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/sched.h>
13 #include <linux/slab.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>
22 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
23 #define NLM_HOST_MAX 64
24 #define NLM_HOST_NRHASH 32
25 #define NLM_ADDRHASH(addr) (ntohl(addr) & (NLM_HOST_NRHASH-1))
26 #define NLM_HOST_REBIND (60 * HZ)
27 #define NLM_HOST_EXPIRE ((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
28 #define NLM_HOST_COLLECT ((nrhosts > NLM_HOST_MAX)? 120 * HZ : 60 * HZ)
30 static struct nlm_host * nlm_hosts[NLM_HOST_NRHASH];
31 static unsigned long next_gc;
33 static DEFINE_MUTEX(nlm_host_mutex);
36 static void nlm_gc_hosts(void);
37 static struct nsm_handle * __nsm_find(const struct sockaddr_in *,
38 const char *, int, int);
41 * Find an NLM server handle in the cache. If there is none, create it.
44 nlmclnt_lookup_host(const struct sockaddr_in *sin, int proto, int version,
45 const char *hostname, int hostname_len)
47 return nlm_lookup_host(0, sin, proto, version,
48 hostname, hostname_len);
52 * Find an NLM client handle in the cache. If there is none, create it.
55 nlmsvc_lookup_host(struct svc_rqst *rqstp,
56 const char *hostname, int hostname_len)
58 return nlm_lookup_host(1, &rqstp->rq_addr,
59 rqstp->rq_prot, rqstp->rq_vers,
60 hostname, hostname_len);
64 * Common host lookup routine for server & client
67 nlm_lookup_host(int server, const struct sockaddr_in *sin,
68 int proto, int version,
72 struct nlm_host *host, **hp;
73 struct nsm_handle *nsm = NULL;
76 dprintk("lockd: nlm_lookup_host(%u.%u.%u.%u, p=%d, v=%d, my role=%s, name=%.*s)\n",
77 NIPQUAD(sin->sin_addr.s_addr), proto, version,
78 server? "server" : "client",
80 hostname? hostname : "<none>");
83 hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
86 mutex_lock(&nlm_host_mutex);
88 if (time_after_eq(jiffies, next_gc))
91 /* We may keep several nlm_host objects for a peer, because each
92 * nlm_host is identified by
93 * (address, protocol, version, server/client)
94 * We could probably simplify this a little by putting all those
95 * different NLM rpc_clients into one single nlm_host object.
96 * This would allow us to have one nlm_host per address.
98 for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
99 if (!nlm_cmp_addr(&host->h_addr, sin))
102 /* See if we have an NSM handle for this client */
103 if (!nsm && (nsm = host->h_nsmhandle) != 0)
104 atomic_inc(&nsm->sm_count);
106 if (host->h_proto != proto)
108 if (host->h_version != version)
110 if (host->h_server != server)
113 if (hp != nlm_hosts + hash) {
115 host->h_next = nlm_hosts[hash];
116 nlm_hosts[hash] = host;
122 /* Sadly, the host isn't in our hash table yet. See if
123 * we have an NSM handle for it. If not, create one.
125 if (!nsm && !(nsm = nsm_find(sin, hostname, hostname_len)))
128 host = kzalloc(sizeof(*host), GFP_KERNEL);
133 host->h_name = nsm->sm_name;
135 host->h_addr.sin_port = 0; /* ouch! */
136 host->h_version = version;
137 host->h_proto = proto;
138 host->h_rpcclnt = NULL;
139 mutex_init(&host->h_mutex);
140 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
141 host->h_expires = jiffies + NLM_HOST_EXPIRE;
142 atomic_set(&host->h_count, 1);
143 init_waitqueue_head(&host->h_gracewait);
144 init_rwsem(&host->h_rwsem);
145 host->h_state = 0; /* pseudo NSM state */
146 host->h_nsmstate = 0; /* real NSM state */
147 host->h_nsmhandle = nsm;
148 host->h_server = server;
149 host->h_next = nlm_hosts[hash];
150 nlm_hosts[hash] = host;
151 INIT_LIST_HEAD(&host->h_lockowners);
152 spin_lock_init(&host->h_lock);
153 INIT_LIST_HEAD(&host->h_granted);
154 INIT_LIST_HEAD(&host->h_reclaim);
156 if (++nrhosts > NLM_HOST_MAX)
160 mutex_unlock(&nlm_host_mutex);
165 nlm_find_client(void)
167 /* find a nlm_host for a client for which h_killed == 0.
