lustre/portals/router/router.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Copyright (C) 2002 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Portals
   7  *   http://sourceforge.net/projects/sandiaportals/
   8  *
   9  *   Portals is free software; you can redistribute it and/or
  10  *   modify it under the terms of version 2 of the GNU General Public
  11  *   License as published by the Free Software Foundation.
  12  *
  13  *   Portals is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *   GNU General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU General Public License
  19  *   along with Portals; if not, write to the Free Software
  20  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  */
  23
  24 #include "router.h"
  25
  26 LIST_HEAD(kpr_routes);
  27 LIST_HEAD(kpr_gateways);
  28 LIST_HEAD(kpr_nals);
  29
  30 unsigned long long kpr_fwd_bytes;
  31 unsigned long      kpr_fwd_packets;
  32 unsigned long      kpr_fwd_errors;
  33 atomic_t           kpr_queue_depth;
  34
  35 /* Mostly the tables are read-only (thread and interrupt context)
  36  *
  37  * Once in a blue moon we register/deregister NALs and add/remove routing
  38  * entries (thread context only)... */
  39 rwlock_t         kpr_rwlock = RW_LOCK_UNLOCKED;
  40
  41 kpr_router_interface_t kpr_router_interface = {
  42         kprri_register:         kpr_register_nal,
  43         kprri_lookup:           kpr_lookup_target,
  44         kprri_fwd_start:        kpr_forward_packet,
  45         kprri_fwd_done:         kpr_complete_packet,
  46         kprri_notify:           kpr_nal_notify,
  47         kprri_shutdown:         kpr_shutdown_nal,
  48         kprri_deregister:       kpr_deregister_nal,
  49 };
  50
  51 kpr_control_interface_t kpr_control_interface = {
  52         kprci_add_route:        kpr_add_route,
  53         kprci_del_route:        kpr_del_route,
  54         kprci_get_route:        kpr_get_route,
  55         kprci_notify:           kpr_sys_notify,
  56 };
  57
  58 int
  59 kpr_register_nal (kpr_nal_interface_t *nalif, void **argp)
  60 {
  61         unsigned long      flags;
  62         struct list_head  *e;
  63         kpr_nal_entry_t   *ne;
  64
  65         CDEBUG (D_NET, "Registering NAL %d\n", nalif->kprni_nalid);
  66
  67         PORTAL_ALLOC (ne, sizeof (*ne));
  68         if (ne == NULL)
  69                 return (-ENOMEM);
  70
  71         memset (ne, 0, sizeof (*ne));
  72         memcpy ((void *)&ne->kpne_interface, (void *)nalif, sizeof (*nalif));
  73
  74         LASSERT (!in_interrupt());
  75         write_lock_irqsave (&kpr_rwlock, flags);
  76
  77         for (e = kpr_nals.next; e != &kpr_nals; e = e->next)
  78         {
  79                 kpr_nal_entry_t *ne2 = list_entry (e, kpr_nal_entry_t, kpne_list);
  80
  81                 if (ne2->kpne_interface.kprni_nalid == ne->kpne_interface.kprni_nalid)
  82                 {
  83                         write_unlock_irqrestore (&kpr_rwlock, flags);
  84
  85                         CERROR ("Attempt to register same NAL %d twice\n", ne->kpne_interface.kprni_nalid);
  86
  87                         PORTAL_FREE (ne, sizeof (*ne));
  88                         return (-EEXIST);
  89                 }
  90         }
  91
  92         list_add (&ne->kpne_list, &kpr_nals);
  93
  94         write_unlock_irqrestore (&kpr_rwlock, flags);
  95
  96         *argp = ne;
  97         PORTAL_MODULE_USE;
  98         return (0);
  99 }
 100
 101 void
 102 kpr_do_upcall (void *arg)
 103 {
 104         kpr_upcall_t *u = (kpr_upcall_t *)arg;
