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> | |
1da177e4 LT |
12 | #include <linux/slab.h> |
13 | #include <linux/in.h> | |
1b333c54 | 14 | #include <linux/in6.h> |
1da177e4 LT |
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 | 20 | |
1b333c54 | 21 | #include <net/ipv6.h> |
1da177e4 LT |
22 | |
23 | #define NLMDBG_FACILITY NLMDBG_HOSTCACHE | |
1da177e4 | 24 | #define NLM_HOST_NRHASH 32 |
1da177e4 | 25 | #define NLM_HOST_REBIND (60 * HZ) |
1447d25e N |
26 | #define NLM_HOST_EXPIRE (300 * HZ) |
27 | #define NLM_HOST_COLLECT (120 * HZ) | |
1da177e4 | 28 | |
0cea3276 | 29 | static struct hlist_head nlm_hosts[NLM_HOST_NRHASH]; |
1da177e4 LT |
30 | static unsigned long next_gc; |
31 | static int nrhosts; | |
353ab6e9 | 32 | static DEFINE_MUTEX(nlm_host_mutex); |
1da177e4 | 33 | |
1da177e4 | 34 | static void nlm_gc_hosts(void); |
1da177e4 | 35 | |
7f1ed18b CL |
36 | struct nlm_lookup_host_info { |
37 | const int server; /* search for server|client */ | |
88541c84 CL |
38 | const struct sockaddr *sap; /* address to search for */ |
39 | const size_t salen; /* it's length */ | |
7f1ed18b CL |
40 | const unsigned short protocol; /* transport to search for*/ |
41 | const u32 version; /* NLM version to search for */ | |
42 | const char *hostname; /* remote's hostname */ | |
43 | const size_t hostname_len; /* it's length */ | |
88541c84 | 44 | const struct sockaddr *src_sap; /* our address (optional) */ |
7f1ed18b | 45 | const size_t src_len; /* it's length */ |
0cb2659b | 46 | const int noresvport; /* use non-priv port */ |
7f1ed18b CL |
47 | }; |
48 | ||
ede2fea0 CL |
49 | /* |
50 | * Hash function must work well on big- and little-endian platforms | |
51 | */ | |
52 | static unsigned int __nlm_hash32(const __be32 n) | |
53 | { | |
54 | unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16); | |
55 | return hash ^ (hash >> 8); | |
56 | } | |
57 | ||
58 | static unsigned int __nlm_hash_addr4(const struct sockaddr *sap) | |
59 | { | |
60 | const struct sockaddr_in *sin = (struct sockaddr_in *)sap; | |
61 | return __nlm_hash32(sin->sin_addr.s_addr); | |
62 | } | |
63 | ||
64 | static unsigned int __nlm_hash_addr6(const struct sockaddr *sap) | |
65 | { | |
66 | const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap; | |
67 | const struct in6_addr addr = sin6->sin6_addr; | |
68 | return __nlm_hash32(addr.s6_addr32[0]) ^ | |
69 | __nlm_hash32(addr.s6_addr32[1]) ^ | |
70 | __nlm_hash32(addr.s6_addr32[2]) ^ | |
71 | __nlm_hash32(addr.s6_addr32[3]); | |
72 | } | |
73 | ||
74 | static unsigned int nlm_hash_address(const struct sockaddr *sap) | |
75 | { | |
76 | unsigned int hash; | |
77 | ||
78 | switch (sap->sa_family) { | |
79 | case AF_INET: | |
80 | hash = __nlm_hash_addr4(sap); | |
81 | break; | |
82 | case AF_INET6: | |
83 | hash = __nlm_hash_addr6(sap); | |
84 | break; | |
85 | default: | |
86 | hash = 0; | |
87 | } | |
88 | return hash & (NLM_HOST_NRHASH - 1); | |
89 | } | |
90 | ||
396cb3d0 CL |
91 | static void nlm_clear_port(struct sockaddr *sap) |
92 | { | |
93 | switch (sap->sa_family) { | |
94 | case AF_INET: | |
95 | ((struct sockaddr_in *)sap)->sin_port = 0; | |
96 | break; | |
97 | case AF_INET6: | |
