1 files changed, 532 insertions, 199 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 82f7a0b1d8a..969d589c848 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -9,153 +9,408 @@
  */
 
 #include <linux/types.h>
-#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/in.h>
+#include <linux/in6.h>
 #include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/addr.h>
 #include <linux/sunrpc/svc.h>
 #include <linux/lockd/lockd.h>
-#include <linux/lockd/sm_inter.h>
+#include <linux/mutex.h>
 
+#include <linux/sunrpc/svc_xprt.h>
+
+#include <net/ipv6.h>
+
+#include "netns.h"
 
 #define NLMDBG_FACILITY		NLMDBG_HOSTCACHE
-#define NLM_HOST_MAX		64
 #define NLM_HOST_NRHASH		32
-#define NLM_ADDRHASH(addr)	(ntohl(addr) & (NLM_HOST_NRHASH-1))
 #define NLM_HOST_REBIND		(60 * HZ)
-#define NLM_HOST_EXPIRE		((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
-#define NLM_HOST_COLLECT	((nrhosts > NLM_HOST_MAX)? 120 * HZ :  60 * HZ)
-#define NLM_HOST_ADDR(sv)	(&(sv)->s_nlmclnt->cl_xprt->addr)
+#define NLM_HOST_EXPIRE		(300 * HZ)
+#define NLM_HOST_COLLECT	(120 * HZ)
+
+static struct hlist_head	nlm_server_hosts[NLM_HOST_NRHASH];
+static struct hlist_head	nlm_client_hosts[NLM_HOST_NRHASH];
+
+#define for_each_host(host, chain, table) \
+	for ((chain) = (table); \
+	     (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
+		hlist_for_each_entry((host), (chain), h_hash)
+
+#define for_each_host_safe(host, next, chain, table) \
+	for ((chain) = (table); \
+	     (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
+		hlist_for_each_entry_safe((host), (next), \
+						(chain), h_hash)
+
+static unsigned long		nrhosts;
+static DEFINE_MUTEX(nlm_host_mutex);
+
+static void			nlm_gc_hosts(struct net *net);
+
+struct nlm_lookup_host_info {
+	const int		server;		/* search for server|client */
+	const struct sockaddr	*sap;		/* address to search for */
+	const size_t		salen;		/* it's length */
+	const unsigned short	protocol;	/* transport to search for*/
+	const u32		version;	/* NLM version to search for */
+	const char		*hostname;	/* remote's hostname */
+	const size_t		hostname_len;	/* it's length */
+	const int		noresvport;	/* use non-priv port */
+	struct net		*net;		/* network namespace to bind */
+};
 
-static struct nlm_host *	nlm_hosts[NLM_HOST_NRHASH];
-static unsigned long		next_gc;
-static int			nrhosts;
-static DECLARE_MUTEX(nlm_host_sema);
+/*
+ * Hash function must work well on big- and little-endian platforms
+ */
+static unsigned int __nlm_hash32(const __be32 n)
+{
+	unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
+	return hash ^ (hash >> 8);
+}
 
+static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
+{
+	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+	return __nlm_hash32(sin->sin_addr.s_addr);
+}
 
-static void			nlm_gc_hosts(void);
+static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
+{
+	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+	const struct in6_addr addr = sin6->sin6_addr;
+	return __nlm_hash32(addr.s6_addr32[0]) ^
+	       __nlm_hash32(addr.s6_addr32[1]) ^
+	       __nlm_hash32(addr.s6_addr32[2]) ^
+	       __nlm_hash32(addr.s6_addr32[3]);
+}
+
+static unsigned int nlm_hash_address(const struct sockaddr *sap)
+{
+	unsigned int hash;
+
+	switch (sap->sa_family) {
+	case AF_INET:
+		hash = __nlm_hash_addr4(sap);
+		break;
+	case AF_INET6:
+		hash = __nlm_hash_addr6(sap);
+		break;
+	default:
+		hash = 0;
+	}
+	return hash & (NLM_HOST_NRHASH - 1);
+}
 
