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_ipv4_address(const struct sockaddr *sap, char *buf,
111 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
112 snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
115 static void nlm_display_ipv6_address(const struct sockaddr *sap, char *buf,
118 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
120 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
121 snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]);
122 else if (sin6->sin6_scope_id != 0)
123 snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr,
124 sin6->sin6_scope_id);
126 snprintf(buf, len, "%pI6", &sin6->sin6_addr);
129 static void nlm_display_address(const struct sockaddr *sap,
130 char *buf, const size_t len)
132 switch (sap->sa_family) {
134 nlm_display_ipv4_address(sap, buf, len);
137 nlm_display_ipv6_address(sap, buf, len);
140 snprintf(buf, len, "unsupported address family");
146 * Common host lookup routine for server & client
148 static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
150 struct hlist_head *chain;
151 struct hlist_node *pos;
152 struct nlm_host *host;
153 struct nsm_handle *nsm = NULL;
155 mutex_lock(&nlm_host_mutex);
157 if (time_after_eq(jiffies, next_gc))
160 /* We may keep several nlm_host objects for a peer, because each
161 * nlm_host is identified by
162 * (address, protocol, version, server/client)
163 * We could probably simplify this a little by putting all those
164 * different NLM rpc_clients into one single nlm_host object.
165 * This would allow us to have one nlm_host per address.
167 chain = &nlm_hosts[nlm_hash_address(ni->sap)];
168 hlist_for_each_entry(host, pos, chain, h_hash) {
169 if (!nlm_cmp_addr(nlm_addr(host), ni->sap))
172 /* See if we have an NSM handle for this client */
174 nsm = host->h_nsmhandle;
176 if (host->h_proto != ni->protocol)
178 if (host->h_version != ni->version)
180 if (host->h_server != ni->server)
183 !nlm_cmp_addr(nlm_srcaddr(host), ni->src_sap))
186 /* Move to head of hash chain. */
187 hlist_del(&host->h_hash);
188 hlist_add_head(&host->h_hash, chain);
191 dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
192 host->h_name, host->h_addrbuf);
197 * The host wasn't in our hash table. If we don't
198 * have an NSM handle for it yet, create one.
201 atomic_inc(&nsm->sm_count);
204 nsm = nsm_find(ni->sap, ni->salen,
205 ni->hostname, ni->hostname_len, 1);
207 dprintk("lockd: nlm_lookup_host failed; "
213 host = kzalloc(sizeof(*host), GFP_KERNEL);
216 dprintk("lockd: nlm_lookup_host failed; no memory\n");
219 host->h_name = nsm->sm_name;
220 host->h_addrbuf = nsm->sm_addrbuf;
221 memcpy(nlm_addr(host), ni->sap, ni->salen);
222 host->h_addrlen = ni->salen;
223 nlm_clear_port(nlm_addr(host));
224 memcpy(nlm_srcaddr(host), ni->src_sap, ni->src_len);
225 host->h_version = ni->version;
226 host->h_proto = ni->protocol;
227 host->h_rpcclnt = NULL;
228 mutex_init(&host->h_mutex);
229 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
230 host->h_expires = jiffies + NLM_HOST_EXPIRE;
231 atomic_set(&host->h_count, 1);
232 init_waitqueue_head(&host->h_gracewait);
233 init_rwsem(&host->h_rwsem);
234 host->h_state = 0; /* pseudo NSM state */
235 host->h_nsmstate = 0; /* real NSM state */
236 host->h_nsmhandle = nsm;
237 host->h_server = ni->server;
238 host->h_noresvport = ni->noresvport;
239 hlist_add_head(&host->h_hash, chain);
240 INIT_LIST_HEAD(&host->h_lockowners);
241 spin_lock_init(&host->h_lock);
242 INIT_LIST_HEAD(&host->h_granted);
243 INIT_LIST_HEAD(&host->h_reclaim);
247 dprintk("lockd: nlm_lookup_host created host %s\n",
251 mutex_unlock(&nlm_host_mutex);
259 nlm_destroy_host(struct nlm_host *host)
261 struct rpc_clnt *clnt;
263 BUG_ON(!list_empty(&host->h_lockowners));
264 BUG_ON(atomic_read(&host->h_count));
267 * Release NSM handle and unmonitor host.
271 clnt = host->h_rpcclnt;
273 rpc_shutdown_client(clnt);
278 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
279 * @sap: network address of server
280 * @salen: length of server address
281 * @protocol: transport protocol to use
282 * @version: NLM protocol version
283 * @hostname: '\0'-terminated hostname of server
284 * @noresvport: 1 if non-privileged port should be used
286 * Returns an nlm_host structure that matches the passed-in
287 * [server address, transport protocol, NLM version, server hostname].
288 * If one doesn't already exist in the host cache, a new handle is
289 * created and returned.
