Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/lockd/host.c | |
3 | * | |
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. | |
7 | * | |
8 | * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> | |
9 | */ | |
10 | ||
11 | #include <linux/types.h> | |
12 | #include <linux/sched.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/in.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> | |
353ab6e9 | 19 | #include <linux/mutex.h> |
1da177e4 LT |
20 | |
21 | ||
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) | |
29 | #define NLM_HOST_ADDR(sv) (&(sv)->s_nlmclnt->cl_xprt->addr) | |
30 | ||
31 | static struct nlm_host * nlm_hosts[NLM_HOST_NRHASH]; | |
32 | static unsigned long next_gc; | |
33 | static int nrhosts; | |
353ab6e9 | 34 | static DEFINE_MUTEX(nlm_host_mutex); |
1da177e4 LT |
35 | |
36 | ||
37 | static void nlm_gc_hosts(void); | |
38 | ||
39 | /* | |
40 | * Find an NLM server handle in the cache. If there is none, create it. | |
41 | */ | |
42 | struct nlm_host * | |
43 | nlmclnt_lookup_host(struct sockaddr_in *sin, int proto, int version) | |
44 | { | |
45 | return nlm_lookup_host(0, sin, proto, version); | |
46 | } | |
47 | ||
48 | /* | |
49 | * Find an NLM client handle in the cache. If there is none, create it. | |
50 | */ | |
51 | struct nlm_host * | |
52 | nlmsvc_lookup_host(struct svc_rqst *rqstp) | |
53 | { | |
54 | return nlm_lookup_host(1, &rqstp->rq_addr, | |
55 | rqstp->rq_prot, rqstp->rq_vers); | |
56 | } | |
57 | ||
58 | /* | |
59 | * Common host lookup routine for server & client | |
60 | */ | |
61 | struct nlm_host * | |
62 | nlm_lookup_host(int server, struct sockaddr_in *sin, | |
63 | int proto, int version) | |
64 | { | |
65 | struct nlm_host *host, **hp; | |
66 | u32 addr; | |
67 | int hash; | |
68 | ||
69 | dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n", | |
70 | (unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version); | |
71 | ||
72 | hash = NLM_ADDRHASH(sin->sin_addr.s_addr); | |
73 | ||
74 | /* Lock hash table */ | |
353ab6e9 | 75 | mutex_lock(&nlm_host_mutex); |
1da177e4 LT |
76 | |
77 | if (time_after_eq(jiffies, next_gc)) | |
78 | nlm_gc_hosts(); | |
79 | ||
80 | for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) { | |
81 | if (host->h_proto != proto) | |
82 | continue; | |
83 | if (host->h_version != version) | |
84 | continue; | |
85 | if (host->h_server != server) | |
86 | continue; | |
87 | ||
88 | if (nlm_cmp_addr(&host->h_addr, sin)) { | |
89 | if (hp != nlm_hosts + hash) { | |
90 | *hp = host->h_next; | |
91 | host->h_next = nlm_hosts[hash]; | |
92 | nlm_hosts[hash] = host; | |
93 | } | |
94 | nlm_get_host(host); | |
353ab6e9 | 95 | mutex_unlock(&nlm_host_mutex); |
1da177e4 LT |
96 | return host; |
97 | } | |
98 | } | |
99 | ||
100 | /* Ooops, no host found, create it */ | |
101 | dprintk("lockd: creating host entry\n"); | |
102 | ||
103 | if (!(host = (struct nlm_host *) kmalloc(sizeof(*host), GFP_KERNEL))) | |
104 | goto nohost; | |
105 | memset(host, 0, sizeof(*host)); | |
106 | ||
107 | addr = sin->sin_addr.s_addr; | |
108 | sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr)); | |
109 | ||
110 | host->h_addr = *sin; | |
111 | host->h_addr.sin_port = 0; /* ouch! */ | |
112 | host->h_version = version; | |
113 | host->h_proto = proto; | |
114 | host->h_rpcclnt = NULL; | |
115 | init_MUTEX(&host->h_sema); | |
116 | host->h_nextrebind = jiffies + NLM_HOST_REBIND; | |
117 | host->h_expires = jiffies + NLM_HOST_EXPIRE; | |
118 | atomic_set(&host->h_count, 1); | |
119 | init_waitqueue_head(&host->h_gracewait); | |
120 | host->h_state = 0; /* pseudo NSM state */ | |
121 | host->h_nsmstate = 0; /* real NSM state */ | |
122 | host->h_server = server; | |
123 | host->h_next = nlm_hosts[hash]; | |
124 | nlm_hosts[hash] = host; | |
