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TOMOYO Linux Cross Reference
Linux/fs/lockd/host.c

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  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * linux/fs/lockd/host.c
  4  *
  5  * Management for NLM peer hosts. The nlm_host struct is shared
  6  * between client and server implementation. The only reason to
  7  * do so is to reduce code bloat.
  8  *
  9  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 10  */
 11 
 12 #include <linux/types.h>
 13 #include <linux/slab.h>
 14 #include <linux/in.h>
 15 #include <linux/in6.h>
 16 #include <linux/sunrpc/clnt.h>
 17 #include <linux/sunrpc/addr.h>
 18 #include <linux/sunrpc/svc.h>
 19 #include <linux/lockd/lockd.h>
 20 #include <linux/mutex.h>
 21 
 22 #include <linux/sunrpc/svc_xprt.h>
 23 
 24 #include <net/ipv6.h>
 25 
 26 #include "netns.h"
 27 
 28 #define NLMDBG_FACILITY         NLMDBG_HOSTCACHE
 29 #define NLM_HOST_NRHASH         32
 30 #define NLM_HOST_REBIND         (60 * HZ)
 31 #define NLM_HOST_EXPIRE         (300 * HZ)
 32 #define NLM_HOST_COLLECT        (120 * HZ)
 33 
 34 static struct hlist_head        nlm_server_hosts[NLM_HOST_NRHASH];
 35 static struct hlist_head        nlm_client_hosts[NLM_HOST_NRHASH];
 36 
 37 #define for_each_host(host, chain, table) \
 38         for ((chain) = (table); \
 39              (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
 40                 hlist_for_each_entry((host), (chain), h_hash)
 41 
 42 #define for_each_host_safe(host, next, chain, table) \
 43         for ((chain) = (table); \
 44              (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
 45                 hlist_for_each_entry_safe((host), (next), \
 46                                                 (chain), h_hash)
 47 
 48 static unsigned long            nrhosts;
 49 static DEFINE_MUTEX(nlm_host_mutex);
 50 
 51 static void                     nlm_gc_hosts(struct net *net);
 52 
 53 struct nlm_lookup_host_info {
 54         const int               server;         /* search for server|client */
 55         const struct sockaddr   *sap;           /* address to search for */
 56         const size_t            salen;          /* it's length */
 57         const unsigned short    protocol;       /* transport to search for*/
 58         const u32               version;        /* NLM version to search for */
 59         const char              *hostname;      /* remote's hostname */
 60         const size_t            hostname_len;   /* it's length */
 61         const int               noresvport;     /* use non-priv port */
 62         struct net              *net;           /* network namespace to bind */
 63         const struct cred       *cred;
 64 };
 65 
 66 /*
 67  * Hash function must work well on big- and little-endian platforms
 68  */
 69 static unsigned int __nlm_hash32(const __be32 n)
 70 {
 71         unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
 72         return hash ^ (hash >> 8);
 73 }
 74 
 75 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
 76 {
 77         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 78         return __nlm_hash32(sin->sin_addr.s_addr);
 79 }
 80 
 81 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
 82 {
 83         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 84         const struct in6_addr addr = sin6->sin6_addr;
 85         return __nlm_hash32(addr.s6_addr32[0]) ^
 86                __nlm_hash32(addr.s6_addr32[1]) ^
 87                __nlm_hash32(addr.s6_addr32[2]) ^
 88                __nlm_hash32(addr.s6_addr32[3]);
 89 }
 90 
 91 static unsigned int nlm_hash_address(const struct sockaddr *sap)
 92 {
 93         unsigned int hash;
 94 
 95         switch (sap->sa_family) {
 96         case AF_INET:
 97                 hash = __nlm_hash_addr4(sap);
 98                 break;
 99         case AF_INET6:
100                 hash = __nlm_hash_addr6(sap);
101                 break;
102         default:
103                 hash = 0;
104         }
105         return hash & (NLM_HOST_NRHASH - 1);
106 }
107 
108 /*
109  * Allocate and initialize an nlm_host.  Common to both client and server.
