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,
42 * Hash function must work well on big- and little-endian platforms
44 static unsigned int __nlm_hash32(const __be32 n)
46 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
47 return hash ^ (hash >> 8);
50 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
52 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
53 return __nlm_hash32(sin->sin_addr.s_addr);
56 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
58 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
59 const struct in6_addr addr = sin6->sin6_addr;
60 return __nlm_hash32(addr.s6_addr32[0]) ^
61 __nlm_hash32(addr.s6_addr32[1]) ^
62 __nlm_hash32(addr.s6_addr32[2]) ^
63 __nlm_hash32(addr.s6_addr32[3]);
66 static unsigned int nlm_hash_address(const struct sockaddr *sap)
70 switch (sap->sa_family) {
72 hash = __nlm_hash_addr4(sap);
75 hash = __nlm_hash_addr6(sap);
80 return hash & (NLM_HOST_NRHASH - 1);
83 static void nlm_clear_port(struct sockaddr *sap)
85 switch (sap->sa_family) {
87 ((struct sockaddr_in *)sap)->sin_port = 0;
90 ((struct sockaddr_in6 *)sap)->sin6_port = 0;
95 static void nlm_display_address(const struct sockaddr *sap,
96 char *buf, const size_t len)
98 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
99 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
101 switch (sap->sa_family) {
103 snprintf(buf, len, "unspecified");
106 snprintf(buf, len, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
109 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
110 snprintf(buf, len, NIPQUAD_FMT,
111 NIPQUAD(sin6->sin6_addr.s6_addr32[3]));
113 snprintf(buf, len, NIP6_FMT, NIP6(sin6->sin6_addr));
116 snprintf(buf, len, "unsupported address family");
122 * Common host lookup routine for server & client
124 static struct nlm_host *nlm_lookup_host(int server,
125 const struct sockaddr_in *sin,
126 int proto, u32 version,
127 const char *hostname,
128 unsigned int hostname_len,
129 const struct sockaddr_in *ssin)
131 struct hlist_head *chain;
132 struct hlist_node *pos;
133 struct nlm_host *host;
134 struct nsm_handle *nsm = NULL;
136 dprintk("lockd: nlm_lookup_host(proto=%d, vers=%u,"
137 " my role is %s, hostname=%.*s)\n",
138 proto, version, server ? "server" : "client",
139 hostname_len, hostname ? hostname : "<none>");
141 mutex_lock(&nlm_host_mutex);
143 if (time_after_eq(jiffies, next_gc))
146 /* We may keep several nlm_host objects for a peer, because each
147 * nlm_host is identified by
148 * (address, protocol, version, server/client)
149 * We could probably simplify this a little by putting all those
150 * different NLM rpc_clients into one single nlm_host object.
151 * This would allow us to have one nlm_host per address.
153 chain = &nlm_hosts[nlm_hash_address((struct sockaddr *)sin)];
154 hlist_for_each_entry(host, pos, chain, h_hash) {
155 if (!nlm_cmp_addr(nlm_addr(host), (struct sockaddr *)sin))
158 /* See if we have an NSM handle for this client */
160 nsm = host->h_nsmhandle;
162 if (host->h_proto != proto)
164 if (host->h_version != version)
166 if (host->h_server != server)
168 if (!nlm_cmp_addr(nlm_srcaddr(host), (struct sockaddr *)ssin))
171 /* Move to head of hash chain. */
172 hlist_del(&host->h_hash);
173 hlist_add_head(&host->h_hash, chain);
176 dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
177 host->h_name, host->h_addrbuf);
182 * The host wasn't in our hash table. If we don't
183 * have an NSM handle for it yet, create one.
186 atomic_inc(&nsm->sm_count);
189 nsm = nsm_find((struct sockaddr *)sin, sizeof(*sin),
190 hostname, hostname_len, 1);
192 dprintk("lockd: nlm_lookup_host failed; "
198 host = kzalloc(sizeof(*host), GFP_KERNEL);
201 dprintk("lockd: nlm_lookup_host failed; no memory\n");
204 host->h_name = nsm->sm_name;
205 memcpy(nlm_addr(host), sin, sizeof(*sin));
206 host->h_addrlen = sizeof(*sin);
207 nlm_clear_port(nlm_addr(host));
208 memcpy(nlm_srcaddr(host), ssin, sizeof(*ssin));
209 host->h_version = version;
210 host->h_proto = proto;
211 host->h_rpcclnt = NULL;
212 mutex_init(&host->h_mutex);
213 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
214 host->h_expires = jiffies + NLM_HOST_EXPIRE;
215 atomic_set(&host->h_count, 1);
216 init_waitqueue_head(&host->h_gracewait);
217 init_rwsem(&host->h_rwsem);
218 host->h_state = 0; /* pseudo NSM state */
219 host->h_nsmstate = 0; /* real NSM state */
220 host->h_nsmhandle = nsm;
221 host->h_server = server;
222 hlist_add_head(&host->h_hash, chain);
223 INIT_LIST_HEAD(&host->h_lockowners);
224 spin_lock_init(&host->h_lock);
225 INIT_LIST_HEAD(&host->h_granted);
226 INIT_LIST_HEAD(&host->h_reclaim);
230 nlm_display_address((struct sockaddr *)&host->h_addr,
231 host->h_addrbuf, sizeof(host->h_addrbuf));
232 nlm_display_address((struct sockaddr *)&host->h_srcaddr,
233 host->h_srcaddrbuf, sizeof(host->h_srcaddrbuf));
235 dprintk("lockd: nlm_lookup_host created host %s\n",
239 mutex_unlock(&nlm_host_mutex);
247 nlm_destroy_host(struct nlm_host *host)
249 struct rpc_clnt *clnt;
251 BUG_ON(!list_empty(&host->h_lockowners));
252 BUG_ON(atomic_read(&host->h_count));
255 * Release NSM handle and unmonitor host.
