fs/afs/server.c

   1 /* AFS server record management
   2  *
   3  * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells ([email protected])
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/sched.h>
  13 #include <linux/slab.h>
  14 #include "afs_fs.h"
  15 #include "internal.h"
  16
  17 static unsigned afs_server_gc_delay = 10;       /* Server record timeout in seconds */
  18 static unsigned afs_server_update_delay = 30;   /* Time till VLDB recheck in secs */
  19
  20 static void afs_inc_servers_outstanding(struct afs_net *net)
  21 {
  22         atomic_inc(&net->servers_outstanding);
  23 }
  24
  25 static void afs_dec_servers_outstanding(struct afs_net *net)
  26 {
  27         if (atomic_dec_and_test(&net->servers_outstanding))
  28                 wake_up_var(&net->servers_outstanding);
  29 }
  30
  31 /*
  32  * Find a server by one of its addresses.
  33  */
  34 struct afs_server *afs_find_server(struct afs_net *net,
  35                                    const struct sockaddr_rxrpc *srx)
  36 {
  37         const struct sockaddr_in6 *a = &srx->transport.sin6, *b;
  38         const struct afs_addr_list *alist;
  39         struct afs_server *server = NULL;
  40         unsigned int i;
  41         bool ipv6 = true;
  42         int seq = 0, diff;
  43
  44         if (srx->transport.sin6.sin6_addr.s6_addr32[0] == 0 ||
  45             srx->transport.sin6.sin6_addr.s6_addr32[1] == 0 ||
  46             srx->transport.sin6.sin6_addr.s6_addr32[2] == htonl(0xffff))
  47                 ipv6 = false;
  48
  49         rcu_read_lock();
  50
  51         do {
  52                 if (server)
  53                         afs_put_server(net, server);
  54                 server = NULL;
  55                 read_seqbegin_or_lock(&net->fs_addr_lock, &seq);
  56
  57                 if (ipv6) {
  58                         hlist_for_each_entry_rcu(server, &net->fs_addresses6, addr6_link) {
  59                                 alist = rcu_dereference(server->addresses);
  60                                 for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
  61                                         b = &alist->addrs[i].transport.sin6;
  62                                         diff = ((u16 __force)a->sin6_port -
  63                                                 (u16 __force)b->sin6_port);
  64                                         if (diff == 0)
  65                                                 diff = memcmp(&a->sin6_addr,
  66                                                               &b->sin6_addr,
  67                                                               sizeof(struct in6_addr));
  68                                         if (diff == 0)
  69                                                 goto found;
  70                                 }
  71                         }
  72                 } else {
  73                         hlist_for_each_entry_rcu(server, &net->fs_addresses4, addr4_link) {
  74                                 alist = rcu_dereference(server->addresses);
  75                                 for (i = 0; i < alist->nr_ipv4; i++) {
  76                                         b = &alist->addrs[i].transport.sin6;
  77                                         diff = ((u16 __force)a->sin6_port -
  78                                                 (u16 __force)b->sin6_port);
  79                                         if (diff == 0)
  80                                                 diff = ((u32 __force)a->sin6_addr.s6_addr32[3] -
  81                                                         (u32 __force)b->sin6_addr.s6_addr32[3]);
  82                                         if (diff == 0)
  83                                                 goto found;
  84                                 }
  85                         }
  86                 }
  87
  88                 server = NULL;
  89         found:
  90                 if (server && !atomic_inc_not_zero(&server->usage))
  91                         server = NULL;
  92
  93         } while (need_seqretry(&net->fs_addr_lock, seq));
  94
  95         done_seqretry(&net->fs_addr_lock, seq);
  96
  97         rcu_read_unlock();
  98         return server;
  99 }
 100
 101 /*
 102  * Look up a server by its UUID
 103  */
 104 struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uuid)
 105 {
 106         struct afs_server *server = NULL;
 107         struct rb_node *p;
 108         int diff, seq = 0;
 109
 110         _enter("%pU", uuid);
 111
 112         do {
 113                 /* Unfortunately, rbtree walking doesn't give reliable results
 114                  * under just the RCU read lock, so we have to check for
 115                  * changes.