110  */
111 static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
112                                        struct nsm_handle *nsm)
113 {
114         struct nlm_host *host = NULL;
115         unsigned long now = jiffies;
116 
117         if (nsm != NULL)
118                 refcount_inc(&nsm->sm_count);
119         else {
120                 host = NULL;
121                 nsm = nsm_get_handle(ni->net, ni->sap, ni->salen,
122                                         ni->hostname, ni->hostname_len);
123                 if (unlikely(nsm == NULL)) {
124                         dprintk("lockd: %s failed; no nsm handle\n",
125                                 __func__);
126                         goto out;
127                 }
128         }
129 
130         host = kmalloc(sizeof(*host), GFP_KERNEL);
131         if (unlikely(host == NULL)) {
132                 dprintk("lockd: %s failed; no memory\n", __func__);
133                 nsm_release(nsm);
134                 goto out;
135         }
136 
137         memcpy(nlm_addr(host), ni->sap, ni->salen);
138         host->h_addrlen    = ni->salen;
139         rpc_set_port(nlm_addr(host), 0);
140         host->h_srcaddrlen = 0;
141 
142         host->h_rpcclnt    = NULL;
143         host->h_name       = nsm->sm_name;
144         host->h_version    = ni->version;
145         host->h_proto      = ni->protocol;
146         host->h_reclaiming = 0;
147         host->h_server     = ni->server;
148         host->h_noresvport = ni->noresvport;
149         host->h_inuse      = 0;
150         init_waitqueue_head(&host->h_gracewait);
151         init_rwsem(&host->h_rwsem);
152         host->h_state      = 0;
153         host->h_nsmstate   = 0;
154         host->h_pidcount   = 0;
155         refcount_set(&host->h_count, 1);
156         mutex_init(&host->h_mutex);
157         host->h_nextrebind = now + NLM_HOST_REBIND;
158         host->h_expires    = now + NLM_HOST_EXPIRE;
159         INIT_LIST_HEAD(&host->h_lockowners);
160         spin_lock_init(&host->h_lock);
161         INIT_LIST_HEAD(&host->h_granted);
162         INIT_LIST_HEAD(&host->h_reclaim);
163         host->h_nsmhandle  = nsm;
164         host->h_addrbuf    = nsm->sm_addrbuf;
165         host->net          = ni->net;
166         host->h_cred       = get_cred(ni->cred),
167         strlcpy(host->nodename, utsname()->nodename, sizeof(host->nodename));
168 
169 out:
170         return host;
171 }
172 
173 /*
174  * Destroy an nlm_host and free associated resources
175  *
176  * Caller must hold nlm_host_mutex.
177  */
178 static void nlm_destroy_host_locked(struct nlm_host *host)
179 {
180         struct rpc_clnt *clnt;
181         struct lockd_net *ln = net_generic(host->net, lockd_net_id);
182 
183         dprintk("lockd: destroy host %s\n", host->h_name);
184 
185         hlist_del_init(&host->h_hash);
186 
187         nsm_unmonitor(host);
188         nsm_release(host->h_nsmhandle);
189 
190         clnt = host->h_rpcclnt;
191         if (clnt != NULL)
192                 rpc_shutdown_client(clnt);
193         put_cred(host->h_cred);
194         kfree(host);
195 
196         ln->nrhosts--;
197         nrhosts--;
198 }
199 
200 /**
201  * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
202  * @sap: network address of server
203  * @salen: length of server address
204  * @protocol: transport protocol to use
205  * @version: NLM protocol version
206  * @hostname: '\0'-terminated hostname of server
207  * @noresvport: 1 if non-privileged port should be used
208  * @net: pointer to net namespace
209  * @cred: pointer to cred
210  *
211  * Returns an nlm_host structure that matches the passed-in
212  * [server address, transport protocol, NLM version, server hostname].
213  * If one doesn't already exist in the host cache, a new handle is
214  * created and returned.
