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/lockd/sm_inter.h>
19 #include <linux/mutex.h>
23 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
24 #define NLM_HOST_NRHASH 32
25 #define NLM_HOST_REBIND (60 * HZ)
26 #define NLM_HOST_EXPIRE (300 * HZ)
27 #define NLM_HOST_COLLECT (120 * HZ)
29 static struct hlist_head nlm_hosts[NLM_HOST_NRHASH];
30 static unsigned long next_gc;
32 static DEFINE_MUTEX(nlm_host_mutex);
34 static void nlm_gc_hosts(void);
35 static struct nsm_handle *nsm_find(const struct sockaddr *sap,
38 const size_t hostname_len,
41 struct nlm_lookup_host_info {
42 const int server; /* search for server|client */
43 const struct sockaddr *sap; /* address to search for */
44 const size_t salen; /* it's length */
45 const unsigned short protocol; /* transport to search for*/
46 const u32 version; /* NLM version to search for */
47 const char *hostname; /* remote's hostname */
48 const size_t hostname_len; /* it's length */
49 const struct sockaddr *src_sap; /* our address (optional) */
50 const size_t src_len; /* it's length */
51 const int noresvport; /* use non-priv port */
55 * Hash function must work well on big- and little-endian platforms
57 static unsigned int __nlm_hash32(const __be32 n)
59 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
60 return hash ^ (hash >> 8);
63 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
65 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
66 return __nlm_hash32(sin->sin_addr.s_addr);
69 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
71 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
72 const struct in6_addr addr = sin6->sin6_addr;
73 return __nlm_hash32(addr.s6_addr32[0]) ^
74 __nlm_hash32(addr.s6_addr32[1]) ^
75 __nlm_hash32(addr.s6_addr32[2]) ^
76 __nlm_hash32(addr.s6_addr32[3]);
79 static unsigned int nlm_hash_address(const struct sockaddr *sap)
83 switch (sap->sa_family) {
85 hash = __nlm_hash_addr4(sap);
88 hash = __nlm_hash_addr6(sap);
93 return hash & (NLM_HOST_NRHASH - 1);
96 static void nlm_clear_port(struct sockaddr *sap)
98 switch (sap->sa_family) {
100 ((struct sockaddr_in *)sap)->sin_port = 0;
103 ((struct sockaddr_in6 *)sap)->sin6_port = 0;
108 static void nlm_display_address(const struct sockaddr *sap,
109 char *buf, const size_t len)
111 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
112 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
114 switch (sap->sa_family) {
116 snprintf(buf, len, "unspecified");
119 snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
122 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
123 snprintf(buf, len, "%pI4",
124 &sin6->sin6_addr.s6_addr32[3]);
126 snprintf(buf, len, "%pI6", &sin6->sin6_addr);
129 snprintf(buf, len, "unsupported address family");
135 * Common host lookup routine for server & client
137 static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
139 struct hlist_head *chain;
140 struct hlist_node *pos;
141 struct nlm_host *host;
142 struct nsm_handle *nsm = NULL;
144 mutex_lock(&nlm_host_mutex);
146 if (time_after_eq(jiffies, next_gc))
149 /* We may keep several nlm_host objects for a peer, because each
150 * nlm_host is identified by
151 * (address, protocol, version, server/client)
152 * We could probably simplify this a little by putting all those
153 * different NLM rpc_clients into one single nlm_host object.
154 * This would allow us to have one nlm_host per address.
156 chain = &nlm_hosts[nlm_hash_address(ni->sap)];
157 hlist_for_each_entry(host, pos, chain, h_hash) {
158 if (!nlm_cmp_addr(nlm_addr(host), ni->sap))
161 /* See if we have an NSM handle for this client */
163 nsm = host->h_nsmhandle;
165 if (host->h_proto != ni->protocol)
167 if (host->h_version != ni->version)
169 if (host->h_server != ni->server)
172 !nlm_cmp_addr(nlm_srcaddr(host), ni->src_sap))
175 /* Move to head of hash chain. */
176 hlist_del(&host->h_hash);
177 hlist_add_head(&host->h_hash, chain);
180 dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
181 host->h_name, host->h_addrbuf);
186 * The host wasn't in our hash table. If we don't
187 * have an NSM handle for it yet, create one.