291 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
293 const unsigned short protocol,
295 const char *hostname,
298 const struct sockaddr source = {
299 .sa_family = AF_UNSPEC,
301 struct nlm_lookup_host_info ni = {
305 .protocol = protocol,
307 .hostname = hostname,
308 .hostname_len = strlen(hostname),
310 .src_len = sizeof(source),
311 .noresvport = noresvport,
314 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
315 (hostname ? hostname : "<none>"), version,
316 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
318 return nlm_lookup_host(&ni);
322 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
323 * @rqstp: incoming NLM request
324 * @hostname: name of client host
325 * @hostname_len: length of client hostname
327 * Returns an nlm_host structure that matches the [client address,
328 * transport protocol, NLM version, client hostname] of the passed-in
329 * NLM request. If one doesn't already exist in the host cache, a
330 * new handle is created and returned.
332 * Before possibly creating a new nlm_host, construct a sockaddr
333 * for a specific source address in case the local system has
334 * multiple network addresses. The family of the address in
335 * rq_daddr is guaranteed to be the same as the family of the
336 * address in rq_addr, so it's safe to use the same family for
337 * the source address.
339 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
340 const char *hostname,
341 const size_t hostname_len)
343 struct sockaddr_in sin = {
344 .sin_family = AF_INET,
346 struct sockaddr_in6 sin6 = {
347 .sin6_family = AF_INET6,
349 struct nlm_lookup_host_info ni = {
351 .sap = svc_addr(rqstp),
352 .salen = rqstp->rq_addrlen,
353 .protocol = rqstp->rq_prot,
354 .version = rqstp->rq_vers,
355 .hostname = hostname,
356 .hostname_len = hostname_len,
357 .src_len = rqstp->rq_addrlen,
360 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
361 (int)hostname_len, hostname, rqstp->rq_vers,
362 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
364 switch (ni.sap->sa_family) {
366 sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
367 ni.src_sap = (struct sockaddr *)&sin;
370 ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
371 ni.src_sap = (struct sockaddr *)&sin6;
377 return nlm_lookup_host(&ni);
381 * Create the NLM RPC client for an NLM peer
384 nlm_bind_host(struct nlm_host *host)
386 struct rpc_clnt *clnt;
388 dprintk("lockd: nlm_bind_host %s (%s)\n",
389 host->h_name, host->h_addrbuf);
391 /* Lock host handle */
392 mutex_lock(&host->h_mutex);
394 /* If we've already created an RPC client, check whether
395 * RPC rebind is required
397 if ((clnt = host->h_rpcclnt) != NULL) {
398 if (time_after_eq(jiffies, host->h_nextrebind)) {
399 rpc_force_rebind(clnt);
400 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
401 dprintk("lockd: next rebind in %lu jiffies\n",
402 host->h_nextrebind - jiffies);
405 unsigned long increment = nlmsvc_timeout;
406 struct rpc_timeout timeparms = {
407 .to_initval = increment,
408 .to_increment = increment,
409 .to_maxval = increment * 6UL,
412 struct rpc_create_args args = {
413 .protocol = host->h_proto,
414 .address = nlm_addr(host),
415 .addrsize = host->h_addrlen,
416 .saddress = nlm_srcaddr(host),
417 .timeout = &timeparms,
418 .servername = host->h_name,
419 .program = &nlm_program,
420 .version = host->h_version,
421 .authflavor = RPC_AUTH_UNIX,
422 .flags = (RPC_CLNT_CREATE_NOPING |
423 RPC_CLNT_CREATE_AUTOBIND),
427 * lockd retries server side blocks automatically so we want
428 * those to be soft RPC calls. Client side calls need to be
432 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
433 if (host->h_noresvport)
434 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
436 clnt = rpc_create(&args);
438 host->h_rpcclnt = clnt;
440 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
445 mutex_unlock(&host->h_mutex);
450 * Force a portmap lookup of the remote lockd port
453 nlm_rebind_host(struct nlm_host *host)
455 dprintk("lockd: rebind host %s\n", host->h_name);
456 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
457 rpc_force_rebind(host->h_rpcclnt);
458 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
463 * Increment NLM host count
465 struct nlm_host * nlm_get_host(struct nlm_host *host)
468 dprintk("lockd: get host %s\n", host->h_name);
469 atomic_inc(&host->h_count);
470 host->h_expires = jiffies + NLM_HOST_EXPIRE;
476 * Release NLM host after use
478 void nlm_release_host(struct nlm_host *host)
481 dprintk("lockd: release host %s\n", host->h_name);
482 BUG_ON(atomic_read(&host->h_count) < 0);
483 if (atomic_dec_and_test(&host->h_count)) {
484 BUG_ON(!list_empty(&host->h_lockowners));
485 BUG_ON(!list_empty(&host->h_granted));
486 BUG_ON(!list_empty(&host->h_reclaim));
492 * We were notified that the host indicated by address &sin
494 * Release all resources held by that peer.