215  */
216 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
217                                      const size_t salen,
218                                      const unsigned short protocol,
219                                      const u32 version,
220                                      const char *hostname,
221                                      int noresvport,
222                                      struct net *net,
223                                      const struct cred *cred)
224 {
225         struct nlm_lookup_host_info ni = {
226                 .server         = 0,
227                 .sap            = sap,
228                 .salen          = salen,
229                 .protocol       = protocol,
230                 .version        = version,
231                 .hostname       = hostname,
232                 .hostname_len   = strlen(hostname),
233                 .noresvport     = noresvport,
234                 .net            = net,
235                 .cred           = cred,
236         };
237         struct hlist_head *chain;
238         struct nlm_host *host;
239         struct nsm_handle *nsm = NULL;
240         struct lockd_net *ln = net_generic(net, lockd_net_id);
241 
242         dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
243                         (hostname ? hostname : "<none>"), version,
244                         (protocol == IPPROTO_UDP ? "udp" : "tcp"));
245 
246         mutex_lock(&nlm_host_mutex);
247 
248         chain = &nlm_client_hosts[nlm_hash_address(sap)];
249         hlist_for_each_entry(host, chain, h_hash) {
250                 if (host->net != net)
251                         continue;
252                 if (!rpc_cmp_addr(nlm_addr(host), sap))
253                         continue;
254 
255                 /* Same address. Share an NSM handle if we already have one */
256                 if (nsm == NULL)
257                         nsm = host->h_nsmhandle;
258 
259                 if (host->h_proto != protocol)
260                         continue;
261                 if (host->h_version != version)
262                         continue;
263 
264                 nlm_get_host(host);
265                 dprintk("lockd: %s found host %s (%s)\n", __func__,
266                         host->h_name, host->h_addrbuf);
267                 goto out;
268         }
269 
270         host = nlm_alloc_host(&ni, nsm);
271         if (unlikely(host == NULL))
272                 goto out;
273 
274         hlist_add_head(&host->h_hash, chain);
275         ln->nrhosts++;
276         nrhosts++;
277 
278         dprintk("lockd: %s created host %s (%s)\n", __func__,
279                 host->h_name, host->h_addrbuf);
280 
281 out:
282         mutex_unlock(&nlm_host_mutex);
283         return host;
284 }
285 
286 /**
287  * nlmclnt_release_host - release client nlm_host
288  * @host: nlm_host to release
289  *
290  */
291 void nlmclnt_release_host(struct nlm_host *host)
292 {
293         if (host == NULL)
294                 return;
295 
296         dprintk("lockd: release client host %s\n", host->h_name);
297 
298         WARN_ON_ONCE(host->h_server);
299 
300         if (refcount_dec_and_mutex_lock(&host->h_count, &nlm_host_mutex)) {
301                 WARN_ON_ONCE(!list_empty(&host->h_lockowners));
302                 WARN_ON_ONCE(!list_empty(&host->h_granted));
303                 WARN_ON_ONCE(!list_empty(&host->h_reclaim));
304 
305                 nlm_destroy_host_locked(host);
306                 mutex_unlock(&nlm_host_mutex);
307         }
308 }
309 
310 /**
311  * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
312  * @rqstp: incoming NLM request
313  * @hostname: name of client host
314  * @hostname_len: length of client hostname
315  *
316  * Returns an nlm_host structure that matches the [client address,
317  * transport protocol, NLM version, client hostname] of the passed-in
318  * NLM request.  If one doesn't already exist in the host cache, a
319  * new handle is created and returned.
320  *
321  * Before possibly creating a new nlm_host, construct a sockaddr
322  * for a specific source address in case the local system has
323  * multiple network addresses.  The family of the address in
324  * rq_daddr is guaranteed to be the same as the family of the
325  * address in rq_addr, so it's safe to use the same family for
326  * the source address.
