2 * linux/fs/lockd/host.c
4 * Management for NLM peer hosts. The nlm_host struct is shared
5 * between client and server implementation. The only reason to
6 * do so is to reduce code bloat.
8 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
11 #include <linux/types.h>
12 #include <linux/slab.h>
14 #include <linux/in6.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/sunrpc/svc.h>
17 #include <linux/lockd/lockd.h>
18 #include <linux/mutex.h>
20 #include <linux/sunrpc/svc_xprt.h>
26 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
27 #define NLM_HOST_NRHASH 32
28 #define NLM_HOST_REBIND (60 * HZ)
29 #define NLM_HOST_EXPIRE (300 * HZ)
30 #define NLM_HOST_COLLECT (120 * HZ)
32 static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH];
33 static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
35 #define for_each_host(host, pos, chain, table) \
36 for ((chain) = (table); \
37 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
38 hlist_for_each_entry((host), (pos), (chain), h_hash)
40 #define for_each_host_safe(host, pos, next, chain, table) \
41 for ((chain) = (table); \
42 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
43 hlist_for_each_entry_safe((host), (pos), (next), \
46 static unsigned long nrhosts;
47 static DEFINE_MUTEX(nlm_host_mutex);
49 static void nlm_gc_hosts(struct net *net);
51 struct nlm_lookup_host_info {
52 const int server; /* search for server|client */
53 const struct sockaddr *sap; /* address to search for */
54 const size_t salen; /* it's length */
55 const unsigned short protocol; /* transport to search for*/
56 const u32 version; /* NLM version to search for */
57 const char *hostname; /* remote's hostname */
58 const size_t hostname_len; /* it's length */
59 const int noresvport; /* use non-priv port */
60 struct net *net; /* network namespace to bind */
64 * Hash function must work well on big- and little-endian platforms
66 static unsigned int __nlm_hash32(const __be32 n)
68 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
69 return hash ^ (hash >> 8);
72 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
74 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
75 return __nlm_hash32(sin->sin_addr.s_addr);
78 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
80 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
81 const struct in6_addr addr = sin6->sin6_addr;
82 return __nlm_hash32(addr.s6_addr32[0]) ^
83 __nlm_hash32(addr.s6_addr32[1]) ^
84 __nlm_hash32(addr.s6_addr32[2]) ^
85 __nlm_hash32(addr.s6_addr32[3]);
88 static unsigned int nlm_hash_address(const struct sockaddr *sap)
92 switch (sap->sa_family) {
94 hash = __nlm_hash_addr4(sap);
97 hash = __nlm_hash_addr6(sap);
102 return hash & (NLM_HOST_NRHASH - 1);
106 * Allocate and initialize an nlm_host. Common to both client and server.
108 static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
109 struct nsm_handle *nsm)
111 struct nlm_host *host = NULL;
112 unsigned long now = jiffies;
115 atomic_inc(&nsm->sm_count);
118 nsm = nsm_get_handle(ni->sap, ni->salen,
119 ni->hostname, ni->hostname_len);
120 if (unlikely(nsm == NULL)) {
121 dprintk("lockd: %s failed; no nsm handle\n",
127 host = kmalloc(sizeof(*host), GFP_KERNEL);
128 if (unlikely(host == NULL)) {
129 dprintk("lockd: %s failed; no memory\n", __func__);
134 memcpy(nlm_addr(host), ni->sap, ni->salen);
135 host->h_addrlen = ni->salen;
136 rpc_set_port(nlm_addr(host), 0);
137 host->h_srcaddrlen = 0;
139 host->h_rpcclnt = NULL;
140 host->h_name = nsm->sm_name;
141 host->h_version = ni->version;
142 host->h_proto = ni->protocol;
143 host->h_reclaiming = 0;
144 host->h_server = ni->server;
145 host->h_noresvport = ni->noresvport;
147 init_waitqueue_head(&host->h_gracewait);
148 init_rwsem(&host->h_rwsem);
150 host->h_nsmstate = 0;
151 host->h_pidcount = 0;
152 atomic_set(&host->h_count, 1);
153 mutex_init(&host->h_mutex);
154 host->h_nextrebind = now + NLM_HOST_REBIND;
155 host->h_expires = now + NLM_HOST_EXPIRE;
156 INIT_LIST_HEAD(&host->h_lockowners);
157 spin_lock_init(&host->h_lock);
158 INIT_LIST_HEAD(&host->h_granted);
159 INIT_LIST_HEAD(&host->h_reclaim);
160 host->h_nsmhandle = nsm;
161 host->h_addrbuf = nsm->sm_addrbuf;
169 * Destroy an nlm_host and free associated resources
171 * Caller must hold nlm_host_mutex.