 /*
- * Find an NLM server handle in the cache. If there is none, create it.
+ * Allocate and initialize an nlm_host.  Common to both client and server.
  */
-struct nlm_host *
-nlmclnt_lookup_host(struct sockaddr_in *sin, int proto, int version)
+static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
+				       struct nsm_handle *nsm)
 {
-	return nlm_lookup_host(0, sin, proto, version);
+	struct nlm_host *host = NULL;
+	unsigned long now = jiffies;
+
+	if (nsm != NULL)
+		atomic_inc(&nsm->sm_count);
+	else {
+		host = NULL;
+		nsm = nsm_get_handle(ni->sap, ni->salen,
+					ni->hostname, ni->hostname_len);
+		if (unlikely(nsm == NULL)) {
+			dprintk("lockd: %s failed; no nsm handle\n",
+				__func__);
+			goto out;
+		}
+	}
+
+	host = kmalloc(sizeof(*host), GFP_KERNEL);
+	if (unlikely(host == NULL)) {
+		dprintk("lockd: %s failed; no memory\n", __func__);
+		nsm_release(nsm);
+		goto out;
+	}
+
+	memcpy(nlm_addr(host), ni->sap, ni->salen);
+	host->h_addrlen    = ni->salen;
+	rpc_set_port(nlm_addr(host), 0);
+	host->h_srcaddrlen = 0;
+
+	host->h_rpcclnt    = NULL;
+	host->h_name	   = nsm->sm_name;
+	host->h_version    = ni->version;
+	host->h_proto      = ni->protocol;
+	host->h_reclaiming = 0;
+	host->h_server     = ni->server;
+	host->h_noresvport = ni->noresvport;
+	host->h_inuse      = 0;
+	init_waitqueue_head(&host->h_gracewait);
+	init_rwsem(&host->h_rwsem);
+	host->h_state      = 0;
+	host->h_nsmstate   = 0;
+	host->h_pidcount   = 0;
+	atomic_set(&host->h_count, 1);
+	mutex_init(&host->h_mutex);
+	host->h_nextrebind = now + NLM_HOST_REBIND;
+	host->h_expires    = now + NLM_HOST_EXPIRE;
+	INIT_LIST_HEAD(&host->h_lockowners);
+	spin_lock_init(&host->h_lock);
+	INIT_LIST_HEAD(&host->h_granted);
+	INIT_LIST_HEAD(&host->h_reclaim);
+	host->h_nsmhandle  = nsm;
+	host->h_addrbuf    = nsm->sm_addrbuf;
+	host->net	   = ni->net;
+
+out:
+	return host;
 }
 
 /*
- * Find an NLM client handle in the cache. If there is none, create it.
+ * Destroy an nlm_host and free associated resources
+ *
+ * Caller must hold nlm_host_mutex.
  */
-struct nlm_host *
-nlmsvc_lookup_host(struct svc_rqst *rqstp)
+static void nlm_destroy_host_locked(struct nlm_host *host)
 {
-	return nlm_lookup_host(1, &rqstp->rq_addr,
-			       rqstp->rq_prot, rqstp->rq_vers);
+	struct rpc_clnt	*clnt;
+	struct lockd_net *ln = net_generic(host->net, lockd_net_id);
+
+	dprintk("lockd: destroy host %s\n", host->h_name);
+
+	hlist_del_init(&host->h_hash);
+
+	nsm_unmonitor(host);
+	nsm_release(host->h_nsmhandle);
+
+	clnt = host->h_rpcclnt;
+	if (clnt != NULL)
+		rpc_shutdown_client(clnt);
+	kfree(host);
+
+	ln->nrhosts--;
+	nrhosts--;
 }
 