 105         char          nalstr[10];
 106         char          nidstr[36];
 107         char          whenstr[36];
 108         char         *argv[] = {
 109                 NULL,
 110                 "ROUTER_NOTIFY",
 111                 nalstr,
 112                 nidstr,
 113                 u->kpru_alive ? "up" : "down",
 114                 whenstr,
 115                 NULL};
 116
 117         snprintf (nalstr, sizeof(nalstr), "%d", u->kpru_nal_id);
 118         snprintf (nidstr, sizeof(nidstr), LPX64, u->kpru_nid);
 119         snprintf (whenstr, sizeof(whenstr), "%ld", u->kpru_when);
 120
 121         portals_run_upcall (argv);
 122
 123         kfree (u);
 124 }
 125
 126 void
 127 kpr_upcall (int gw_nalid, ptl_nid_t gw_nid, int alive, time_t when)
 128 {
 129         char str[PTL_NALFMT_SIZE];
 130
 131         /* May be in arbitrary context */
 132         kpr_upcall_t  *u = kmalloc (sizeof (kpr_upcall_t), GFP_ATOMIC);
 133
 134         if (u == NULL) {
 135                 CERROR ("Upcall out of memory: nal %d nid "LPX64" (%s) %s\n",
 136                         gw_nalid, gw_nid,
 137                         portals_nid2str(gw_nalid, gw_nid, str),
 138                         alive ? "up" : "down");
 139                 return;
 140         }
 141
 142         u->kpru_nal_id     = gw_nalid;
 143         u->kpru_nid        = gw_nid;
 144         u->kpru_alive      = alive;
 145         u->kpru_when       = when;
 146
 147         prepare_work (&u->kpru_tq, kpr_do_upcall, u);
 148         schedule_work (&u->kpru_tq);
 149 }
 150
 151 int
 152 kpr_do_notify (int byNal, int gateway_nalid, ptl_nid_t gateway_nid,
 153                int alive, time_t when)
 154 {
 155         unsigned long        flags;
 156         int                  found;
 157         kpr_nal_entry_t     *ne = NULL;
 158         kpr_gateway_entry_t *ge = NULL;
 159         struct timeval       now;
 160         struct list_head    *e;
 161         struct list_head    *n;
 162         char                 str[PTL_NALFMT_SIZE];
 163
 164         CDEBUG (D_NET, "%s notifying [%d] "LPX64": %s\n",
 165                 byNal ? "NAL" : "userspace",
 166                 gateway_nalid, gateway_nid, alive ? "up" : "down");
 167
 168         /* can't do predictions... */
 169         do_gettimeofday (&now);
 170         if (when > now.tv_sec) {
 171                 CWARN ("Ignoring prediction from %s of [%d] "LPX64" %s "
 172                        "%ld seconds in the future\n",
 173                        byNal ? "NAL" : "userspace",
 174                        gateway_nalid, gateway_nid,
 175                        alive ? "up" : "down",
 176                        when - now.tv_sec);
 177                 return (EINVAL);
 178         }
 179
 180         LASSERT (when <= now.tv_sec);
 181
 182         /* Serialise with lookups (i.e. write lock) */
 183         write_lock_irqsave(&kpr_rwlock, flags);
 184
 185         found = 0;
 186         list_for_each_safe (e, n, &kpr_gateways) {
 187
 188                 ge = list_entry(e, kpr_gateway_entry_t, kpge_list);
 189                 if ((gateway_nalid != 0 &&
 190                      ge->kpge_nalid != gateway_nalid) ||
 191                     ge->kpge_nid != gateway_nid)
 192                         continue;
 193
 194                 found = 1;
 195                 break;
 196         }
 197
 198         if (!found) {
 199                 /* gateway not found */
 200                 write_unlock_irqrestore(&kpr_rwlock, flags);
 201                 CDEBUG (D_NET, "Gateway not found\n");