 116                  */
 117                 if (server)
 118                         afs_put_server(net, server);
 119                 server = NULL;
 120
 121                 read_seqbegin_or_lock(&net->fs_lock, &seq);
 122
 123                 p = net->fs_servers.rb_node;
 124                 while (p) {
 125                         server = rb_entry(p, struct afs_server, uuid_rb);
 126
 127                         diff = memcmp(uuid, &server->uuid, sizeof(*uuid));
 128                         if (diff < 0) {
 129                                 p = p->rb_left;
 130                         } else if (diff > 0) {
 131                                 p = p->rb_right;
 132                         } else {
 133                                 afs_get_server(server);
 134                                 break;
 135                         }
 136
 137                         server = NULL;
 138                 }
 139         } while (need_seqretry(&net->fs_lock, seq));
 140
 141         done_seqretry(&net->fs_lock, seq);
 142
 143         _leave(" = %p", server);
 144         return server;
 145 }
 146
 147 /*
 148  * Install a server record in the namespace tree
 149  */
 150 static struct afs_server *afs_install_server(struct afs_net *net,
 151                                              struct afs_server *candidate)
 152 {
 153         const struct afs_addr_list *alist;
 154         struct afs_server *server;
 155         struct rb_node **pp, *p;
 156         int ret = -EEXIST, diff;
 157
 158         _enter("%p", candidate);
 159
 160         write_seqlock(&net->fs_lock);
 161
 162         /* Firstly install the server in the UUID lookup tree */
 163         pp = &net->fs_servers.rb_node;
 164         p = NULL;
 165         while (*pp) {
 166                 p = *pp;
 167                 _debug("- consider %p", p);
 168                 server = rb_entry(p, struct afs_server, uuid_rb);
 169                 diff = memcmp(&candidate->uuid, &server->uuid, sizeof(uuid_t));
 170                 if (diff < 0)
 171                         pp = &(*pp)->rb_left;
 172                 else if (diff > 0)
 173                         pp = &(*pp)->rb_right;
 174                 else
 175                         goto exists;
 176         }
 177
 178         server = candidate;
 179         rb_link_node(&server->uuid_rb, p, pp);
 180         rb_insert_color(&server->uuid_rb, &net->fs_servers);
 181         hlist_add_head_rcu(&server->proc_link, &net->fs_proc);
 182
 183         write_seqlock(&net->fs_addr_lock);
 184         alist = rcu_dereference_protected(server->addresses,
 185                                           lockdep_is_held(&net->fs_addr_lock.lock));
 186
 187         /* Secondly, if the server has any IPv4 and/or IPv6 addresses, install
 188          * it in the IPv4 and/or IPv6 reverse-map lists.
 189          *
 190          * TODO: For speed we want to use something other than a flat list
 191          * here; even sorting the list in terms of lowest address would help a
 192          * bit, but anything we might want to do gets messy and memory
 193          * intensive.
 194          */
 195         if (alist->nr_ipv4 > 0)
 196                 hlist_add_head_rcu(&server->addr4_link, &net->fs_addresses4);
 197         if (alist->nr_addrs > alist->nr_ipv4)
 198                 hlist_add_head_rcu(&server->addr6_link, &net->fs_addresses6);
 199
 200         write_sequnlock(&net->fs_addr_lock);
 201         ret = 0;
 202         goto out;
 203
 204 exists:
 205         afs_get_server(server);
 206 out:
 207         write_sequnlock(&net->fs_lock);
 208         return server;
 209 }
 210
 211 /*
 212  * allocate a new server record
 213  */
 214 static struct afs_server *afs_alloc_server(struct afs_net *net,
 215                                            const uuid_t *uuid,
 216                                            struct afs_addr_list *alist)
 217 {
 218         struct afs_server *server;
 219
 220         _enter("");
 221
 222         server = kzalloc(sizeof(struct afs_server), GFP_KERNEL);
 223         if (!server)
 224                 goto enomem;
 225
 226         atomic_set(&server->usage, 1);
 227         RCU_INIT_POINTER(server->addresses, alist);
 228         server->addr_version = alist->version;
 229         server->uuid = *uuid;
 230         server->flags = (1UL << AFS_SERVER_FL_NEW);
 231         server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
 232         rwlock_init(&server->fs_lock);
 233         INIT_HLIST_HEAD(&server->cb_volumes);
 234         rwlock_init(&server->cb_break_lock);
 235
 236         afs_inc_servers_outstanding(net);
 237         _leave(" = %p", server);
 238         return server;
 239
 240 enomem:
 241         _leave(" = NULL [nomem]");
 242         return NULL;
 243 }
 244
 245 /*
 246  * Look up an address record for a server
 247  */
 248 static struct afs_addr_list *afs_vl_lookup_addrs(struct afs_cell *cell,
 249                                                  struct key *key, const uuid_t *uuid)
 250 {
 251         struct afs_addr_cursor ac;
 252         struct afs_addr_list *alist;
 253         int ret;
 254
 255         ret = afs_set_vl_cursor(&ac, cell);
 256         if (ret < 0)
 257                 return ERR_PTR(ret);
 258
 259         while (afs_iterate_addresses(&ac)) {
 260                 if (test_bit(ac.index, &ac.alist->yfs))
 261                         alist = afs_yfsvl_get_endpoints(cell->net, &ac, key, uuid);
 262                 else
 263                         alist = afs_vl_get_addrs_u(cell->net, &ac, key, uuid);
 264                 switch (ac.error) {
 265                 case 0:
 266                         afs_end_cursor(&ac);
 267                         return alist;
 268                 case -ECONNABORTED:
 269                         ac.error = afs_abort_to_error(ac.abort_code);
 270                         goto error;
 271                 case -ENOMEM:
 272                 case -ENONET:
 273                         goto error;
 274                 case -ENETUNREACH:
 275                 case -EHOSTUNREACH:
 276                 case -ECONNREFUSED:
 277                         break;
 278                 default:
 279                         ac.error = -EIO;
 280                         goto error;
 281                 }
 282         }
 283
 284 error:
 285         return ERR_PTR(afs_end_cursor(&ac));
 286 }
 287
 288 /*
 289  * Get or create a fileserver record.