125 | INIT_LIST_HEAD(&host->h_lockowners); | |
126 | spin_lock_init(&host->h_lock); | |
26bcbf96 CH |
127 | INIT_LIST_HEAD(&host->h_granted); |
128 | INIT_LIST_HEAD(&host->h_reclaim); | |
1da177e4 LT |
129 | |
130 | if (++nrhosts > NLM_HOST_MAX) | |
131 | next_gc = 0; | |
132 | ||
133 | nohost: | |
353ab6e9 | 134 | mutex_unlock(&nlm_host_mutex); |
1da177e4 LT |
135 | return host; |
136 | } | |
137 | ||
138 | struct nlm_host * | |
139 | nlm_find_client(void) | |
140 | { | |
141 | /* find a nlm_host for a client for which h_killed == 0. | |
142 | * and return it | |
143 | */ | |
144 | int hash; | |
353ab6e9 | 145 | mutex_lock(&nlm_host_mutex); |
1da177e4 LT |
146 | for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) { |
147 | struct nlm_host *host, **hp; | |
148 | for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) { | |
149 | if (host->h_server && | |
150 | host->h_killed == 0) { | |
151 | nlm_get_host(host); | |
353ab6e9 | 152 | mutex_unlock(&nlm_host_mutex); |
1da177e4 LT |
153 | return host; |
154 | } | |
155 | } | |
156 | } | |
353ab6e9 | 157 | mutex_unlock(&nlm_host_mutex); |
1da177e4 LT |
158 | return NULL; |
159 | } | |
160 | ||
161 | ||
162 | /* | |
163 | * Create the NLM RPC client for an NLM peer | |
164 | */ | |
165 | struct rpc_clnt * | |
166 | nlm_bind_host(struct nlm_host *host) | |
167 | { | |
168 | struct rpc_clnt *clnt; | |
169 | struct rpc_xprt *xprt; | |
170 | ||
171 | dprintk("lockd: nlm_bind_host(%08x)\n", | |
172 | (unsigned)ntohl(host->h_addr.sin_addr.s_addr)); | |
173 | ||
174 | /* Lock host handle */ | |
175 | down(&host->h_sema); | |
176 | ||
177 | /* If we've already created an RPC client, check whether | |
178 | * RPC rebind is required | |
1da177e4 LT |
179 | */ |
180 | if ((clnt = host->h_rpcclnt) != NULL) { | |
181 | xprt = clnt->cl_xprt; | |
43118c29 | 182 | if (time_after_eq(jiffies, host->h_nextrebind)) { |
35f5a422 | 183 | rpc_force_rebind(clnt); |
1da177e4 LT |
184 | host->h_nextrebind = jiffies + NLM_HOST_REBIND; |
185 | dprintk("lockd: next rebind in %ld jiffies\n", | |
186 | host->h_nextrebind - jiffies); | |
187 | } | |
188 | } else { | |
189 | xprt = xprt_create_proto(host->h_proto, &host->h_addr, NULL); | |
190 | if (IS_ERR(xprt)) | |
191 | goto forgetit; | |
192 | ||
193 | xprt_set_timeout(&xprt->timeout, 5, nlmsvc_timeout); | |
5ee0ed7d | 194 | xprt->resvport = 1; /* NLM requires a reserved port */ |
1da177e4 LT |
195 | |
196 | /* Existing NLM servers accept AUTH_UNIX only */ | |
04266473 | 197 | clnt = rpc_new_client(xprt, host->h_name, &nlm_program, |
1da177e4 | 198 | host->h_version, RPC_AUTH_UNIX); |
5b616f5d | 199 | if (IS_ERR(clnt)) |
1da177e4 | 200 | goto forgetit; |
1da177e4 | 201 | clnt->cl_autobind = 1; /* turn on pmap queries */ |
04266473 | 202 | clnt->cl_softrtry = 1; /* All queries are soft */ |
1da177e4 LT |
203 | |
204 | host->h_rpcclnt = clnt; | |
205 | } | |
206 | ||
207 | up(&host->h_sema); | |
208 | return clnt; | |
209 | ||
210 | forgetit: | |
211 | printk("lockd: couldn't create RPC handle for %s\n", host->h_name); | |
212 | up(&host->h_sema); | |
213 | return NULL; | |
214 | } | |
215 | ||
216 | /* | |
217 | * Force a portmap lookup of the remote lockd port | |
218 | */ | |
219 | void | |
220 | nlm_rebind_host(struct nlm_host *host) | |
221 | { | |
222 | dprintk("lockd: rebind host %s\n", host->h_name); | |
223 | if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) { | |
35f5a422 | 224 | rpc_force_rebind(host->h_rpcclnt); |
1da177e4 LT |
225 | host->h_nextrebind = jiffies + NLM_HOST_REBIND; |
226 | } | |
227 | } | |
228 | ||
229 | /* | |
230 | * Increment NLM host count | |
231 | */ | |
232 | struct nlm_host * nlm_get_host(struct nlm_host *host) | |
233 | { | |
234 | if (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; | |