173 static void nlm_destroy_host_locked(struct nlm_host *host)
175 struct rpc_clnt *clnt;
177 dprintk("lockd: destroy host %s\n", host->h_name);
179 BUG_ON(!list_empty(&host->h_lockowners));
180 BUG_ON(atomic_read(&host->h_count));
182 hlist_del_init(&host->h_hash);
185 nsm_release(host->h_nsmhandle);
187 clnt = host->h_rpcclnt;
189 rpc_shutdown_client(clnt);
196 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
197 * @sap: network address of server
198 * @salen: length of server address
199 * @protocol: transport protocol to use
200 * @version: NLM protocol version
201 * @hostname: '\0'-terminated hostname of server
202 * @noresvport: 1 if non-privileged port should be used
204 * Returns an nlm_host structure that matches the passed-in
205 * [server address, transport protocol, NLM version, server hostname].
206 * If one doesn't already exist in the host cache, a new handle is
207 * created and returned.
209 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
211 const unsigned short protocol,
213 const char *hostname,
217 struct nlm_lookup_host_info ni = {
221 .protocol = protocol,
223 .hostname = hostname,
224 .hostname_len = strlen(hostname),
225 .noresvport = noresvport,
228 struct hlist_head *chain;
229 struct hlist_node *pos;
230 struct nlm_host *host;
231 struct nsm_handle *nsm = NULL;
233 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
234 (hostname ? hostname : "<none>"), version,
235 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
237 mutex_lock(&nlm_host_mutex);
239 chain = &nlm_client_hosts[nlm_hash_address(sap)];
240 hlist_for_each_entry(host, pos, chain, h_hash) {
241 if (host->net != net)
243 if (!rpc_cmp_addr(nlm_addr(host), sap))
246 /* Same address. Share an NSM handle if we already have one */
248 nsm = host->h_nsmhandle;
250 if (host->h_proto != protocol)
252 if (host->h_version != version)
256 dprintk("lockd: %s found host %s (%s)\n", __func__,
257 host->h_name, host->h_addrbuf);
261 host = nlm_alloc_host(&ni, nsm);
262 if (unlikely(host == NULL))
265 hlist_add_head(&host->h_hash, chain);
268 dprintk("lockd: %s created host %s (%s)\n", __func__,
269 host->h_name, host->h_addrbuf);
272 mutex_unlock(&nlm_host_mutex);
277 * nlmclnt_release_host - release client nlm_host
278 * @host: nlm_host to release
281 void nlmclnt_release_host(struct nlm_host *host)
286 dprintk("lockd: release client host %s\n", host->h_name);
288 BUG_ON(atomic_read(&host->h_count) < 0);
289 BUG_ON(host->h_server);
291 if (atomic_dec_and_test(&host->h_count)) {
292 BUG_ON(!list_empty(&host->h_lockowners));
293 BUG_ON(!list_empty(&host->h_granted));
294 BUG_ON(!list_empty(&host->h_reclaim));
296 mutex_lock(&nlm_host_mutex);
297 nlm_destroy_host_locked(host);
298 mutex_unlock(&nlm_host_mutex);
303 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
304 * @rqstp: incoming NLM request
305 * @hostname: name of client host
306 * @hostname_len: length of client hostname
308 * Returns an nlm_host structure that matches the [client address,
309 * transport protocol, NLM version, client hostname] of the passed-in
310 * NLM request. If one doesn't already exist in the host cache, a
311 * new handle is created and returned.
313 * Before possibly creating a new nlm_host, construct a sockaddr
314 * for a specific source address in case the local system has
315 * multiple network addresses. The family of the address in
316 * rq_daddr is guaranteed to be the same as the family of the
317 * address in rq_addr, so it's safe to use the same family for
318 * the source address.
