fs/lockd/host.c

   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/svc.h>
  17 #include <linux/lockd/lockd.h>
  18 #include <linux/mutex.h>
  19
  20 #include <net/ipv6.h>
  21
  22 #define NLMDBG_FACILITY         NLMDBG_HOSTCACHE
  23 #define NLM_HOST_NRHASH         32
  24 #define NLM_HOST_REBIND         (60 * HZ)
  25 #define NLM_HOST_EXPIRE         (300 * HZ)
  26 #define NLM_HOST_COLLECT        (120 * HZ)
  27
  28 static struct hlist_head        nlm_server_hosts[NLM_HOST_NRHASH];
  29 static struct hlist_head        nlm_client_hosts[NLM_HOST_NRHASH];
  30
  31 #define for_each_host(host, pos, chain, table) \
  32         for ((chain) = (table); \
  33              (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
  34                 hlist_for_each_entry((host), (pos), (chain), h_hash)
  35
  36 #define for_each_host_safe(host, pos, next, chain, table) \
  37         for ((chain) = (table); \
  38              (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \
  39                 hlist_for_each_entry_safe((host), (pos), (next), \
  40                                                 (chain), h_hash)
  41
  42 static unsigned long            next_gc;
  43 static unsigned long            nrhosts;
  44 static DEFINE_MUTEX(nlm_host_mutex);
  45
  46 static void                     nlm_gc_hosts(void);
  47
  48 struct nlm_lookup_host_info {
  49         const int               server;         /* search for server|client */
  50         const struct sockaddr   *sap;           /* address to search for */
  51         const size_t            salen;          /* it's length */
  52         const unsigned short    protocol;       /* transport to search for*/
  53         const u32               version;        /* NLM version to search for */
  54         const char              *hostname;      /* remote's hostname */
  55         const size_t            hostname_len;   /* it's length */
  56         const struct sockaddr   *src_sap;       /* our address (optional) */
  57         const size_t            src_len;        /* it's length */
  58         const int               noresvport;     /* use non-priv port */
  59 };
  60
  61 /*
  62  * Hash function must work well on big- and little-endian platforms
  63  */
  64 static unsigned int __nlm_hash32(const __be32 n)
  65 {
  66         unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
  67         return hash ^ (hash >> 8);
  68 }
  69
  70 static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
  71 {
  72         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
  73         return __nlm_hash32(sin->sin_addr.s_addr);
  74 }
  75
  76 static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
  77 {
  78         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
  79         const struct in6_addr addr = sin6->sin6_addr;
  80         return __nlm_hash32(addr.s6_addr32[0]) ^
  81                __nlm_hash32(addr.s6_addr32[1]) ^
  82                __nlm_hash32(addr.s6_addr32[2]) ^
  83                __nlm_hash32(addr.s6_addr32[3]);
  84 }
  85
  86 static unsigned int nlm_hash_address(const struct sockaddr *sap)
  87 {
  88         unsigned int hash;
  89
  90         switch (sap->sa_family) {
  91         case AF_INET:
  92                 hash = __nlm_hash_addr4(sap);
  93                 break;
  94         case AF_INET6:
  95                 hash = __nlm_hash_addr6(sap);
  96                 break;
  97         default:
  98                 hash = 0;
  99         }
 100         return hash & (NLM_HOST_NRHASH - 1);
 101 }
 102
 103 /*
 104  * Allocate and initialize an nlm_host.  Common to both client and server.