 202                 return (0);
 203         }
 204
 205         if (when < ge->kpge_timestamp) {
 206                 /* out of date information */
 207                 write_unlock_irqrestore (&kpr_rwlock, flags);
 208                 CDEBUG (D_NET, "Out of date\n");
 209                 return (0);
 210         }
 211
 212         /* update timestamp */
 213         ge->kpge_timestamp = when;
 214
 215         if ((!ge->kpge_alive) == (!alive)) {
 216                 /* new date for old news */
 217                 write_unlock_irqrestore (&kpr_rwlock, flags);
 218                 CDEBUG (D_NET, "Old news\n");
 219                 return (0);
 220         }
 221
 222         ge->kpge_alive = alive;
 223         CDEBUG(D_NET, "set "LPX64" [%p] %d\n", gateway_nid, ge, alive);
 224
 225         if (alive) {
 226                 /* Reset all gateway weights so the newly-enabled gateway
 227                  * doesn't have to play catch-up */
 228                 list_for_each_safe (e, n, &kpr_gateways) {
 229                         kpr_gateway_entry_t *ge = list_entry(e, kpr_gateway_entry_t,
 230                                                              kpge_list);
 231                         atomic_set (&ge->kpge_weight, 0);
 232                 }
 233         }
 234
 235         found = 0;
 236         if (!byNal) {
 237                 /* userland notified me: notify NAL? */
 238                 ne = kpr_find_nal_entry_locked (ge->kpge_nalid);
 239                 if (ne != NULL) {
 240                         if (!ne->kpne_shutdown &&
 241                             ne->kpne_interface.kprni_notify != NULL) {
 242                                 /* take a ref on this NAL until notifying
 243                                  * it has completed... */
 244                                 atomic_inc (&ne->kpne_refcount);
 245                                 found = 1;
 246                         }
 247                 }
 248         }
 249
 250         write_unlock_irqrestore(&kpr_rwlock, flags);
 251
 252         if (found) {
 253                 ne->kpne_interface.kprni_notify (ne->kpne_interface.kprni_arg,
 254                                                  gateway_nid, alive);
 255                 /* 'ne' can disappear now... */
 256                 atomic_dec (&ne->kpne_refcount);
 257         }
 258
 259         if (byNal) {
 260                 /* It wasn't userland that notified me... */
 261                 CWARN ("Upcall: NAL %d NID "LPX64" (%s) is %s\n",
 262                        gateway_nalid, gateway_nid,
 263                        portals_nid2str(gateway_nalid, gateway_nid, str),
 264                        alive ? "alive" : "dead");
 265                 kpr_upcall (gateway_nalid, gateway_nid, alive, when);
 266         } else {
 267                 CDEBUG (D_NET, " NOT Doing upcall\n");
 268         }
 269
 270         return (0);
 271 }
 272
 273 void
 274 kpr_nal_notify (void *arg, ptl_nid_t peer, int alive, time_t when)
 275 {
 276         kpr_nal_entry_t *ne = (kpr_nal_entry_t *)arg;
 277
 278         kpr_do_notify (1, ne->kpne_interface.kprni_nalid, peer, alive, when);
 279 }
 280
 281 void
 282 kpr_shutdown_nal (void *arg)
 283 {
 284         unsigned long    flags;
 285         kpr_nal_entry_t *ne = (kpr_nal_entry_t *)arg;
 286
 287         CDEBUG (D_NET, "Shutting down NAL %d\n", ne->kpne_interface.kprni_nalid);
 288
 289         LASSERT (!ne->kpne_shutdown);
 290         LASSERT (!in_interrupt());
 291
 292         write_lock_irqsave (&kpr_rwlock, flags); /* locking a bit spurious... */
