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>
21 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
22 #define NLM_HOST_MAX 64
23 #define NLM_HOST_NRHASH 32
24 #define NLM_ADDRHASH(addr) (ntohl(addr) & (NLM_HOST_NRHASH-1))
25 #define NLM_HOST_REBIND (60 * HZ)
26 #define NLM_HOST_EXPIRE ((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
27 #define NLM_HOST_COLLECT ((nrhosts > NLM_HOST_MAX)? 120 * HZ : 60 * HZ)
28 #define NLM_HOST_ADDR(sv) (&(sv)->s_nlmclnt->cl_xprt->addr)
30 static struct nlm_host * nlm_hosts[NLM_HOST_NRHASH];
31 static unsigned long next_gc;
33 static DECLARE_MUTEX(nlm_host_sema);
36 static void nlm_gc_hosts(void);
39 * Find an NLM server handle in the cache. If there is none, create it.
42 nlmclnt_lookup_host(struct sockaddr_in *sin, int proto, int version)
44 return nlm_lookup_host(0, sin, proto, version);
48 * Find an NLM client handle in the cache. If there is none, create it.
51 nlmsvc_lookup_host(struct svc_rqst *rqstp)
53 return nlm_lookup_host(1, &rqstp->rq_addr,
54 rqstp->rq_prot, rqstp->rq_vers);
58 * Common host lookup routine for server & client
61 nlm_lookup_host(int server, struct sockaddr_in *sin,
62 int proto, int version)
64 struct nlm_host *host, **hp;
68 dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
69 (unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version);
71 hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
76 if (time_after_eq(jiffies, next_gc))
79 for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
80 if (host->h_proto != proto)
82 if (host->h_version != version)
84 if (host->h_server != server)
87 if (nlm_cmp_addr(&host->h_addr, sin)) {
88 if (hp != nlm_hosts + hash) {
90 host->h_next = nlm_hosts[hash];
91 nlm_hosts[hash] = host;
99 /* Ooops, no host found, create it */
100 dprintk("lockd: creating host entry\n");
102 if (!(host = (struct nlm_host *) kmalloc(sizeof(*host), GFP_KERNEL)))
104 memset(host, 0, sizeof(*host));
106 addr = sin->sin_addr.s_addr;
107 sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));
110 host->h_addr.sin_port = 0; /* ouch! */
111 host->h_version = version;
112 host->h_proto = proto;
113 host->h_rpcclnt = NULL;
114 init_MUTEX(&host->h_sema);
115 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
116 host->h_expires = jiffies + NLM_HOST_EXPIRE;
117 atomic_set(&host->h_count, 1);
118 init_waitqueue_head(&host->h_gracewait);
119 host->h_state = 0; /* pseudo NSM state */
120 host->h_nsmstate = 0; /* real NSM state */
121 host->h_server = server;
122 host->h_next = nlm_hosts[hash];
123 nlm_hosts[hash] = host;
124 INIT_LIST_HEAD(&host->h_lockowners);
125 spin_lock_init(&host->h_lock);
127 if (++nrhosts > NLM_HOST_MAX)
136 nlm_find_client(void)
138 /* find a nlm_host for a client for which h_killed == 0.
142 down(&nlm_host_sema);
143 for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
144 struct nlm_host *host, **hp;
145 for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
146 if (host->h_server &&
147 host->h_killed == 0) {
160 * Create the NLM RPC client for an NLM peer
163 nlm_bind_host(struct nlm_host *host)
165 struct rpc_clnt *clnt;
166 struct rpc_xprt *xprt;
168 dprintk("lockd: nlm_bind_host(%08x)\n",
169 (unsigned)ntohl(host->h_addr.sin_addr.s_addr));
171 /* Lock host handle */
174 /* If we've already created an RPC client, check whether
175 * RPC rebind is required
176 * Note: why keep rebinding if we're on a tcp connection?