 105  */
 106 static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,
 107                                        struct nsm_handle *nsm)
 108 {
 109         struct nlm_host *host = NULL;
 110         unsigned long now = jiffies;
 111
 112         if (nsm != NULL)
 113                 atomic_inc(&nsm->sm_count);
 114         else {
 115                 host = NULL;
 116                 nsm = nsm_get_handle(ni->sap, ni->salen,
 117                                         ni->hostname, ni->hostname_len);
 118                 if (unlikely(nsm == NULL)) {
 119                         dprintk("lockd: %s failed; no nsm handle\n",
 120                                 __func__);
 121                         goto out;
 122                 }
 123         }
 124
 125         host = kmalloc(sizeof(*host), GFP_KERNEL);
 126         if (unlikely(host == NULL)) {
 127                 dprintk("lockd: %s failed; no memory\n", __func__);
 128                 nsm_release(nsm);
 129                 goto out;
 130         }
 131
 132         memcpy(nlm_addr(host), ni->sap, ni->salen);
 133         host->h_addrlen    = ni->salen;
 134         rpc_set_port(nlm_addr(host), 0);
 135         host->h_srcaddrlen = 0;
 136
 137         host->h_rpcclnt    = NULL;
 138         host->h_name       = nsm->sm_name;
 139         host->h_version    = ni->version;
 140         host->h_proto      = ni->protocol;
 141         host->h_reclaiming = 0;
 142         host->h_server     = ni->server;
 143         host->h_noresvport = ni->noresvport;
 144         host->h_inuse      = 0;
 145         init_waitqueue_head(&host->h_gracewait);
 146         init_rwsem(&host->h_rwsem);
 147         host->h_state      = 0;
 148         host->h_nsmstate   = 0;
 149         host->h_pidcount   = 0;
 150         atomic_set(&host->h_count, 1);
 151         mutex_init(&host->h_mutex);
 152         host->h_nextrebind = now + NLM_HOST_REBIND;
 153         host->h_expires    = now + NLM_HOST_EXPIRE;
 154         INIT_LIST_HEAD(&host->h_lockowners);
 155         spin_lock_init(&host->h_lock);
 156         INIT_LIST_HEAD(&host->h_granted);
 157         INIT_LIST_HEAD(&host->h_reclaim);
 158         host->h_nsmhandle  = nsm;
 159         host->h_addrbuf    = nsm->sm_addrbuf;
 160
 161 out:
 162         return host;
 163 }
 164
 165 /*
 166  * Destroy an nlm_host and free associated resources
 167  *
 168  * Caller must hold nlm_host_mutex.
 169  */
 170 static void nlm_destroy_host_locked(struct nlm_host *host)
 171 {
 172         struct rpc_clnt *clnt;
 173
 174         dprintk("lockd: destroy host %s\n", host->h_name);
 175
 176         BUG_ON(!list_empty(&host->h_lockowners));
 177         BUG_ON(atomic_read(&host->h_count));
 178
 179         hlist_del_init(&host->h_hash);
 180
 181         nsm_unmonitor(host);
 182         nsm_release(host->h_nsmhandle);
 183
 184         clnt = host->h_rpcclnt;
 185         if (clnt != NULL)
 186                 rpc_shutdown_client(clnt);
 187         kfree(host);
 188
 189         nrhosts--;
 190 }
 191
 192 /**
 193  * nlmclnt_lookup_host - Find an NLM host handle matching a remote server
 194  * @sap: network address of server
 195  * @salen: length of server address
 196  * @protocol: transport protocol to use
 197  * @version: NLM protocol version
 198  * @hostname: '\0'-terminated hostname of server
 199  * @noresvport: 1 if non-privileged port should be used
 200  *
 201  * Returns an nlm_host structure that matches the passed-in
 202  * [server address, transport protocol, NLM version, server hostname].
 203  * If one doesn't already exist in the host cache, a new handle is
 204  * created and returned.
