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>
20 #include <linux/sunrpc/svc_xprt.h>
26 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
27 #define NLM_HOST_NRHASH 32
28 #define NLM_HOST_REBIND (60 * HZ)
29 #define NLM_HOST_EXPIRE (300 * HZ)
30 #define NLM_HOST_COLLECT (120 * HZ)
32 static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH];
33 static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
35 #define for_each_host(host, chain, table) \
36 for ((chain) = (table); \
37 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
38 hlist_for_each_entry((host), (chain), h_hash)
40 #define for_each_host_safe(host, next, chain, table) \
41 for ((chain) = (table); \
42 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
43 hlist_for_each_entry_safe((host), (next), \
46 static unsigned long nrhosts;
47 static DEFINE_MUTEX(nlm_host_mutex);
49 static void nlm_gc_hosts(struct net *net);
51 struct nlm_lookup_host_info {
52 const int server; /* search for server|client */
53 const struct sockaddr *sap; /* address to search for */
54 const size_t salen; /* it's length */
55 const unsigned short protocol; /* transport to search for*/
56 const u32 version; /* NLM version to search for */
57 const char *hostname; /* remote's hostname */
58 const size_t hostname_len; /* it's length */
59 const int noresvport; /* use non-priv port */
60 struct net *net; /* network namespace to bind */
64 * Hash function must work well on big- and little-endian platforms
66 static unsigned int __nlm_hash32(const __be32 n)
68 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
69 return hash ^ (hash >> 8);
72 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
74 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
75 return __nlm_hash32(sin->sin_addr.s_addr);
78 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
80 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
81 const struct in6_addr addr = sin6->sin6_addr;
82 return __nlm_hash32(addr.s6_addr32[0]) ^
83 __nlm_hash32(addr.s6_addr32[1]) ^
84 __nlm_hash32(addr.s6_addr32[2]) ^
85 __nlm_hash32(addr.s6_addr32[3]);
88 static unsigned int nlm_hash_address(const struct sockaddr *sap)
92 switch (sap->sa_family) {
94 hash = __nlm_hash_addr4(sap);
97 hash = __nlm_hash_addr6(sap);
102 return hash & (NLM_HOST_NRHASH - 1);
106 * Allocate and initialize an nlm_host. Common to both client and server.
108 static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
109 struct nsm_handle *nsm)
111 struct nlm_host *host = NULL;
112 unsigned long now = jiffies;
115 atomic_inc(&nsm->sm_count);
118 nsm = nsm_get_handle(ni->sap, ni->salen,
119 ni->hostname, ni->hostname_len);
120 if (unlikely(nsm == NULL)) {
121 dprintk("lockd: %s failed; no nsm handle\n",
127 host = kmalloc(sizeof(*host), GFP_KERNEL);
128 if (unlikely(host == NULL)) {
129 dprintk("lockd: %s failed; no memory\n", __func__);
134 memcpy(nlm_addr(host), ni->sap, ni->salen);
135 host->h_addrlen = ni->salen;
136 rpc_set_port(nlm_addr(host), 0);
137 host->h_srcaddrlen = 0;
139 host->h_rpcclnt = NULL;
140 host->h_name = nsm->sm_name;
141 host->h_version = ni->version;
142 host->h_proto = ni->protocol;
143 host->h_reclaiming = 0;
144 host->h_server = ni->server;
145 host->h_noresvport = ni->noresvport;
147 init_waitqueue_head(&host->h_gracewait);
148 init_rwsem(&host->h_rwsem);
150 host->h_nsmstate = 0;
151 host->h_pidcount = 0;
152 atomic_set(&host->h_count, 1);
153 mutex_init(&host->h_mutex);
154 host->h_nextrebind = now + NLM_HOST_REBIND;
155 host->h_expires = now + NLM_HOST_EXPIRE;
156 INIT_LIST_HEAD(&host->h_lockowners);
157 spin_lock_init(&host->h_lock);
158 INIT_LIST_HEAD(&host->h_granted);
159 INIT_LIST_HEAD(&host->h_reclaim);
160 host->h_nsmhandle = nsm;
161 host->h_addrbuf = nsm->sm_addrbuf;
169 * Destroy an nlm_host and free associated resources
171 * Caller must hold nlm_host_mutex.
