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ARM: dts: Add keep-power-in-suspend to WiFi SDIO node for exynos5250-snow
[linux-2.6/btrfs-unstable.git] / fs / lockd / host.c
blob969d589c848df8e066754e5ca5f3b02729eed919
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/slab.h>
13 #include <linux/in.h>
14 #include <linux/in6.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/sunrpc/addr.h>
17 #include <linux/sunrpc/svc.h>
18 #include <linux/lockd/lockd.h>
19 #include <linux/mutex.h>
20
21 #include <linux/sunrpc/svc_xprt.h>
22
23 #include <net/ipv6.h>
24
25 #include "netns.h"
26
27 #define NLMDBG_FACILITY NLMDBG_HOSTCACHE
28 #define NLM_HOST_NRHASH 32
29 #define NLM_HOST_REBIND (60 * HZ)
30 #define NLM_HOST_EXPIRE (300 * HZ)
31 #define NLM_HOST_COLLECT (120 * HZ)
32
33 static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH];
34 static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH];
35
36 #define for_each_host(host, chain, table) \
37 for ((chain) = (table); \
38 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
39 hlist_for_each_entry((host), (chain), h_hash)
40
41 #define for_each_host_safe(host, next, chain, table) \
42 for ((chain) = (table); \
43 (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
44 hlist_for_each_entry_safe((host), (next), \
45 (chain), h_hash)
46
47 static unsigned long nrhosts;
48 static DEFINE_MUTEX(nlm_host_mutex);
49
50 static void nlm_gc_hosts(struct net *net);
51
52 struct nlm_lookup_host_info {
53 const int server; /* search for server|client */
54 const struct sockaddr *sap; /* address to search for */
55 const size_t salen; /* it's length */
56 const unsigned short protocol; /* transport to search for*/
57 const u32 version; /* NLM version to search for */
58 const char *hostname; /* remote's hostname */
59 const size_t hostname_len; /* it's length */
60 const int noresvport; /* use non-priv port */
61 struct net *net; /* network namespace to bind */
62 };
63
64 /*
65 * Hash function must work well on big- and little-endian platforms
66 */
67 static unsigned int __nlm_hash32(const __be32 n)
68 {
69 unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
70 return hash ^ (hash >> 8);
71 }
72
73 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
74 {
75 const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
76 return __nlm_hash32(sin->sin_addr.s_addr);
77 }
78
79 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
80 {
81 const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
82 const struct in6_addr addr = sin6->sin6_addr;
83 return __nlm_hash32(addr.s6_addr32[0]) ^
84 __nlm_hash32(addr.s6_addr32[1]) ^
85 __nlm_hash32(addr.s6_addr32[2]) ^
86 __nlm_hash32(addr.s6_addr32[3]);
87 }
88
89 static unsigned int nlm_hash_address(const struct sockaddr *sap)
90 {
91 unsigned int hash;
92
93 switch (sap->sa_family) {
94 case AF_INET:
95 hash = __nlm_hash_addr4(sap);
96 break;
97 case AF_INET6:
98 hash = __nlm_hash_addr6(sap);
99 break;
100 default:
101 hash = 0;
102 }
103 return hash & (NLM_HOST_NRHASH - 1);
104 }
105
106 /*
107 * Allocate and initialize an nlm_host. Common to both client and server.
