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_in *sin; /* address to search for */
44 const unsigned short protocol; /* transport to search for*/
45 const u32 version; /* NLM version to search for */
46 const char *hostname; /* remote's hostname */
47 const size_t hostname_len; /* it's length */
48 const struct sockaddr_in *src_sin; /* our address (optional) */
49 const size_t src_len; /* it's length */
53 * Hash function must work well on big- and little-endian platforms
55 static unsigned int __nlm_hash32(const __be32 n)
57 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
58 return hash ^ (hash >> 8);
61 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
63 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
64 return __nlm_hash32(sin->sin_addr.s_addr);
67 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
69 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
70 const struct in6_addr addr = sin6->sin6_addr;
71 return __nlm_hash32(addr.s6_addr32[0]) ^
72 __nlm_hash32(addr.s6_addr32[1]) ^
73 __nlm_hash32(addr.s6_addr32[2]) ^
74 __nlm_hash32(addr.s6_addr32[3]);
77 static unsigned int nlm_hash_address(const struct sockaddr *sap)
81 switch (sap->sa_family) {
83 hash = __nlm_hash_addr4(sap);
86 hash = __nlm_hash_addr6(sap);
91 return hash & (NLM_HOST_NRHASH - 1);
94 static void nlm_clear_port(struct sockaddr *sap)
96 switch (sap->sa_family) {
98 ((struct sockaddr_in *)sap)->sin_port = 0;
101 ((struct sockaddr_in6 *)sap)->sin6_port = 0;
106 static void nlm_display_address(const struct sockaddr *sap,
107 char *buf, const size_t len)
109 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
110 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
112 switch (sap->sa_family) {
114 snprintf(buf, len, "unspecified");
117 snprintf(buf, len, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
120 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
121 snprintf(buf, len, NIPQUAD_FMT,
122 NIPQUAD(sin6->sin6_addr.s6_addr32[3]));
124 snprintf(buf, len, NIP6_FMT, NIP6(sin6->sin6_addr));
127 snprintf(buf, len, "unsupported address family");
133 * Common host lookup routine for server & client
135 static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
137 struct hlist_head *chain;
138 struct hlist_node *pos;
139 struct nlm_host *host;
140 struct nsm_handle *nsm = NULL;
142 mutex_lock(&nlm_host_mutex);
144 if (time_after_eq(jiffies, next_gc))
147 /* We may keep several nlm_host objects for a peer, because each
148 * nlm_host is identified by
149 * (address, protocol, version, server/client)
150 * We could probably simplify this a little by putting all those
151 * different NLM rpc_clients into one single nlm_host object.
152 * This would allow us to have one nlm_host per address.
154 chain = &nlm_hosts[nlm_hash_address((struct sockaddr *)ni->sin)];
155 hlist_for_each_entry(host, pos, chain, h_hash) {
156 if (!nlm_cmp_addr(nlm_addr(host), (struct sockaddr *)ni->sin))
159 /* See if we have an NSM handle for this client */
161 nsm = host->h_nsmhandle;
163 if (host->h_proto != ni->protocol)
165 if (host->h_version != ni->version)
167 if (host->h_server != ni->server)
169 if (!nlm_cmp_addr(nlm_srcaddr(host),
170 (struct sockaddr *)ni->src_sin))
173 /* Move to head of hash chain. */
174 hlist_del(&host->h_hash);
175 hlist_add_head(&host->h_hash, chain);
178 dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
179 host->h_name, host->h_addrbuf);
184 * The host wasn't in our hash table. If we don't
185 * have an NSM handle for it yet, create one.