 293         ne->kpne_shutdown = 1;
 294         write_unlock_irqrestore (&kpr_rwlock, flags); /* except it's a memory barrier */
 295
 296         while (atomic_read (&ne->kpne_refcount) != 0)
 297         {
 298                 CDEBUG (D_NET, "Waiting for refcount on NAL %d to reach zero (%d)\n",
 299                         ne->kpne_interface.kprni_nalid, atomic_read (&ne->kpne_refcount));
 300
 301                 set_current_state (TASK_UNINTERRUPTIBLE);
 302                 schedule_timeout (HZ);
 303         }
 304 }
 305
 306 void
 307 kpr_deregister_nal (void *arg)
 308 {
 309         unsigned long     flags;
 310         kpr_nal_entry_t  *ne = (kpr_nal_entry_t *)arg;
 311
 312         CDEBUG (D_NET, "Deregister NAL %d\n", ne->kpne_interface.kprni_nalid);
 313
 314         LASSERT (ne->kpne_shutdown);            /* caller must have issued shutdown already */
 315         LASSERT (atomic_read (&ne->kpne_refcount) == 0); /* can't be busy */
 316         LASSERT (!in_interrupt());
 317
 318         write_lock_irqsave (&kpr_rwlock, flags);
 319
 320         list_del (&ne->kpne_list);
 321
 322         write_unlock_irqrestore (&kpr_rwlock, flags);
 323
 324         PORTAL_FREE (ne, sizeof (*ne));
 325         PORTAL_MODULE_UNUSE;
 326 }
 327
 328 int
 329 kpr_ge_isbetter (kpr_gateway_entry_t *ge1, kpr_gateway_entry_t *ge2)
 330 {
 331         const int significant_bits = 0x00ffffff;
 332         /* We use atomic_t to record/compare route weights for
 333          * load-balancing.  Here we limit ourselves to only using
 334          * 'significant_bits' when we do an 'after' comparison */
 335
 336         int    diff = (atomic_read (&ge1->kpge_weight) -
 337                        atomic_read (&ge2->kpge_weight)) & significant_bits;
 338         int    rc = (diff > (significant_bits >> 1));
 339
 340         CDEBUG(D_NET, "[%p]"LPX64"=%d %s [%p]"LPX64"=%d\n",
 341                ge1, ge1->kpge_nid, atomic_read (&ge1->kpge_weight),
 342                rc ? ">" : "<",
 343                ge2, ge2->kpge_nid, atomic_read (&ge2->kpge_weight));
 344
 345         return (rc);
 346 }
 347
 348 void
 349 kpr_update_weight (kpr_gateway_entry_t *ge, int nob)
 350 {
 351         int weight = 1 + (nob + sizeof (ptl_hdr_t)/2)/sizeof (ptl_hdr_t);
 352
 353         /* We've chosen this route entry (i.e. gateway) to forward payload
 354          * of length 'nob'; update the route's weight to make it less
 355          * favoured.  Note that the weight is 1 plus the payload size
 356          * rounded and scaled to the portals header size, so we get better
 357          * use of the significant bits in kpge_weight. */
 358
 359         CDEBUG(D_NET, "gateway [%p]"LPX64" += %d\n", ge,
 360                ge->kpge_nid, weight);
 361
 362         atomic_add (weight, &ge->kpge_weight);
 363 }
 364
 365 int
 366 kpr_lookup_target (void *arg, ptl_nid_t target_nid, int nob,
 367                    ptl_nid_t *gateway_nidp)
 368 {
 369         kpr_nal_entry_t     *ne = (kpr_nal_entry_t *)arg;
 370         struct list_head    *e;
 371         kpr_route_entry_t   *re;
 372         kpr_gateway_entry_t *ge = NULL;
 373         int                  rc = -ENOENT;
 374
 375         /* Caller wants to know if 'target_nid' can be reached via a gateway
 376          * ON HER OWN NETWORK */
 377
 378         CDEBUG (D_NET, "lookup "LPX64" from NAL %d\n", target_nid,
 379                 ne->kpne_interface.kprni_nalid);
 380
 381         if (ne->kpne_shutdown)          /* caller is shutting down */