 290  */
 291 struct afs_server *afs_lookup_server(struct afs_cell *cell, struct key *key,
 292                                      const uuid_t *uuid)
 293 {
 294         struct afs_addr_list *alist;
 295         struct afs_server *server, *candidate;
 296
 297         _enter("%p,%pU", cell->net, uuid);
 298
 299         server = afs_find_server_by_uuid(cell->net, uuid);
 300         if (server)
 301                 return server;
 302
 303         alist = afs_vl_lookup_addrs(cell, key, uuid);
 304         if (IS_ERR(alist))
 305                 return ERR_CAST(alist);
 306
 307         candidate = afs_alloc_server(cell->net, uuid, alist);
 308         if (!candidate) {
 309                 afs_put_addrlist(alist);
 310                 return ERR_PTR(-ENOMEM);
 311         }
 312
 313         server = afs_install_server(cell->net, candidate);
 314         if (server != candidate) {
 315                 afs_put_addrlist(alist);
 316                 kfree(candidate);
 317         }
 318
 319         _leave(" = %p{%d}", server, atomic_read(&server->usage));
 320         return server;
 321 }
 322
 323 /*
 324  * Set the server timer to fire after a given delay, assuming it's not already
 325  * set for an earlier time.
 326  */
 327 static void afs_set_server_timer(struct afs_net *net, time64_t delay)
 328 {
 329         if (net->live) {
 330                 afs_inc_servers_outstanding(net);
 331                 if (timer_reduce(&net->fs_timer, jiffies + delay * HZ))
 332                         afs_dec_servers_outstanding(net);
 333         }
 334 }
 335
 336 /*
 337  * Server management timer.  We have an increment on fs_outstanding that we
 338  * need to pass along to the work item.
 339  */
 340 void afs_servers_timer(struct timer_list *timer)
 341 {
 342         struct afs_net *net = container_of(timer, struct afs_net, fs_timer);
 343
 344         _enter("");
 345         if (!queue_work(afs_wq, &net->fs_manager))
 346                 afs_dec_servers_outstanding(net);
 347 }
 348
 349 /*
 350  * Release a reference on a server record.
 351  */
 352 void afs_put_server(struct afs_net *net, struct afs_server *server)
 353 {
 354         unsigned int usage;
 355
 356         if (!server)
 357                 return;
 358
 359         server->put_time = ktime_get_real_seconds();
 360
 361         usage = atomic_dec_return(&server->usage);
 362
 363         _enter("{%u}", usage);
 364
 365         if (likely(usage > 0))
 366                 return;
 367
 368         afs_set_server_timer(net, afs_server_gc_delay);
 369 }
 370
 371 static void afs_server_rcu(struct rcu_head *rcu)
 372 {
 373         struct afs_server *server = container_of(rcu, struct afs_server, rcu);
 374
 375         afs_put_addrlist(rcu_access_pointer(server->addresses));
 376         kfree(server);
 377 }
 378
 379 /*
 380  * destroy a dead server
 381  */
 382 static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
 383 {
 384         struct afs_addr_list *alist = rcu_access_pointer(server->addresses);
 385         struct afs_addr_cursor ac = {
 386                 .alist  = alist,
 387                 .start  = alist->index,
 388                 .index  = 0,
 389                 .addr   = &alist->addrs[alist->index],
 390                 .error  = 0,
 391         };
 392         _enter("%p", server);
 393
 394         if (test_bit(AFS_SERVER_FL_MAY_HAVE_CB, &server->flags))
 395                 afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
 396
 397         call_rcu(&server->rcu, afs_server_rcu);
 398         afs_dec_servers_outstanding(net);
 399 }
 400
 401 /*
 402  * Garbage collect any expired servers.
