 		if (nrhosts == 0)
 			return;
@@ -589,9 +603,9 @@ static void nlm_complain_hosts(struct net *net)
 	for_each_host(host, chain, nlm_server_hosts) {
 		if (net && host->net != net)
 			continue;
-		dprintk("       %s (cnt %d use %d exp %ld net %p)\n",
-			host->h_name, atomic_read(&host->h_count),
-			host->h_inuse, host->h_expires, host->net);
+		dprintk("       %s (cnt %d use %d exp %ld net %x)\n",
+			host->h_name, refcount_read(&host->h_count),
+			host->h_inuse, host->h_expires, host->net->ns.inum);
 	}
 }
 
@@ -604,7 +618,8 @@ nlm_shutdown_hosts_net(struct net *net)
 	mutex_lock(&nlm_host_mutex);
 
 	/* First, make all hosts eligible for gc */
-	dprintk("lockd: nuking all hosts in net %p...\n", net);
+	dprintk("lockd: nuking all hosts in net %x...\n",
+		net ? net->ns.inum : 0);
 	for_each_host(host, chain, nlm_server_hosts) {
 		if (net && host->net != net)
 			continue;
@@ -613,13 +628,13 @@ nlm_shutdown_hosts_net(struct net *net)
 			rpc_shutdown_client(host->h_rpcclnt);
 			host->h_rpcclnt = NULL;
 		}
+		nlmsvc_free_host_resources(host);
 	}
 
 	/* Then, perform a garbage collection pass */
 	nlm_gc_hosts(net);
-	mutex_unlock(&nlm_host_mutex);
-
 	nlm_complain_hosts(net);
+	mutex_unlock(&nlm_host_mutex);
 }
 
 /*
@@ -645,7 +660,8 @@ nlm_gc_hosts(struct net *net)
 	struct hlist_node *next;
 	struct nlm_host	*host;
 
-	dprintk("lockd: host garbage collection for net %p\n", net);
+	dprintk("lockd: host garbage collection for net %x\n",
+		net ? net->ns.inum : 0);
 	for_each_host(host, chain, nlm_server_hosts) {
 		if (net && host->net != net)
 			continue;
@@ -658,15 +674,16 @@ nlm_gc_hosts(struct net *net)
 	for_each_host_safe(host, next, chain, nlm_server_hosts) {
 		if (net && host->net != net)
 			continue;
-		if (atomic_read(&host->h_count) || host->h_inuse
-		 || time_before(jiffies, host->h_expires)) {
+		if (host->h_inuse || time_before(jiffies, host->h_expires)) {
 			dprintk("nlm_gc_hosts skipping %s "
-				"(cnt %d use %d exp %ld net %p)\n",
-				host->h_name, atomic_read(&host->h_count),
-				host->h_inuse, host->h_expires, host->net);
+				"(cnt %d use %d exp %ld net %x)\n",
+				host->h_name, refcount_read(&host->h_count),
+				host->h_inuse, host->h_expires,
+				host->net->ns.inum);
 			continue;
 		}
-		nlm_destroy_host_locked(host);
+		if (refcount_dec_if_one(&host->h_count))
+			nlm_destroy_host_locked(host);
 	}
 
 	if (net) {