98 | ((struct sockaddr_in6 *)sap)->sin6_port = 0; | |
99 | break; | |
100 | } | |
101 | } | |
102 | ||
1da177e4 LT |
103 | /* |
104 | * Common host lookup routine for server & client | |
105 | */ | |
7f1ed18b | 106 | static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni) |
1da177e4 | 107 | { |
0cea3276 OK |
108 | struct hlist_head *chain; |
109 | struct hlist_node *pos; | |
110 | struct nlm_host *host; | |
8dead0db | 111 | struct nsm_handle *nsm = NULL; |
1da177e4 | 112 | |
353ab6e9 | 113 | mutex_lock(&nlm_host_mutex); |
1da177e4 LT |
114 | |
115 | if (time_after_eq(jiffies, next_gc)) | |
116 | nlm_gc_hosts(); | |
117 | ||
8dead0db OK |
118 | /* We may keep several nlm_host objects for a peer, because each |
119 | * nlm_host is identified by | |
120 | * (address, protocol, version, server/client) | |
121 | * We could probably simplify this a little by putting all those | |
122 | * different NLM rpc_clients into one single nlm_host object. | |
123 | * This would allow us to have one nlm_host per address. | |
124 | */ | |
88541c84 | 125 | chain = &nlm_hosts[nlm_hash_address(ni->sap)]; |
0cea3276 | 126 | hlist_for_each_entry(host, pos, chain, h_hash) { |
88541c84 | 127 | if (!nlm_cmp_addr(nlm_addr(host), ni->sap)) |
8dead0db OK |
128 | continue; |
129 | ||
130 | /* See if we have an NSM handle for this client */ | |
6b54dae2 N |
131 | if (!nsm) |
132 | nsm = host->h_nsmhandle; | |
8dead0db | 133 | |
7f1ed18b | 134 | if (host->h_proto != ni->protocol) |
1da177e4 | 135 | continue; |
7f1ed18b | 136 | if (host->h_version != ni->version) |
1da177e4 | 137 | continue; |
7f1ed18b | 138 | if (host->h_server != ni->server) |
1da177e4 | 139 | continue; |
a8d82d9b CL |
140 | if (ni->server && |
141 | !nlm_cmp_addr(nlm_srcaddr(host), ni->src_sap)) | |
c98451bd | 142 | continue; |
1da177e4 | 143 | |
0cea3276 OK |
144 | /* Move to head of hash chain. */ |
145 | hlist_del(&host->h_hash); | |
146 | hlist_add_head(&host->h_hash, chain); | |
147 | ||
f0737a39 | 148 | nlm_get_host(host); |
1b333c54 CL |
149 | dprintk("lockd: nlm_lookup_host found host %s (%s)\n", |
150 | host->h_name, host->h_addrbuf); | |
f0737a39 | 151 | goto out; |
1da177e4 LT |
152 | } |
153 | ||
c2526f42 CL |
154 | /* |
155 | * The host wasn't in our hash table. If we don't | |
156 | * have an NSM handle for it yet, create one. | |
8dead0db | 157 | */ |
c2526f42 CL |
158 | if (nsm) |
159 | atomic_inc(&nsm->sm_count); | |
160 | else { | |
161 | host = NULL; | |
88541c84 | 162 | nsm = nsm_find(ni->sap, ni->salen, |
7f1ed18b | 163 | ni->hostname, ni->hostname_len, 1); |
1b333c54 CL |
164 | if (!nsm) { |
165 | dprintk("lockd: nlm_lookup_host failed; " | |
166 | "no nsm handle\n"); | |
c2526f42 | 167 | goto out; |
1b333c54 | 168 | } |
c2526f42 | 169 | } |
1da177e4 | 170 | |
f8314dc6 | 171 | host = kzalloc(sizeof(*host), GFP_KERNEL); |
8dead0db OK |
172 | if (!host) { |
173 | nsm_release(nsm); | |
1b333c54 | 174 | dprintk("lockd: nlm_lookup_host failed; no memory\n"); |
8dead0db OK |
175 | goto out; |
176 | } | |
177 | host->h_name = nsm->sm_name; | |
1df40b60 | 178 | host->h_addrbuf = nsm->sm_addrbuf; |
88541c84 CL |
179 | memcpy(nlm_addr(host), ni->sap, ni->salen); |