320 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
321 const char *hostname,
322 const size_t hostname_len)
324 struct hlist_head *chain;
325 struct hlist_node *pos;
326 struct nlm_host *host = NULL;
327 struct nsm_handle *nsm = NULL;
328 struct sockaddr *src_sap = svc_daddr(rqstp);
329 size_t src_len = rqstp->rq_daddrlen;
330 struct net *net = rqstp->rq_xprt->xpt_net;
331 struct nlm_lookup_host_info ni = {
333 .sap = svc_addr(rqstp),
334 .salen = rqstp->rq_addrlen,
335 .protocol = rqstp->rq_prot,
336 .version = rqstp->rq_vers,
337 .hostname = hostname,
338 .hostname_len = hostname_len,
341 struct lockd_net *ln = net_generic(net, lockd_net_id);
343 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
344 (int)hostname_len, hostname, rqstp->rq_vers,
345 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
347 mutex_lock(&nlm_host_mutex);
349 if (time_after_eq(jiffies, ln->next_gc))
352 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
353 hlist_for_each_entry(host, pos, chain, h_hash) {
354 if (host->net != net)
356 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
359 /* Same address. Share an NSM handle if we already have one */
361 nsm = host->h_nsmhandle;
363 if (host->h_proto != ni.protocol)
365 if (host->h_version != ni.version)
367 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
370 /* Move to head of hash chain. */
371 hlist_del(&host->h_hash);
372 hlist_add_head(&host->h_hash, chain);
375 dprintk("lockd: %s found host %s (%s)\n",
376 __func__, host->h_name, host->h_addrbuf);
380 host = nlm_alloc_host(&ni, nsm);
381 if (unlikely(host == NULL))
384 memcpy(nlm_srcaddr(host), src_sap, src_len);
385 host->h_srcaddrlen = src_len;
386 hlist_add_head(&host->h_hash, chain);
389 dprintk("lockd: %s created host %s (%s)\n",
390 __func__, host->h_name, host->h_addrbuf);
393 mutex_unlock(&nlm_host_mutex);
398 * nlmsvc_release_host - release server nlm_host
399 * @host: nlm_host to release
401 * Host is destroyed later in nlm_gc_host().
403 void nlmsvc_release_host(struct nlm_host *host)
408 dprintk("lockd: release server host %s\n", host->h_name);
410 BUG_ON(atomic_read(&host->h_count) < 0);
411 BUG_ON(!host->h_server);
412 atomic_dec(&host->h_count);
416 * Create the NLM RPC client for an NLM peer
419 nlm_bind_host(struct nlm_host *host)
421 struct rpc_clnt *clnt;
423 dprintk("lockd: nlm_bind_host %s (%s)\n",
424 host->h_name, host->h_addrbuf);
426 /* Lock host handle */
427 mutex_lock(&host->h_mutex);
429 /* If we've already created an RPC client, check whether
430 * RPC rebind is required
432 if ((clnt = host->h_rpcclnt) != NULL) {
433 if (time_after_eq(jiffies, host->h_nextrebind)) {
434 rpc_force_rebind(clnt);
435 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
436 dprintk("lockd: next rebind in %lu jiffies\n",
437 host->h_nextrebind - jiffies);
440 unsigned long increment = nlmsvc_timeout;
441 struct rpc_timeout timeparms = {
442 .to_initval = increment,
443 .to_increment = increment,
444 .to_maxval = increment * 6UL,
447 struct rpc_create_args args = {
449 .protocol = host->h_proto,
450 .address = nlm_addr(host),
451 .addrsize = host->h_addrlen,
452 .timeout = &timeparms,
453 .servername = host->h_name,
454 .program = &nlm_program,
455 .version = host->h_version,
456 .authflavor = RPC_AUTH_UNIX,
457 .flags = (RPC_CLNT_CREATE_NOPING |
458 RPC_CLNT_CREATE_AUTOBIND),
462 * lockd retries server side blocks automatically so we want
463 * those to be soft RPC calls. Client side calls need to be
467 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
468 if (host->h_noresvport)
469 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
470 if (host->h_srcaddrlen)
471 args.saddress = nlm_srcaddr(host);
473 clnt = rpc_create(&args);
475 host->h_rpcclnt = clnt;
477 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
482 mutex_unlock(&host->h_mutex);
487 * Force a portmap lookup of the remote lockd port
490 nlm_rebind_host(struct nlm_host *host)
492 dprintk("lockd: rebind host %s\n", host->h_name);
493 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
494 rpc_force_rebind(host->h_rpcclnt);
495 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
500 * Increment NLM host count
502 struct nlm_host * nlm_get_host(struct nlm_host *host)
505 dprintk("lockd: get host %s\n", host->h_name);
506 atomic_inc(&host->h_count);
507 host->h_expires = jiffies + NLM_HOST_EXPIRE;
512 static struct nlm_host *next_host_state(struct hlist_head *cache,
513 struct nsm_handle *nsm,
514 const struct nlm_reboot *info)
516 struct nlm_host *host;
517 struct hlist_head *chain;
518 struct hlist_node *pos;
520 mutex_lock(&nlm_host_mutex);
521 for_each_host(host, pos, chain, cache) {
522 if (host->h_nsmhandle == nsm
523 && host->h_nsmstate != info->state) {
524 host->h_nsmstate = info->state;
528 mutex_unlock(&nlm_host_mutex);
533 mutex_unlock(&nlm_host_mutex);
538 * nlm_host_rebooted - Release all resources held by rebooted host
539 * @info: pointer to decoded results of NLM_SM_NOTIFY call
541 * We were notified that the specified host has rebooted. Release
542 * all resources held by that peer.
