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 */
54 * Hash function must work well on big- and little-endian platforms
56 static unsigned int __nlm_hash32(const __be32 n)
58 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
59 return hash ^ (hash >> 8);
62 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
64 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
65 return __nlm_hash32(sin->sin_addr.s_addr);
68 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
70 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
71 const struct in6_addr addr = sin6->sin6_addr;
72 return __nlm_hash32(addr.s6_addr32[0]) ^
73 __nlm_hash32(addr.s6_addr32[1]) ^
74 __nlm_hash32(addr.s6_addr32[2]) ^
75 __nlm_hash32(addr.s6_addr32[3]);
78 static unsigned int nlm_hash_address(const struct sockaddr *sap)
82 switch (sap->sa_family) {
84 hash = __nlm_hash_addr4(sap);
87 hash = __nlm_hash_addr6(sap);
92 return hash & (NLM_HOST_NRHASH - 1);
95 static void nlm_clear_port(struct sockaddr *sap)
97 switch (sap->sa_family) {
99 ((struct sockaddr_in *)sap)->sin_port = 0;
102 ((struct sockaddr_in6 *)sap)->sin6_port = 0;
107 static void nlm_display_address(const struct sockaddr *sap,
108 char *buf, const size_t len)
110 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
111 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
113 switch (sap->sa_family) {
115 snprintf(buf, len, "unspecified");
118 snprintf(buf, len, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
121 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
122 snprintf(buf, len, NIPQUAD_FMT,
123 NIPQUAD(sin6->sin6_addr.s6_addr32[3]));
125 snprintf(buf, len, NIP6_FMT, NIP6(sin6->sin6_addr));
128 snprintf(buf, len, "unsupported address family");
134 * Common host lookup routine for server & client
136 static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
138 struct hlist_head *chain;
139 struct hlist_node *pos;
140 struct nlm_host *host;
141 struct nsm_handle *nsm = NULL;
143 mutex_lock(&nlm_host_mutex);
145 if (time_after_eq(jiffies, next_gc))
148 /* We may keep several nlm_host objects for a peer, because each
149 * nlm_host is identified by
150 * (address, protocol, version, server/client)
151 * We could probably simplify this a little by putting all those
152 * different NLM rpc_clients into one single nlm_host object.
153 * This would allow us to have one nlm_host per address.
155 chain = &nlm_hosts[nlm_hash_address(ni->sap)];
156 hlist_for_each_entry(host, pos, chain, h_hash) {
157 if (!nlm_cmp_addr(nlm_addr(host), ni->sap))
160 /* See if we have an NSM handle for this client */
162 nsm = host->h_nsmhandle;
164 if (host->h_proto != ni->protocol)
166 if (host->h_version != ni->version)
168 if (host->h_server != ni->server)
170 if (!nlm_cmp_addr(nlm_srcaddr(host), ni->src_sap))
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(ni->sap, ni->salen,
192 ni->hostname, ni->hostname_len, 1);
194 dprintk("lockd: nlm_lookup_host failed; "
200 host = kzalloc(sizeof(*host), GFP_KERNEL);
203 dprintk("lockd: nlm_lookup_host failed; no memory\n");
206 host->h_name = nsm->sm_name;
207 memcpy(nlm_addr(host), ni->sap, ni->salen);
208 host->h_addrlen = ni->salen;
209 nlm_clear_port(nlm_addr(host));
210 memcpy(nlm_srcaddr(host), ni->src_sap, ni->src_len);
211 host->h_version = ni->version;
212 host->h_proto = ni->protocol;
213 host->h_rpcclnt = NULL;
214 mutex_init(&host->h_mutex);
215 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
216 host->h_expires = jiffies + NLM_HOST_EXPIRE;
217 atomic_set(&host->h_count, 1);
218 init_waitqueue_head(&host->h_gracewait);
219 init_rwsem(&host->h_rwsem);
220 host->h_state = 0; /* pseudo NSM state */
221 host->h_nsmstate = 0; /* real NSM state */
222 host->h_nsmhandle = nsm;
223 host->h_server = ni->server;
224 hlist_add_head(&host->h_hash, chain);
225 INIT_LIST_HEAD(&host->h_lockowners);
226 spin_lock_init(&host->h_lock);
227 INIT_LIST_HEAD(&host->h_granted);
228 INIT_LIST_HEAD(&host->h_reclaim);
232 nlm_display_address((struct sockaddr *)&host->h_addr,
233 host->h_addrbuf, sizeof(host->h_addrbuf));
234 nlm_display_address((struct sockaddr *)&host->h_srcaddr,
235 host->h_srcaddrbuf, sizeof(host->h_srcaddrbuf));
237 dprintk("lockd: nlm_lookup_host created host %s\n",
241 mutex_unlock(&nlm_host_mutex);
249 nlm_destroy_host(struct nlm_host *host)
251 struct rpc_clnt *clnt;
253 BUG_ON(!list_empty(&host->h_lockowners));
254 BUG_ON(atomic_read(&host->h_count));
257 * Release NSM handle and unmonitor host.