180 | host->h_addrlen = ni->salen; | |
b4ed58fd | 181 | nlm_clear_port(nlm_addr(host)); |
88541c84 | 182 | memcpy(nlm_srcaddr(host), ni->src_sap, ni->src_len); |
7f1ed18b CL |
183 | host->h_version = ni->version; |
184 | host->h_proto = ni->protocol; | |
1da177e4 | 185 | host->h_rpcclnt = NULL; |
50467914 | 186 | mutex_init(&host->h_mutex); |
1da177e4 LT |
187 | host->h_nextrebind = jiffies + NLM_HOST_REBIND; |
188 | host->h_expires = jiffies + NLM_HOST_EXPIRE; | |
189 | atomic_set(&host->h_count, 1); | |
190 | init_waitqueue_head(&host->h_gracewait); | |
28df955a | 191 | init_rwsem(&host->h_rwsem); |
1da177e4 LT |
192 | host->h_state = 0; /* pseudo NSM state */ |
193 | host->h_nsmstate = 0; /* real NSM state */ | |
8dead0db | 194 | host->h_nsmhandle = nsm; |
7f1ed18b | 195 | host->h_server = ni->server; |
0cb2659b | 196 | host->h_noresvport = ni->noresvport; |
0cea3276 | 197 | hlist_add_head(&host->h_hash, chain); |
1da177e4 LT |
198 | INIT_LIST_HEAD(&host->h_lockowners); |
199 | spin_lock_init(&host->h_lock); | |
26bcbf96 CH |
200 | INIT_LIST_HEAD(&host->h_granted); |
201 | INIT_LIST_HEAD(&host->h_reclaim); | |
1da177e4 | 202 | |
1447d25e | 203 | nrhosts++; |
1b333c54 | 204 | |
1b333c54 CL |
205 | dprintk("lockd: nlm_lookup_host created host %s\n", |
206 | host->h_name); | |
207 | ||
8dead0db | 208 | out: |
353ab6e9 | 209 | mutex_unlock(&nlm_host_mutex); |
1da177e4 LT |
210 | return host; |
211 | } | |
212 | ||
c53c1bb9 OK |
213 | /* |
214 | * Destroy a host | |
215 | */ | |
216 | static void | |
217 | nlm_destroy_host(struct nlm_host *host) | |
218 | { | |
219 | struct rpc_clnt *clnt; | |
220 | ||
221 | BUG_ON(!list_empty(&host->h_lockowners)); | |
222 | BUG_ON(atomic_read(&host->h_count)); | |
223 | ||
c53c1bb9 | 224 | nsm_unmonitor(host); |
c8c23c42 | 225 | nsm_release(host->h_nsmhandle); |
c53c1bb9 | 226 | |
34f52e35 TM |
227 | clnt = host->h_rpcclnt; |
228 | if (clnt != NULL) | |
229 | rpc_shutdown_client(clnt); | |
c53c1bb9 OK |
230 | kfree(host); |
231 | } | |
232 | ||
d7d20440 CL |
233 | /** |
234 | * nlmclnt_lookup_host - Find an NLM host handle matching a remote server | |
235 | * @sap: network address of server | |
236 | * @salen: length of server address | |
237 | * @protocol: transport protocol to use | |
238 | * @version: NLM protocol version | |
239 | * @hostname: '\0'-terminated hostname of server | |
0cb2659b | 240 | * @noresvport: 1 if non-privileged port should be used |
d7d20440 CL |
241 | * |
242 | * Returns an nlm_host structure that matches the passed-in | |
243 | * [server address, transport protocol, NLM version, server hostname]. | |
244 | * If one doesn't already exist in the host cache, a new handle is | |
245 | * created and returned. | |
c585646d | 246 | */ |
d7d20440 CL |
247 | struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap, |
248 | const size_t salen, | |
249 | const unsigned short protocol, | |
0cb2659b CL |
250 | const u32 version, |
251 | const char *hostname, | |
252 | int noresvport) | |
c585646d | 253 | { |
88541c84 CL |
254 | const struct sockaddr source = { |
255 | .sa_family = AF_UNSPEC, | |
2860a022 | 256 | }; |
7f1ed18b CL |
257 | struct nlm_lookup_host_info ni = { |
258 | .server = 0, | |
