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/sunrpc/clnt.h>
15 #include <linux/sunrpc/svc.h>
16 #include <linux/lockd/lockd.h>
17 #include <linux/lockd/sm_inter.h>
18 #include <linux/mutex.h>
21 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
22 #define NLM_HOST_NRHASH 32
23 #define NLM_ADDRHASH(addr) (ntohl(addr) & (NLM_HOST_NRHASH-1))
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 unsigned long next_gc;
31 static DEFINE_MUTEX(nlm_host_mutex);
34 static void nlm_gc_hosts(void);
35 static struct nsm_handle * __nsm_find(const struct sockaddr_in *,
36 const char *, unsigned int, int);
37 static struct nsm_handle * nsm_find(const struct sockaddr_in *sin,
39 unsigned int hostname_len);
42 * Common host lookup routine for server & client
44 static struct nlm_host *nlm_lookup_host(int server,
45 const struct sockaddr_in *sin,
46 int proto, u32 version,
48 unsigned int hostname_len,
49 const struct sockaddr_in *ssin)
51 struct hlist_head *chain;
52 struct hlist_node *pos;
53 struct nlm_host *host;
54 struct nsm_handle *nsm = NULL;
57 dprintk("lockd: nlm_lookup_host("NIPQUAD_FMT"->"NIPQUAD_FMT
58 ", p=%d, v=%u, my role=%s, name=%.*s)\n",
59 NIPQUAD(ssin->sin_addr.s_addr),
60 NIPQUAD(sin->sin_addr.s_addr), proto, version,
61 server? "server" : "client",
63 hostname? hostname : "<none>");
66 hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
69 mutex_lock(&nlm_host_mutex);
71 if (time_after_eq(jiffies, next_gc))
74 /* We may keep several nlm_host objects for a peer, because each
75 * nlm_host is identified by
76 * (address, protocol, version, server/client)
77 * We could probably simplify this a little by putting all those
78 * different NLM rpc_clients into one single nlm_host object.
79 * This would allow us to have one nlm_host per address.
81 chain = &nlm_hosts[hash];
82 hlist_for_each_entry(host, pos, chain, h_hash) {
83 if (!nlm_cmp_addr(&host->h_addr, sin))
86 /* See if we have an NSM handle for this client */
88 nsm = host->h_nsmhandle;
90 if (host->h_proto != proto)
92 if (host->h_version != version)
94 if (host->h_server != server)
96 if (!nlm_cmp_addr(&host->h_saddr, ssin))
99 /* Move to head of hash chain. */
100 hlist_del(&host->h_hash);
101 hlist_add_head(&host->h_hash, chain);
108 * The host wasn't in our hash table. If we don't
109 * have an NSM handle for it yet, create one.
112 atomic_inc(&nsm->sm_count);
115 nsm = nsm_find(sin, hostname, hostname_len);
120 host = kzalloc(sizeof(*host), GFP_KERNEL);
125 host->h_name = nsm->sm_name;
127 host->h_addr.sin_port = 0; /* ouch! */
128 host->h_saddr = *ssin;
129 host->h_version = version;
130 host->h_proto = proto;
131 host->h_rpcclnt = NULL;
132 mutex_init(&host->h_mutex);
133 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
134 host->h_expires = jiffies + NLM_HOST_EXPIRE;
135 atomic_set(&host->h_count, 1);
136 init_waitqueue_head(&host->h_gracewait);
137 init_rwsem(&host->h_rwsem);
138 host->h_state = 0; /* pseudo NSM state */
139 host->h_nsmstate = 0; /* real NSM state */
140 host->h_nsmhandle = nsm;
141 host->h_server = server;
142 hlist_add_head(&host->h_hash, chain);
143 INIT_LIST_HEAD(&host->h_lockowners);
144 spin_lock_init(&host->h_lock);
145 INIT_LIST_HEAD(&host->h_granted);
146 INIT_LIST_HEAD(&host->h_reclaim);
150 mutex_unlock(&nlm_host_mutex);
158 nlm_destroy_host(struct nlm_host *host)
160 struct rpc_clnt *clnt;
162 BUG_ON(!list_empty(&host->h_lockowners));
163 BUG_ON(atomic_read(&host->h_count));
166 * Release NSM handle and unmonitor host.
170 clnt = host->h_rpcclnt;
172 rpc_shutdown_client(clnt);
177 * Find an NLM server handle in the cache. If there is none, create it.