188 atomic_inc(&nsm->sm_count);
191 nsm = nsm_find((struct sockaddr *)ni->sin,
192 sizeof(struct sockaddr_in),
193 ni->hostname, ni->hostname_len, 1);
195 dprintk("lockd: nlm_lookup_host failed; "
201 host = kzalloc(sizeof(*host), GFP_KERNEL);
204 dprintk("lockd: nlm_lookup_host failed; no memory\n");
207 host->h_name = nsm->sm_name;
208 memcpy(nlm_addr(host), ni->sin, sizeof(struct sockaddr_in));
209 host->h_addrlen = sizeof(struct sockaddr_in);
210 nlm_clear_port(nlm_addr(host));
211 memcpy(nlm_srcaddr(host), ni->src_sin, sizeof(struct sockaddr_in));
212 host->h_version = ni->version;
213 host->h_proto = ni->protocol;
214 host->h_rpcclnt = NULL;
215 mutex_init(&host->h_mutex);
216 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
217 host->h_expires = jiffies + NLM_HOST_EXPIRE;
218 atomic_set(&host->h_count, 1);
219 init_waitqueue_head(&host->h_gracewait);
220 init_rwsem(&host->h_rwsem);
221 host->h_state = 0; /* pseudo NSM state */
222 host->h_nsmstate = 0; /* real NSM state */
223 host->h_nsmhandle = nsm;
224 host->h_server = ni->server;
225 hlist_add_head(&host->h_hash, chain);
226 INIT_LIST_HEAD(&host->h_lockowners);
227 spin_lock_init(&host->h_lock);
228 INIT_LIST_HEAD(&host->h_granted);
229 INIT_LIST_HEAD(&host->h_reclaim);
233 nlm_display_address((struct sockaddr *)&host->h_addr,
234 host->h_addrbuf, sizeof(host->h_addrbuf));
235 nlm_display_address((struct sockaddr *)&host->h_srcaddr,
236 host->h_srcaddrbuf, sizeof(host->h_srcaddrbuf));
238 dprintk("lockd: nlm_lookup_host created host %s\n",
242 mutex_unlock(&nlm_host_mutex);
250 nlm_destroy_host(struct nlm_host *host)
252 struct rpc_clnt *clnt;
254 BUG_ON(!list_empty(&host->h_lockowners));
255 BUG_ON(atomic_read(&host->h_count));
258 * Release NSM handle and unmonitor host.
262 clnt = host->h_rpcclnt;
264 rpc_shutdown_client(clnt);
269 * Find an NLM server handle in the cache. If there is none, create it.
271 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr_in *sin,
272 int proto, u32 version,
273 const char *hostname,
274 unsigned int hostname_len)
276 const struct sockaddr_in source = {
277 .sin_family = AF_UNSPEC,
279 struct nlm_lookup_host_info ni = {
284 .hostname = hostname,
285 .hostname_len = hostname_len,
289 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
290 (hostname ? hostname : "<none>"), version,
291 (proto == IPPROTO_UDP ? "udp" : "tcp"));
293 return nlm_lookup_host(&ni);
297 * Find an NLM client handle in the cache. If there is none, create it.