108 */
109 static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
110 struct nsm_handle *nsm)
111 {
112 struct nlm_host *host = NULL;
113 unsigned long now = jiffies;
114
115 if (nsm != NULL)
116 atomic_inc(&nsm->sm_count);
117 else {
118 host = NULL;
119 nsm = nsm_get_handle(ni->sap, ni->salen,
120 ni->hostname, ni->hostname_len);
121 if (unlikely(nsm == NULL)) {
122 dprintk("lockd: %s failed; no nsm handle\n",
123 __func__);
124 goto out;
125 }
126 }
127
128 host = kmalloc(sizeof(*host), GFP_KERNEL);
129 if (unlikely(host == NULL)) {
130 dprintk("lockd: %s failed; no memory\n", __func__);
131 nsm_release(nsm);
132 goto out;
133 }
134
135 memcpy(nlm_addr(host), ni->sap, ni->salen);
136 host->h_addrlen = ni->salen;
137 rpc_set_port(nlm_addr(host), 0);
138 host->h_srcaddrlen = 0;
139
140 host->h_rpcclnt = NULL;
141 host->h_name = nsm->sm_name;
142 host->h_version = ni->version;
143 host->h_proto = ni->protocol;
144 host->h_reclaiming = 0;
145 host->h_server = ni->server;
146 host->h_noresvport = ni->noresvport;
147 host->h_inuse = 0;
148 init_waitqueue_head(&host->h_gracewait);
149 init_rwsem(&host->h_rwsem);
150 host->h_state = 0;
151 host->h_nsmstate = 0;
152 host->h_pidcount = 0;
153 atomic_set(&host->h_count, 1);
154 mutex_init(&host->h_mutex);
155 host->h_nextrebind = now + NLM_HOST_REBIND;
156 host->h_expires = now + NLM_HOST_EXPIRE;
157 INIT_LIST_HEAD(&host->h_lockowners);
158 spin_lock_init(&host->h_lock);
159 INIT_LIST_HEAD(&host->h_granted);
160 INIT_LIST_HEAD(&host->h_reclaim);
161 host->h_nsmhandle = nsm;
162 host->h_addrbuf = nsm->sm_addrbuf;
163 host->net = ni->net;
164
165 out:
166 return host;
167 }
168
169 /*
170 * Destroy an nlm_host and free associated resources
171 *
172 * Caller must hold nlm_host_mutex.
173 */
174 static void nlm_destroy_host_locked(struct nlm_host *host)
175 {
176 struct rpc_clnt *clnt;
177 struct lockd_net *ln = net_generic(host->net, lockd_net_id);
178
179 dprintk("lockd: destroy host %s\n", host->h_name);
180
181 hlist_del_init(&host->h_hash);
182
183 nsm_unmonitor(host);
184 nsm_release(host->h_nsmhandle);
185
186 clnt = host->h_rpcclnt;
187 if (clnt != NULL)
188 rpc_shutdown_client(clnt);
189 kfree(host);
190
191 ln->nrhosts--;
192 nrhosts--;
193 }
194
195 /**
196 * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
197 * @sap: network address of server
198 * @salen: length of server address
199 * @protocol: transport protocol to use
200 * @version: NLM protocol version
201 * @hostname: '\0'-terminated hostname of server
202 * @noresvport: 1 if non-privileged port should be used
203 *
204 * Returns an nlm_host structure that matches the passed-in
205 * [server address, transport protocol, NLM version, server hostname].
206 * If one doesn't already exist in the host cache, a new handle is
207 * created and returned.
208 */
209 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
210 const size_t salen,
211 const unsigned short protocol,
212 const u32 version,
213 const char *hostname,
214 int noresvport,
215 struct net *net)
216 {
217 struct nlm_lookup_host_info ni = {
218 .server = 0,
219 .sap = sap,
220 .salen = salen,
221 .protocol = protocol,
222 .version = version,
223 .hostname = hostname,
224 .hostname_len = strlen(hostname),
225 .noresvport = noresvport,
226 .net = net,
227 };
228 struct hlist_head *chain;
229 struct nlm_host *host;
230 struct nsm_handle *nsm = NULL;
231 struct lockd_net *ln = net_generic(net, lockd_net_id);
232
233 dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
234 (hostname ? hostname : "<none>"), version,
235 (protocol == IPPROTO_UDP ? "udp" : "tcp"));
236
237 mutex_lock(&nlm_host_mutex);
238
239 chain = &nlm_client_hosts[nlm_hash_address(sap)];
240 hlist_for_each_entry(host, chain, h_hash) {
241 if (host->net != net)
242 continue;
243 if (!rpc_cmp_addr(nlm_addr(host), sap))
244 continue;
245
246 /* Same address. Share an NSM handle if we already have one */
247 if (nsm == NULL)
248 nsm = host->h_nsmhandle;
249
250 if (host->h_proto != protocol)
251 continue;
252 if (host->h_version != version)
253 continue;
254
255 nlm_get_host(host);
256 dprintk("lockd: %s found host %s (%s)\n", __func__,