 205  */
 206 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
 207                                      const size_t salen,
 208                                      const unsigned short protocol,
 209                                      const u32 version,
 210                                      const char *hostname,
 211                                      int noresvport)
 212 {
 213         struct nlm_lookup_host_info ni = {
 214                 .server         = 0,
 215                 .sap            = sap,
 216                 .salen          = salen,
 217                 .protocol       = protocol,
 218                 .version        = version,
 219                 .hostname       = hostname,
 220                 .hostname_len   = strlen(hostname),
 221                 .noresvport     = noresvport,
 222         };
 223         struct hlist_head *chain;
 224         struct hlist_node *pos;
 225         struct nlm_host *host;
 226         struct nsm_handle *nsm = NULL;
 227
 228         dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
 229                         (hostname ? hostname : "<none>"), version,
 230                         (protocol == IPPROTO_UDP ? "udp" : "tcp"));
 231
 232         mutex_lock(&nlm_host_mutex);
 233
 234         chain = &nlm_client_hosts[nlm_hash_address(sap)];
 235         hlist_for_each_entry(host, pos, chain, h_hash) {
 236                 if (!rpc_cmp_addr(nlm_addr(host), sap))
 237                         continue;
 238
 239                 /* Same address. Share an NSM handle if we already have one */
 240                 if (nsm == NULL)
 241                         nsm = host->h_nsmhandle;
 242
 243                 if (host->h_proto != protocol)
 244                         continue;
 245                 if (host->h_version != version)
 246                         continue;
 247
 248                 nlm_get_host(host);
 249                 dprintk("lockd: %s found host %s (%s)\n", __func__,
 250                         host->h_name, host->h_addrbuf);
 251                 goto out;
 252         }
 253
 254         host = nlm_alloc_host(&ni, nsm);
 255         if (unlikely(host == NULL))
 256                 goto out;
 257
 258         hlist_add_head(&host->h_hash, chain);
 259         nrhosts++;
 260
 261         dprintk("lockd: %s created host %s (%s)\n", __func__,
 262                 host->h_name, host->h_addrbuf);
 263
 264 out:
 265         mutex_unlock(&nlm_host_mutex);
 266         return host;
 267 }
 268
 269 /**
 270  * nlmclnt_release_host - release client nlm_host
 271  * @host: nlm_host to release
 272  *
 273  */
 274 void nlmclnt_release_host(struct nlm_host *host)
 275 {
 276         if (host == NULL)
 277                 return;
 278
 279         dprintk("lockd: release client host %s\n", host->h_name);
 280
 281         BUG_ON(atomic_read(&host->h_count) < 0);
 282         BUG_ON(host->h_server);
 283
 284         if (atomic_dec_and_test(&host->h_count)) {
 285                 BUG_ON(!list_empty(&host->h_lockowners));
 286                 BUG_ON(!list_empty(&host->h_granted));
 287                 BUG_ON(!list_empty(&host->h_reclaim));
 288
 289                 mutex_lock(&nlm_host_mutex);
 290                 nlm_destroy_host_locked(host);
 291                 mutex_unlock(&nlm_host_mutex);
 292         }
 293 }
 294
 295 /**
 296  * nlmsvc_lookup_host - Find an NLM host handle matching a remote client
 297  * @rqstp: incoming NLM request
 298  * @hostname: name of client host
 299  * @hostname_len: length of client hostname
 300  *
 301  * Returns an nlm_host structure that matches the [client address,
 302  * transport protocol, NLM version, client hostname] of the passed-in
 303  * NLM request.  If one doesn't already exist in the host cache, a
 304  * new handle is created and returned.
 305  *
 306  * Before possibly creating a new nlm_host, construct a sockaddr
 307  * for a specific source address in case the local system has
 308  * multiple network addresses.  The family of the address in
 309  * rq_daddr is guaranteed to be the same as the family of the
 310  * address in rq_addr, so it's safe to use the same family for
 311  * the source address.