259 clnt = host->h_rpcclnt;
261 rpc_shutdown_client(clnt);
266 * Find an NLM server handle in the cache. If there is none, create it.
268 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr_in *sin,
269 int proto, u32 version,
270 const char *hostname,
271 unsigned int hostname_len)
273 const struct sockaddr_in source = {
274 .sin_family = AF_UNSPEC,
277 return nlm_lookup_host(0, sin, proto, version,
278 hostname, hostname_len, &source);
282 * Find an NLM client handle in the cache. If there is none, create it.
285 nlmsvc_lookup_host(struct svc_rqst *rqstp,
286 const char *hostname, unsigned int hostname_len)
288 const struct sockaddr_in source = {
289 .sin_family = AF_INET,
290 .sin_addr = rqstp->rq_daddr.addr,
293 return nlm_lookup_host(1, svc_addr_in(rqstp),
294 rqstp->rq_prot, rqstp->rq_vers,
295 hostname, hostname_len, &source);
299 * Create the NLM RPC client for an NLM peer
302 nlm_bind_host(struct nlm_host *host)
304 struct rpc_clnt *clnt;
306 dprintk("lockd: nlm_bind_host %s (%s), my addr=%s\n",
307 host->h_name, host->h_addrbuf, host->h_srcaddrbuf);
309 /* Lock host handle */
310 mutex_lock(&host->h_mutex);
312 /* If we've already created an RPC client, check whether
313 * RPC rebind is required
315 if ((clnt = host->h_rpcclnt) != NULL) {
316 if (time_after_eq(jiffies, host->h_nextrebind)) {
317 rpc_force_rebind(clnt);
318 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
319 dprintk("lockd: next rebind in %lu jiffies\n",
320 host->h_nextrebind - jiffies);
323 unsigned long increment = nlmsvc_timeout;
324 struct rpc_timeout timeparms = {
325 .to_initval = increment,
326 .to_increment = increment,
327 .to_maxval = increment * 6UL,
330 struct rpc_create_args args = {
331 .protocol = host->h_proto,
332 .address = nlm_addr(host),
333 .addrsize = host->h_addrlen,
334 .saddress = nlm_srcaddr(host),
335 .timeout = &timeparms,
336 .servername = host->h_name,
337 .program = &nlm_program,
338 .version = host->h_version,
339 .authflavor = RPC_AUTH_UNIX,
340 .flags = (RPC_CLNT_CREATE_NOPING |
341 RPC_CLNT_CREATE_AUTOBIND),
345 * lockd retries server side blocks automatically so we want
346 * those to be soft RPC calls. Client side calls need to be
350 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
352 clnt = rpc_create(&args);
354 host->h_rpcclnt = clnt;
356 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
361 mutex_unlock(&host->h_mutex);
366 * Force a portmap lookup of the remote lockd port
369 nlm_rebind_host(struct nlm_host *host)
371 dprintk("lockd: rebind host %s\n", host->h_name);
372 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
373 rpc_force_rebind(host->h_rpcclnt);
374 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
379 * Increment NLM host count
381 struct nlm_host * nlm_get_host(struct nlm_host *host)
384 dprintk("lockd: get host %s\n", host->h_name);
385 atomic_inc(&host->h_count);
386 host->h_expires = jiffies + NLM_HOST_EXPIRE;
392 * Release NLM host after use
394 void nlm_release_host(struct nlm_host *host)
397 dprintk("lockd: release host %s\n", host->h_name);
398 BUG_ON(atomic_read(&host->h_count) < 0);
399 if (atomic_dec_and_test(&host->h_count)) {
400 BUG_ON(!list_empty(&host->h_lockowners));
401 BUG_ON(!list_empty(&host->h_granted));
402 BUG_ON(!list_empty(&host->h_reclaim));
408 * We were notified that the host indicated by address &sin
410 * Release all resources held by that peer.