257 host->h_name, host->h_addrbuf);
258 goto out;
259 }
260
261 host = nlm_alloc_host(&ni, nsm);
262 if (unlikely(host == NULL))
263 goto out;
264
265 hlist_add_head(&host->h_hash, chain);
266 ln->nrhosts++;
267 nrhosts++;
268
269 dprintk("lockd: %s created host %s (%s)\n", __func__,
270 host->h_name, host->h_addrbuf);
271
272 out:
273 mutex_unlock(&nlm_host_mutex);
274 return host;
275 }
276
277 /**
278 * nlmclnt_release_host - release client nlm_host
279 * @host: nlm_host to release
280 *
281 */
282 void nlmclnt_release_host(struct nlm_host *host)
283 {
284 if (host == NULL)
285 return;
286
287 dprintk("lockd: release client host %s\n", host->h_name);
288
289 WARN_ON_ONCE(host->h_server);
290
291 if (atomic_dec_and_test(&host->h_count)) {
292 WARN_ON_ONCE(!list_empty(&host->h_lockowners));
293 WARN_ON_ONCE(!list_empty(&host->h_granted));
294 WARN_ON_ONCE(!list_empty(&host->h_reclaim));
295
296 mutex_lock(&nlm_host_mutex);
297 nlm_destroy_host_locked(host);
298 mutex_unlock(&nlm_host_mutex);
299 }
300 }
301
302 /**
303 * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
304 * @rqstp: incoming NLM request
305 * @hostname: name of client host
306 * @hostname_len: length of client hostname
307 *
308 * Returns an nlm_host structure that matches the [client address,
309 * transport protocol, NLM version, client hostname] of the passed-in
310 * NLM request. If one doesn't already exist in the host cache, a
311 * new handle is created and returned.
312 *
313 * Before possibly creating a new nlm_host, construct a sockaddr
314 * for a specific source address in case the local system has
315 * multiple network addresses. The family of the address in
316 * rq_daddr is guaranteed to be the same as the family of the
317 * address in rq_addr, so it's safe to use the same family for
318 * the source address.
319 */
320 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
321 const char *hostname,
322 const size_t hostname_len)
323 {
324 struct hlist_head *chain;
325 struct nlm_host *host = NULL;
326 struct nsm_handle *nsm = NULL;
327 struct sockaddr *src_sap = svc_daddr(rqstp);
328 size_t src_len = rqstp->rq_daddrlen;
329 struct net *net = SVC_NET(rqstp);
330 struct nlm_lookup_host_info ni = {
331 .server = 1,
332 .sap = svc_addr(rqstp),
333 .salen = rqstp->rq_addrlen,
334 .protocol = rqstp->rq_prot,
335 .version = rqstp->rq_vers,
336 .hostname = hostname,
337 .hostname_len = hostname_len,
338 .net = net,
339 };
340 struct lockd_net *ln = net_generic(net, lockd_net_id);
341
342 dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
343 (int)hostname_len, hostname, rqstp->rq_vers,
344 (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
345
346 mutex_lock(&nlm_host_mutex);
347
348 if (time_after_eq(jiffies, ln->next_gc))
349 nlm_gc_hosts(net);
350
351 chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
352 hlist_for_each_entry(host, chain, h_hash) {
353 if (host->net != net)
354 continue;
355 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
356 continue;
357
358 /* Same address. Share an NSM handle if we already have one */
359 if (nsm == NULL)
360 nsm = host->h_nsmhandle;
361
362 if (host->h_proto != ni.protocol)
363 continue;
364 if (host->h_version != ni.version)
365 continue;
366 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
367 continue;
368
369 /* Move to head of hash chain. */
370 hlist_del(&host->h_hash);
371 hlist_add_head(&host->h_hash, chain);
372
373 nlm_get_host(host);
374 dprintk("lockd: %s found host %s (%s)\n",
375 __func__, host->h_name, host->h_addrbuf);
376 goto out;
377 }
378
379 host = nlm_alloc_host(&ni, nsm);
380 if (unlikely(host == NULL))
381 goto out;
382
383 memcpy(nlm_srcaddr(host), src_sap, src_len);
384 host->h_srcaddrlen = src_len;
385 hlist_add_head(&host->h_hash, chain);
386 ln->nrhosts++;
387 nrhosts++;
388
389 dprintk("lockd: %s created host %s (%s)\n",
390 __func__, host->h_name, host->h_addrbuf);
391
392 out:
393 mutex_unlock(&nlm_host_mutex);
394 return host;
395 }
396
397 /**
398 * nlmsvc_release_host - release server nlm_host
399 * @host: nlm_host to release
400 *
401 * Host is destroyed later in nlm_gc_host().