d7d20440 CL |
259 | .sap = sap, |
260 | .salen = salen, | |
261 | .protocol = protocol, | |
7f1ed18b CL |
262 | .version = version, |
263 | .hostname = hostname, | |
d7d20440 | 264 | .hostname_len = strlen(hostname), |
88541c84 CL |
265 | .src_sap = &source, |
266 | .src_len = sizeof(source), | |
0cb2659b | 267 | .noresvport = noresvport, |
7f1ed18b | 268 | }; |
c98451bd | 269 | |
7f1ed18b CL |
270 | dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__, |
271 | (hostname ? hostname : "<none>"), version, | |
d7d20440 | 272 | (protocol == IPPROTO_UDP ? "udp" : "tcp")); |
7f1ed18b CL |
273 | |
274 | return nlm_lookup_host(&ni); | |
c585646d AB |
275 | } |
276 | ||
6bfbe8af CL |
277 | /** |
278 | * nlmsvc_lookup_host - Find an NLM host handle matching a remote client | |
279 | * @rqstp: incoming NLM request | |
280 | * @hostname: name of client host | |
281 | * @hostname_len: length of client hostname | |
282 | * | |
283 | * Returns an nlm_host structure that matches the [client address, | |
284 | * transport protocol, NLM version, client hostname] of the passed-in | |
285 | * NLM request. If one doesn't already exist in the host cache, a | |
286 | * new handle is created and returned. | |
287 | * | |
288 | * Before possibly creating a new nlm_host, construct a sockaddr | |
289 | * for a specific source address in case the local system has | |
290 | * multiple network addresses. The family of the address in | |
291 | * rq_daddr is guaranteed to be the same as the family of the | |
292 | * address in rq_addr, so it's safe to use the same family for | |
293 | * the source address. | |
c585646d | 294 | */ |
6bfbe8af CL |
295 | struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp, |
296 | const char *hostname, | |
297 | const size_t hostname_len) | |
c585646d | 298 | { |
6bfbe8af | 299 | struct sockaddr_in sin = { |
2860a022 | 300 | .sin_family = AF_INET, |
6bfbe8af CL |
301 | }; |
302 | struct sockaddr_in6 sin6 = { | |
303 | .sin6_family = AF_INET6, | |
2860a022 | 304 | }; |
7f1ed18b CL |
305 | struct nlm_lookup_host_info ni = { |
306 | .server = 1, | |
88541c84 CL |
307 | .sap = svc_addr(rqstp), |
308 | .salen = rqstp->rq_addrlen, | |
7f1ed18b CL |
309 | .protocol = rqstp->rq_prot, |
310 | .version = rqstp->rq_vers, | |
311 | .hostname = hostname, | |
312 | .hostname_len = hostname_len, | |
6bfbe8af | 313 | .src_len = rqstp->rq_addrlen, |
7f1ed18b CL |
314 | }; |
315 | ||
316 | dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__, | |
317 | (int)hostname_len, hostname, rqstp->rq_vers, | |
318 | (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp")); | |
c98451bd | 319 | |
6bfbe8af CL |
320 | switch (ni.sap->sa_family) { |
321 | case AF_INET: | |
322 | sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr; | |
323 | ni.src_sap = (struct sockaddr *)&sin; | |
324 | break; | |
325 | case AF_INET6: | |
326 | ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6); | |
327 | ni.src_sap = (struct sockaddr *)&sin6; | |
328 | break; | |
329 | default: | |
330 | return NULL; | |
331 | } | |
332 | ||
7f1ed18b | 333 | return nlm_lookup_host(&ni); |
c585646d AB |
334 | } |
335 | ||
1da177e4 LT |
336 | /* |