 312  */
 313 struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 314                                     const char *hostname,
 315                                     const size_t hostname_len)
 316 {
 317         struct hlist_head *chain;
 318         struct hlist_node *pos;
 319         struct nlm_host *host = NULL;
 320         struct nsm_handle *nsm = NULL;
 321         struct sockaddr_in sin = {
 322                 .sin_family     = AF_INET,
 323         };
 324         struct sockaddr_in6 sin6 = {
 325                 .sin6_family    = AF_INET6,
 326         };
 327         struct nlm_lookup_host_info ni = {
 328                 .server         = 1,
 329                 .sap            = svc_addr(rqstp),
 330                 .salen          = rqstp->rq_addrlen,
 331                 .protocol       = rqstp->rq_prot,
 332                 .version        = rqstp->rq_vers,
 333                 .hostname       = hostname,
 334                 .hostname_len   = hostname_len,
 335                 .src_len        = rqstp->rq_addrlen,
 336         };
 337
 338         dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
 339                         (int)hostname_len, hostname, rqstp->rq_vers,
 340                         (rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
 341
 342         mutex_lock(&nlm_host_mutex);
 343
 344         switch (ni.sap->sa_family) {
 345         case AF_INET:
 346                 sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
 347                 ni.src_sap = (struct sockaddr *)&sin;
 348                 break;
 349         case AF_INET6:
 350                 ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
 351                 ni.src_sap = (struct sockaddr *)&sin6;
 352                 break;
 353         default:
 354                 dprintk("lockd: %s failed; unrecognized address family\n",
 355                         __func__);
 356                 goto out;
 357         }
 358
 359         if (time_after_eq(jiffies, next_gc))
 360                 nlm_gc_hosts();
 361
 362         chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];
 363         hlist_for_each_entry(host, pos, chain, h_hash) {
 364                 if (!rpc_cmp_addr(nlm_addr(host), ni.sap))
 365                         continue;
 366
 367                 /* Same address. Share an NSM handle if we already have one */
 368                 if (nsm == NULL)
 369                         nsm = host->h_nsmhandle;
 370
 371                 if (host->h_proto != ni.protocol)
 372                         continue;
 373                 if (host->h_version != ni.version)
 374                         continue;
 375                 if (!rpc_cmp_addr(nlm_srcaddr(host), ni.src_sap))
 376                         continue;
 377
 378                 /* Move to head of hash chain. */
 379                 hlist_del(&host->h_hash);
 380                 hlist_add_head(&host->h_hash, chain);
 381
 382                 nlm_get_host(host);
 383                 dprintk("lockd: %s found host %s (%s)\n",
 384                         __func__, host->h_name, host->h_addrbuf);
 385                 goto out;
 386         }
 387
 388         host = nlm_alloc_host(&ni, nsm);
 389         if (unlikely(host == NULL))
 390                 goto out;
 391
 392         memcpy(nlm_srcaddr(host), ni.src_sap, ni.src_len);
 393         host->h_srcaddrlen = ni.src_len;
 394         hlist_add_head(&host->h_hash, chain);
 395         nrhosts++;
 396
 397         dprintk("lockd: %s created host %s (%s)\n",
 398                 __func__, host->h_name, host->h_addrbuf);
 399
 400 out:
 401         mutex_unlock(&nlm_host_mutex);
 402         return host;
 403 }
 404
 405 /**
 406  * nlmsvc_release_host - release server nlm_host
 407  * @host: nlm_host to release
 408  *
 409  * Host is destroyed later in nlm_gc_host().