327  */
328 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
329                                     const char *hostname,
330                                     const size_t hostname_len)
331 {
332         struct hlist_head *chain;
333         struct nlm_host *host = NULL;
334         struct nsm_handle *nsm = NULL;
335         struct sockaddr *src_sap = svc_daddr(rqstp);
336         size_t src_len = rqstp->rq_daddrlen;
337         struct net *net = SVC_NET(rqstp);
338         struct nlm_lookup_host_info ni = {
339                 .server         = 1,
340                 .sap            = svc_addr(rqstp),
341                 .salen          = rqstp->rq_addrlen,
342                 .protocol       = rqstp->rq_prot,
343                 .version        = rqstp->rq_vers,
344                 .hostname       = hostname,
345                 .hostname_len   = hostname_len,
346                 .net            = net,
347         };
348         struct lockd_net *ln = net_generic(net, lockd_net_id);
349 
350         dprintk("lockd: %s(host='%.*s', vers=%u, proto=%s)\n", __func__,
351                         (int)hostname_len, hostname, rqstp->rq_vers,
352                         (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
353 
354         mutex_lock(&nlm_host_mutex);
355 
356         if (time_after_eq(jiffies, ln->next_gc))
357                 nlm_gc_hosts(net);
358 
359         chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
360         hlist_for_each_entry(host, chain, h_hash) {
361                 if (host->net != net)
362                         continue;
363                 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
364                         continue;
365 
366                 /* Same address. Share an NSM handle if we already have one */
367                 if (nsm == NULL)
368                         nsm = host->h_nsmhandle;
369 
370                 if (host->h_proto != ni.protocol)
371                         continue;
372                 if (host->h_version != ni.version)
373                         continue;
374                 if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))
375                         continue;
376 
377                 /* Move to head of hash chain. */
378                 hlist_del(&host->h_hash);
379                 hlist_add_head(&host->h_hash, chain);
380 
381                 nlm_get_host(host);
382                 dprintk("lockd: %s found host %s (%s)\n",
383                         __func__, host->h_name, host->h_addrbuf);
384                 goto out;
385         }
386 
387         host = nlm_alloc_host(&ni, nsm);
388         if (unlikely(host == NULL))
389                 goto out;
390 
391         memcpy(nlm_srcaddr(host), src_sap, src_len);
392         host->h_srcaddrlen = src_len;
393         hlist_add_head(&host->h_hash, chain);
394         ln->nrhosts++;
395         nrhosts++;
396 
397         refcount_inc(&host->h_count);
398 
399         dprintk("lockd: %s created host %s (%s)\n",
400                 __func__, host->h_name, host->h_addrbuf);
401 
402 out:
403         mutex_unlock(&nlm_host_mutex);
404         return host;
405 }
406 
407 /**
408  * nlmsvc_release_host - release server nlm_host
409  * @host: nlm_host to release
410  *
411  * Host is destroyed later in nlm_gc_host().
412  */
413 void nlmsvc_release_host(struct nlm_host *host)
414 {
415         if (host == NULL)
416                 return;
417 
418         dprintk("lockd: release server host %s\n", host->h_name);
419 
420         WARN_ON_ONCE(!host->h_server);
421         refcount_dec(&host->h_count);
422 }
423 
424 /*
425  * Create the NLM RPC client for an NLM peer
426  */
427 struct rpc_clnt *
428 nlm_bind_host(struct nlm_host *host)
429 {
430         struct rpc_clnt *clnt;
431 
432         dprintk("lockd: nlm_bind_host %s (%s)\n",
433                         host->h_name, host->h_addrbuf);
434 
435         /* Lock host handle */
436         mutex_lock(&host->h_mutex);
437 
438         /* If we've already created an RPC client, check whether
439          * RPC rebind is required
440          */
441         if ((clnt = host->h_rpcclnt) != NULL) {
442                 if (time_after_eq(jiffies, host->h_nextrebind)) {
443                         rpc_force_rebind(clnt);
444                         host->h_nextrebind = jiffies + NLM_HOST_REBIND;
445                         dprintk("lockd: next rebind in %lu jiffies\n",
446                                         host->h_nextrebind - jiffies);
447                 }
448         } else {
449                 unsigned long increment = nlmsvc_timeout;
450                 struct rpc_timeout timeparms = {
451                         .to_initval     = increment,
452                         .to_increment   = increment,
453                         .to_maxval      = increment * 6UL,
454                         .to_retries     = 5U,
455                 };
456                 struct rpc_create_args args = {
457                         .net            = host->net,
458                         .protocol       = host->h_proto,
459                         .address        = nlm_addr(host),
460                         .addrsize       = host->h_addrlen,
461                         .timeout        = &timeparms,
462                         .servername     = host->h_name,
463                         .program        = &nlm_program,
464                         .version        = host->h_version,
465                         .authflavor     = RPC_AUTH_UNIX,
466                         .flags          = (RPC_CLNT_CREATE_NOPING |
467                                            RPC_CLNT_CREATE_AUTOBIND),
468                         .cred           = host->h_cred,
469                 };
470 
471                 /*
472                  * lockd retries server side blocks automatically so we want
473                  * those to be soft RPC calls. Client side calls need to be
474                  * hard RPC tasks.