 382                 return (-ENOENT);
 383
 384         read_lock (&kpr_rwlock);
 385
 386         /* Search routes for one that has a gateway to target_nid on the callers network */
 387
 388         list_for_each (e, &kpr_routes) {
 389                 re = list_entry (e, kpr_route_entry_t, kpre_list);
 390
 391                 if (re->kpre_lo_nid > target_nid ||
 392                     re->kpre_hi_nid < target_nid)
 393                         continue;
 394
 395                 /* found table entry */
 396
 397                 if (re->kpre_gateway->kpge_nalid != ne->kpne_interface.kprni_nalid ||
 398                     !re->kpre_gateway->kpge_alive) {
 399                         /* different NAL or gateway down */
 400                         rc = -EHOSTUNREACH;
 401                         continue;
 402                 }
 403
 404                 if (ge == NULL ||
 405                     kpr_ge_isbetter (re->kpre_gateway, ge))
 406                     ge = re->kpre_gateway;
 407         }
 408
 409         if (ge != NULL) {
 410                 kpr_update_weight (ge, nob);
 411                 *gateway_nidp = ge->kpge_nid;
 412                 rc = 0;
 413         }
 414
 415         read_unlock (&kpr_rwlock);
 416
 417         /* NB can't deref 're' now; it might have been removed! */
 418
 419         CDEBUG (D_NET, "lookup "LPX64" from NAL %d: %d ("LPX64")\n",
 420                 target_nid, ne->kpne_interface.kprni_nalid, rc,
 421                 (rc == 0) ? *gateway_nidp : (ptl_nid_t)0);
 422         return (rc);
 423 }
 424
 425 kpr_nal_entry_t *
 426 kpr_find_nal_entry_locked (int nal_id)
 427 {
 428         struct list_head    *e;
 429
 430         /* Called with kpr_rwlock held */
 431
 432         list_for_each (e, &kpr_nals) {
 433                 kpr_nal_entry_t *ne = list_entry (e, kpr_nal_entry_t, kpne_list);
 434
 435                 if (nal_id != ne->kpne_interface.kprni_nalid) /* no match */
 436                         continue;
 437
 438                 return (ne);
 439         }
 440
 441         return (NULL);
 442 }
 443
 444 void
 445 kpr_forward_packet (void *arg, kpr_fwd_desc_t *fwd)
 446 {
 447         kpr_nal_entry_t     *src_ne = (kpr_nal_entry_t *)arg;
 448         ptl_nid_t            target_nid = fwd->kprfd_target_nid;
 449         int                  nob = fwd->kprfd_nob;
 450         kpr_gateway_entry_t *ge = NULL;
 451         kpr_nal_entry_t     *dst_ne = NULL;
 452         struct list_head    *e;
 453         kpr_route_entry_t   *re;
 454         kpr_nal_entry_t     *tmp_ne;
 455
 456         CDEBUG (D_NET, "forward [%p] "LPX64" from NAL %d\n", fwd,
 457                 target_nid, src_ne->kpne_interface.kprni_nalid);
 458
 459         LASSERT (nob == lib_kiov_nob (fwd->kprfd_niov, fwd->kprfd_kiov));
 460
 461         atomic_inc (&kpr_queue_depth);
 462         atomic_inc (&src_ne->kpne_refcount); /* source nal is busy until fwd completes */
 463
 464         kpr_fwd_packets++;                   /* (loose) stats accounting */
 465         kpr_fwd_bytes += nob + sizeof(ptl_hdr_t);
 466
 467         if (src_ne->kpne_shutdown)           /* caller is shutting down */
 468                 goto out;
 469
 470         fwd->kprfd_router_arg = src_ne;      /* stash caller's nal entry */
 471
 472         read_lock (&kpr_rwlock);
 473
 474         /* Search routes for one that has a gateway to target_nid NOT on the caller's network */
 475
 476         list_for_each (e, &kpr_routes) {
 477                 re = list_entry (e, kpr_route_entry_t, kpre_list);
 478