179 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr_in *sin,
180 int proto, u32 version,
181 const char *hostname,
182 unsigned int hostname_len)
184 struct sockaddr_in ssin = {0};
186 return nlm_lookup_host(0, sin, proto, version,
187 hostname, hostname_len, &ssin);
191 * Find an NLM client handle in the cache. If there is none, create it.
194 nlmsvc_lookup_host(struct svc_rqst *rqstp,
195 const char *hostname, unsigned int hostname_len)
197 struct sockaddr_in ssin = {0};
199 ssin.sin_addr = rqstp->rq_daddr.addr;
200 return nlm_lookup_host(1, svc_addr_in(rqstp),
201 rqstp->rq_prot, rqstp->rq_vers,
202 hostname, hostname_len, &ssin);
206 * Create the NLM RPC client for an NLM peer
209 nlm_bind_host(struct nlm_host *host)
211 struct rpc_clnt *clnt;
213 dprintk("lockd: nlm_bind_host("NIPQUAD_FMT"->"NIPQUAD_FMT")\n",
214 NIPQUAD(host->h_saddr.sin_addr),
215 NIPQUAD(host->h_addr.sin_addr));
217 /* Lock host handle */
218 mutex_lock(&host->h_mutex);
220 /* If we've already created an RPC client, check whether
221 * RPC rebind is required
223 if ((clnt = host->h_rpcclnt) != NULL) {
224 if (time_after_eq(jiffies, host->h_nextrebind)) {
225 rpc_force_rebind(clnt);
226 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
227 dprintk("lockd: next rebind in %ld jiffies\n",
228 host->h_nextrebind - jiffies);
231 unsigned long increment = nlmsvc_timeout;
232 struct rpc_timeout timeparms = {
233 .to_initval = increment,
234 .to_increment = increment,
235 .to_maxval = increment * 6UL,
238 struct rpc_create_args args = {
239 .protocol = host->h_proto,
240 .address = (struct sockaddr *)&host->h_addr,
241 .addrsize = sizeof(host->h_addr),
242 .saddress = (struct sockaddr *)&host->h_saddr,
243 .timeout = &timeparms,
244 .servername = host->h_name,
245 .program = &nlm_program,
246 .version = host->h_version,
247 .authflavor = RPC_AUTH_UNIX,
248 .flags = (RPC_CLNT_CREATE_NOPING |
249 RPC_CLNT_CREATE_AUTOBIND),
253 * lockd retries server side blocks automatically so we want
254 * those to be soft RPC calls. Client side calls need to be
258 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
260 clnt = rpc_create(&args);
262 host->h_rpcclnt = clnt;
264 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
269 mutex_unlock(&host->h_mutex);
274 * Force a portmap lookup of the remote lockd port
277 nlm_rebind_host(struct nlm_host *host)
279 dprintk("lockd: rebind host %s\n", host->h_name);
280 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
281 rpc_force_rebind(host->h_rpcclnt);
282 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
287 * Increment NLM host count
289 struct nlm_host * nlm_get_host(struct nlm_host *host)
292 dprintk("lockd: get host %s\n", host->h_name);
293 atomic_inc(&host->h_count);
294 host->h_expires = jiffies + NLM_HOST_EXPIRE;
300 * Release NLM host after use
302 void nlm_release_host(struct nlm_host *host)
305 dprintk("lockd: release host %s\n", host->h_name);
306 BUG_ON(atomic_read(&host->h_count) < 0);
307 if (atomic_dec_and_test(&host->h_count)) {
308 BUG_ON(!list_empty(&host->h_lockowners));
309 BUG_ON(!list_empty(&host->h_granted));
310 BUG_ON(!list_empty(&host->h_reclaim));
316 * We were notified that the host indicated by address &sin
318 * Release all resources held by that peer.
320 void nlm_host_rebooted(const struct sockaddr_in *sin,
321 const char *hostname,
322 unsigned int hostname_len,
325 struct hlist_head *chain;
326 struct hlist_node *pos;
327 struct nsm_handle *nsm;
328 struct nlm_host *host;
330 dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
331 hostname, NIPQUAD(sin->sin_addr));
333 /* Find the NSM handle for this peer */
334 if (!(nsm = __nsm_find(sin, hostname, hostname_len, 0)))
337 /* When reclaiming locks on this peer, make sure that
338 * we set up a new notification */
339 nsm->sm_monitored = 0;
341 /* Mark all hosts tied to this NSM state as having rebooted.
342 * We run the loop repeatedly, because we drop the host table
344 * To avoid processing a host several times, we match the nsmstate.