496 void nlm_host_rebooted(const struct sockaddr_in *sin,
497 const char *hostname,
498 unsigned int hostname_len,
501 struct hlist_head *chain;
502 struct hlist_node *pos;
503 struct nsm_handle *nsm;
504 struct nlm_host *host;
506 nsm = nsm_find((struct sockaddr *)sin, sizeof(*sin),
507 hostname, hostname_len, 0);
509 dprintk("lockd: never saw rebooted peer '%.*s' before\n",
510 hostname_len, hostname);
514 dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n",
515 hostname_len, hostname, nsm->sm_addrbuf);
517 /* When reclaiming locks on this peer, make sure that
518 * we set up a new notification */
519 nsm->sm_monitored = 0;
521 /* Mark all hosts tied to this NSM state as having rebooted.
522 * We run the loop repeatedly, because we drop the host table
524 * To avoid processing a host several times, we match the nsmstate.
526 again: mutex_lock(&nlm_host_mutex);
527 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
528 hlist_for_each_entry(host, pos, chain, h_hash) {
529 if (host->h_nsmhandle == nsm
530 && host->h_nsmstate != new_state) {
531 host->h_nsmstate = new_state;
535 mutex_unlock(&nlm_host_mutex);
537 if (host->h_server) {
538 /* We're server for this guy, just ditch
539 * all the locks he held. */
540 nlmsvc_free_host_resources(host);
542 /* He's the server, initiate lock recovery. */
543 nlmclnt_recovery(host);
546 nlm_release_host(host);
552 mutex_unlock(&nlm_host_mutex);
556 * Shut down the hosts module.
557 * Note that this routine is called only at server shutdown time.
560 nlm_shutdown_hosts(void)
562 struct hlist_head *chain;
563 struct hlist_node *pos;
564 struct nlm_host *host;
566 dprintk("lockd: shutting down host module\n");
567 mutex_lock(&nlm_host_mutex);
569 /* First, make all hosts eligible for gc */
570 dprintk("lockd: nuking all hosts...\n");
571 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
572 hlist_for_each_entry(host, pos, chain, h_hash) {
573 host->h_expires = jiffies - 1;
574 if (host->h_rpcclnt) {
575 rpc_shutdown_client(host->h_rpcclnt);
576 host->h_rpcclnt = NULL;
581 /* Then, perform a garbage collection pass */
583 mutex_unlock(&nlm_host_mutex);
585 /* complain if any hosts are left */
587 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
588 dprintk("lockd: %d hosts left:\n", nrhosts);
589 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
590 hlist_for_each_entry(host, pos, chain, h_hash) {
591 dprintk(" %s (cnt %d use %d exp %ld)\n",
592 host->h_name, atomic_read(&host->h_count),
593 host->h_inuse, host->h_expires);
600 * Garbage collect any unused NLM hosts.
601 * This GC combines reference counting for async operations with
602 * mark & sweep for resources held by remote clients.
607 struct hlist_head *chain;
608 struct hlist_node *pos, *next;
609 struct nlm_host *host;
611 dprintk("lockd: host garbage collection\n");
612 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
613 hlist_for_each_entry(host, pos, chain, h_hash)
617 /* Mark all hosts that hold locks, blocks or shares */
618 nlmsvc_mark_resources();
620 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
621 hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
622 if (atomic_read(&host->h_count) || host->h_inuse
623 || time_before(jiffies, host->h_expires)) {
624 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
625 host->h_name, atomic_read(&host->h_count),
626 host->h_inuse, host->h_expires);
629 dprintk("lockd: delete host %s\n", host->h_name);
630 hlist_del_init(&host->h_hash);
632 nlm_destroy_host(host);
637 next_gc = jiffies + NLM_HOST_COLLECT;
644 static LIST_HEAD(nsm_handles);
645 static DEFINE_SPINLOCK(nsm_lock);
647 static struct nsm_handle *nsm_find(const struct sockaddr *sap,
649 const char *hostname,
650 const size_t hostname_len,
653 struct nsm_handle *nsm = NULL;
654 struct nsm_handle *pos;
659 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
660 if (printk_ratelimit()) {
661 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
662 "in NFS lock request\n",
663 (int)hostname_len, hostname);
669 spin_lock(&nsm_lock);
670 list_for_each_entry(pos, &nsm_handles, sm_link) {
672 if (hostname && nsm_use_hostnames) {
673 if (strlen(pos->sm_name) != hostname_len
674 || memcmp(pos->sm_name, hostname, hostname_len))
676 } else if (!nlm_cmp_addr(nsm_addr(pos), sap))
678 atomic_inc(&pos->sm_count);
684 list_add(&nsm->sm_link, &nsm_handles);
687 spin_unlock(&nsm_lock);
692 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
696 memcpy(nsm_addr(nsm), sap, salen);
697 nsm->sm_addrlen = salen;
698 nsm->sm_name = (char *) (nsm + 1);
699 memcpy(nsm->sm_name, hostname, hostname_len);
700 nsm->sm_name[hostname_len] = '\0';
701 nlm_display_address((struct sockaddr *)&nsm->sm_addr,
702 nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
703 atomic_set(&nsm->sm_count, 1);
707 spin_unlock(&nsm_lock);
712 * Release an NSM handle
715 nsm_release(struct nsm_handle *nsm)
719 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
720 list_del(&nsm->sm_link);
721 spin_unlock(&nsm_lock);