 479                 if (re->kpre_lo_nid > target_nid || /* no match */
 480                     re->kpre_hi_nid < target_nid)
 481                         continue;
 482
 483                 if (re->kpre_gateway->kpge_nalid == src_ne->kpne_interface.kprni_nalid)
 484                         continue;               /* don't route to same NAL */
 485
 486                 if (!re->kpre_gateway->kpge_alive)
 487                         continue;               /* gateway is dead */
 488
 489                 tmp_ne = kpr_find_nal_entry_locked (re->kpre_gateway->kpge_nalid);
 490
 491                 if (tmp_ne == NULL ||
 492                     tmp_ne->kpne_shutdown) {
 493                         /* NAL must be registered and not shutting down */
 494                         continue;
 495                 }
 496
 497                 if (ge == NULL ||
 498                     kpr_ge_isbetter (re->kpre_gateway, ge)) {
 499                         ge = re->kpre_gateway;
 500                         dst_ne = tmp_ne;
 501                 }
 502         }
 503
 504         if (ge != NULL) {
 505                 LASSERT (dst_ne != NULL);
 506
 507                 kpr_update_weight (ge, nob);
 508
 509                 fwd->kprfd_gateway_nid = ge->kpge_nid;
 510                 atomic_inc (&dst_ne->kpne_refcount); /* dest nal is busy until fwd completes */
 511
 512                 read_unlock (&kpr_rwlock);
 513
 514                 CDEBUG (D_NET, "forward [%p] "LPX64" from NAL %d: "
 515                         "to "LPX64" on NAL %d\n",
 516                         fwd, target_nid, src_ne->kpne_interface.kprni_nalid,
 517                         fwd->kprfd_gateway_nid, dst_ne->kpne_interface.kprni_nalid);
 518
 519                 dst_ne->kpne_interface.kprni_fwd (dst_ne->kpne_interface.kprni_arg, fwd);
 520                 return;
 521         }
 522
 523         read_unlock (&kpr_rwlock);
 524  out:
 525         kpr_fwd_errors++;
 526
 527         CDEBUG (D_NET, "Failed to forward [%p] "LPX64" from NAL %d\n", fwd,
 528                 target_nid, src_ne->kpne_interface.kprni_nalid);
 529
 530         /* Can't find anywhere to forward to */
 531         (fwd->kprfd_callback)(fwd->kprfd_callback_arg, -EHOSTUNREACH);
 532
 533         atomic_dec (&kpr_queue_depth);
 534         atomic_dec (&src_ne->kpne_refcount);
 535 }
 536
 537 void
 538 kpr_complete_packet (void *arg, kpr_fwd_desc_t *fwd, int error)
 539 {
 540         kpr_nal_entry_t *dst_ne = (kpr_nal_entry_t *)arg;
 541         kpr_nal_entry_t *src_ne = (kpr_nal_entry_t *)fwd->kprfd_router_arg;
 542
 543         CDEBUG (D_NET, "complete(1) [%p] from NAL %d to NAL %d: %d\n", fwd,
 544                 src_ne->kpne_interface.kprni_nalid, dst_ne->kpne_interface.kprni_nalid, error);
 545
 546         atomic_dec (&dst_ne->kpne_refcount);    /* CAVEAT EMPTOR dst_ne can disappear now!!! */
 547
 548         (fwd->kprfd_callback)(fwd->kprfd_callback_arg, error);
 549
 550         CDEBUG (D_NET, "complete(2) [%p] from NAL %d: %d\n", fwd,
 551                 src_ne->kpne_interface.kprni_nalid, error);
 552
 553         atomic_dec (&kpr_queue_depth);
 554         atomic_dec (&src_ne->kpne_refcount);    /* CAVEAT EMPTOR src_ne can disappear now!!! */
 555 }
 556
 557 int
 558 kpr_add_route (int gateway_nalid, ptl_nid_t gateway_nid,
 559                ptl_nid_t lo_nid, ptl_nid_t hi_nid)
 560 {
 561         unsigned long        flags;
 562         struct list_head    *e;
 563         kpr_route_entry_t   *re;
 564         kpr_gateway_entry_t *ge;
 565         int                  dup = 0;
 566