190 atomic_inc(&nsm->sm_count);
193 nsm = nsm_find(ni->sap, ni->salen,
194 ni->hostname, ni->hostname_len, 1);
196 dprintk("lockd: nlm_lookup_host failed; "
202 host = kzalloc(sizeof(*host), GFP_KERNEL);
205 dprintk("lockd: nlm_lookup_host failed; no memory\n");
208 host->h_name = nsm->sm_name;
209 memcpy(nlm_addr(host), ni->sap, ni->salen);
210 host->h_addrlen = ni->salen;
211 nlm_clear_port(nlm_addr(host));
212 memcpy(nlm_srcaddr(host), ni->src_sap, ni->src_len);
213 host->h_version = ni->version;
214 host->h_proto = ni->protocol;
215 host->h_rpcclnt = NULL;
216 mutex_init(&host->h_mutex);
217 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
218 host->h_expires = jiffies + NLM_HOST_EXPIRE;
219 atomic_set(&host->h_count, 1);
220 init_waitqueue_head(&host->h_gracewait);
221 init_rwsem(&host->h_rwsem);
222 host->h_state = 0; /* pseudo NSM state */
223 host->h_nsmstate = 0; /* real NSM state */
224 host->h_nsmhandle = nsm;
225 host->h_server = ni->server;
226 host->h_noresvport = ni->noresvport;
227 hlist_add_head(&host->h_hash, chain);
228 INIT_LIST_HEAD(&host->h_lockowners);
229 spin_lock_init(&host->h_lock);
230 INIT_LIST_HEAD(&host->h_granted);
231 INIT_LIST_HEAD(&host->h_reclaim);
235 nlm_display_address((struct sockaddr *)&host->h_addr,
236 host->h_addrbuf, sizeof(host->h_addrbuf));
237 nlm_display_address((struct sockaddr *)&host->h_srcaddr,
238 host->h_srcaddrbuf, sizeof(host->h_srcaddrbuf));
240 dprintk("lockd: nlm_lookup_host created host %s\n",
244 mutex_unlock(&nlm_host_mutex);
252 nlm_destroy_host(struct nlm_host *host)
254 struct rpc_clnt *clnt;
256 BUG_ON(!list_empty(&host->h_lockowners));
257 BUG_ON(atomic_read(&host->h_count));
260 * Release NSM handle and unmonitor host.
264 clnt = host->h_rpcclnt;
266 rpc_shutdown_client(clnt);
271 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
272 * @sap: network address of server
273 * @salen: length of server address
274 * @protocol: transport protocol to use
275 * @version: NLM protocol version
276 * @hostname: '\0'-terminated hostname of server
277 * @noresvport: 1 if non-privileged port should be used
279 * Returns an nlm_host structure that matches the passed-in
280 * [server address, transport protocol, NLM version, server hostname].
281 * If one doesn't already exist in the host cache, a new handle is
282 * created and returned.
284 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
286 const unsigned short protocol,
288 const char *hostname,
291 const struct sockaddr source = {
292 .sa_family = AF_UNSPEC,
294 struct nlm_lookup_host_info ni = {
298 .protocol = protocol,
300 .hostname = hostname,
301 .hostname_len = strlen(hostname),
303 .src_len = sizeof(source),
304 .noresvport = noresvport,
307 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
308 (hostname ? hostname : "<none>"), version,
309 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
311 return nlm_lookup_host(&ni);
315 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
316 * @rqstp: incoming NLM request
317 * @hostname: name of client host
318 * @hostname_len: length of client hostname
320 * Returns an nlm_host structure that matches the [client address,
321 * transport protocol, NLM version, client hostname] of the passed-in
322 * NLM request. If one doesn't already exist in the host cache, a
323 * new handle is created and returned.
325 * Before possibly creating a new nlm_host, construct a sockaddr
326 * for a specific source address in case the local system has
327 * multiple network addresses. The family of the address in
328 * rq_daddr is guaranteed to be the same as the family of the
329 * address in rq_addr, so it's safe to use the same family for
330 * the source address.
