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/mutex.h>
22 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
23 #define NLM_HOST_NRHASH 32
24 #define NLM_HOST_REBIND (60 * HZ)
25 #define NLM_HOST_EXPIRE (300 * HZ)
26 #define NLM_HOST_COLLECT (120 * HZ)
28 static struct hlist_head nlm_hosts[NLM_HOST_NRHASH];
29 static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
31 #define for_each_host(host, pos, chain, table) \
32 for ((chain) = (table); \
33 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
34 hlist_for_each_entry((host), (pos), (chain), h_hash)
36 #define for_each_host_safe(host, pos, next, chain, table) \
37 for ((chain) = (table); \
38 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
39 hlist_for_each_entry_safe((host), (pos), (next), \
42 static unsigned long next_gc;
44 static DEFINE_MUTEX(nlm_host_mutex);
46 static void nlm_gc_hosts(void);
48 struct nlm_lookup_host_info {
49 const int server; /* search for server|client */
50 const struct sockaddr *sap; /* address to search for */
51 const size_t salen; /* it's length */
52 const unsigned short protocol; /* transport to search for*/
53 const u32 version; /* NLM version to search for */
54 const char *hostname; /* remote's hostname */
55 const size_t hostname_len; /* it's length */
56 const struct sockaddr *src_sap; /* our address (optional) */
57 const size_t src_len; /* it's length */
58 const int noresvport; /* use non-priv port */
62 * Hash function must work well on big- and little-endian platforms
64 static unsigned int __nlm_hash32(const __be32 n)
66 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
67 return hash ^ (hash >> 8);
70 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
72 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
73 return __nlm_hash32(sin->sin_addr.s_addr);
76 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
78 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
79 const struct in6_addr addr = sin6->sin6_addr;
80 return __nlm_hash32(addr.s6_addr32[0]) ^
81 __nlm_hash32(addr.s6_addr32[1]) ^
82 __nlm_hash32(addr.s6_addr32[2]) ^
83 __nlm_hash32(addr.s6_addr32[3]);
86 static unsigned int nlm_hash_address(const struct sockaddr *sap)
90 switch (sap->sa_family) {
92 hash = __nlm_hash_addr4(sap);
95 hash = __nlm_hash_addr6(sap);
100 return hash & (NLM_HOST_NRHASH - 1);
104 * Allocate and initialize an nlm_host. Common to both client and server.
106 static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
107 struct nsm_handle *nsm)
109 struct nlm_host *host = NULL;
110 unsigned long now = jiffies;
113 atomic_inc(&nsm->sm_count);
116 nsm = nsm_get_handle(ni->sap, ni->salen,
117 ni->hostname, ni->hostname_len);
118 if (unlikely(nsm == NULL)) {
119 dprintk("lockd: %s failed; no nsm handle\n",
125 host = kmalloc(sizeof(*host), GFP_KERNEL);
126 if (unlikely(host == NULL)) {
127 dprintk("lockd: %s failed; no memory\n", __func__);
132 memcpy(nlm_addr(host), ni->sap, ni->salen);
133 host->h_addrlen = ni->salen;
134 rpc_set_port(nlm_addr(host), 0);
135 host->h_srcaddrlen = 0;
137 host->h_rpcclnt = NULL;
138 host->h_name = nsm->sm_name;
139 host->h_version = ni->version;
140 host->h_proto = ni->protocol;
141 host->h_reclaiming = 0;
142 host->h_server = ni->server;
143 host->h_noresvport = ni->noresvport;
145 init_waitqueue_head(&host->h_gracewait);
146 init_rwsem(&host->h_rwsem);
148 host->h_nsmstate = 0;
149 host->h_pidcount = 0;
150 atomic_set(&host->h_count, 1);
151 mutex_init(&host->h_mutex);
152 host->h_nextrebind = now + NLM_HOST_REBIND;
153 host->h_expires = now + NLM_HOST_EXPIRE;
154 INIT_LIST_HEAD(&host->h_lockowners);
155 spin_lock_init(&host->h_lock);
156 INIT_LIST_HEAD(&host->h_granted);
157 INIT_LIST_HEAD(&host->h_reclaim);
158 host->h_nsmhandle = nsm;
159 host->h_addrbuf = nsm->sm_addrbuf;
166 * Common host lookup routine for server & client
168 static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
170 struct hlist_head *chain;
171 struct hlist_node *pos;
172 struct nlm_host *host;
173 struct nsm_handle *nsm = NULL;
175 mutex_lock(&nlm_host_mutex);
177 if (time_after_eq(jiffies, next_gc))
180 /* We may keep several nlm_host objects for a peer, because each
181 * nlm_host is identified by
182 * (address, protocol, version, server/client)
183 * We could probably simplify this a little by putting all those
184 * different NLM rpc_clients into one single nlm_host object.