337 | * Create the NLM RPC client for an NLM peer | |
338 | */ | |
339 | struct rpc_clnt * | |
340 | nlm_bind_host(struct nlm_host *host) | |
341 | { | |
342 | struct rpc_clnt *clnt; | |
1da177e4 | 343 | |
1df40b60 CL |
344 | dprintk("lockd: nlm_bind_host %s (%s)\n", |
345 | host->h_name, host->h_addrbuf); | |
1da177e4 LT |
346 | |
347 | /* Lock host handle */ | |
50467914 | 348 | mutex_lock(&host->h_mutex); |
1da177e4 LT |
349 | |
350 | /* If we've already created an RPC client, check whether | |
351 | * RPC rebind is required | |
1da177e4 LT |
352 | */ |
353 | if ((clnt = host->h_rpcclnt) != NULL) { | |
43118c29 | 354 | if (time_after_eq(jiffies, host->h_nextrebind)) { |
35f5a422 | 355 | rpc_force_rebind(clnt); |
1da177e4 | 356 | host->h_nextrebind = jiffies + NLM_HOST_REBIND; |
1b333c54 | 357 | dprintk("lockd: next rebind in %lu jiffies\n", |
1da177e4 LT |
358 | host->h_nextrebind - jiffies); |
359 | } | |
360 | } else { | |
21051ba6 | 361 | unsigned long increment = nlmsvc_timeout; |
e1ec7892 CL |
362 | struct rpc_timeout timeparms = { |
363 | .to_initval = increment, | |
364 | .to_increment = increment, | |
365 | .to_maxval = increment * 6UL, | |
366 | .to_retries = 5U, | |
367 | }; | |
368 | struct rpc_create_args args = { | |
369 | .protocol = host->h_proto, | |
b4ed58fd CL |
370 | .address = nlm_addr(host), |
371 | .addrsize = host->h_addrlen, | |
90151e6e | 372 | .saddress = nlm_srcaddr(host), |
e1ec7892 CL |
373 | .timeout = &timeparms, |
374 | .servername = host->h_name, | |
375 | .program = &nlm_program, | |
376 | .version = host->h_version, | |
377 | .authflavor = RPC_AUTH_UNIX, | |
90bd17c8 | 378 | .flags = (RPC_CLNT_CREATE_NOPING | |
e1ec7892 CL |
379 | RPC_CLNT_CREATE_AUTOBIND), |
380 | }; | |
381 | ||
90bd17c8 JL |
382 | /* |
383 | * lockd retries server side blocks automatically so we want | |
384 | * those to be soft RPC calls. Client side calls need to be | |
385 | * hard RPC tasks. | |
386 | */ | |
387 | if (!host->h_server) | |
388 | args.flags |= RPC_CLNT_CREATE_HARDRTRY; | |
0cb2659b CL |
389 | if (host->h_noresvport) |
390 | args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; | |
90bd17c8 | 391 | |
e1ec7892 CL |
392 | clnt = rpc_create(&args); |
393 | if (!IS_ERR(clnt)) | |
394 | host->h_rpcclnt = clnt; | |
395 | else { | |
396 | printk("lockd: couldn't create RPC handle for %s\n", host->h_name); | |
397 | clnt = NULL; | |
398 | } | |
1da177e4 LT |
399 | } |
400 | ||
50467914 | 401 | mutex_unlock(&host->h_mutex); |
1da177e4 | 402 | return clnt; |
1da177e4 LT |
403 | } |
404 | ||
405 | /* | |
406 | * Force a portmap lookup of the remote lockd port | |
407 | */ | |
408 | void | |
409 | nlm_rebind_host(struct nlm_host *host) | |
410 | { | |
411 | dprintk("lockd: rebind host %s\n", host->h_name); | |
412 | if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) { | |
35f5a422 | 413 | rpc_force_rebind(host->h_rpcclnt); |
1da177e4 LT |
414 | host->h_nextrebind = jiffies + NLM_HOST_REBIND; |
415 | } | |
416 | } | |
417 | ||
418 | /* | |
419 | * Increment NLM host count | |
420 | */ | |
421 | struct nlm_host * nlm_get_host(struct nlm_host *host) | |
422 | { | |
423 | if (host) { | |
424 | dprintk("lockd: get host %s\n", host->h_name); | |