332 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
333 const char *hostname,
334 const size_t hostname_len)
336 struct sockaddr_in sin = {
337 .sin_family = AF_INET,
339 struct sockaddr_in6 sin6 = {
340 .sin6_family = AF_INET6,
342 struct nlm_lookup_host_info ni = {
344 .sap = svc_addr(rqstp),
345 .salen = rqstp->rq_addrlen,
346 .protocol = rqstp->rq_prot,
347 .version = rqstp->rq_vers,
348 .hostname = hostname,
349 .hostname_len = hostname_len,
350 .src_len = rqstp->rq_addrlen,
353 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
354 (int)hostname_len, hostname, rqstp->rq_vers,
355 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
357 switch (ni.sap->sa_family) {
359 sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
360 ni.src_sap = (struct sockaddr *)&sin;
363 ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
364 ni.src_sap = (struct sockaddr *)&sin6;
370 return nlm_lookup_host(&ni);
374 * Create the NLM RPC client for an NLM peer
377 nlm_bind_host(struct nlm_host *host)
379 struct rpc_clnt *clnt;
381 dprintk("lockd: nlm_bind_host %s (%s), my addr=%s\n",
382 host->h_name, host->h_addrbuf, host->h_srcaddrbuf);
384 /* Lock host handle */
385 mutex_lock(&host->h_mutex);
387 /* If we've already created an RPC client, check whether
388 * RPC rebind is required
390 if ((clnt = host->h_rpcclnt) != NULL) {
391 if (time_after_eq(jiffies, host->h_nextrebind)) {
392 rpc_force_rebind(clnt);
393 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
394 dprintk("lockd: next rebind in %lu jiffies\n",
395 host->h_nextrebind - jiffies);
398 unsigned long increment = nlmsvc_timeout;
399 struct rpc_timeout timeparms = {
400 .to_initval = increment,
401 .to_increment = increment,
402 .to_maxval = increment * 6UL,
405 struct rpc_create_args args = {
406 .protocol = host->h_proto,
407 .address = nlm_addr(host),
408 .addrsize = host->h_addrlen,
409 .saddress = nlm_srcaddr(host),
410 .timeout = &timeparms,
411 .servername = host->h_name,
412 .program = &nlm_program,
413 .version = host->h_version,
414 .authflavor = RPC_AUTH_UNIX,
415 .flags = (RPC_CLNT_CREATE_NOPING |
416 RPC_CLNT_CREATE_AUTOBIND),
420 * lockd retries server side blocks automatically so we want
421 * those to be soft RPC calls. Client side calls need to be
425 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
426 if (host->h_noresvport)
427 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
429 clnt = rpc_create(&args);
431 host->h_rpcclnt = clnt;
433 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
438 mutex_unlock(&host->h_mutex);
443 * Force a portmap lookup of the remote lockd port
446 nlm_rebind_host(struct nlm_host *host)
448 dprintk("lockd: rebind host %s\n", host->h_name);
449 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
450 rpc_force_rebind(host->h_rpcclnt);
451 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
456 * Increment NLM host count
458 struct nlm_host * nlm_get_host(struct nlm_host *host)
461 dprintk("lockd: get host %s\n", host->h_name);
462 atomic_inc(&host->h_count);
463 host->h_expires = jiffies + NLM_HOST_EXPIRE;
469 * Release NLM host after use
471 void nlm_release_host(struct nlm_host *host)
474 dprintk("lockd: release host %s\n", host->h_name);
475 BUG_ON(atomic_read(&host->h_count) < 0);
476 if (atomic_dec_and_test(&host->h_count)) {
477 BUG_ON(!list_empty(&host->h_lockowners));
478 BUG_ON(!list_empty(&host->h_granted));
479 BUG_ON(!list_empty(&host->h_reclaim));
485 * We were notified that the host indicated by address &sin
487 * Release all resources held by that peer.
489 void nlm_host_rebooted(const struct sockaddr_in *sin,
490 const char *hostname,
491 unsigned int hostname_len,
494 struct hlist_head *chain;
495 struct hlist_node *pos;
496 struct nsm_handle *nsm;
497 struct nlm_host *host;
499 nsm = nsm_find((struct sockaddr *)sin, sizeof(*sin),
500 hostname, hostname_len, 0);
502 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
503 hostname_len, hostname);
507 dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n",
508 hostname_len, hostname, nsm->sm_addrbuf);
510 /* When reclaiming locks on this peer, make sure that
511 * we set up a new notification */
512 nsm->sm_monitored = 0;
514 /* Mark all hosts tied to this NSM state as having rebooted.
515 * We run the loop repeatedly, because we drop the host table
517 * To avoid processing a host several times, we match the nsmstate.