185 * This would allow us to have one nlm_host per address.
187 chain = &nlm_hosts[nlm_hash_address(ni->sap)];
188 hlist_for_each_entry(host, pos, chain, h_hash) {
189 if (!rpc_cmp_addr(nlm_addr(host), ni->sap))
192 /* See if we have an NSM handle for this client */
194 nsm = host->h_nsmhandle;
196 if (host->h_proto != ni->protocol)
198 if (host->h_version != ni->version)
200 if (host->h_server != ni->server)
202 if (ni->server && ni->src_len != 0 &&
203 !rpc_cmp_addr(nlm_srcaddr(host), ni->src_sap))
206 /* Move to head of hash chain. */
207 hlist_del(&host->h_hash);
208 hlist_add_head(&host->h_hash, chain);
211 dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
212 host->h_name, host->h_addrbuf);
216 host = nlm_alloc_host(ni, nsm);
217 if (unlikely(host == NULL))
220 memcpy(nlm_srcaddr(host), ni->src_sap, ni->src_len);
221 host->h_srcaddrlen = ni->src_len;
222 hlist_add_head(&host->h_hash, chain);
226 dprintk("lockd: nlm_lookup_host created host %s\n",
230 mutex_unlock(&nlm_host_mutex);
235 * Destroy an nlm_host and free associated resources
237 * Caller must hold nlm_host_mutex.
239 static void nlm_destroy_host_locked(struct nlm_host *host)
241 struct rpc_clnt *clnt;
243 dprintk("lockd: destroy host %s\n", host->h_name);
245 BUG_ON(!list_empty(&host->h_lockowners));
246 BUG_ON(atomic_read(&host->h_count));
248 hlist_del_init(&host->h_hash);
251 nsm_release(host->h_nsmhandle);
253 clnt = host->h_rpcclnt;
255 rpc_shutdown_client(clnt);
262 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
263 * @sap: network address of server
264 * @salen: length of server address
265 * @protocol: transport protocol to use
266 * @version: NLM protocol version
267 * @hostname: '\0'-terminated hostname of server
268 * @noresvport: 1 if non-privileged port should be used
270 * Returns an nlm_host structure that matches the passed-in
271 * [server address, transport protocol, NLM version, server hostname].
272 * If one doesn't already exist in the host cache, a new handle is
273 * created and returned.
275 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
277 const unsigned short protocol,
279 const char *hostname,
282 struct nlm_lookup_host_info ni = {
286 .protocol = protocol,
288 .hostname = hostname,
289 .hostname_len = strlen(hostname),
290 .noresvport = noresvport,
292 struct hlist_head *chain;
293 struct hlist_node *pos;
294 struct nlm_host *host;
295 struct nsm_handle *nsm = NULL;
297 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
298 (hostname ? hostname : "<none>"), version,
299 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
301 mutex_lock(&nlm_host_mutex);
303 chain = &nlm_client_hosts[nlm_hash_address(sap)];
304 hlist_for_each_entry(host, pos, chain, h_hash) {
305 if (!rpc_cmp_addr(nlm_addr(host), sap))
308 /* Same address. Share an NSM handle if we already have one */
310 nsm = host->h_nsmhandle;
312 if (host->h_proto != protocol)
314 if (host->h_version != version)
318 dprintk("lockd: %s found host %s (%s)\n", __func__,
319 host->h_name, host->h_addrbuf);
323 host = nlm_alloc_host(&ni, nsm);
324 if (unlikely(host == NULL))
327 hlist_add_head(&host->h_hash, chain);
330 dprintk("lockd: %s created host %s (%s)\n", __func__,
331 host->h_name, host->h_addrbuf);
334 mutex_unlock(&nlm_host_mutex);
339 * nlmclnt_release_host - release client nlm_host
340 * @host: nlm_host to release
343 void nlmclnt_release_host(struct nlm_host *host)
348 dprintk("lockd: release client host %s\n", host->h_name);
350 BUG_ON(atomic_read(&host->h_count) < 0);
351 BUG_ON(host->h_server);
353 if (atomic_dec_and_test(&host->h_count)) {
354 BUG_ON(!list_empty(&host->h_lockowners));
355 BUG_ON(!list_empty(&host->h_granted));
356 BUG_ON(!list_empty(&host->h_reclaim));
358 mutex_lock(&nlm_host_mutex);
359 nlm_destroy_host_locked(host);
360 mutex_unlock(&nlm_host_mutex);
365 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
366 * @rqstp: incoming NLM request
367 * @hostname: name of client host
368 * @hostname_len: length of client hostname
370 * Returns an nlm_host structure that matches the [client address,
371 * transport protocol, NLM version, client hostname] of the passed-in
372 * NLM request. If one doesn't already exist in the host cache, a
373 * new handle is created and returned.