-/*
- * Common host lookup routine for server & client
+/**
+ * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
+ * @sap: network address of server
+ * @salen: length of server address
+ * @protocol: transport protocol to use
+ * @version: NLM protocol version
+ * @hostname: '\0'-terminated hostname of server
+ * @noresvport: 1 if non-privileged port should be used
+ *
+ * Returns an nlm_host structure that matches the passed-in
+ * [server address, transport protocol, NLM version, server hostname].
+ * If one doesn't already exist in the host cache, a new handle is
+ * created and returned.
  */
-struct nlm_host *
-nlm_lookup_host(int server, struct sockaddr_in *sin,
-					int proto, int version)
+struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
+				     const size_t salen,
+				     const unsigned short protocol,
+				     const u32 version,
+				     const char *hostname,
+				     int noresvport,
+				     struct net *net)
 {
-	struct nlm_host	*host, **hp;
-	u32		addr;
-	int		hash;
+	struct nlm_lookup_host_info ni = {
+		.server		= 0,
+		.sap		= sap,
+		.salen		= salen,
+		.protocol	= protocol,
+		.version	= version,
+		.hostname	= hostname,
+		.hostname_len	= strlen(hostname),
+		.noresvport	= noresvport,
+		.net		= net,
+	};
+	struct hlist_head *chain;
+	struct nlm_host	*host;
+	struct nsm_handle *nsm = NULL;
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
 
-	dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
-			(unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version);
+	dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
+			(hostname ? hostname : "<none>"), version,
+			(protocol == IPPROTO_UDP ? "udp" : "tcp"));
 
-	hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
+	mutex_lock(&nlm_host_mutex);
 
-	/* Lock hash table */
-	down(&nlm_host_sema);
+	chain = &nlm_client_hosts[nlm_hash_address(sap)];
+	hlist_for_each_entry(host, chain, h_hash) {
+		if (host->net != net)
+			continue;
+		if (!rpc_cmp_addr(nlm_addr(host), sap))
+			continue;
 
-	if (time_after_eq(jiffies, next_gc))
-		nlm_gc_hosts();
+		/* Same address. Share an NSM handle if we already have one */
+		if (nsm == NULL)
+			nsm = host->h_nsmhandle;
 
-	for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
-		if (host->h_proto != proto)
+		if (host->h_proto != protocol)
 			continue;
 		if (host->h_version != version)
 			continue;
-		if (host->h_server != server)
-			continue;
 
-		if (nlm_cmp_addr(&host->h_addr, sin)) {
-			if (hp != nlm_hosts + hash) {
-				*hp = host->h_next;
-				host->h_next = nlm_hosts[hash];
-				nlm_hosts[hash] = host;
-			}
-			nlm_get_host(host);
-			up(&nlm_host_sema);
-			return host;
-		}
+		nlm_get_host(host);
+		dprintk("lockd: %s found host %s (%s)\n", __func__,
+			host->h_name, host->h_addrbuf);
+		goto out;
 	}
 
-	/* Ooops, no host found, create it */
-	dprintk("lockd: creating host entry\n");
+	host = nlm_alloc_host(&ni, nsm);
+	if (unlikely(host == NULL))
+		goto out;
 
-	if (!(host = (struct nlm_host *) kmalloc(sizeof(*host), GFP_KERNEL)))
-		goto nohost;
-	memset(host, 0, sizeof(*host));
+	hlist_add_head(&host->h_hash, chain);
+	ln->nrhosts++;
+	nrhosts++;
 
-	addr = sin->sin_addr.s_addr;
-	sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));
+	dprintk("lockd: %s created host %s (%s)\n", __func__,
+		host->h_name, host->h_addrbuf);
 
-	host->h_addr       = *sin;
-	host->h_addr.sin_port = 0;	/* ouch! */
-	host->h_version    = version;
-	host->h_proto      = proto;
-	host->h_rpcclnt    = NULL;
-	init_MUTEX(&host->h_sema);
-	host->h_nextrebind = jiffies + NLM_HOST_REBIND;
-	host->h_expires    = jiffies + NLM_HOST_EXPIRE;
-	atomic_set(&host->h_count, 1);
-	init_waitqueue_head(&host->h_gracewait);
-	host->h_state      = 0;			/* pseudo NSM state */
-	host->h_nsmstate   = 0;			/* real NSM state */
-	host->h_server	   = server;
-	host->h_next       = nlm_hosts[hash];
-	nlm_hosts[hash]    = host;
-	INIT_LIST_HEAD(&host->h_lockowners);
-	spin_lock_init(&host->h_lock);
+out:
+	mutex_unlock(&nlm_host_mutex);
+	return host;
+}
 