300 nlmsvc_lookup_host(struct svc_rqst *rqstp,
301 const char *hostname, unsigned int hostname_len)
303 const struct sockaddr_in source = {
304 .sin_family = AF_INET,
305 .sin_addr = rqstp->rq_daddr.addr,
307 struct nlm_lookup_host_info ni = {
309 .sin = svc_addr_in(rqstp),
310 .protocol = rqstp->rq_prot,
311 .version = rqstp->rq_vers,
312 .hostname = hostname,
313 .hostname_len = hostname_len,
317 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
318 (int)hostname_len, hostname, rqstp->rq_vers,
319 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
321 return nlm_lookup_host(&ni);
325 * Create the NLM RPC client for an NLM peer
328 nlm_bind_host(struct nlm_host *host)
330 struct rpc_clnt *clnt;
332 dprintk("lockd: nlm_bind_host %s (%s), my addr=%s\n",
333 host->h_name, host->h_addrbuf, host->h_srcaddrbuf);
335 /* Lock host handle */
336 mutex_lock(&host->h_mutex);
338 /* If we've already created an RPC client, check whether
339 * RPC rebind is required
341 if ((clnt = host->h_rpcclnt) != NULL) {
342 if (time_after_eq(jiffies, host->h_nextrebind)) {
343 rpc_force_rebind(clnt);
344 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
345 dprintk("lockd: next rebind in %lu jiffies\n",
346 host->h_nextrebind - jiffies);
349 unsigned long increment = nlmsvc_timeout;
350 struct rpc_timeout timeparms = {
351 .to_initval = increment,
352 .to_increment = increment,
353 .to_maxval = increment * 6UL,
356 struct rpc_create_args args = {
357 .protocol = host->h_proto,
358 .address = nlm_addr(host),
359 .addrsize = host->h_addrlen,
360 .saddress = nlm_srcaddr(host),
361 .timeout = &timeparms,
362 .servername = host->h_name,
363 .program = &nlm_program,
364 .version = host->h_version,
365 .authflavor = RPC_AUTH_UNIX,
366 .flags = (RPC_CLNT_CREATE_NOPING |
367 RPC_CLNT_CREATE_AUTOBIND),
371 * lockd retries server side blocks automatically so we want
372 * those to be soft RPC calls. Client side calls need to be
376 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
378 clnt = rpc_create(&args);
380 host->h_rpcclnt = clnt;
382 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
387 mutex_unlock(&host->h_mutex);
392 * Force a portmap lookup of the remote lockd port
395 nlm_rebind_host(struct nlm_host *host)
397 dprintk("lockd: rebind host %s\n", host->h_name);
398 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
399 rpc_force_rebind(host->h_rpcclnt);
400 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
405 * Increment NLM host count
407 struct nlm_host * nlm_get_host(struct nlm_host *host)
410 dprintk("lockd: get host %s\n", host->h_name);
411 atomic_inc(&host->h_count);
412 host->h_expires = jiffies + NLM_HOST_EXPIRE;
418 * Release NLM host after use
420 void nlm_release_host(struct nlm_host *host)
423 dprintk("lockd: release host %s\n", host->h_name);
424 BUG_ON(atomic_read(&host->h_count) < 0);
425 if (atomic_dec_and_test(&host->h_count)) {
426 BUG_ON(!list_empty(&host->h_lockowners));
427 BUG_ON(!list_empty(&host->h_granted));
428 BUG_ON(!list_empty(&host->h_reclaim));
434 * We were notified that the host indicated by address &sin
436 * Release all resources held by that peer.
438 void nlm_host_rebooted(const struct sockaddr_in *sin,
439 const char *hostname,
440 unsigned int hostname_len,
443 struct hlist_head *chain;
444 struct hlist_node *pos;
445 struct nsm_handle *nsm;
446 struct nlm_host *host;
448 nsm = nsm_find((struct sockaddr *)sin, sizeof(*sin),
449 hostname, hostname_len, 0);
451 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
452 hostname_len, hostname);
456 dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n",
457 hostname_len, hostname, nsm->sm_addrbuf);
459 /* When reclaiming locks on this peer, make sure that
460 * we set up a new notification */
461 nsm->sm_monitored = 0;
463 /* Mark all hosts tied to this NSM state as having rebooted.
464 * We run the loop repeatedly, because we drop the host table
466 * To avoid processing a host several times, we match the nsmstate.
468 again: mutex_lock(&nlm_host_mutex);
469 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
470 hlist_for_each_entry(host, pos, chain, h_hash) {
471 if (host->h_nsmhandle == nsm
472 && host->h_nsmstate != new_state) {
473 host->h_nsmstate = new_state;
477 mutex_unlock(&nlm_host_mutex);
479 if (host->h_server) {
480 /* We're server for this guy, just ditch
481 * all the locks he held. */
482 nlmsvc_free_host_resources(host);
484 /* He's the server, initiate lock recovery. */
485 nlmclnt_recovery(host);
488 nlm_release_host(host);
494 mutex_unlock(&nlm_host_mutex);
498 * Shut down the hosts module.