171 mutex_lock(&nlm_host_mutex);
172 for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
173 struct nlm_host *host, **hp;
174 for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
175 if (host->h_server &&
176 host->h_killed == 0) {
178 mutex_unlock(&nlm_host_mutex);
183 mutex_unlock(&nlm_host_mutex);
189 * Create the NLM RPC client for an NLM peer
192 nlm_bind_host(struct nlm_host *host)
194 struct rpc_clnt *clnt;
196 dprintk("lockd: nlm_bind_host(%08x)\n",
197 (unsigned)ntohl(host->h_addr.sin_addr.s_addr));
199 /* Lock host handle */
200 mutex_lock(&host->h_mutex);
202 /* If we've already created an RPC client, check whether
203 * RPC rebind is required
205 if ((clnt = host->h_rpcclnt) != NULL) {
206 if (time_after_eq(jiffies, host->h_nextrebind)) {
207 rpc_force_rebind(clnt);
208 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
209 dprintk("lockd: next rebind in %ld jiffies\n",
210 host->h_nextrebind - jiffies);
213 unsigned long increment = nlmsvc_timeout * HZ;
214 struct rpc_timeout timeparms = {
215 .to_initval = increment,
216 .to_increment = increment,
217 .to_maxval = increment * 6UL,
220 struct rpc_create_args args = {
221 .protocol = host->h_proto,
222 .address = (struct sockaddr *)&host->h_addr,
223 .addrsize = sizeof(host->h_addr),
224 .timeout = &timeparms,
225 .servername = host->h_name,
226 .program = &nlm_program,
227 .version = host->h_version,
228 .authflavor = RPC_AUTH_UNIX,
229 .flags = (RPC_CLNT_CREATE_HARDRTRY |
230 RPC_CLNT_CREATE_AUTOBIND),
233 clnt = rpc_create(&args);
235 host->h_rpcclnt = clnt;
237 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
242 mutex_unlock(&host->h_mutex);
247 * Force a portmap lookup of the remote lockd port
250 nlm_rebind_host(struct nlm_host *host)
252 dprintk("lockd: rebind host %s\n", host->h_name);
253 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
254 rpc_force_rebind(host->h_rpcclnt);
255 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
260 * Increment NLM host count
262 struct nlm_host * nlm_get_host(struct nlm_host *host)
265 dprintk("lockd: get host %s\n", host->h_name);
266 atomic_inc(&host->h_count);
267 host->h_expires = jiffies + NLM_HOST_EXPIRE;
273 * Release NLM host after use
275 void nlm_release_host(struct nlm_host *host)
278 dprintk("lockd: release host %s\n", host->h_name);
279 BUG_ON(atomic_read(&host->h_count) < 0);
280 if (atomic_dec_and_test(&host->h_count)) {
281 BUG_ON(!list_empty(&host->h_lockowners));
282 BUG_ON(!list_empty(&host->h_granted));
283 BUG_ON(!list_empty(&host->h_reclaim));
289 * We were notified that the host indicated by address &sin
291 * Release all resources held by that peer.
293 void nlm_host_rebooted(const struct sockaddr_in *sin,
294 const char *hostname, int hostname_len,
297 struct nsm_handle *nsm;
298 struct nlm_host *host, **hp;
301 dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
302 hostname, NIPQUAD(sin->sin_addr));
304 /* Find the NSM handle for this peer */
305 if (!(nsm = __nsm_find(sin, hostname, hostname_len, 0)))
308 /* When reclaiming locks on this peer, make sure that
309 * we set up a new notification */
310 nsm->sm_monitored = 0;
312 /* Mark all hosts tied to this NSM state as having rebooted.
313 * We run the loop repeatedly, because we drop the host table
315 * To avoid processing a host several times, we match the nsmstate.