412 void nlm_host_rebooted(const struct sockaddr_in *sin,
413 const char *hostname,
414 unsigned int hostname_len,
417 struct hlist_head *chain;
418 struct hlist_node *pos;
419 struct nsm_handle *nsm;
420 struct nlm_host *host;
422 nsm = nsm_find((struct sockaddr *)sin, sizeof(*sin),
423 hostname, hostname_len, 0);
425 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
426 hostname_len, hostname);
430 dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n",
431 hostname_len, hostname, nsm->sm_addrbuf);
433 /* When reclaiming locks on this peer, make sure that
434 * we set up a new notification */
435 nsm->sm_monitored = 0;
437 /* Mark all hosts tied to this NSM state as having rebooted.
438 * We run the loop repeatedly, because we drop the host table
440 * To avoid processing a host several times, we match the nsmstate.
442 again: mutex_lock(&nlm_host_mutex);
443 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
444 hlist_for_each_entry(host, pos, chain, h_hash) {
445 if (host->h_nsmhandle == nsm
446 && host->h_nsmstate != new_state) {
447 host->h_nsmstate = new_state;
451 mutex_unlock(&nlm_host_mutex);
453 if (host->h_server) {
454 /* We're server for this guy, just ditch
455 * all the locks he held. */
456 nlmsvc_free_host_resources(host);
458 /* He's the server, initiate lock recovery. */
459 nlmclnt_recovery(host);
462 nlm_release_host(host);
468 mutex_unlock(&nlm_host_mutex);
472 * Shut down the hosts module.
473 * Note that this routine is called only at server shutdown time.
476 nlm_shutdown_hosts(void)
478 struct hlist_head *chain;
479 struct hlist_node *pos;
480 struct nlm_host *host;
482 dprintk("lockd: shutting down host module\n");
483 mutex_lock(&nlm_host_mutex);
485 /* First, make all hosts eligible for gc */
486 dprintk("lockd: nuking all hosts...\n");
487 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
488 hlist_for_each_entry(host, pos, chain, h_hash) {
489 host->h_expires = jiffies - 1;
490 if (host->h_rpcclnt) {
491 rpc_shutdown_client(host->h_rpcclnt);
492 host->h_rpcclnt = NULL;
497 /* Then, perform a garbage collection pass */
499 mutex_unlock(&nlm_host_mutex);
501 /* complain if any hosts are left */
503 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
504 dprintk("lockd: %d hosts left:\n", nrhosts);
505 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
506 hlist_for_each_entry(host, pos, chain, h_hash) {
507 dprintk(" %s (cnt %d use %d exp %ld)\n",
508 host->h_name, atomic_read(&host->h_count),
509 host->h_inuse, host->h_expires);
516 * Garbage collect any unused NLM hosts.
517 * This GC combines reference counting for async operations with
518 * mark & sweep for resources held by remote clients.
523 struct hlist_head *chain;
524 struct hlist_node *pos, *next;
525 struct nlm_host *host;
527 dprintk("lockd: host garbage collection\n");
528 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
529 hlist_for_each_entry(host, pos, chain, h_hash)
533 /* Mark all hosts that hold locks, blocks or shares */
534 nlmsvc_mark_resources();
536 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
537 hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
538 if (atomic_read(&host->h_count) || host->h_inuse
539 || time_before(jiffies, host->h_expires)) {
540 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
541 host->h_name, atomic_read(&host->h_count),
542 host->h_inuse, host->h_expires);
545 dprintk("lockd: delete host %s\n", host->h_name);
546 hlist_del_init(&host->h_hash);
548 nlm_destroy_host(host);
553 next_gc = jiffies + NLM_HOST_COLLECT;
560 static LIST_HEAD(nsm_handles);
561 static DEFINE_SPINLOCK(nsm_lock);
563 static struct nsm_handle *nsm_find(const struct sockaddr *sap,
565 const char *hostname,
566 const size_t hostname_len,
569 struct nsm_handle *nsm = NULL;
570 struct nsm_handle *pos;
575 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
576 if (printk_ratelimit()) {
577 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
578 "in NFS lock request\n",
579 (int)hostname_len, hostname);
585 spin_lock(&nsm_lock);
586 list_for_each_entry(pos, &nsm_handles, sm_link) {
588 if (hostname && nsm_use_hostnames) {
589 if (strlen(pos->sm_name) != hostname_len
590 || memcmp(pos->sm_name, hostname, hostname_len))
592 } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
594 atomic_inc(&pos->sm_count);
600 list_add(&nsm->sm_link, &nsm_handles);
603 spin_unlock(&nsm_lock);
608 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
612 memcpy(nsm_addr(nsm), sap, salen);
613 nsm->sm_addrlen = salen;
614 nsm->sm_name = (char *) (nsm + 1);
615 memcpy(nsm->sm_name, hostname, hostname_len);
616 nsm->sm_name[hostname_len] = '\0';
617 nlm_display_address((struct sockaddr *)&nsm->sm_addr,
618 nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
619 atomic_set(&nsm->sm_count, 1);
623 spin_unlock(&nsm_lock);
628 * Release an NSM handle
631 nsm_release(struct nsm_handle *nsm)
635 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
636 list_del(&nsm->sm_link);
637 spin_unlock(&nsm_lock);