519 again: mutex_lock(&nlm_host_mutex);
520 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
521 hlist_for_each_entry(host, pos, chain, h_hash) {
522 if (host->h_nsmhandle == nsm
523 && host->h_nsmstate != new_state) {
524 host->h_nsmstate = new_state;
528 mutex_unlock(&nlm_host_mutex);
530 if (host->h_server) {
531 /* We're server for this guy, just ditch
532 * all the locks he held. */
533 nlmsvc_free_host_resources(host);
535 /* He's the server, initiate lock recovery. */
536 nlmclnt_recovery(host);
539 nlm_release_host(host);
545 mutex_unlock(&nlm_host_mutex);
549 * Shut down the hosts module.
550 * Note that this routine is called only at server shutdown time.
553 nlm_shutdown_hosts(void)
555 struct hlist_head *chain;
556 struct hlist_node *pos;
557 struct nlm_host *host;
559 dprintk("lockd: shutting down host module\n");
560 mutex_lock(&nlm_host_mutex);
562 /* First, make all hosts eligible for gc */
563 dprintk("lockd: nuking all hosts...\n");
564 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
565 hlist_for_each_entry(host, pos, chain, h_hash) {
566 host->h_expires = jiffies - 1;
567 if (host->h_rpcclnt) {
568 rpc_shutdown_client(host->h_rpcclnt);
569 host->h_rpcclnt = NULL;
574 /* Then, perform a garbage collection pass */
576 mutex_unlock(&nlm_host_mutex);
578 /* complain if any hosts are left */
580 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
581 dprintk("lockd: %d hosts left:\n", nrhosts);
582 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
583 hlist_for_each_entry(host, pos, chain, h_hash) {
584 dprintk(" %s (cnt %d use %d exp %ld)\n",
585 host->h_name, atomic_read(&host->h_count),
586 host->h_inuse, host->h_expires);
593 * Garbage collect any unused NLM hosts.
594 * This GC combines reference counting for async operations with
595 * mark & sweep for resources held by remote clients.
600 struct hlist_head *chain;
601 struct hlist_node *pos, *next;
602 struct nlm_host *host;
604 dprintk("lockd: host garbage collection\n");
605 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
606 hlist_for_each_entry(host, pos, chain, h_hash)
610 /* Mark all hosts that hold locks, blocks or shares */
611 nlmsvc_mark_resources();
613 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
614 hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
615 if (atomic_read(&host->h_count) || host->h_inuse
616 || time_before(jiffies, host->h_expires)) {
617 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
618 host->h_name, atomic_read(&host->h_count),
619 host->h_inuse, host->h_expires);
622 dprintk("lockd: delete host %s\n", host->h_name);
623 hlist_del_init(&host->h_hash);
625 nlm_destroy_host(host);
630 next_gc = jiffies + NLM_HOST_COLLECT;
637 static LIST_HEAD(nsm_handles);
638 static DEFINE_SPINLOCK(nsm_lock);
640 static struct nsm_handle *nsm_find(const struct sockaddr *sap,
642 const char *hostname,
643 const size_t hostname_len,
646 struct nsm_handle *nsm = NULL;
647 struct nsm_handle *pos;
652 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
653 if (printk_ratelimit()) {
654 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
655 "in NFS lock request\n",
656 (int)hostname_len, hostname);
662 spin_lock(&nsm_lock);
663 list_for_each_entry(pos, &nsm_handles, sm_link) {
665 if (hostname && nsm_use_hostnames) {
666 if (strlen(pos->sm_name) != hostname_len
667 || memcmp(pos->sm_name, hostname, hostname_len))
669 } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
671 atomic_inc(&pos->sm_count);
677 list_add(&nsm->sm_link, &nsm_handles);
680 spin_unlock(&nsm_lock);
685 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
689 memcpy(nsm_addr(nsm), sap, salen);
690 nsm->sm_addrlen = salen;
691 nsm->sm_name = (char *) (nsm + 1);
692 memcpy(nsm->sm_name, hostname, hostname_len);
693 nsm->sm_name[hostname_len] = '\0';
694 nlm_display_address((struct sockaddr *)&nsm->sm_addr,
695 nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
696 atomic_set(&nsm->sm_count, 1);
700 spin_unlock(&nsm_lock);
705 * Release an NSM handle
708 nsm_release(struct nsm_handle *nsm)
712 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
713 list_del(&nsm->sm_link);
714 spin_unlock(&nsm_lock);