261 clnt = host->h_rpcclnt;
263 rpc_shutdown_client(clnt);
268 * Find an NLM server handle in the cache. If there is none, create it.
270 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr_in *sin,
271 int proto, u32 version,
272 const char *hostname,
273 unsigned int hostname_len)
275 const struct sockaddr source = {
276 .sa_family = AF_UNSPEC,
278 struct nlm_lookup_host_info ni = {
280 .sap = (struct sockaddr *)sin,
281 .salen = sizeof(*sin),
284 .hostname = hostname,
285 .hostname_len = hostname_len,
287 .src_len = sizeof(source),
290 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
291 (hostname ? hostname : "<none>"), version,
292 (proto == IPPROTO_UDP ? "udp" : "tcp"));
294 return nlm_lookup_host(&ni);
298 * Find an NLM client handle in the cache. If there is none, create it.
301 nlmsvc_lookup_host(struct svc_rqst *rqstp,
302 const char *hostname, unsigned int hostname_len)
304 const struct sockaddr_in source = {
305 .sin_family = AF_INET,
306 .sin_addr = rqstp->rq_daddr.addr,
308 struct nlm_lookup_host_info ni = {
310 .sap = svc_addr(rqstp),
311 .salen = rqstp->rq_addrlen,
312 .protocol = rqstp->rq_prot,
313 .version = rqstp->rq_vers,
314 .hostname = hostname,
315 .hostname_len = hostname_len,
316 .src_sap = (struct sockaddr *)&source,
317 .src_len = sizeof(source),
320 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
321 (int)hostname_len, hostname, rqstp->rq_vers,
322 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
324 return nlm_lookup_host(&ni);
328 * Create the NLM RPC client for an NLM peer
331 nlm_bind_host(struct nlm_host *host)
333 struct rpc_clnt *clnt;
335 dprintk("lockd: nlm_bind_host %s (%s), my addr=%s\n",
336 host->h_name, host->h_addrbuf, host->h_srcaddrbuf);
338 /* Lock host handle */
339 mutex_lock(&host->h_mutex);
341 /* If we've already created an RPC client, check whether
342 * RPC rebind is required
344 if ((clnt = host->h_rpcclnt) != NULL) {
345 if (time_after_eq(jiffies, host->h_nextrebind)) {
346 rpc_force_rebind(clnt);
347 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
348 dprintk("lockd: next rebind in %lu jiffies\n",
349 host->h_nextrebind - jiffies);
352 unsigned long increment = nlmsvc_timeout;
353 struct rpc_timeout timeparms = {
354 .to_initval = increment,
355 .to_increment = increment,
356 .to_maxval = increment * 6UL,
359 struct rpc_create_args args = {
360 .protocol = host->h_proto,
361 .address = nlm_addr(host),
362 .addrsize = host->h_addrlen,
363 .saddress = nlm_srcaddr(host),
364 .timeout = &timeparms,
365 .servername = host->h_name,
366 .program = &nlm_program,
367 .version = host->h_version,
368 .authflavor = RPC_AUTH_UNIX,
369 .flags = (RPC_CLNT_CREATE_NOPING |
370 RPC_CLNT_CREATE_AUTOBIND),
374 * lockd retries server side blocks automatically so we want
375 * those to be soft RPC calls. Client side calls need to be
379 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
381 clnt = rpc_create(&args);
383 host->h_rpcclnt = clnt;
385 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
390 mutex_unlock(&host->h_mutex);
395 * Force a portmap lookup of the remote lockd port
398 nlm_rebind_host(struct nlm_host *host)
400 dprintk("lockd: rebind host %s\n", host->h_name);
401 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
402 rpc_force_rebind(host->h_rpcclnt);
403 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
408 * Increment NLM host count
410 struct nlm_host * nlm_get_host(struct nlm_host *host)
413 dprintk("lockd: get host %s\n", host->h_name);
414 atomic_inc(&host->h_count);
415 host->h_expires = jiffies + NLM_HOST_EXPIRE;
421 * Release NLM host after use
423 void nlm_release_host(struct nlm_host *host)
426 dprintk("lockd: release host %s\n", host->h_name);
427 BUG_ON(atomic_read(&host->h_count) < 0);
428 if (atomic_dec_and_test(&host->h_count)) {
429 BUG_ON(!list_empty(&host->h_lockowners));
430 BUG_ON(!list_empty(&host->h_granted));
431 BUG_ON(!list_empty(&host->h_reclaim));
437 * We were notified that the host indicated by address &sin
439 * Release all resources held by that peer.