238 | } | |
239 | return host; | |
240 | } | |
241 | ||
242 | /* | |
243 | * Release NLM host after use | |
244 | */ | |
245 | void nlm_release_host(struct nlm_host *host) | |
246 | { | |
247 | if (host != NULL) { | |
248 | dprintk("lockd: release host %s\n", host->h_name); | |
1da177e4 | 249 | BUG_ON(atomic_read(&host->h_count) < 0); |
4c060b53 TM |
250 | if (atomic_dec_and_test(&host->h_count)) { |
251 | BUG_ON(!list_empty(&host->h_lockowners)); | |
252 | BUG_ON(!list_empty(&host->h_granted)); | |
253 | BUG_ON(!list_empty(&host->h_reclaim)); | |
254 | } | |
1da177e4 LT |
255 | } |
256 | } | |
257 | ||
258 | /* | |
259 | * Shut down the hosts module. | |
260 | * Note that this routine is called only at server shutdown time. | |
261 | */ | |
262 | void | |
263 | nlm_shutdown_hosts(void) | |
264 | { | |
265 | struct nlm_host *host; | |
266 | int i; | |
267 | ||
268 | dprintk("lockd: shutting down host module\n"); | |
353ab6e9 | 269 | mutex_lock(&nlm_host_mutex); |
1da177e4 LT |
270 | |
271 | /* First, make all hosts eligible for gc */ | |
272 | dprintk("lockd: nuking all hosts...\n"); | |
273 | for (i = 0; i < NLM_HOST_NRHASH; i++) { | |
274 | for (host = nlm_hosts[i]; host; host = host->h_next) | |
275 | host->h_expires = jiffies - 1; | |
276 | } | |
277 | ||
278 | /* Then, perform a garbage collection pass */ | |
279 | nlm_gc_hosts(); | |
353ab6e9 | 280 | mutex_unlock(&nlm_host_mutex); |
1da177e4 LT |
281 | |
282 | /* complain if any hosts are left */ | |
283 | if (nrhosts) { | |
284 | printk(KERN_WARNING "lockd: couldn't shutdown host module!\n"); | |
285 | dprintk("lockd: %d hosts left:\n", nrhosts); | |
286 | for (i = 0; i < NLM_HOST_NRHASH; i++) { | |
287 | for (host = nlm_hosts[i]; host; host = host->h_next) { | |
288 | dprintk(" %s (cnt %d use %d exp %ld)\n", | |
289 | host->h_name, atomic_read(&host->h_count), | |
290 | host->h_inuse, host->h_expires); | |
291 | } | |
292 | } | |
293 | } | |
294 | } | |
295 | ||
296 | /* | |
297 | * Garbage collect any unused NLM hosts. | |
298 | * This GC combines reference counting for async operations with | |
299 | * mark & sweep for resources held by remote clients. | |
300 | */ | |
301 | static void | |
302 | nlm_gc_hosts(void) | |
303 | { | |
304 | struct nlm_host **q, *host; | |
305 | struct rpc_clnt *clnt; | |
306 | int i; | |
307 | ||
308 | dprintk("lockd: host garbage collection\n"); | |
309 | for (i = 0; i < NLM_HOST_NRHASH; i++) { | |
310 | for (host = nlm_hosts[i]; host; host = host->h_next) | |
311 | host->h_inuse = 0; | |
312 | } | |
313 | ||
314 | /* Mark all hosts that hold locks, blocks or shares */ | |
315 | nlmsvc_mark_resources(); | |
316 | ||
317 | for (i = 0; i < NLM_HOST_NRHASH; i++) { | |
318 | q = &nlm_hosts[i]; | |
319 | while ((host = *q) != NULL) { | |
320 | if (atomic_read(&host->h_count) || host->h_inuse | |
321 | || time_before(jiffies, host->h_expires)) { | |
322 | dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n", | |
323 | host->h_name, atomic_read(&host->h_count), | |
324 | host->h_inuse, host->h_expires); | |
325 | q = &host->h_next; | |
326 | continue; | |
327 | } | |
328 | dprintk("lockd: delete host %s\n", host->h_name); | |
329 | *q = host->h_next; | |
330 | /* Don't unmonitor hosts that have been invalidated */ | |
331 | if (host->h_monitored && !host->h_killed) | |
332 | nsm_unmonitor(host); | |
333 | if ((clnt = host->h_rpcclnt) != NULL) { | |
334 | if (atomic_read(&clnt->cl_users)) { | |
335 | printk(KERN_WARNING | |
336 | "lockd: active RPC handle\n"); | |
337 | clnt->cl_dead = 1; | |
338 | } else { | |
339 | rpc_destroy_client(host->h_rpcclnt); | |
340 | } | |
341 | } | |
1da177e4 LT |
342 | kfree(host); |
343 | nrhosts--; | |
344 | } | |
345 | } | |
346 | ||
347 | next_gc = jiffies + NLM_HOST_COLLECT; | |
348 | } | |
349 |