544 void nlm_host_rebooted(const struct nlm_reboot *info)
546 struct nsm_handle *nsm;
547 struct nlm_host *host;
549 nsm = nsm_reboot_lookup(info);
550 if (unlikely(nsm == NULL))
553 /* Mark all hosts tied to this NSM state as having rebooted.
554 * We run the loop repeatedly, because we drop the host table
556 * To avoid processing a host several times, we match the nsmstate.
558 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
559 nlmsvc_free_host_resources(host);
560 nlmsvc_release_host(host);
562 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
563 nlmclnt_recovery(host);
564 nlmclnt_release_host(host);
571 nlm_shutdown_hosts_net(struct net *net)
573 struct hlist_head *chain;
574 struct hlist_node *pos;
575 struct nlm_host *host;
577 dprintk("lockd: shutting down host module\n");
578 mutex_lock(&nlm_host_mutex);
580 /* First, make all hosts eligible for gc */
581 dprintk("lockd: nuking all hosts...\n");
582 for_each_host(host, pos, chain, nlm_server_hosts) {
583 if (net && host->net != net)
585 host->h_expires = jiffies - 1;
586 if (host->h_rpcclnt) {
587 rpc_shutdown_client(host->h_rpcclnt);
588 host->h_rpcclnt = NULL;
592 /* Then, perform a garbage collection pass */
594 mutex_unlock(&nlm_host_mutex);
598 * Shut down the hosts module.
599 * Note that this routine is called only at server shutdown time.
602 nlm_shutdown_hosts(void)
604 struct hlist_head *chain;
605 struct hlist_node *pos;
606 struct nlm_host *host;
608 nlm_shutdown_hosts_net(NULL);
610 /* complain if any hosts are left */
612 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
613 dprintk("lockd: %lu hosts left:\n", nrhosts);
614 for_each_host(host, pos, chain, nlm_server_hosts) {
615 dprintk(" %s (cnt %d use %d exp %ld net %p)\n",
616 host->h_name, atomic_read(&host->h_count),
617 host->h_inuse, host->h_expires, host->net);
623 * Garbage collect any unused NLM hosts.
624 * This GC combines reference counting for async operations with
625 * mark & sweep for resources held by remote clients.
628 nlm_gc_hosts(struct net *net)
630 struct hlist_head *chain;
631 struct hlist_node *pos, *next;
632 struct nlm_host *host;
634 dprintk("lockd: host garbage collection for net %p\n", net);
635 for_each_host(host, pos, chain, nlm_server_hosts) {
636 if (net && host->net != net)
641 /* Mark all hosts that hold locks, blocks or shares */
642 nlmsvc_mark_resources(net);
644 for_each_host_safe(host, pos, next, chain, nlm_server_hosts) {
645 if (net && host->net != net)
647 if (atomic_read(&host->h_count) || host->h_inuse
648 || time_before(jiffies, host->h_expires)) {
649 dprintk("nlm_gc_hosts skipping %s "
650 "(cnt %d use %d exp %ld net %p)\n",
651 host->h_name, atomic_read(&host->h_count),
652 host->h_inuse, host->h_expires, host->net);
655 nlm_destroy_host_locked(host);
659 struct lockd_net *ln = net_generic(net, lockd_net_id);
661 ln->next_gc = jiffies + NLM_HOST_COLLECT;