375 * Before possibly creating a new nlm_host, construct a sockaddr
376 * for a specific source address in case the local system has
377 * multiple network addresses. The family of the address in
378 * rq_daddr is guaranteed to be the same as the family of the
379 * address in rq_addr, so it's safe to use the same family for
380 * the source address.
382 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
383 const char *hostname,
384 const size_t hostname_len)
386 struct hlist_head *chain;
387 struct hlist_node *pos;
388 struct nlm_host *host = NULL;
389 struct nsm_handle *nsm = NULL;
390 struct sockaddr_in sin = {
391 .sin_family = AF_INET,
393 struct sockaddr_in6 sin6 = {
394 .sin6_family = AF_INET6,
396 struct nlm_lookup_host_info ni = {
398 .sap = svc_addr(rqstp),
399 .salen = rqstp->rq_addrlen,
400 .protocol = rqstp->rq_prot,
401 .version = rqstp->rq_vers,
402 .hostname = hostname,
403 .hostname_len = hostname_len,
404 .src_len = rqstp->rq_addrlen,
407 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
408 (int)hostname_len, hostname, rqstp->rq_vers,
409 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
411 mutex_lock(&nlm_host_mutex);
413 switch (ni.sap->sa_family) {
415 sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
416 ni.src_sap = (struct sockaddr *)&sin;
419 ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
420 ni.src_sap = (struct sockaddr *)&sin6;
423 dprintk("lockd: %s failed; unrecognized address family\n",
428 if (time_after_eq(jiffies, next_gc))
431 chain = &nlm_hosts[nlm_hash_address(ni.sap)];
432 hlist_for_each_entry(host, pos, chain, h_hash) {
433 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
436 /* Same address. Share an NSM handle if we already have one */
438 nsm = host->h_nsmhandle;
440 if (host->h_proto != ni.protocol)
442 if (host->h_version != ni.version)
444 if (!rpc_cmp_addr(nlm_srcaddr(host), ni.src_sap))
447 /* Move to head of hash chain. */
448 hlist_del(&host->h_hash);
449 hlist_add_head(&host->h_hash, chain);
452 dprintk("lockd: %s found host %s (%s)\n",
453 __func__, host->h_name, host->h_addrbuf);
457 host = nlm_alloc_host(&ni, nsm);
458 if (unlikely(host == NULL))
461 memcpy(nlm_srcaddr(host), ni.src_sap, ni.src_len);
462 host->h_srcaddrlen = ni.src_len;
463 hlist_add_head(&host->h_hash, chain);
466 dprintk("lockd: %s created host %s (%s)\n",
467 __func__, host->h_name, host->h_addrbuf);
470 mutex_unlock(&nlm_host_mutex);
475 * nlmsvc_release_host - release server nlm_host
476 * @host: nlm_host to release
478 * Host is destroyed later in nlm_gc_host().
480 void nlmsvc_release_host(struct nlm_host *host)
485 dprintk("lockd: release server host %s\n", host->h_name);
487 BUG_ON(atomic_read(&host->h_count) < 0);
488 BUG_ON(!host->h_server);
489 atomic_dec(&host->h_count);
493 * Create the NLM RPC client for an NLM peer
496 nlm_bind_host(struct nlm_host *host)
498 struct rpc_clnt *clnt;
500 dprintk("lockd: nlm_bind_host %s (%s)\n",
501 host->h_name, host->h_addrbuf);
503 /* Lock host handle */
504 mutex_lock(&host->h_mutex);
506 /* If we've already created an RPC client, check whether
507 * RPC rebind is required
509 if ((clnt = host->h_rpcclnt) != NULL) {
510 if (time_after_eq(jiffies, host->h_nextrebind)) {
511 rpc_force_rebind(clnt);
512 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
513 dprintk("lockd: next rebind in %lu jiffies\n",
514 host->h_nextrebind - jiffies);
517 unsigned long increment = nlmsvc_timeout;
518 struct rpc_timeout timeparms = {
519 .to_initval = increment,
520 .to_increment = increment,
521 .to_maxval = increment * 6UL,
524 struct rpc_create_args args = {
526 .protocol = host->h_proto,
527 .address = nlm_addr(host),
528 .addrsize = host->h_addrlen,
529 .timeout = &timeparms,
530 .servername = host->h_name,
531 .program = &nlm_program,
532 .version = host->h_version,
533 .authflavor = RPC_AUTH_UNIX,
534 .flags = (RPC_CLNT_CREATE_NOPING |
535 RPC_CLNT_CREATE_AUTOBIND),
539 * lockd retries server side blocks automatically so we want
540 * those to be soft RPC calls. Client side calls need to be