 410  */
 411 void nlmsvc_release_host(struct nlm_host *host)
 412 {
 413         if (host == NULL)
 414                 return;
 415
 416         dprintk("lockd: release server host %s\n", host->h_name);
 417
 418         BUG_ON(atomic_read(&host->h_count) < 0);
 419         BUG_ON(!host->h_server);
 420         atomic_dec(&host->h_count);
 421 }
 422
 423 /*
 424  * Create the NLM RPC client for an NLM peer
 425  */
 426 struct rpc_clnt *
 427 nlm_bind_host(struct nlm_host *host)
 428 {
 429         struct rpc_clnt *clnt;
 430
 431         dprintk("lockd: nlm_bind_host %s (%s)\n",
 432                         host->h_name, host->h_addrbuf);
 433
 434         /* Lock host handle */
 435         mutex_lock(&host->h_mutex);
 436
 437         /* If we've already created an RPC client, check whether
 438          * RPC rebind is required
 439          */
 440         if ((clnt = host->h_rpcclnt) != NULL) {
 441                 if (time_after_eq(jiffies, host->h_nextrebind)) {
 442                         rpc_force_rebind(clnt);
 443                         host->h_nextrebind = jiffies + NLM_HOST_REBIND;
 444                         dprintk("lockd: next rebind in %lu jiffies\n",
 445                                         host->h_nextrebind - jiffies);
 446                 }
 447         } else {
 448                 unsigned long increment = nlmsvc_timeout;
 449                 struct rpc_timeout timeparms = {
 450                         .to_initval     = increment,
 451                         .to_increment   = increment,
 452                         .to_maxval      = increment * 6UL,
 453                         .to_retries     = 5U,
 454                 };
 455                 struct rpc_create_args args = {
 456                         .net            = &init_net,
 457                         .protocol       = host->h_proto,
 458                         .address        = nlm_addr(host),
 459                         .addrsize       = host->h_addrlen,
 460                         .timeout        = &timeparms,
 461                         .servername     = host->h_name,
 462                         .program        = &nlm_program,
 463                         .version        = host->h_version,
 464                         .authflavor     = RPC_AUTH_UNIX,
 465                         .flags          = (RPC_CLNT_CREATE_NOPING |
 466                                            RPC_CLNT_CREATE_AUTOBIND),
 467                 };
 468
 469                 /*
 470                  * lockd retries server side blocks automatically so we want
 471                  * those to be soft RPC calls. Client side calls need to be
 472                  * hard RPC tasks.
 473                  */
 474                 if (!host->h_server)
 475                         args.flags |= RPC_CLNT_CREATE_HARDRTRY;
 476                 if (host->h_noresvport)
 477                         args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 478                 if (host->h_srcaddrlen)
 479                         args.saddress = nlm_srcaddr(host);
 480
 481                 clnt = rpc_create(&args);
 482                 if (!IS_ERR(clnt))
 483                         host->h_rpcclnt = clnt;
 484                 else {
 485                         printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
 486                         clnt = NULL;
 487                 }
 488         }
 489
 490         mutex_unlock(&host->h_mutex);
 491         return clnt;
 492 }
 493
 494 /*
 495  * Force a portmap lookup of the remote lockd port
 496  */
 497 void
 498 nlm_rebind_host(struct nlm_host *host)
 499 {
 500         dprintk("lockd: rebind host %s\n", host->h_name);
 501         if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
 502                 rpc_force_rebind(host->h_rpcclnt);
 503                 host->h_nextrebind = jiffies + NLM_HOST_REBIND;
 504         }
 505 }
 506
 507 /*
 508  * Increment NLM host count
 509  */
 510 struct nlm_host * nlm_get_host(struct nlm_host *host)
 511 {
 512         if (host) {
 513                 dprintk("lockd: get host %s\n", host->h_name);
 514                 atomic_inc(&host->h_count);
 515                 host->h_expires = jiffies + NLM_HOST_EXPIRE;
 516         }
 517         return host;
 518 }
 519
 520 static struct nlm_host *next_host_state(struct hlist_head *cache,
 521                                         struct nsm_handle *nsm,
 522                                         const struct nlm_reboot *info)
 523 {
 524         struct nlm_host *host = NULL;
 525         struct hlist_head *chain;
 526         struct hlist_node *pos;
 527
 528         mutex_lock(&nlm_host_mutex);
 529         for_each_host(host, pos, chain, cache) {
 530                 if (host->h_nsmhandle == nsm
 531                     && host->h_nsmstate != info->state) {
 532                         host->h_nsmstate = info->state;
 533                         host->h_state++;
 534
 535                         nlm_get_host(host);
 536                         mutex_unlock(&nlm_host_mutex);
 537                         goto out;
 538                 }
 539         }
 540 out:
 541         mutex_unlock(&nlm_host_mutex);
 542         return host;
 543 }
 544
 545 /**
 546  * nlm_host_rebooted - Release all resources held by rebooted host
 547  * @info: pointer to decoded results of NLM_SM_NOTIFY call
 548  *
 549  * We were notified that the specified host has rebooted.  Release
 550  * all resources held by that peer.
