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)
114 if (hp != nlm_hosts + hash) {
116 host->h_next = nlm_hosts[hash];
117 nlm_hosts[hash] = host;
120 mutex_unlock(&nlm_host_mutex);
125 /* Sadly, the host isn't in our hash table yet. See if
126 * we have an NSM handle for it. If not, create one.
128 if (!nsm && !(nsm = nsm_find(sin, hostname, hostname_len)))
131 host = kzalloc(sizeof(*host), GFP_KERNEL);
136 host->h_name = nsm->sm_name;
138 host->h_addr.sin_port = 0; /* ouch! */
139 host->h_version = version;
140 host->h_proto = proto;
141 host->h_rpcclnt = NULL;
142 mutex_init(&host->h_mutex);
143 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
144 host->h_expires = jiffies + NLM_HOST_EXPIRE;
145 atomic_set(&host->h_count, 1);
146 init_waitqueue_head(&host->h_gracewait);
147 init_rwsem(&host->h_rwsem);
148 host->h_state = 0; /* pseudo NSM state */
149 host->h_nsmstate = 0; /* real NSM state */
150 host->h_nsmhandle = nsm;
151 host->h_server = server;
152 host->h_next = nlm_hosts[hash];
153 nlm_hosts[hash] = host;
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);
159 if (++nrhosts > NLM_HOST_MAX)
163 mutex_unlock(&nlm_host_mutex);
168 nlm_find_client(void)
170 /* find a nlm_host for a client for which h_killed == 0.
174 mutex_lock(&nlm_host_mutex);
175 for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
176 struct nlm_host *host, **hp;
177 for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
178 if (host->h_server &&
179 host->h_killed == 0) {
181 mutex_unlock(&nlm_host_mutex);
186 mutex_unlock(&nlm_host_mutex);
192 * Create the NLM RPC client for an NLM peer
195 nlm_bind_host(struct nlm_host *host)
197 struct rpc_clnt *clnt;
199 dprintk("lockd: nlm_bind_host(%08x)\n",
200 (unsigned)ntohl(host->h_addr.sin_addr.s_addr));
202 /* Lock host handle */
203 mutex_lock(&host->h_mutex);
205 /* If we've already created an RPC client, check whether
206 * RPC rebind is required
208 if ((clnt = host->h_rpcclnt) != NULL) {
209 if (time_after_eq(jiffies, host->h_nextrebind)) {
210 rpc_force_rebind(clnt);
211 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
212 dprintk("lockd: next rebind in %ld jiffies\n",
213 host->h_nextrebind - jiffies);
216 unsigned long increment = nlmsvc_timeout * HZ;
217 struct rpc_timeout timeparms = {
218 .to_initval = increment,
219 .to_increment = increment,
220 .to_maxval = increment * 6UL,
223 struct rpc_create_args args = {
224 .protocol = host->h_proto,
225 .address = (struct sockaddr *)&host->h_addr,
226 .addrsize = sizeof(host->h_addr),
227 .timeout = &timeparms,
228 .servername = host->h_name,
229 .program = &nlm_program,
230 .version = host->h_version,
231 .authflavor = RPC_AUTH_UNIX,
232 .flags = (RPC_CLNT_CREATE_HARDRTRY |
233 RPC_CLNT_CREATE_AUTOBIND),
236 clnt = rpc_create(&args);
238 host->h_rpcclnt = clnt;
240 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
245 mutex_unlock(&host->h_mutex);
250 * Force a portmap lookup of the remote lockd port
253 nlm_rebind_host(struct nlm_host *host)
255 dprintk("lockd: rebind host %s\n", host->h_name);
256 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
257 rpc_force_rebind(host->h_rpcclnt);
258 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
263 * Increment NLM host count
265 struct nlm_host * nlm_get_host(struct nlm_host *host)
268 dprintk("lockd: get host %s\n", host->h_name);
269 atomic_inc(&host->h_count);
270 host->h_expires = jiffies + NLM_HOST_EXPIRE;
276 * Release NLM host after use
278 void nlm_release_host(struct nlm_host *host)
281 dprintk("lockd: release host %s\n", host->h_name);
282 BUG_ON(atomic_read(&host->h_count) < 0);
283 if (atomic_dec_and_test(&host->h_count)) {
284 BUG_ON(!list_empty(&host->h_lockowners));
285 BUG_ON(!list_empty(&host->h_granted));
286 BUG_ON(!list_empty(&host->h_reclaim));
292 * We were notified that the host indicated by address &sin
294 * Release all resources held by that peer.