441 void nlm_host_rebooted(const struct sockaddr_in *sin,
442 const char *hostname,
443 unsigned int hostname_len,
446 struct hlist_head *chain;
447 struct hlist_node *pos;
448 struct nsm_handle *nsm;
449 struct nlm_host *host;
451 nsm = nsm_find((struct sockaddr *)sin, sizeof(*sin),
452 hostname, hostname_len, 0);
454 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
455 hostname_len, hostname);
459 dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n",
460 hostname_len, hostname, nsm->sm_addrbuf);
462 /* When reclaiming locks on this peer, make sure that
463 * we set up a new notification */
464 nsm->sm_monitored = 0;
466 /* Mark all hosts tied to this NSM state as having rebooted.
467 * We run the loop repeatedly, because we drop the host table
469 * To avoid processing a host several times, we match the nsmstate.
471 again: mutex_lock(&nlm_host_mutex);
472 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
473 hlist_for_each_entry(host, pos, chain, h_hash) {
474 if (host->h_nsmhandle == nsm
475 && host->h_nsmstate != new_state) {
476 host->h_nsmstate = new_state;
480 mutex_unlock(&nlm_host_mutex);
482 if (host->h_server) {
483 /* We're server for this guy, just ditch
484 * all the locks he held. */
485 nlmsvc_free_host_resources(host);
487 /* He's the server, initiate lock recovery. */
488 nlmclnt_recovery(host);
491 nlm_release_host(host);
497 mutex_unlock(&nlm_host_mutex);
501 * Shut down the hosts module.
502 * Note that this routine is called only at server shutdown time.
505 nlm_shutdown_hosts(void)
507 struct hlist_head *chain;
508 struct hlist_node *pos;
509 struct nlm_host *host;
511 dprintk("lockd: shutting down host module\n");
512 mutex_lock(&nlm_host_mutex);
514 /* First, make all hosts eligible for gc */
515 dprintk("lockd: nuking all hosts...\n");
516 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
517 hlist_for_each_entry(host, pos, chain, h_hash) {
518 host->h_expires = jiffies - 1;
519 if (host->h_rpcclnt) {
520 rpc_shutdown_client(host->h_rpcclnt);
521 host->h_rpcclnt = NULL;
526 /* Then, perform a garbage collection pass */
528 mutex_unlock(&nlm_host_mutex);
530 /* complain if any hosts are left */
532 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
533 dprintk("lockd: %d hosts left:\n", nrhosts);
534 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
535 hlist_for_each_entry(host, pos, chain, h_hash) {
536 dprintk(" %s (cnt %d use %d exp %ld)\n",
537 host->h_name, atomic_read(&host->h_count),
538 host->h_inuse, host->h_expires);
545 * Garbage collect any unused NLM hosts.
546 * This GC combines reference counting for async operations with
547 * mark & sweep for resources held by remote clients.
552 struct hlist_head *chain;
553 struct hlist_node *pos, *next;
554 struct nlm_host *host;
556 dprintk("lockd: host garbage collection\n");
557 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
558 hlist_for_each_entry(host, pos, chain, h_hash)
562 /* Mark all hosts that hold locks, blocks or shares */
563 nlmsvc_mark_resources();
565 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
566 hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
567 if (atomic_read(&host->h_count) || host->h_inuse
568 || time_before(jiffies, host->h_expires)) {
569 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
570 host->h_name, atomic_read(&host->h_count),
571 host->h_inuse, host->h_expires);
574 dprintk("lockd: delete host %s\n", host->h_name);
575 hlist_del_init(&host->h_hash);
577 nlm_destroy_host(host);
582 next_gc = jiffies + NLM_HOST_COLLECT;
589 static LIST_HEAD(nsm_handles);
590 static DEFINE_SPINLOCK(nsm_lock);
592 static struct nsm_handle *nsm_find(const struct sockaddr *sap,
594 const char *hostname,
595 const size_t hostname_len,
598 struct nsm_handle *nsm = NULL;
599 struct nsm_handle *pos;
604 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
605 if (printk_ratelimit()) {
606 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
607 "in NFS lock request\n",
608 (int)hostname_len, hostname);
614 spin_lock(&nsm_lock);
615 list_for_each_entry(pos, &nsm_handles, sm_link) {
617 if (hostname && nsm_use_hostnames) {
618 if (strlen(pos->sm_name) != hostname_len
619 || memcmp(pos->sm_name, hostname, hostname_len))
621 } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
623 atomic_inc(&pos->sm_count);
629 list_add(&nsm->sm_link, &nsm_handles);
632 spin_unlock(&nsm_lock);
637 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
641 memcpy(nsm_addr(nsm), sap, salen);
642 nsm->sm_addrlen = salen;
643 nsm->sm_name = (char *) (nsm + 1);
644 memcpy(nsm->sm_name, hostname, hostname_len);
645 nsm->sm_name[hostname_len] = '\0';
646 nlm_display_address((struct sockaddr *)&nsm->sm_addr,
647 nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
648 atomic_set(&nsm->sm_count, 1);
652 spin_unlock(&nsm_lock);
657 * Release an NSM handle
660 nsm_release(struct nsm_handle *nsm)
664 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
665 list_del(&nsm->sm_link);
666 spin_unlock(&nsm_lock);