425 | atomic_inc(&host->h_count); | |
426 | host->h_expires = jiffies + NLM_HOST_EXPIRE; | |
427 | } | |
428 | return host; | |
429 | } | |
430 | ||
431 | /* | |
432 | * Release NLM host after use | |
433 | */ | |
434 | void nlm_release_host(struct nlm_host *host) | |
435 | { | |
436 | if (host != NULL) { | |
437 | dprintk("lockd: release host %s\n", host->h_name); | |
1da177e4 | 438 | BUG_ON(atomic_read(&host->h_count) < 0); |
4c060b53 TM |
439 | if (atomic_dec_and_test(&host->h_count)) { |
440 | BUG_ON(!list_empty(&host->h_lockowners)); | |
441 | BUG_ON(!list_empty(&host->h_granted)); | |
442 | BUG_ON(!list_empty(&host->h_reclaim)); | |
443 | } | |
1da177e4 LT |
444 | } |
445 | } | |
446 | ||
cf712c24 OK |
447 | /* |
448 | * We were notified that the host indicated by address &sin | |
449 | * has rebooted. | |
450 | * Release all resources held by that peer. | |
451 | */ | |
5c8dd29c | 452 | void nlm_host_rebooted(const struct sockaddr_in *sin, |
48df020a CL |
453 | const char *hostname, |
454 | unsigned int hostname_len, | |
5c8dd29c | 455 | u32 new_state) |
cf712c24 | 456 | { |
0cea3276 OK |
457 | struct hlist_head *chain; |
458 | struct hlist_node *pos; | |
5c8dd29c | 459 | struct nsm_handle *nsm; |
0cea3276 | 460 | struct nlm_host *host; |
cf712c24 | 461 | |
e018040a CL |
462 | nsm = nsm_find((struct sockaddr *)sin, sizeof(*sin), |
463 | hostname, hostname_len, 0); | |
1b333c54 CL |
464 | if (nsm == NULL) { |
465 | dprintk("lockd: never saw rebooted peer '%.*s' before\n", | |
466 | hostname_len, hostname); | |
db4e4c9a | 467 | return; |
1b333c54 CL |
468 | } |
469 | ||
470 | dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n", | |
471 | hostname_len, hostname, nsm->sm_addrbuf); | |
db4e4c9a | 472 | |
5c8dd29c OK |
473 | /* When reclaiming locks on this peer, make sure that |
474 | * we set up a new notification */ | |
475 | nsm->sm_monitored = 0; | |
476 | ||
477 | /* Mark all hosts tied to this NSM state as having rebooted. | |
478 | * We run the loop repeatedly, because we drop the host table | |
479 | * lock for this. | |
480 | * To avoid processing a host several times, we match the nsmstate. | |
481 | */ | |
482 | again: mutex_lock(&nlm_host_mutex); | |
0cea3276 OK |
483 | for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) { |
484 | hlist_for_each_entry(host, pos, chain, h_hash) { | |
5c8dd29c OK |
485 | if (host->h_nsmhandle == nsm |
486 | && host->h_nsmstate != new_state) { | |
487 | host->h_nsmstate = new_state; | |
488 | host->h_state++; | |
489 | ||
490 | nlm_get_host(host); | |
491 | mutex_unlock(&nlm_host_mutex); | |
492 | ||
493 | if (host->h_server) { | |
494 | /* We're server for this guy, just ditch | |
495 | * all the locks he held. */ | |
496 | nlmsvc_free_host_resources(host); | |
497 | } else { | |
498 | /* He's the server, initiate lock recovery. */ | |
499 | nlmclnt_recovery(host); | |
500 | } | |
501 | ||
502 | nlm_release_host(host); | |
503 | goto again; | |
504 | } | |
505 | } | |
cf712c24 | 506 | } |
5c8dd29c OK |
507 | |
508 | mutex_unlock(&nlm_host_mutex); | |
cf712c24 OK |
509 | } |
510 | ||
1da177e4 LT |
511 | /* |
512 | * Shut down the hosts module. | |