 551  */
 552 void nlm_host_rebooted(const struct nlm_reboot *info)
 553 {
 554         struct nsm_handle *nsm;
 555         struct nlm_host *host;
 556
 557         nsm = nsm_reboot_lookup(info);
 558         if (unlikely(nsm == NULL))
 559                 return;
 560
 561         /* Mark all hosts tied to this NSM state as having rebooted.
 562          * We run the loop repeatedly, because we drop the host table
 563          * lock for this.
 564          * To avoid processing a host several times, we match the nsmstate.
 565          */
 566         while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) {
 567                 nlmsvc_free_host_resources(host);
 568                 nlmsvc_release_host(host);
 569         }
 570         while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) {
 571                 nlmclnt_recovery(host);
 572                 nlmclnt_release_host(host);
 573         }
 574
 575         nsm_release(nsm);
 576 }
 577
 578 /*
 579  * Shut down the hosts module.
 580  * Note that this routine is called only at server shutdown time.
 581  */
 582 void
 583 nlm_shutdown_hosts(void)
 584 {
 585         struct hlist_head *chain;
 586         struct hlist_node *pos;
 587         struct nlm_host *host;
 588
 589         dprintk("lockd: shutting down host module\n");
 590         mutex_lock(&nlm_host_mutex);
 591
 592         /* First, make all hosts eligible for gc */
 593         dprintk("lockd: nuking all hosts...\n");
 594         for_each_host(host, pos, chain, nlm_server_hosts) {
 595                 host->h_expires = jiffies - 1;
 596                 if (host->h_rpcclnt) {
 597                         rpc_shutdown_client(host->h_rpcclnt);
 598                         host->h_rpcclnt = NULL;
 599                 }
 600         }
 601
 602         /* Then, perform a garbage collection pass */
 603         nlm_gc_hosts();
 604         mutex_unlock(&nlm_host_mutex);
 605
 606         /* complain if any hosts are left */
 607         if (nrhosts != 0) {
 608                 printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
 609                 dprintk("lockd: %lu hosts left:\n", nrhosts);
 610                 for_each_host(host, pos, chain, nlm_server_hosts) {
 611                         dprintk("       %s (cnt %d use %d exp %ld)\n",
 612                                 host->h_name, atomic_read(&host->h_count),
 613                                 host->h_inuse, host->h_expires);
 614                 }
 615         }
 616 }
 617
 618 /*
 619  * Garbage collect any unused NLM hosts.
 620  * This GC combines reference counting for async operations with
 621  * mark & sweep for resources held by remote clients.
 622  */
 623 static void
 624 nlm_gc_hosts(void)
 625 {
 626         struct hlist_head *chain;
 627         struct hlist_node *pos, *next;
 628         struct nlm_host *host;
 629
 630         dprintk("lockd: host garbage collection\n");
 631         for_each_host(host, pos, chain, nlm_server_hosts)
 632                 host->h_inuse = 0;
 633
 634         /* Mark all hosts that hold locks, blocks or shares */
 635         nlmsvc_mark_resources();
 636
 637         for_each_host_safe(host, pos, next, chain, nlm_server_hosts) {
 638                 if (atomic_read(&host->h_count) || host->h_inuse
 639                  || time_before(jiffies, host->h_expires)) {
 640                         dprintk("nlm_gc_hosts skipping %s "
 641                                 "(cnt %d use %d exp %ld)\n",
 642                                 host->h_name, atomic_read(&host->h_count),
 643                                 host->h_inuse, host->h_expires);
 644                         continue;
 645                 }
 646                 nlm_destroy_host_locked(host);
 647         }
 648
 649         next_gc = jiffies + NLM_HOST_COLLECT;
 650 }