499 * Note that this routine is called only at server shutdown time.
502 nlm_shutdown_hosts(void)
504 struct hlist_head *chain;
505 struct hlist_node *pos;
506 struct nlm_host *host;
508 dprintk("lockd: shutting down host module\n");
509 mutex_lock(&nlm_host_mutex);
511 /* First, make all hosts eligible for gc */
512 dprintk("lockd: nuking all hosts...\n");
513 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
514 hlist_for_each_entry(host, pos, chain, h_hash) {
515 host->h_expires = jiffies - 1;
516 if (host->h_rpcclnt) {
517 rpc_shutdown_client(host->h_rpcclnt);
518 host->h_rpcclnt = NULL;
523 /* Then, perform a garbage collection pass */
525 mutex_unlock(&nlm_host_mutex);
527 /* complain if any hosts are left */
529 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
530 dprintk("lockd: %d hosts left:\n", nrhosts);
531 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
532 hlist_for_each_entry(host, pos, chain, h_hash) {
533 dprintk(" %s (cnt %d use %d exp %ld)\n",
534 host->h_name, atomic_read(&host->h_count),
535 host->h_inuse, host->h_expires);
542 * Garbage collect any unused NLM hosts.
543 * This GC combines reference counting for async operations with
544 * mark & sweep for resources held by remote clients.
549 struct hlist_head *chain;
550 struct hlist_node *pos, *next;
551 struct nlm_host *host;
553 dprintk("lockd: host garbage collection\n");
554 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
555 hlist_for_each_entry(host, pos, chain, h_hash)
559 /* Mark all hosts that hold locks, blocks or shares */
560 nlmsvc_mark_resources();
562 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
563 hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
564 if (atomic_read(&host->h_count) || host->h_inuse
565 || time_before(jiffies, host->h_expires)) {
566 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
567 host->h_name, atomic_read(&host->h_count),
568 host->h_inuse, host->h_expires);
571 dprintk("lockd: delete host %s\n", host->h_name);
572 hlist_del_init(&host->h_hash);
574 nlm_destroy_host(host);
579 next_gc = jiffies + NLM_HOST_COLLECT;
586 static LIST_HEAD(nsm_handles);
587 static DEFINE_SPINLOCK(nsm_lock);
589 static struct nsm_handle *nsm_find(const struct sockaddr *sap,
591 const char *hostname,
592 const size_t hostname_len,
595 struct nsm_handle *nsm = NULL;
596 struct nsm_handle *pos;
601 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
602 if (printk_ratelimit()) {
603 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
604 "in NFS lock request\n",
605 (int)hostname_len, hostname);
611 spin_lock(&nsm_lock);
612 list_for_each_entry(pos, &nsm_handles, sm_link) {
614 if (hostname && nsm_use_hostnames) {
615 if (strlen(pos->sm_name) != hostname_len
616 || memcmp(pos->sm_name, hostname, hostname_len))
618 } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
620 atomic_inc(&pos->sm_count);
626 list_add(&nsm->sm_link, &nsm_handles);
629 spin_unlock(&nsm_lock);
634 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
638 memcpy(nsm_addr(nsm), sap, salen);
639 nsm->sm_addrlen = salen;
640 nsm->sm_name = (char *) (nsm + 1);
641 memcpy(nsm->sm_name, hostname, hostname_len);
642 nsm->sm_name[hostname_len] = '\0';
643 nlm_display_address((struct sockaddr *)&nsm->sm_addr,
644 nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
645 atomic_set(&nsm->sm_count, 1);
649 spin_unlock(&nsm_lock);
654 * Release an NSM handle
657 nsm_release(struct nsm_handle *nsm)
661 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
662 list_del(&nsm->sm_link);
663 spin_unlock(&nsm_lock);