173 static void nlm_destroy_host_locked(struct nlm_host *host)
175 struct rpc_clnt *clnt;
176 struct lockd_net *ln = net_generic(host->net, lockd_net_id);
178 dprintk("lockd: destroy host %s\n", host->h_name);
180 hlist_del_init(&host->h_hash);
183 nsm_release(host->h_nsmhandle);
185 clnt = host->h_rpcclnt;
187 rpc_shutdown_client(clnt);
195 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
196 * @sap: network address of server
197 * @salen: length of server address
198 * @protocol: transport protocol to use
199 * @version: NLM protocol version
200 * @hostname: '\0'-terminated hostname of server
201 * @noresvport: 1 if non-privileged port should be used
203 * Returns an nlm_host structure that matches the passed-in
204 * [server address, transport protocol, NLM version, server hostname].
205 * If one doesn't already exist in the host cache, a new handle is
206 * created and returned.
208 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
210 const unsigned short protocol,
212 const char *hostname,
216 struct nlm_lookup_host_info ni = {
220 .protocol = protocol,
222 .hostname = hostname,
223 .hostname_len = strlen(hostname),
224 .noresvport = noresvport,
227 struct hlist_head *chain;
228 struct nlm_host *host;
229 struct nsm_handle *nsm = NULL;
230 struct lockd_net *ln = net_generic(net, lockd_net_id);
232 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
233 (hostname ? hostname : "<none>"), version,
234 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
236 mutex_lock(&nlm_host_mutex);
238 chain = &nlm_client_hosts[nlm_hash_address(sap)];
239 hlist_for_each_entry(host, chain, h_hash) {
240 if (host->net != net)
242 if (!rpc_cmp_addr(nlm_addr(host), sap))
245 /* Same address. Share an NSM handle if we already have one */
247 nsm = host->h_nsmhandle;
249 if (host->h_proto != protocol)
251 if (host->h_version != version)
255 dprintk("lockd: %s found host %s (%s)\n", __func__,
256 host->h_name, host->h_addrbuf);
260 host = nlm_alloc_host(&ni, nsm);
261 if (unlikely(host == NULL))
264 hlist_add_head(&host->h_hash, chain);
268 dprintk("lockd: %s created host %s (%s)\n", __func__,
269 host->h_name, host->h_addrbuf);
272 mutex_unlock(&nlm_host_mutex);
277 * nlmclnt_release_host - release client nlm_host
278 * @host: nlm_host to release
281 void nlmclnt_release_host(struct nlm_host *host)
286 dprintk("lockd: release client host %s\n", host->h_name);
288 WARN_ON_ONCE(host->h_server);
290 if (atomic_dec_and_test(&host->h_count)) {
291 WARN_ON_ONCE(!list_empty(&host->h_lockowners));
292 WARN_ON_ONCE(!list_empty(&host->h_granted));
293 WARN_ON_ONCE(!list_empty(&host->h_reclaim));
295 mutex_lock(&nlm_host_mutex);
296 nlm_destroy_host_locked(host);
297 mutex_unlock(&nlm_host_mutex);
302 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
303 * @rqstp: incoming NLM request
304 * @hostname: name of client host
305 * @hostname_len: length of client hostname
307 * Returns an nlm_host structure that matches the [client address,
308 * transport protocol, NLM version, client hostname] of the passed-in
309 * NLM request. If one doesn't already exist in the host cache, a
310 * new handle is created and returned.
312 * Before possibly creating a new nlm_host, construct a sockaddr
313 * for a specific source address in case the local system has
314 * multiple network addresses. The family of the address in
315 * rq_daddr is guaranteed to be the same as the family of the
316 * address in rq_addr, so it's safe to use the same family for
317 * the source address.