-	if (++nrhosts > NLM_HOST_MAX)
-		next_gc = 0;
+/**
+ * nlmclnt_release_host - release client nlm_host
+ * @host: nlm_host to release
+ *
+ */
+void nlmclnt_release_host(struct nlm_host *host)
+{
+	if (host == NULL)
+		return;
 
-nohost:
-	up(&nlm_host_sema);
-	return host;
+	dprintk("lockd: release client host %s\n", host->h_name);
+
+	WARN_ON_ONCE(host->h_server);
+
+	if (atomic_dec_and_test(&host->h_count)) {
+		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);
+	}
 }
 
-struct nlm_host *
-nlm_find_client(void)
+/**
+ * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
+ * @rqstp: incoming NLM request
+ * @hostname: name of client host
+ * @hostname_len: length of client hostname
+ *
+ * Returns an nlm_host structure that matches the [client address,
+ * transport protocol, NLM version, client hostname] of the passed-in
+ * NLM request.  If one doesn't already exist in the host cache, a
+ * new handle is created and returned.
+ *
+ * Before possibly creating a new nlm_host, construct a sockaddr
+ * for a specific source address in case the local system has
+ * multiple network addresses.  The family of the address in
+ * rq_daddr is guaranteed to be the same as the family of the
+ * address in rq_addr, so it's safe to use the same family for
+ * the source address.
+ */
+struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
+				    const char *hostname,
+				    const size_t hostname_len)
 {
-	/* find a nlm_host for a client for which h_killed == 0.
-	 * and return it
-	 */
-	int hash;
-	down(&nlm_host_sema);
-	for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
-		struct nlm_host *host, **hp;
-		for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
-			if (host->h_server &&
-			    host->h_killed == 0) {
-				nlm_get_host(host);
-				up(&nlm_host_sema);
-				return host;
-			}
-		}
+	struct hlist_head *chain;
+	struct nlm_host	*host = NULL;
+	struct nsm_handle *nsm = NULL;
+	struct sockaddr *src_sap = svc_daddr(rqstp);
+	size_t src_len = rqstp->rq_daddrlen;
+	struct net *net = SVC_NET(rqstp);
+	struct nlm_lookup_host_info ni = {
+		.server		= 1,
+		.sap		= svc_addr(rqstp),
+		.salen		= rqstp->rq_addrlen,
+		.protocol	= rqstp->rq_prot,
+		.version	= rqstp->rq_vers,
+		.hostname	= hostname,
+		.hostname_len	= hostname_len,
+		.net		= net,
+	};
+	struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+	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"));
+
+	mutex_lock(&nlm_host_mutex);
+
+	if (time_after_eq(jiffies, ln->next_gc))
+		nlm_gc_hosts(net);
+
+	chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
+	hlist_for_each_entry(host, chain, h_hash) {
+		if (host->net != net)
+			continue;
+		if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
+			continue;
+
+		/* Same address. Share an NSM handle if we already have one */
+		if (nsm == NULL)
+			nsm = host->h_nsmhandle;
+
+		if (host->h_proto != ni.protocol)
+			continue;
+		if (host->h_version != ni.version)
+			continue;
+		if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
+			continue;
+
+		/* Move to head of hash chain. */
+		hlist_del(&host->h_hash);
+		hlist_add_head(&host->h_hash, chain);
+
+		nlm_get_host(host);
+		dprintk("lockd: %s found host %s (%s)\n",
+			__func__, host->h_name, host->h_addrbuf);
+		goto out;
 	}
-	up(&nlm_host_sema);
-	return NULL;
+
+	host = nlm_alloc_host(&ni, nsm);
+	if (unlikely(host == NULL))
+		goto out;
+
+	memcpy(nlm_srcaddr(host), src_sap, src_len);
+	host->h_srcaddrlen = src_len;
+	hlist_add_head(&host->h_hash, chain);
+	ln->nrhosts++;
+	nrhosts++;
+
+	dprintk("lockd: %s created host %s (%s)\n",
+		__func__, host->h_name, host->h_addrbuf);
+
+out:
+	mutex_unlock(&nlm_host_mutex);
+	return host;
+}
+
+/**
+ * nlmsvc_release_host - release server nlm_host
+ * @host: nlm_host to release
+ *
+ * Host is destroyed later in nlm_gc_host().
+ */
+void nlmsvc_release_host(struct nlm_host *host)
+{
+	if (host == NULL)
+		return;
+
+	dprintk("lockd: release server host %s\n", host->h_name);
+
+	WARN_ON_ONCE(!host->h_server);
+	atomic_dec(&host->h_count);
 }
 