 567         CDEBUG(D_NET, "Add route: %d "LPX64" : "LPX64" - "LPX64"\n",
 568                gateway_nalid, gateway_nid, lo_nid, hi_nid);
 569
 570         if (gateway_nalid == PTL_NID_ANY ||
 571             lo_nid == PTL_NID_ANY ||
 572             hi_nid == PTL_NID_ANY ||
 573             lo_nid > hi_nid)
 574                 return (-EINVAL);
 575
 576         PORTAL_ALLOC (ge, sizeof (*ge));
 577         if (ge == NULL)
 578                 return (-ENOMEM);
 579
 580         ge->kpge_nalid = gateway_nalid;
 581         ge->kpge_nid   = gateway_nid;
 582         ge->kpge_alive = 1;
 583         ge->kpge_timestamp = 0;
 584         ge->kpge_refcount = 0;
 585         atomic_set (&ge->kpge_weight, 0);
 586
 587         PORTAL_ALLOC (re, sizeof (*re));
 588         if (re == NULL) {
 589                 PORTAL_FREE (ge, sizeof (*ge));
 590                 return (-ENOMEM);
 591         }
 592
 593         re->kpre_lo_nid = lo_nid;
 594         re->kpre_hi_nid = hi_nid;
 595
 596         LASSERT(!in_interrupt());
 597         write_lock_irqsave (&kpr_rwlock, flags);
 598
 599         list_for_each (e, &kpr_gateways) {
 600                 kpr_gateway_entry_t *ge2 = list_entry(e, kpr_gateway_entry_t,
 601                                                       kpge_list);
 602
 603                 if (ge2->kpge_nalid == gateway_nalid &&
 604                     ge2->kpge_nid == gateway_nid) {
 605                         PORTAL_FREE (ge, sizeof (*ge));
 606                         ge = ge2;
 607                         dup = 1;
 608                         break;
 609                 }
 610         }
 611
 612         if (!dup) {
 613                 /* Adding a new gateway... */
 614
 615                 list_add (&ge->kpge_list, &kpr_gateways);
 616
 617                 /* ...zero all gateway weights so this one doesn't have to
 618                  * play catch-up */
 619
 620                 list_for_each (e, &kpr_gateways) {
 621                         kpr_gateway_entry_t *ge2 = list_entry(e, kpr_gateway_entry_t,
 622                                                               kpge_list);
 623                         atomic_set (&ge2->kpge_weight, 0);
 624                 }
 625
 626         }
 627
 628         re->kpre_gateway = ge;
 629         ge->kpge_refcount++;
 630         list_add (&re->kpre_list, &kpr_routes);
 631
 632         write_unlock_irqrestore (&kpr_rwlock, flags);
 633         return (0);
 634 }
 635
 636 int
 637 kpr_sys_notify (int gateway_nalid, ptl_nid_t gateway_nid,
 638             int alive, time_t when)
 639 {
 640         return (kpr_do_notify (0, gateway_nalid, gateway_nid, alive, when));
 641 }
 642
 643 int
 644 kpr_del_route (int gw_nalid, ptl_nid_t gw_nid,
 645                ptl_nid_t lo, ptl_nid_t hi)
 646 {
 647         int                specific = (lo != PTL_NID_ANY);
 648         unsigned long      flags;
 649         int                rc = -ENOENT;
 650         struct list_head  *e;
 651         struct list_head  *n;
 652
 653         CDEBUG(D_NET, "Del route [%d] "LPX64" : "LPX64" - "LPX64"\n",
 654                gw_nalid, gw_nid, lo, hi);
 655
 656         LASSERT(!in_interrupt());
 657
 658         /* NB Caller may specify either all routes via the given gateway
 659          * (lo/hi == PTL_NID_ANY) or a specific route entry (lo/hi are
 660          * actual NIDs) */
 661
 662         if (specific ? (hi == PTL_NID_ANY || hi < lo) : (hi != PTL_NID_ANY))
 663                 return (-EINVAL);
 664
 665         write_lock_irqsave(&kpr_rwlock, flags);
 666