346 again: mutex_lock(&nlm_host_mutex);
347 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
348 hlist_for_each_entry(host, pos, chain, h_hash) {
349 if (host->h_nsmhandle == nsm
350 && host->h_nsmstate != new_state) {
351 host->h_nsmstate = new_state;
355 mutex_unlock(&nlm_host_mutex);
357 if (host->h_server) {
358 /* We're server for this guy, just ditch
359 * all the locks he held. */
360 nlmsvc_free_host_resources(host);
362 /* He's the server, initiate lock recovery. */
363 nlmclnt_recovery(host);
366 nlm_release_host(host);
372 mutex_unlock(&nlm_host_mutex);
376 * Shut down the hosts module.
377 * Note that this routine is called only at server shutdown time.
380 nlm_shutdown_hosts(void)
382 struct hlist_head *chain;
383 struct hlist_node *pos;
384 struct nlm_host *host;
386 dprintk("lockd: shutting down host module\n");
387 mutex_lock(&nlm_host_mutex);
389 /* First, make all hosts eligible for gc */
390 dprintk("lockd: nuking all hosts...\n");
391 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
392 hlist_for_each_entry(host, pos, chain, h_hash) {
393 host->h_expires = jiffies - 1;
394 if (host->h_rpcclnt) {
395 rpc_shutdown_client(host->h_rpcclnt);
396 host->h_rpcclnt = NULL;
401 /* Then, perform a garbage collection pass */
403 mutex_unlock(&nlm_host_mutex);
405 /* complain if any hosts are left */
407 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
408 dprintk("lockd: %d hosts left:\n", nrhosts);
409 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
410 hlist_for_each_entry(host, pos, chain, h_hash) {
411 dprintk(" %s (cnt %d use %d exp %ld)\n",
412 host->h_name, atomic_read(&host->h_count),
413 host->h_inuse, host->h_expires);
420 * Garbage collect any unused NLM hosts.
421 * This GC combines reference counting for async operations with
422 * mark & sweep for resources held by remote clients.
427 struct hlist_head *chain;
428 struct hlist_node *pos, *next;
429 struct nlm_host *host;
431 dprintk("lockd: host garbage collection\n");
432 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
433 hlist_for_each_entry(host, pos, chain, h_hash)
437 /* Mark all hosts that hold locks, blocks or shares */
438 nlmsvc_mark_resources();
440 for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
441 hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
442 if (atomic_read(&host->h_count) || host->h_inuse
443 || time_before(jiffies, host->h_expires)) {
444 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
445 host->h_name, atomic_read(&host->h_count),
446 host->h_inuse, host->h_expires);
449 dprintk("lockd: delete host %s\n", host->h_name);
450 hlist_del_init(&host->h_hash);
452 nlm_destroy_host(host);
457 next_gc = jiffies + NLM_HOST_COLLECT;
464 static LIST_HEAD(nsm_handles);
465 static DEFINE_SPINLOCK(nsm_lock);
467 static struct nsm_handle *
468 __nsm_find(const struct sockaddr_in *sin,
469 const char *hostname, unsigned int hostname_len,
472 struct nsm_handle *nsm = NULL;
473 struct nsm_handle *pos;
478 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
479 if (printk_ratelimit()) {
480 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
481 "in NFS lock request\n",
482 hostname_len, hostname);
488 spin_lock(&nsm_lock);
489 list_for_each_entry(pos, &nsm_handles, sm_link) {
491 if (hostname && nsm_use_hostnames) {
492 if (strlen(pos->sm_name) != hostname_len
493 || memcmp(pos->sm_name, hostname, hostname_len))
495 } else if (!nlm_cmp_addr(&pos->sm_addr, sin))
497 atomic_inc(&pos->sm_count);
503 list_add(&nsm->sm_link, &nsm_handles);
506 spin_unlock(&nsm_lock);
511 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
516 nsm->sm_name = (char *) (nsm + 1);
517 memcpy(nsm->sm_name, hostname, hostname_len);
518 nsm->sm_name[hostname_len] = '\0';
519 atomic_set(&nsm->sm_count, 1);
523 spin_unlock(&nsm_lock);
527 static struct nsm_handle *
528 nsm_find(const struct sockaddr_in *sin, const char *hostname,
529 unsigned int hostname_len)
531 return __nsm_find(sin, hostname, hostname_len, 1);
535 * Release an NSM handle
538 nsm_release(struct nsm_handle *nsm)
542 if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
543 list_del(&nsm->sm_link);
544 spin_unlock(&nsm_lock);