-				
 /*
  * Create the NLM RPC client for an NLM peer
  */
@@ -163,50 +418,68 @@ struct rpc_clnt *
 nlm_bind_host(struct nlm_host *host)
 {
 	struct rpc_clnt	*clnt;
-	struct rpc_xprt	*xprt;
 
-	dprintk("lockd: nlm_bind_host(%08x)\n",
-			(unsigned)ntohl(host->h_addr.sin_addr.s_addr));
+	dprintk("lockd: nlm_bind_host %s (%s)\n",
+			host->h_name, host->h_addrbuf);
 
 	/* Lock host handle */
-	down(&host->h_sema);
+	mutex_lock(&host->h_mutex);
 
 	/* If we've already created an RPC client, check whether
 	 * RPC rebind is required
 	 */
 	if ((clnt = host->h_rpcclnt) != NULL) {
-		xprt = clnt->cl_xprt;
 		if (time_after_eq(jiffies, host->h_nextrebind)) {
 			rpc_force_rebind(clnt);
 			host->h_nextrebind = jiffies + NLM_HOST_REBIND;
-			dprintk("lockd: next rebind in %ld jiffies\n",
+			dprintk("lockd: next rebind in %lu jiffies\n",
 					host->h_nextrebind - jiffies);
 		}
 	} else {
-		xprt = xprt_create_proto(host->h_proto, &host->h_addr, NULL);
-		if (IS_ERR(xprt))
-			goto forgetit;
-
-		xprt_set_timeout(&xprt->timeout, 5, nlmsvc_timeout);
-		xprt->resvport = 1;	/* NLM requires a reserved port */
-
-		/* Existing NLM servers accept AUTH_UNIX only */
-		clnt = rpc_create_client(xprt, host->h_name, &nlm_program,
-					host->h_version, RPC_AUTH_UNIX);
-		if (IS_ERR(clnt))
-			goto forgetit;
-		clnt->cl_autobind = 1;	/* turn on pmap queries */
-
-		host->h_rpcclnt = clnt;
+		unsigned long increment = nlmsvc_timeout;
+		struct rpc_timeout timeparms = {
+			.to_initval	= increment,
+			.to_increment	= increment,
+			.to_maxval	= increment * 6UL,
+			.to_retries	= 5U,
+		};
+		struct rpc_create_args args = {
+			.net		= host->net,
+			.protocol	= host->h_proto,
+			.address	= nlm_addr(host),
+			.addrsize	= host->h_addrlen,
+			.timeout	= &timeparms,
+			.servername	= host->h_name,
+			.program	= &nlm_program,
+			.version	= host->h_version,
+			.authflavor	= RPC_AUTH_UNIX,
+			.flags		= (RPC_CLNT_CREATE_NOPING |
+					   RPC_CLNT_CREATE_AUTOBIND),
+		};
+
+		/*
+		 * lockd retries server side blocks automatically so we want
+		 * those to be soft RPC calls. Client side calls need to be
+		 * hard RPC tasks.
+		 */
+		if (!host->h_server)
+			args.flags |= RPC_CLNT_CREATE_HARDRTRY;
+		if (host->h_noresvport)
+			args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+		if (host->h_srcaddrlen)
+			args.saddress = nlm_srcaddr(host);
+
+		clnt = rpc_create(&args);
+		if (!IS_ERR(clnt))
+			host->h_rpcclnt = clnt;
+		else {
+			printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
+			clnt = NULL;
+		}
 	}
 