513 | * Note that this routine is called only at server shutdown time. | |
514 | */ | |
515 | void | |
516 | nlm_shutdown_hosts(void) | |
517 | { | |
0cea3276 OK |
518 | struct hlist_head *chain; |
519 | struct hlist_node *pos; | |
1da177e4 | 520 | struct nlm_host *host; |
1da177e4 LT |
521 | |
522 | dprintk("lockd: shutting down host module\n"); | |
353ab6e9 | 523 | mutex_lock(&nlm_host_mutex); |
1da177e4 LT |
524 | |
525 | /* First, make all hosts eligible for gc */ | |
526 | dprintk("lockd: nuking all hosts...\n"); | |
0cea3276 | 527 | for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) { |
d801b861 | 528 | hlist_for_each_entry(host, pos, chain, h_hash) { |
1da177e4 | 529 | host->h_expires = jiffies - 1; |
d801b861 JL |
530 | if (host->h_rpcclnt) { |
531 | rpc_shutdown_client(host->h_rpcclnt); | |
532 | host->h_rpcclnt = NULL; | |
533 | } | |
534 | } | |
1da177e4 LT |
535 | } |
536 | ||
537 | /* Then, perform a garbage collection pass */ | |
538 | nlm_gc_hosts(); | |
353ab6e9 | 539 | mutex_unlock(&nlm_host_mutex); |
1da177e4 LT |
540 | |
541 | /* complain if any hosts are left */ | |
542 | if (nrhosts) { | |
543 | printk(KERN_WARNING "lockd: couldn't shutdown host module!\n"); | |
544 | dprintk("lockd: %d hosts left:\n", nrhosts); | |
0cea3276 OK |
545 | for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) { |
546 | hlist_for_each_entry(host, pos, chain, h_hash) { | |
1da177e4 LT |
547 | dprintk(" %s (cnt %d use %d exp %ld)\n", |
548 | host->h_name, atomic_read(&host->h_count), | |
549 | host->h_inuse, host->h_expires); | |
550 | } | |
551 | } | |
552 | } | |
553 | } | |
554 | ||
555 | /* | |
556 | * Garbage collect any unused NLM hosts. | |
557 | * This GC combines reference counting for async operations with | |
558 | * mark & sweep for resources held by remote clients. | |
559 | */ | |
560 | static void | |
561 | nlm_gc_hosts(void) | |
562 | { | |
0cea3276 OK |
563 | struct hlist_head *chain; |
564 | struct hlist_node *pos, *next; | |
565 | struct nlm_host *host; | |
1da177e4 LT |
566 | |
567 | dprintk("lockd: host garbage collection\n"); | |
0cea3276 OK |
568 | for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) { |
569 | hlist_for_each_entry(host, pos, chain, h_hash) | |
1da177e4 LT |
570 | host->h_inuse = 0; |
571 | } | |
572 | ||
573 | /* Mark all hosts that hold locks, blocks or shares */ | |
574 | nlmsvc_mark_resources(); | |
575 | ||
0cea3276 OK |
576 | for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) { |
577 | hlist_for_each_entry_safe(host, pos, next, chain, h_hash) { | |
1da177e4 LT |
578 | if (atomic_read(&host->h_count) || host->h_inuse |
579 | || time_before(jiffies, host->h_expires)) { | |
580 | dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n", | |
581 | host->h_name, atomic_read(&host->h_count), | |
582 | host->h_inuse, host->h_expires); | |
1da177e4 LT |
583 | continue; |
584 | } | |
585 | dprintk("lockd: delete host %s\n", host->h_name); | |
0cea3276 | 586 | hlist_del_init(&host->h_hash); |
977faf39 | 587 | |
c53c1bb9 | 588 | nlm_destroy_host(host); |
1da177e4 LT |
589 | nrhosts--; |
590 | } | |
591 | } | |
592 | ||
593 | next_gc = jiffies + NLM_HOST_COLLECT; | |
594 | } |