402 */
403 void nlmsvc_release_host(struct nlm_host *host)
404 {
405 if (host == NULL)
406 return;
407
408 dprintk("lockd: release server host %s\n", host->h_name);
409
410 WARN_ON_ONCE(!host->h_server);
411 atomic_dec(&host->h_count);
412 }
413
414 /*
415 * Create the NLM RPC client for an NLM peer
416 */
417 struct rpc_clnt *
418 nlm_bind_host(struct nlm_host *host)
419 {
420 struct rpc_clnt *clnt;
421
422 dprintk("lockd: nlm_bind_host %s (%s)\n",
423 host->h_name, host->h_addrbuf);
424
425 /* Lock host handle */
426 mutex_lock(&host->h_mutex);
427
428 /* If we've already created an RPC client, check whether
429 * RPC rebind is required
430 */
431 if ((clnt = host->h_rpcclnt) != NULL) {
432 if (time_after_eq(jiffies, host->h_nextrebind)) {
433 rpc_force_rebind(clnt);
434 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
435 dprintk("lockd: next rebind in %lu jiffies\n",
436 host->h_nextrebind - jiffies);
437 }
438 } else {
439 unsigned long increment = nlmsvc_timeout;
440 struct rpc_timeout timeparms = {
441 .to_initval = increment,
442 .to_increment = increment,
443 .to_maxval = increment * 6UL,
444 .to_retries = 5U,
445 };
446 struct rpc_create_args args = {
447 .net = host->net,
448 .protocol = host->h_proto,
449 .address = nlm_addr(host),
450 .addrsize = host->h_addrlen,
451 .timeout = &timeparms,
452 .servername = host->h_name,
453 .program = &nlm_program,
454 .version = host->h_version,
455 .authflavor = RPC_AUTH_UNIX,
456 .flags = (RPC_CLNT_CREATE_NOPING |
457 RPC_CLNT_CREATE_AUTOBIND),
458 };
459
460 /*
461 * lockd retries server side blocks automatically so we want
462 * those to be soft RPC calls. Client side calls need to be
463 * hard RPC tasks.
464 */
465 if (!host->h_server)
466 args.flags |= RPC_CLNT_CREATE_HARDRTRY;
467 if (host->h_noresvport)
468 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
469 if (host->h_srcaddrlen)
470 args.saddress = nlm_srcaddr(host);
471
472 clnt = rpc_create(&args);
473 if (!IS_ERR(clnt))
474 host->h_rpcclnt = clnt;
475 else {
476 printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
477 clnt = NULL;
478 }
479 }
480
481 mutex_unlock(&host->h_mutex);
482 return clnt;
483 }
484
485 /*
486 * Force a portmap lookup of the remote lockd port
487 */
488 void
489 nlm_rebind_host(struct nlm_host *host)
490 {
491 dprintk("lockd: rebind host %s\n", host->h_name);
492 if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
493 rpc_force_rebind(host->h_rpcclnt);
494 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
495 }
496 }
497
498 /*
499 * Increment NLM host count
500 */
501 struct nlm_host * nlm_get_host(struct nlm_host *host)
502 {
503 if (host) {
504 dprintk("lockd: get host %s\n", host->h_name);
505 atomic_inc(&host->h_count);
506 host->h_expires = jiffies + NLM_HOST_EXPIRE;
507 }
508 return host;
509 }
510
511 static struct nlm_host *next_host_state(struct hlist_head *cache,
512 struct nsm_handle *nsm,
513 const struct nlm_reboot *info)
514 {
515 struct nlm_host *host;
516 struct hlist_head *chain;
517
518 mutex_lock(&nlm_host_mutex);
519 for_each_host(host, chain, cache) {
520 if (host->h_nsmhandle == nsm
521 && host->h_nsmstate != info->state) {
522 host->h_nsmstate = info->state;
523 host->h_state++;
524
525 nlm_get_host(host);
526 mutex_unlock(&nlm_host_mutex);
527 return host;
528 }
529 }
530
531 mutex_unlock(&nlm_host_mutex);
532 return NULL;
533 }
534
535 /**
536 * nlm_host_rebooted - Release all resources held by rebooted host
537 * @info: pointer to decoded results of NLM_SM_NOTIFY call
538 *
539 * We were notified that the specified host has rebooted. Release
540 * all resources held by that peer.