-	up(&host->h_sema);
+	mutex_unlock(&host->h_mutex);
 	return clnt;
-
-forgetit:
-	printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
-	up(&host->h_sema);
-	return NULL;
 }
 
 /*
@@ -235,54 +508,127 @@ struct nlm_host * nlm_get_host(struct nlm_host *host)
 	return host;
 }
 
-/*
- * Release NLM host after use
- */
-void nlm_release_host(struct nlm_host *host)
+static struct nlm_host *next_host_state(struct hlist_head *cache,
+					struct nsm_handle *nsm,
+					const struct nlm_reboot *info)
 {
-	if (host != NULL) {
-		dprintk("lockd: release host %s\n", host->h_name);
-		atomic_dec(&host->h_count);
-		BUG_ON(atomic_read(&host->h_count) < 0);
+	struct nlm_host *host;
+	struct hlist_head *chain;
+
+	mutex_lock(&nlm_host_mutex);
+	for_each_host(host, chain, cache) {
+		if (host->h_nsmhandle == nsm
+		    && host->h_nsmstate != info->state) {
+			host->h_nsmstate = info->state;
+			host->h_state++;
+
+			nlm_get_host(host);
+			mutex_unlock(&nlm_host_mutex);
+			return host;
+		}
 	}
+
+	mutex_unlock(&nlm_host_mutex);
+	return NULL;
 }
 
-/*
- * Shut down the hosts module.
- * Note that this routine is called only at server shutdown time.
+/**
+ * nlm_host_rebooted - Release all resources held by rebooted host
+ * @info: pointer to decoded results of NLM_SM_NOTIFY call
+ *
+ * We were notified that the specified host has rebooted.  Release
+ * all resources held by that peer.
  */
-void
-nlm_shutdown_hosts(void)
+void nlm_host_rebooted(const struct nlm_reboot *info)
 {
+	struct nsm_handle *nsm;
 	struct nlm_host	*host;
-	int		i;
 
-	dprintk("lockd: shutting down host module\n");
-	down(&nlm_host_sema);
+	nsm = nsm_reboot_lookup(info);
+	if (unlikely(nsm == NULL))
+		return;
 
-	/* First, make all hosts eligible for gc */
-	dprintk("lockd: nuking all hosts...\n");
-	for (i = 0; i < NLM_HOST_NRHASH; i++) {
-		for (host = nlm_hosts[i]; host; host = host->h_next)
-			host->h_expires = jiffies - 1;
+	/* Mark all hosts tied to this NSM state as having rebooted.
+	 * We run the loop repeatedly, because we drop the host table
+	 * lock for this.
+	 * To avoid processing a host several times, we match the nsmstate.
+	 */
+	while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
+		nlmsvc_free_host_resources(host);
+		nlmsvc_release_host(host);
+	}
+	while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
+		nlmclnt_recovery(host);
+		nlmclnt_release_host(host);
 	}
 
-	/* Then, perform a garbage collection pass */
-	nlm_gc_hosts();
-	up(&nlm_host_sema);
+	nsm_release(nsm);
+}
+
+static void nlm_complain_hosts(struct net *net)
+{
+	struct hlist_head *chain;
+	struct nlm_host	*host;
+
+	if (net) {
+		struct lockd_net *ln = net_generic(net, lockd_net_id);
 