 667         list_for_each_safe (e, n, &kpr_routes) {
 668                 kpr_route_entry_t   *re = list_entry(e, kpr_route_entry_t,
 669                                                    kpre_list);
 670                 kpr_gateway_entry_t *ge = re->kpre_gateway;
 671
 672                 if (ge->kpge_nalid != gw_nalid ||
 673                     ge->kpge_nid != gw_nid ||
 674                     (specific &&
 675                      (lo != re->kpre_lo_nid || hi != re->kpre_hi_nid)))
 676                         continue;
 677
 678                 rc = 0;
 679
 680                 if (--ge->kpge_refcount == 0) {
 681                         list_del (&ge->kpge_list);
 682                         PORTAL_FREE (ge, sizeof (*ge));
 683                 }
 684
 685                 list_del (&re->kpre_list);
 686                 PORTAL_FREE(re, sizeof (*re));
 687
 688                 if (specific)
 689                         break;
 690         }
 691
 692         write_unlock_irqrestore(&kpr_rwlock, flags);
 693         return (rc);
 694 }
 695
 696 int
 697 kpr_get_route (int idx, int *gateway_nalid, ptl_nid_t *gateway_nid,
 698                ptl_nid_t *lo_nid, ptl_nid_t *hi_nid, int *alive)
 699 {
 700         struct list_head  *e;
 701
 702         read_lock(&kpr_rwlock);
 703
 704         for (e = kpr_routes.next; e != &kpr_routes; e = e->next) {
 705                 kpr_route_entry_t   *re = list_entry(e, kpr_route_entry_t,
 706                                                      kpre_list);
 707                 kpr_gateway_entry_t *ge = re->kpre_gateway;
 708
 709                 if (idx-- == 0) {
 710                         *gateway_nalid = ge->kpge_nalid;
 711                         *gateway_nid = ge->kpge_nid;
 712                         *alive = ge->kpge_alive;
 713                         *lo_nid = re->kpre_lo_nid;
 714                         *hi_nid = re->kpre_hi_nid;
 715
 716                         read_unlock(&kpr_rwlock);
 717                         return (0);
 718                 }
 719         }
 720
 721         read_unlock (&kpr_rwlock);
 722         return (-ENOENT);
 723 }
 724
 725 static void /*__exit*/
 726 kpr_finalise (void)
 727 {
 728         LASSERT (list_empty (&kpr_nals));
 729
 730         while (!list_empty (&kpr_routes)) {
 731                 kpr_route_entry_t *re = list_entry(kpr_routes.next,
 732                                                    kpr_route_entry_t,
 733                                                    kpre_list);
 734
 735                 list_del(&re->kpre_list);
 736                 PORTAL_FREE(re, sizeof (*re));
 737         }
 738
 739         kpr_proc_fini();
 740
 741         PORTAL_SYMBOL_UNREGISTER(kpr_router_interface);
 742         PORTAL_SYMBOL_UNREGISTER(kpr_control_interface);
 743
 744         CDEBUG(D_MALLOC, "kpr_finalise: kmem back to %d\n",
 745                atomic_read(&portal_kmemory));
 746 }
 747
 748 static int __init
 749 kpr_initialise (void)
 750 {
 751         CDEBUG(D_MALLOC, "kpr_initialise: kmem %d\n",
 752                atomic_read(&portal_kmemory));
 753
 754         kpr_proc_init();
 755
 756         PORTAL_SYMBOL_REGISTER(kpr_router_interface);
 757         PORTAL_SYMBOL_REGISTER(kpr_control_interface);
 758         return (0);
 759 }
 760
 761 MODULE_AUTHOR("Eric Barton");
 762 MODULE_DESCRIPTION("Kernel Portals Router v0.01");
 763 MODULE_LICENSE("GPL");
 764
 765 module_init (kpr_initialise);
 766 module_exit (kpr_finalise);
 767
 768 EXPORT_SYMBOL (kpr_control_interface);
 769 EXPORT_SYMBOL (kpr_router_interface);