317 again: mutex_lock(&nlm_host_mutex);
318 for (hash = 0; hash < NLM_HOST_NRHASH; hash++) {
319 for (hp = &nlm_hosts[hash]; (host = *hp); hp = &host->h_next) {
320 if (host->h_nsmhandle == nsm
321 && host->h_nsmstate != new_state) {
322 host->h_nsmstate = new_state;
326 mutex_unlock(&nlm_host_mutex);
328 if (host->h_server) {
329 /* We're server for this guy, just ditch
330 * all the locks he held. */
331 nlmsvc_free_host_resources(host);
333 /* He's the server, initiate lock recovery. */
334 nlmclnt_recovery(host);
337 nlm_release_host(host);
343 mutex_unlock(&nlm_host_mutex);
347 * Shut down the hosts module.
348 * Note that this routine is called only at server shutdown time.
351 nlm_shutdown_hosts(void)
353 struct nlm_host *host;
356 dprintk("lockd: shutting down host module\n");
357 mutex_lock(&nlm_host_mutex);
359 /* First, make all hosts eligible for gc */
360 dprintk("lockd: nuking all hosts...\n");
361 for (i = 0; i < NLM_HOST_NRHASH; i++) {
362 for (host = nlm_hosts[i]; host; host = host->h_next)
363 host->h_expires = jiffies - 1;
366 /* Then, perform a garbage collection pass */
368 mutex_unlock(&nlm_host_mutex);
370 /* complain if any hosts are left */
372 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
373 dprintk("lockd: %d hosts left:\n", nrhosts);
374 for (i = 0; i < NLM_HOST_NRHASH; i++) {
375 for (host = nlm_hosts[i]; host; host = host->h_next) {
376 dprintk(" %s (cnt %d use %d exp %ld)\n",
377 host->h_name, atomic_read(&host->h_count),
378 host->h_inuse, host->h_expires);
385 * Garbage collect any unused NLM hosts.
386 * This GC combines reference counting for async operations with
387 * mark & sweep for resources held by remote clients.
392 struct nlm_host **q, *host;
393 struct rpc_clnt *clnt;
396 dprintk("lockd: host garbage collection\n");
397 for (i = 0; i < NLM_HOST_NRHASH; i++) {
398 for (host = nlm_hosts[i]; host; host = host->h_next)
402 /* Mark all hosts that hold locks, blocks or shares */
403 nlmsvc_mark_resources();
405 for (i = 0; i < NLM_HOST_NRHASH; i++) {
407 while ((host = *q) != NULL) {
408 if (atomic_read(&host->h_count) || host->h_inuse
409 || time_before(jiffies, host->h_expires)) {
410 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
411 host->h_name, atomic_read(&host->h_count),
412 host->h_inuse, host->h_expires);
416 dprintk("lockd: delete host %s\n", host->h_name);
420 * Unmonitor unless host was invalidated (i.e. lockd restarted)
424 if ((clnt = host->h_rpcclnt) != NULL) {
425 if (atomic_read(&clnt->cl_users)) {
427 "lockd: active RPC handle\n");
430 rpc_destroy_client(host->h_rpcclnt);
438 next_gc = jiffies + NLM_HOST_COLLECT;
445 static LIST_HEAD(nsm_handles);
446 static DECLARE_MUTEX(nsm_sema);
448 static struct nsm_handle *
449 __nsm_find(const struct sockaddr_in *sin,
450 const char *hostname, int hostname_len,
453 struct nsm_handle *nsm = NULL;
454 struct list_head *pos;
459 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
460 if (printk_ratelimit()) {
461 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
462 "in NFS lock request\n",
463 hostname_len, hostname);
469 list_for_each(pos, &nsm_handles) {
470 nsm = list_entry(pos, struct nsm_handle, sm_link);
472 if (!nlm_cmp_addr(&nsm->sm_addr, sin))
474 atomic_inc(&nsm->sm_count);
483 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
486 nsm->sm_name = (char *) (nsm + 1);
487 memcpy(nsm->sm_name, hostname, hostname_len);
488 nsm->sm_name[hostname_len] = '\0';
489 atomic_set(&nsm->sm_count, 1);
491 list_add(&nsm->sm_link, &nsm_handles);
499 nsm_find(const struct sockaddr_in *sin, const char *hostname, int hostname_len)
501 return __nsm_find(sin, hostname, hostname_len, 1);
505 * Release an NSM handle
508 nsm_release(struct nsm_handle *nsm)
512 if (atomic_dec_and_test(&nsm->sm_count)) {
514 if (atomic_read(&nsm->sm_count) == 0) {
515 list_del(&nsm->sm_link);