296 void nlm_host_rebooted(const struct sockaddr_in *sin, const struct nlm_reboot *argp)
298 struct nlm_host *host;
301 /* Obtain the host pointer for this NFS server and try to
302 * reclaim all locks we hold on this server.
304 server = (argp->proto & 1)? 1 : 0;
305 host = nlm_lookup_host(server, sin, argp->proto >> 1, argp->vers,
306 argp->mon, argp->len);
311 /* We are client, he's the server: try to reclaim all locks. */
312 nlmclnt_recovery(host, argp->state);
314 /* He's the client, we're the server: delete all locks held by the client */
315 nlmsvc_free_host_resources(host);
317 nlm_release_host(host);
321 * Shut down the hosts module.
322 * Note that this routine is called only at server shutdown time.
325 nlm_shutdown_hosts(void)
327 struct nlm_host *host;
330 dprintk("lockd: shutting down host module\n");
331 mutex_lock(&nlm_host_mutex);
333 /* First, make all hosts eligible for gc */
334 dprintk("lockd: nuking all hosts...\n");
335 for (i = 0; i < NLM_HOST_NRHASH; i++) {
336 for (host = nlm_hosts[i]; host; host = host->h_next)
337 host->h_expires = jiffies - 1;
340 /* Then, perform a garbage collection pass */
342 mutex_unlock(&nlm_host_mutex);
344 /* complain if any hosts are left */
346 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
347 dprintk("lockd: %d hosts left:\n", nrhosts);
348 for (i = 0; i < NLM_HOST_NRHASH; i++) {
349 for (host = nlm_hosts[i]; host; host = host->h_next) {
350 dprintk(" %s (cnt %d use %d exp %ld)\n",
351 host->h_name, atomic_read(&host->h_count),
352 host->h_inuse, host->h_expires);
359 * Garbage collect any unused NLM hosts.
360 * This GC combines reference counting for async operations with
361 * mark & sweep for resources held by remote clients.
366 struct nlm_host **q, *host;
367 struct rpc_clnt *clnt;
370 dprintk("lockd: host garbage collection\n");
371 for (i = 0; i < NLM_HOST_NRHASH; i++) {
372 for (host = nlm_hosts[i]; host; host = host->h_next)
376 /* Mark all hosts that hold locks, blocks or shares */
377 nlmsvc_mark_resources();
379 for (i = 0; i < NLM_HOST_NRHASH; i++) {
381 while ((host = *q) != NULL) {
382 if (atomic_read(&host->h_count) || host->h_inuse
383 || time_before(jiffies, host->h_expires)) {
384 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
385 host->h_name, atomic_read(&host->h_count),
386 host->h_inuse, host->h_expires);
390 dprintk("lockd: delete host %s\n", host->h_name);
394 * Unmonitor unless host was invalidated (i.e. lockd restarted)
398 if ((clnt = host->h_rpcclnt) != NULL) {
399 if (atomic_read(&clnt->cl_users)) {
401 "lockd: active RPC handle\n");
404 rpc_destroy_client(host->h_rpcclnt);
412 next_gc = jiffies + NLM_HOST_COLLECT;
419 static LIST_HEAD(nsm_handles);
420 static DECLARE_MUTEX(nsm_sema);
422 static struct nsm_handle *
423 __nsm_find(const struct sockaddr_in *sin,
424 const char *hostname, int hostname_len,
427 struct nsm_handle *nsm = NULL;
428 struct list_head *pos;
433 if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
434 if (printk_ratelimit()) {
435 printk(KERN_WARNING "Invalid hostname \"%.*s\" "
436 "in NFS lock request\n",
437 hostname_len, hostname);
443 list_for_each(pos, &nsm_handles) {
444 nsm = list_entry(pos, struct nsm_handle, sm_link);
446 if (!nlm_cmp_addr(&nsm->sm_addr, sin))
448 atomic_inc(&nsm->sm_count);
457 nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
460 nsm->sm_name = (char *) (nsm + 1);
461 memcpy(nsm->sm_name, hostname, hostname_len);
462 nsm->sm_name[hostname_len] = '\0';
463 atomic_set(&nsm->sm_count, 1);
465 list_add(&nsm->sm_link, &nsm_handles);
473 nsm_find(const struct sockaddr_in *sin, const char *hostname, int hostname_len)
475 return __nsm_find(sin, hostname, hostname_len, 1);
479 * Release an NSM handle
482 nsm_release(struct nsm_handle *nsm)
486 if (atomic_dec_and_test(&nsm->sm_count)) {
488 if (atomic_read(&nsm->sm_count) == 0) {
489 list_del(&nsm->sm_link);