475                  */
476                 if (!host->h_server)
477                         args.flags |= RPC_CLNT_CREATE_HARDRTRY;
478                 if (host->h_noresvport)
479                         args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
480                 if (host->h_srcaddrlen)
481                         args.saddress = nlm_srcaddr(host);
482 
483                 clnt = rpc_create(&args);
484                 if (!IS_ERR(clnt))
485                         host->h_rpcclnt = clnt;
486                 else {
487                         printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
488                         clnt = NULL;
489                 }
490         }
491 
492         mutex_unlock(&host->h_mutex);
493         return clnt;
494 }
495 
496 /*
497  * Force a portmap lookup of the remote lockd port
498  */
499 void
500 nlm_rebind_host(struct nlm_host *host)
501 {
502         dprintk("lockd: rebind host %s\n", host->h_name);
503         if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
504                 rpc_force_rebind(host->h_rpcclnt);
505                 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
506         }
507 }
508 
509 /*
510  * Increment NLM host count
511  */
512 struct nlm_host * nlm_get_host(struct nlm_host *host)
513 {
514         if (host) {
515                 dprintk("lockd: get host %s\n", host->h_name);
516                 refcount_inc(&host->h_count);
517                 host->h_expires = jiffies + NLM_HOST_EXPIRE;
518         }
519         return host;
520 }
521 
522 static struct nlm_host *next_host_state(struct hlist_head *cache,
523                                         struct nsm_handle *nsm,
524                                         const struct nlm_reboot *info)
525 {
526         struct nlm_host *host;
527         struct hlist_head *chain;
528 
529         mutex_lock(&nlm_host_mutex);
530         for_each_host(host, chain, cache) {
531                 if (host->h_nsmhandle == nsm
532                     && host->h_nsmstate != info->state) {
533                         host->h_nsmstate = info->state;
534                         host->h_state++;
535 
536                         nlm_get_host(host);
537                         mutex_unlock(&nlm_host_mutex);
538                         return host;
539                 }
540         }
541 
542         mutex_unlock(&nlm_host_mutex);
543         return NULL;
544 }
545 
546 /**
547  * nlm_host_rebooted - Release all resources held by rebooted host
548  * @net:  network namespace
549  * @info: pointer to decoded results of NLM_SM_NOTIFY call
550  *
551  * We were notified that the specified host has rebooted.  Release
552  * all resources held by that peer.
553  */
554 void nlm_host_rebooted(const struct net *net, const struct nlm_reboot *info)
555 {
556         struct nsm_handle *nsm;
557         struct nlm_host *host;
558 
559         nsm = nsm_reboot_lookup(net, info);
560         if (unlikely(nsm == NULL))
561                 return;
562 
563         /* Mark all hosts tied to this NSM state as having rebooted.
564          * We run the loop repeatedly, because we drop the host table
565          * lock for this.
566          * To avoid processing a host several times, we match the nsmstate.