 403  */
 404 static void afs_gc_servers(struct afs_net *net, struct afs_server *gc_list)
 405 {
 406         struct afs_server *server;
 407         bool deleted;
 408         int usage;
 409
 410         while ((server = gc_list)) {
 411                 gc_list = server->gc_next;
 412
 413                 write_seqlock(&net->fs_lock);
 414                 usage = 1;
 415                 deleted = atomic_try_cmpxchg(&server->usage, &usage, 0);
 416                 if (deleted) {
 417                         rb_erase(&server->uuid_rb, &net->fs_servers);
 418                         hlist_del_rcu(&server->proc_link);
 419                 }
 420                 write_sequnlock(&net->fs_lock);
 421
 422                 if (deleted) {
 423                         write_seqlock(&net->fs_addr_lock);
 424                         if (!hlist_unhashed(&server->addr4_link))
 425                                 hlist_del_rcu(&server->addr4_link);
 426                         if (!hlist_unhashed(&server->addr6_link))
 427                                 hlist_del_rcu(&server->addr6_link);
 428                         write_sequnlock(&net->fs_addr_lock);
 429                         afs_destroy_server(net, server);
 430                 }
 431         }
 432 }
 433
 434 /*
 435  * Manage the records of servers known to be within a network namespace.  This
 436  * includes garbage collecting unused servers.
 437  *
 438  * Note also that we were given an increment on net->servers_outstanding by
 439  * whoever queued us that we need to deal with before returning.
 440  */
 441 void afs_manage_servers(struct work_struct *work)
 442 {
 443         struct afs_net *net = container_of(work, struct afs_net, fs_manager);
 444         struct afs_server *gc_list = NULL;
 445         struct rb_node *cursor;
 446         time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX;
 447         bool purging = !net->live;
 448
 449         _enter("");
 450
 451         /* Trawl the server list looking for servers that have expired from
 452          * lack of use.
 453          */
 454         read_seqlock_excl(&net->fs_lock);
 455
 456         for (cursor = rb_first(&net->fs_servers); cursor; cursor = rb_next(cursor)) {
 457                 struct afs_server *server =
 458                         rb_entry(cursor, struct afs_server, uuid_rb);
 459                 int usage = atomic_read(&server->usage);
 460
 461                 _debug("manage %pU %u", &server->uuid, usage);
 462
 463                 ASSERTCMP(usage, >=, 1);
 464                 ASSERTIFCMP(purging, usage, ==, 1);
 465
 466                 if (usage == 1) {
 467                         time64_t expire_at = server->put_time;
 468
 469                         if (!test_bit(AFS_SERVER_FL_VL_FAIL, &server->flags) &&
 470                             !test_bit(AFS_SERVER_FL_NOT_FOUND, &server->flags))
 471                                 expire_at += afs_server_gc_delay;
 472                         if (purging || expire_at <= now) {
 473                                 server->gc_next = gc_list;
 474                                 gc_list = server;
 475                         } else if (expire_at < next_manage) {
 476                                 next_manage = expire_at;
 477                         }
 478                 }
 479         }
 480
 481         read_sequnlock_excl(&net->fs_lock);
 482
 483         /* Update the timer on the way out.  We have to pass an increment on
 484          * servers_outstanding in the namespace that we are in to the timer or
 485          * the work scheduler.
 486          */
 487         if (!purging && next_manage < TIME64_MAX) {
 488                 now = ktime_get_real_seconds();
 489
 490                 if (next_manage - now <= 0) {
 491                         if (queue_work(afs_wq, &net->fs_manager))
 492                                 afs_inc_servers_outstanding(net);
 493                 } else {
 494                         afs_set_server_timer(net, next_manage - now);
 495                 }
 496         }
 497
 498         afs_gc_servers(net, gc_list);
 499
 500         afs_dec_servers_outstanding(net);
 501         _leave(" [%d]", atomic_read(&net->servers_outstanding));
 502 }
 503
 504 static void afs_queue_server_manager(struct afs_net *net)
 505 {
 506         afs_inc_servers_outstanding(net);
 507         if (!queue_work(afs_wq, &net->fs_manager))
 508                 afs_dec_servers_outstanding(net);
 509 }
 510
 511 /*
 512  * Purge list of servers.