319 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
320 const char *hostname,
321 const size_t hostname_len)
323 struct hlist_head *chain;
324 struct nlm_host *host = NULL;
325 struct nsm_handle *nsm = NULL;
326 struct sockaddr *src_sap = svc_daddr(rqstp);
327 size_t src_len = rqstp->rq_daddrlen;
328 struct net *net = SVC_NET(rqstp);
329 struct nlm_lookup_host_info ni = {
331 .sap = svc_addr(rqstp),
332 .salen = rqstp->rq_addrlen,
333 .protocol = rqstp->rq_prot,
334 .version = rqstp->rq_vers,
335 .hostname = hostname,
336 .hostname_len = hostname_len,
339 struct lockd_net *ln = net_generic(net, lockd_net_id);
341 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
342 (int)hostname_len, hostname, rqstp->rq_vers,
343 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
345 mutex_lock(&nlm_host_mutex);
347 if (time_after_eq(jiffies, ln->next_gc))
350 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
351 hlist_for_each_entry(host, chain, h_hash) {
352 if (host->net != net)
354 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
357 /* Same address. Share an NSM handle if we already have one */
359 nsm = host->h_nsmhandle;
361 if (host->h_proto != ni.protocol)
363 if (host->h_version != ni.version)
365 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
368 /* Move to head of hash chain. */
369 hlist_del(&host->h_hash);
370 hlist_add_head(&host->h_hash, chain);
373 dprintk("lockd: %s found host %s (%s)\n",
374 __func__, host->h_name, host->h_addrbuf);
378 host = nlm_alloc_host(&ni, nsm);
379 if (unlikely(host == NULL))
382 memcpy(nlm_srcaddr(host), src_sap, src_len);
383 host->h_srcaddrlen = src_len;
384 hlist_add_head(&host->h_hash, chain);
388 dprintk("lockd: %s created host %s (%s)\n",
389 __func__, host->h_name, host->h_addrbuf);
392 mutex_unlock(&nlm_host_mutex);
397 * nlmsvc_release_host - release server nlm_host
398 * @host: nlm_host to release
400 * Host is destroyed later in nlm_gc_host().
402 void nlmsvc_release_host(struct nlm_host *host)
407 dprintk("lockd: release server host %s\n", host->h_name);
409 WARN_ON_ONCE(!host->h_server);
410 atomic_dec(&host->h_count);
414 * Create the NLM RPC client for an NLM peer
417 nlm_bind_host(struct nlm_host *host)
419 struct rpc_clnt *clnt;
421 dprintk("lockd: nlm_bind_host %s (%s)\n",
422 host->h_name, host->h_addrbuf);
424 /* Lock host handle */
425 mutex_lock(&host->h_mutex);
427 /* If we've already created an RPC client, check whether
428 * RPC rebind is required
430 if ((clnt = host->h_rpcclnt) != NULL) {
431 if (time_after_eq(jiffies, host->h_nextrebind)) {
432 rpc_force_rebind(clnt);
433 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
434 dprintk("lockd: next rebind in %lu jiffies\n",
435 host->h_nextrebind - jiffies);
438 unsigned long increment = nlmsvc_timeout;
439 struct rpc_timeout timeparms = {
440 .to_initval = increment,
441 .to_increment = increment,
442 .to_maxval = increment * 6UL,
445 struct rpc_create_args args = {
447 .protocol = host->h_proto,
448 .address = nlm_addr(host),
449 .addrsize = host->h_addrlen,
450 .timeout = &timeparms,
451 .servername = host->h_name,
452 .program = &nlm_program,
453 .version = host->h_version,
454 .authflavor = RPC_AUTH_UNIX,
455 .flags = (RPC_CLNT_CREATE_NOPING |
456 RPC_CLNT_CREATE_AUTOBIND),
460 * lockd retries server side blocks automatically so we want
461 * those to be soft RPC calls. Client side calls need to be
465 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
466 if (host->h_noresvport)
467 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
468 if (host->h_srcaddrlen)
469 args.saddress = nlm_srcaddr(host);
471 clnt = rpc_create(&args);
473 host->h_rpcclnt = clnt;
475 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
480 mutex_unlock(&host->h_mutex);
485 * Force a portmap lookup of the remote lockd port
488 nlm_rebind_host(struct nlm_host *host)
490 dprintk("lockd: rebind host %s\n", host->h_name);
491 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
492 rpc_force_rebind(host->h_rpcclnt);
493 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
498 * Increment NLM host count
500 struct nlm_host * nlm_get_host(struct nlm_host *host)
503 dprintk("lockd: get host %s\n", host->h_name);
504 atomic_inc(&host->h_count);
505 host->h_expires = jiffies + NLM_HOST_EXPIRE;
510 static struct nlm_host *next_host_state(struct hlist_head *cache,
511 struct nsm_handle *nsm,
512 const struct nlm_reboot *info)
514 struct nlm_host *host;
515 struct hlist_head *chain;
517 mutex_lock(&nlm_host_mutex);
518 for_each_host(host, chain, cache) {
519 if (host->h_nsmhandle == nsm
520 && host->h_nsmstate != info->state) {
521 host->h_nsmstate = info->state;
525 mutex_unlock(&nlm_host_mutex);
530 mutex_unlock(&nlm_host_mutex);
535 * nlm_host_rebooted - Release all resources held by rebooted host
536 * @info: pointer to decoded results of NLM_SM_NOTIFY call
538 * We were notified that the specified host has rebooted. Release
539 * all resources held by that peer.