541 */
542 void nlm_host_rebooted(const struct nlm_reboot *info)
543 {
544 struct nsm_handle *nsm;
545 struct nlm_host *host;
546
547 nsm = nsm_reboot_lookup(info);
548 if (unlikely(nsm == NULL))
549 return;
550
551 /* Mark all hosts tied to this NSM state as having rebooted.
552 * We run the loop repeatedly, because we drop the host table
553 * lock for this.
554 * To avoid processing a host several times, we match the nsmstate.
555 */
556 while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
557 nlmsvc_free_host_resources(host);
558 nlmsvc_release_host(host);
559 }
560 while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
561 nlmclnt_recovery(host);
562 nlmclnt_release_host(host);
563 }
564
565 nsm_release(nsm);
566 }
567
568 static void nlm_complain_hosts(struct net *net)
569 {
570 struct hlist_head *chain;
571 struct nlm_host *host;
572
573 if (net) {
574 struct lockd_net *ln = net_generic(net, lockd_net_id);
575
576 if (ln->nrhosts == 0)
577 return;
578 printk(KERN_WARNING "lockd: couldn't shutdown host module for net %p!\n", net);
579 dprintk("lockd: %lu hosts left in net %p:\n", ln->nrhosts, net);
580 } else {
581 if (nrhosts == 0)
582 return;
583 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
584 dprintk("lockd: %lu hosts left:\n", nrhosts);
585 }
586
587 for_each_host(host, chain, nlm_server_hosts) {
588 if (net && host->net != net)
589 continue;
590 dprintk(" %s (cnt %d use %d exp %ld net %p)\n",
591 host->h_name, atomic_read(&host->h_count),
592 host->h_inuse, host->h_expires, host->net);
593 }
594 }
595
596 void
597 nlm_shutdown_hosts_net(struct net *net)
598 {
599 struct hlist_head *chain;
600 struct nlm_host *host;
601
602 mutex_lock(&nlm_host_mutex);
603
604 /* First, make all hosts eligible for gc */
605 dprintk("lockd: nuking all hosts in net %p...\n", net);
606 for_each_host(host, chain, nlm_server_hosts) {
607 if (net && host->net != net)
608 continue;
609 host->h_expires = jiffies - 1;
610 if (host->h_rpcclnt) {
611 rpc_shutdown_client(host->h_rpcclnt);
612 host->h_rpcclnt = NULL;
613 }
614 }
615
616 /* Then, perform a garbage collection pass */
617 nlm_gc_hosts(net);
618 mutex_unlock(&nlm_host_mutex);
619
620 nlm_complain_hosts(net);
621 }
622
623 /*
624 * Shut down the hosts module.
625 * Note that this routine is called only at server shutdown time.
626 */
627 void
628 nlm_shutdown_hosts(void)
629 {
630 dprintk("lockd: shutting down host module\n");
631 nlm_shutdown_hosts_net(NULL);
632 }
633
634 /*
635 * Garbage collect any unused NLM hosts.
636 * This GC combines reference counting for async operations with
637 * mark & sweep for resources held by remote clients.
638 */
639 static void
640 nlm_gc_hosts(struct net *net)
641 {
642 struct hlist_head *chain;
643 struct hlist_node *next;
644 struct nlm_host *host;
645
646 dprintk("lockd: host garbage collection for net %p\n", net);
647 for_each_host(host, chain, nlm_server_hosts) {
648 if (net && host->net != net)
649 continue;
650 host->h_inuse = 0;
651 }
652
653 /* Mark all hosts that hold locks, blocks or shares */
654 nlmsvc_mark_resources(net);
655
656 for_each_host_safe(host, next, chain, nlm_server_hosts) {
657 if (net && host->net != net)
658 continue;
659 if (atomic_read(&host->h_count) || host->h_inuse
660 || time_before(jiffies, host->h_expires)) {
661 dprintk("nlm_gc_hosts skipping %s "
662 "(cnt %d use %d exp %ld net %p)\n",
663 host->h_name, atomic_read(&host->h_count),
664 host->h_inuse, host->h_expires, host->net);
665 continue;
666 }
667 nlm_destroy_host_locked(host);
668 }
669
670 if (net) {
671 struct lockd_net *ln = net_generic(net, lockd_net_id);
672
673 ln->next_gc = jiffies + NLM_HOST_COLLECT;
674 }
675 }
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