178 if ((clnt = host->h_rpcclnt) != NULL) {
179 xprt = clnt->cl_xprt;
180 if (!xprt->stream && time_after_eq(jiffies, host->h_nextrebind)) {
182 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
183 dprintk("lockd: next rebind in %ld jiffies\n",
184 host->h_nextrebind - jiffies);
187 xprt = xprt_create_proto(host->h_proto, &host->h_addr, NULL);
191 xprt_set_timeout(&xprt->timeout, 5, nlmsvc_timeout);
193 /* Existing NLM servers accept AUTH_UNIX only */
194 clnt = rpc_create_client(xprt, host->h_name, &nlm_program,
195 host->h_version, RPC_AUTH_UNIX);
200 clnt->cl_autobind = 1; /* turn on pmap queries */
201 xprt->nocong = 1; /* No congestion control for NLM */
202 xprt->resvport = 1; /* NLM requires a reserved port */
204 host->h_rpcclnt = clnt;
211 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
217 * Force a portmap lookup of the remote lockd port
220 nlm_rebind_host(struct nlm_host *host)
222 dprintk("lockd: rebind host %s\n", host->h_name);
223 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
224 host->h_rpcclnt->cl_port = 0;
225 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
230 * Increment NLM host count
232 struct nlm_host * nlm_get_host(struct nlm_host *host)
235 dprintk("lockd: get host %s\n", host->h_name);
236 atomic_inc(&host->h_count);
237 host->h_expires = jiffies + NLM_HOST_EXPIRE;
243 * Release NLM host after use
245 void nlm_release_host(struct nlm_host *host)
248 dprintk("lockd: release host %s\n", host->h_name);
249 atomic_dec(&host->h_count);
250 BUG_ON(atomic_read(&host->h_count) < 0);
255 * Shut down the hosts module.
256 * Note that this routine is called only at server shutdown time.
259 nlm_shutdown_hosts(void)
261 struct nlm_host *host;
264 dprintk("lockd: shutting down host module\n");
265 down(&nlm_host_sema);
267 /* First, make all hosts eligible for gc */
268 dprintk("lockd: nuking all hosts...\n");
269 for (i = 0; i < NLM_HOST_NRHASH; i++) {
270 for (host = nlm_hosts[i]; host; host = host->h_next)
271 host->h_expires = jiffies - 1;
274 /* Then, perform a garbage collection pass */
278 /* complain if any hosts are left */
280 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
281 dprintk("lockd: %d hosts left:\n", nrhosts);
282 for (i = 0; i < NLM_HOST_NRHASH; i++) {
283 for (host = nlm_hosts[i]; host; host = host->h_next) {
284 dprintk(" %s (cnt %d use %d exp %ld)\n",
285 host->h_name, atomic_read(&host->h_count),
286 host->h_inuse, host->h_expires);
293 * Garbage collect any unused NLM hosts.
294 * This GC combines reference counting for async operations with
295 * mark & sweep for resources held by remote clients.
300 struct nlm_host **q, *host;
301 struct rpc_clnt *clnt;
304 dprintk("lockd: host garbage collection\n");
305 for (i = 0; i < NLM_HOST_NRHASH; i++) {
306 for (host = nlm_hosts[i]; host; host = host->h_next)
310 /* Mark all hosts that hold locks, blocks or shares */
311 nlmsvc_mark_resources();
313 for (i = 0; i < NLM_HOST_NRHASH; i++) {
315 while ((host = *q) != NULL) {
316 if (atomic_read(&host->h_count) || host->h_inuse
317 || time_before(jiffies, host->h_expires)) {
318 dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
319 host->h_name, atomic_read(&host->h_count),
320 host->h_inuse, host->h_expires);
324 dprintk("lockd: delete host %s\n", host->h_name);
326 /* Don't unmonitor hosts that have been invalidated */
327 if (host->h_monitored && !host->h_killed)
329 if ((clnt = host->h_rpcclnt) != NULL) {
330 if (atomic_read(&clnt->cl_users)) {
332 "lockd: active RPC handle\n");
335 rpc_destroy_client(host->h_rpcclnt);
338 BUG_ON(!list_empty(&host->h_lockowners));
344 next_gc = jiffies + NLM_HOST_COLLECT;