-	/* complain if any hosts are left */
-	if (nrhosts) {
+		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);
+	} else {
+		if (nrhosts == 0)
+			return;
 		printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
-		dprintk("lockd: %d hosts left:\n", nrhosts);
-		for (i = 0; i < NLM_HOST_NRHASH; i++) {
-			for (host = nlm_hosts[i]; host; host = host->h_next) {
-				dprintk("       %s (cnt %d use %d exp %ld)\n",
-					host->h_name, atomic_read(&host->h_count),
-					host->h_inuse, host->h_expires);
-			}
+		dprintk("lockd: %lu hosts left:\n", nrhosts);
+	}
+
+	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);
+	}
+}
+
+void
+nlm_shutdown_hosts_net(struct net *net)
+{
+	struct hlist_head *chain;
+	struct nlm_host	*host;
+
+	mutex_lock(&nlm_host_mutex);
+
+	/* First, make all hosts eligible for gc */
+	dprintk("lockd: nuking all hosts in net %p...\n", net);
+	for_each_host(host, chain, nlm_server_hosts) {
+		if (net && host->net != net)
+			continue;
+		host->h_expires = jiffies - 1;
+		if (host->h_rpcclnt) {
+			rpc_shutdown_client(host->h_rpcclnt);
+			host->h_rpcclnt = NULL;
 		}
 	}
+
+	/* Then, perform a garbage collection pass */
+	nlm_gc_hosts(net);
+	mutex_unlock(&nlm_host_mutex);
+
+	nlm_complain_hosts(net);
+}
+
+/*
+ * Shut down the hosts module.
+ * Note that this routine is called only at server shutdown time.
+ */
+void
+nlm_shutdown_hosts(void)
+{
+	dprintk("lockd: shutting down host module\n");
+	nlm_shutdown_hosts_net(NULL);
 }
 
 /*
@@ -291,52 +637,39 @@ nlm_shutdown_hosts(void)
  * mark & sweep for resources held by remote clients.
  */
 static void
-nlm_gc_hosts(void)
+nlm_gc_hosts(struct net *net)
 {
-	struct nlm_host	**q, *host;
-	struct rpc_clnt	*clnt;
-	int		i;
+	struct hlist_head *chain;
+	struct hlist_node *next;
+	struct nlm_host	*host;
 
-	dprintk("lockd: host garbage collection\n");
-	for (i = 0; i < NLM_HOST_NRHASH; i++) {
-		for (host = nlm_hosts[i]; host; host = host->h_next)
-			host->h_inuse = 0;
+	dprintk("lockd: host garbage collection for net %p\n", net);
+	for_each_host(host, chain, nlm_server_hosts) {
+		if (net && host->net != net)
+			continue;
+		host->h_inuse = 0;
 	}
 
 	/* Mark all hosts that hold locks, blocks or shares */
-	nlmsvc_mark_resources();
-
-	for (i = 0; i < NLM_HOST_NRHASH; i++) {
-		q = &nlm_hosts[i];
-		while ((host = *q) != NULL) {
-			if (atomic_read(&host->h_count) || host->h_inuse
-			 || time_before(jiffies, host->h_expires)) {
-				dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
-					host->h_name, atomic_read(&host->h_count),
-					host->h_inuse, host->h_expires);
-				q = &host->h_next;
-				continue;
-			}
-			dprintk("lockd: delete host %s\n", host->h_name);
-			*q = host->h_next;
-			/* Don't unmonitor hosts that have been invalidated */
-			if (host->h_monitored && !host->h_killed)
-				nsm_unmonitor(host);
-			if ((clnt = host->h_rpcclnt) != NULL) {
-				if (atomic_read(&clnt->cl_users)) {
-					printk(KERN_WARNING
-						"lockd: active RPC handle\n");
-					clnt->cl_dead = 1;
-				} else {
-					rpc_destroy_client(host->h_rpcclnt);
-				}
-			}
-			BUG_ON(!list_empty(&host->h_lockowners));
-			kfree(host);
-			nrhosts--;
+	nlmsvc_mark_resources(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)) {
+			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);
+			continue;
 		}
+		nlm_destroy_host_locked(host);
 	}
 
-	next_gc = jiffies + NLM_HOST_COLLECT;
-}
+	if (net) {
+		struct lockd_net *ln = net_generic(net, lockd_net_id);
 
+		ln->next_gc = jiffies + NLM_HOST_COLLECT;
+	}
+}