541 void nlm_host_rebooted(const struct nlm_reboot *info)
543 struct nsm_handle *nsm;
544 struct nlm_host *host;
546 nsm = nsm_reboot_lookup(info);
547 if (unlikely(nsm == NULL))
550 /* Mark all hosts tied to this NSM state as having rebooted.
551 * We run the loop repeatedly, because we drop the host table
553 * To avoid processing a host several times, we match the nsmstate.
555 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
556 nlmsvc_free_host_resources(host);
557 nlmsvc_release_host(host);
559 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
560 nlmclnt_recovery(host);
561 nlmclnt_release_host(host);
567 static void nlm_complain_hosts(struct net *net)
569 struct hlist_head *chain;
570 struct nlm_host *host;
573 struct lockd_net *ln = net_generic(net, lockd_net_id);
575 if (ln->nrhosts == 0)
577 printk(KERN_WARNING "lockd: couldn't shutdown host module for net %p!\n", net);
578 dprintk("lockd: %lu hosts left in net %p:\n", ln->nrhosts, net);
582 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
583 dprintk("lockd: %lu hosts left:\n", nrhosts);
586 for_each_host(host, chain, nlm_server_hosts) {
587 if (net && host->net != net)
589 dprintk(" %s (cnt %d use %d exp %ld net %p)\n",
590 host->h_name, atomic_read(&host->h_count),
591 host->h_inuse, host->h_expires, host->net);
596 nlm_shutdown_hosts_net(struct net *net)
598 struct hlist_head *chain;
599 struct nlm_host *host;
601 mutex_lock(&nlm_host_mutex);
603 /* First, make all hosts eligible for gc */
604 dprintk("lockd: nuking all hosts in net %p...\n", net);
605 for_each_host(host, chain, nlm_server_hosts) {
606 if (net && host->net != net)
608 host->h_expires = jiffies - 1;
609 if (host->h_rpcclnt) {
610 rpc_shutdown_client(host->h_rpcclnt);
611 host->h_rpcclnt = NULL;
615 /* Then, perform a garbage collection pass */
617 mutex_unlock(&nlm_host_mutex);
619 nlm_complain_hosts(net);
623 * Shut down the hosts module.
624 * Note that this routine is called only at server shutdown time.
627 nlm_shutdown_hosts(void)
629 dprintk("lockd: shutting down host module\n");
630 nlm_shutdown_hosts_net(NULL);
634 * Garbage collect any unused NLM hosts.
635 * This GC combines reference counting for async operations with
636 * mark & sweep for resources held by remote clients.
639 nlm_gc_hosts(struct net *net)
641 struct hlist_head *chain;
642 struct hlist_node *next;
643 struct nlm_host *host;
645 dprintk("lockd: host garbage collection for net %p\n", net);
646 for_each_host(host, chain, nlm_server_hosts) {
647 if (net && host->net != net)
652 /* Mark all hosts that hold locks, blocks or shares */
653 nlmsvc_mark_resources(net);
655 for_each_host_safe(host, next, chain, nlm_server_hosts) {
656 if (net && host->net != net)
658 if (atomic_read(&host->h_count) || host->h_inuse
659 || time_before(jiffies, host->h_expires)) {
660 dprintk("nlm_gc_hosts skipping %s "
661 "(cnt %d use %d exp %ld net %p)\n",
662 host->h_name, atomic_read(&host->h_count),
663 host->h_inuse, host->h_expires, host->net);
666 nlm_destroy_host_locked(host);
670 struct lockd_net *ln = net_generic(net, lockd_net_id);
672 ln->next_gc = jiffies + NLM_HOST_COLLECT;