567          */
568         while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
569                 nlmsvc_free_host_resources(host);
570                 nlmsvc_release_host(host);
571         }
572         while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
573                 nlmclnt_recovery(host);
574                 nlmclnt_release_host(host);
575         }
576 
577         nsm_release(nsm);
578 }
579 
580 static void nlm_complain_hosts(struct net *net)
581 {
582         struct hlist_head *chain;
583         struct nlm_host *host;
584 
585         if (net) {
586                 struct lockd_net *ln = net_generic(net, lockd_net_id);
587 
588                 if (ln->nrhosts == 0)
589                         return;
590                 pr_warn("lockd: couldn't shutdown host module for net %x!\n",
591                         net->ns.inum);
592                 dprintk("lockd: %lu hosts left in net %x:\n", ln->nrhosts,
593                         net->ns.inum);
594         } else {
595                 if (nrhosts == 0)
596                         return;
597                 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
598                 dprintk("lockd: %lu hosts left:\n", nrhosts);
599         }
600 
601         for_each_host(host, chain, nlm_server_hosts) {
602                 if (net && host->net != net)
603                         continue;
604                 dprintk("       %s (cnt %d use %d exp %ld net %x)\n",
605                         host->h_name, refcount_read(&host->h_count),
606                         host->h_inuse, host->h_expires, host->net->ns.inum);
607         }
608 }
609 
610 void
611 nlm_shutdown_hosts_net(struct net *net)
612 {
613         struct hlist_head *chain;
614         struct nlm_host *host;
615 
616         mutex_lock(&nlm_host_mutex);
617 
618         /* First, make all hosts eligible for gc */
619         dprintk("lockd: nuking all hosts in net %x...\n",
620                 net ? net->ns.inum : 0);
621         for_each_host(host, chain, nlm_server_hosts) {
622                 if (net && host->net != net)
623                         continue;
624                 host->h_expires = jiffies - 1;
625                 if (host->h_rpcclnt) {
626                         rpc_shutdown_client(host->h_rpcclnt);
627                         host->h_rpcclnt = NULL;
628                 }
629         }
630 
631         /* Then, perform a garbage collection pass */
632         nlm_gc_hosts(net);
633         nlm_complain_hosts(net);
634         mutex_unlock(&nlm_host_mutex);
635 }
636 
637 /*
638  * Shut down the hosts module.
639  * Note that this routine is called only at server shutdown time.
640  */
641 void
642 nlm_shutdown_hosts(void)
643 {
644         dprintk("lockd: shutting down host module\n");
645         nlm_shutdown_hosts_net(NULL);
646 }
647 
648 /*
649  * Garbage collect any unused NLM hosts.
650  * This GC combines reference counting for async operations with
651  * mark & sweep for resources held by remote clients.
652  */
653 static void
654 nlm_gc_hosts(struct net *net)
655 {
656         struct hlist_head *chain;
657         struct hlist_node *next;
658         struct nlm_host *host;
659 
660         dprintk("lockd: host garbage collection for net %x\n",
661                 net ? net->ns.inum : 0);
662         for_each_host(host, chain, nlm_server_hosts) {
663                 if (net && host->net != net)
664                         continue;
665                 host->h_inuse = 0;
666         }
667 
668         /* Mark all hosts that hold locks, blocks or shares */
669         nlmsvc_mark_resources(net);
670 
671         for_each_host_safe(host, next, chain, nlm_server_hosts) {
672                 if (net && host->net != net)
673                         continue;
674                 if (host->h_inuse || time_before(jiffies, host->h_expires)) {
675                         dprintk("nlm_gc_hosts skipping %s "
676                                 "(cnt %d use %d exp %ld net %x)\n",
677                                 host->h_name, refcount_read(&host->h_count),
678                                 host->h_inuse, host->h_expires,
679                                 host->net->ns.inum);
680                         continue;
681                 }
682                 if (refcount_dec_if_one(&host->h_count))
683                         nlm_destroy_host_locked(host);
684         }
685 
686         if (net) {
687                 struct lockd_net *ln = net_generic(net, lockd_net_id);
688 
689                 ln->next_gc = jiffies + NLM_HOST_COLLECT;
690         }
691 }
692 

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