544 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
545 if (host->h_noresvport)
546 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
547 if (host->h_srcaddrlen)
548 args.saddress = nlm_srcaddr(host);
550 clnt = rpc_create(&args);
552 host->h_rpcclnt = clnt;
554 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
559 mutex_unlock(&host->h_mutex);
564 * Force a portmap lookup of the remote lockd port
567 nlm_rebind_host(struct nlm_host *host)
569 dprintk("lockd: rebind host %s\n", host->h_name);
570 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
571 rpc_force_rebind(host->h_rpcclnt);
572 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
577 * Increment NLM host count
579 struct nlm_host * nlm_get_host(struct nlm_host *host)
582 dprintk("lockd: get host %s\n", host->h_name);
583 atomic_inc(&host->h_count);
584 host->h_expires = jiffies + NLM_HOST_EXPIRE;
589 static struct nlm_host *next_host_state(struct hlist_head *cache,
590 struct nsm_handle *nsm,
591 const struct nlm_reboot *info)
593 struct nlm_host *host = NULL;
594 struct hlist_head *chain;
595 struct hlist_node *pos;
597 mutex_lock(&nlm_host_mutex);
598 for_each_host(host, pos, chain, cache) {
599 if (host->h_nsmhandle == nsm
600 && host->h_nsmstate != info->state) {
601 host->h_nsmstate = info->state;
605 mutex_unlock(&nlm_host_mutex);
610 mutex_unlock(&nlm_host_mutex);
615 * nlm_host_rebooted - Release all resources held by rebooted host
616 * @info: pointer to decoded results of NLM_SM_NOTIFY call
618 * We were notified that the specified host has rebooted. Release
619 * all resources held by that peer.
621 void nlm_host_rebooted(const struct nlm_reboot *info)
623 struct nsm_handle *nsm;
624 struct nlm_host *host;
626 nsm = nsm_reboot_lookup(info);
627 if (unlikely(nsm == NULL))
630 /* Mark all hosts tied to this NSM state as having rebooted.
631 * We run the loop repeatedly, because we drop the host table
633 * To avoid processing a host several times, we match the nsmstate.
635 while ((host = next_host_state(nlm_hosts, nsm, info)) != NULL) {
636 nlmsvc_free_host_resources(host);
637 nlmsvc_release_host(host);
639 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
640 nlmclnt_recovery(host);
641 nlmclnt_release_host(host);
648 * Shut down the hosts module.
649 * Note that this routine is called only at server shutdown time.
652 nlm_shutdown_hosts(void)
654 struct hlist_head *chain;
655 struct hlist_node *pos;
656 struct nlm_host *host;
658 dprintk("lockd: shutting down host module\n");
659 mutex_lock(&nlm_host_mutex);
661 /* First, make all hosts eligible for gc */
662 dprintk("lockd: nuking all hosts...\n");
663 for_each_host(host, pos, chain, nlm_hosts) {
664 host->h_expires = jiffies - 1;
665 if (host->h_rpcclnt) {
666 rpc_shutdown_client(host->h_rpcclnt);
667 host->h_rpcclnt = NULL;
671 /* Then, perform a garbage collection pass */
673 mutex_unlock(&nlm_host_mutex);
675 /* complain if any hosts are left */
677 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
678 dprintk("lockd: %d hosts left:\n", nrhosts);
679 for_each_host(host, pos, chain, nlm_hosts) {
680 dprintk(" %s (cnt %d use %d exp %ld)\n",
681 host->h_name, atomic_read(&host->h_count),
682 host->h_inuse, host->h_expires);
688 * Garbage collect any unused NLM hosts.
689 * This GC combines reference counting for async operations with
690 * mark & sweep for resources held by remote clients.
695 struct hlist_head *chain;
696 struct hlist_node *pos, *next;
697 struct nlm_host *host;
699 dprintk("lockd: host garbage collection\n");
700 for_each_host(host, pos, chain, nlm_hosts)
703 /* Mark all hosts that hold locks, blocks or shares */
704 nlmsvc_mark_resources();
706 for_each_host_safe(host, pos, next, chain, nlm_hosts) {
707 if (atomic_read(&host->h_count) || host->h_inuse
708 || time_before(jiffies, host->h_expires)) {
709 dprintk("nlm_gc_hosts skipping %s "
710 "(cnt %d use %d exp %ld)\n",
711 host->h_name, atomic_read(&host->h_count),
712 host->h_inuse, host->h_expires);
715 nlm_destroy_host_locked(host);
718 next_gc = jiffies + NLM_HOST_COLLECT;