 513  */
 514 void afs_purge_servers(struct afs_net *net)
 515 {
 516         _enter("");
 517
 518         if (del_timer_sync(&net->fs_timer))
 519                 atomic_dec(&net->servers_outstanding);
 520
 521         afs_queue_server_manager(net);
 522
 523         _debug("wait");
 524         wait_var_event(&net->servers_outstanding,
 525                        !atomic_read(&net->servers_outstanding));
 526         _leave("");
 527 }
 528
 529 /*
 530  * Probe a fileserver to find its capabilities.
 531  *
 532  * TODO: Try service upgrade.
 533  */
 534 static bool afs_do_probe_fileserver(struct afs_fs_cursor *fc)
 535 {
 536         _enter("");
 537
 538         fc->ac.addr = NULL;
 539         fc->ac.start = READ_ONCE(fc->ac.alist->index);
 540         fc->ac.index = fc->ac.start;
 541         fc->ac.error = 0;
 542         fc->ac.begun = false;
 543
 544         while (afs_iterate_addresses(&fc->ac)) {
 545                 afs_fs_get_capabilities(afs_v2net(fc->vnode), fc->cbi->server,
 546                                         &fc->ac, fc->key);
 547                 switch (fc->ac.error) {
 548                 case 0:
 549                         afs_end_cursor(&fc->ac);
 550                         set_bit(AFS_SERVER_FL_PROBED, &fc->cbi->server->flags);
 551                         return true;
 552                 case -ECONNABORTED:
 553                         fc->ac.error = afs_abort_to_error(fc->ac.abort_code);
 554                         goto error;
 555                 case -ENOMEM:
 556                 case -ENONET:
 557                         goto error;
 558                 case -ENETUNREACH:
 559                 case -EHOSTUNREACH:
 560                 case -ECONNREFUSED:
 561                 case -ETIMEDOUT:
 562                 case -ETIME:
 563                         break;
 564                 default:
 565                         fc->ac.error = -EIO;
 566                         goto error;
 567                 }
 568         }
 569
 570 error:
 571         afs_end_cursor(&fc->ac);
 572         return false;
 573 }
 574
 575 /*
 576  * If we haven't already, try probing the fileserver to get its capabilities.
 577  * We try not to instigate parallel probes, but it's possible that the parallel
 578  * probes will fail due to authentication failure when ours would succeed.
 579  *
 580  * TODO: Try sending an anonymous probe if an authenticated probe fails.
 581  */
 582 bool afs_probe_fileserver(struct afs_fs_cursor *fc)
 583 {
 584         bool success;
 585         int ret, retries = 0;
 586
 587         _enter("");
 588
 589 retry:
 590         if (test_bit(AFS_SERVER_FL_PROBED, &fc->cbi->server->flags)) {
 591                 _leave(" = t");
 592                 return true;
 593         }
 594
 595         if (!test_and_set_bit_lock(AFS_SERVER_FL_PROBING, &fc->cbi->server->flags)) {
 596                 success = afs_do_probe_fileserver(fc);
 597                 clear_bit_unlock(AFS_SERVER_FL_PROBING, &fc->cbi->server->flags);
 598                 wake_up_bit(&fc->cbi->server->flags, AFS_SERVER_FL_PROBING);
 599                 _leave(" = t");
 600                 return success;
 601         }
 602
 603         _debug("wait");
 604         ret = wait_on_bit(&fc->cbi->server->flags, AFS_SERVER_FL_PROBING,
 605                           TASK_INTERRUPTIBLE);
 606         if (ret == -ERESTARTSYS) {
 607                 fc->ac.error = ret;
 608                 _leave(" = f [%d]", ret);
 609                 return false;
 610         }
 611
 612         retries++;
 613         if (retries == 4) {
 614                 fc->ac.error = -ESTALE;
 615                 _leave(" = f [stale]");
 616                 return false;
 617         }
 618         _debug("retry");
 619         goto retry;
 620 }
 621
 622 /*
 623  * Get an update for a server's address list.
 624  */
 625 static noinline bool afs_update_server_record(struct afs_fs_cursor *fc, struct afs_server *server)
 626 {
 627         struct afs_addr_list *alist, *discard;
 628
 629         _enter("");
 630
 631         alist = afs_vl_lookup_addrs(fc->vnode->volume->cell, fc->key,
 632                                     &server->uuid);
 633         if (IS_ERR(alist)) {
 634                 fc->ac.error = PTR_ERR(alist);
 635                 _leave(" = f [%d]", fc->ac.error);
 636                 return false;
 637         }
 638
 639         discard = alist;
 640         if (server->addr_version != alist->version) {
 641                 write_lock(&server->fs_lock);
 642                 discard = rcu_dereference_protected(server->addresses,
 643                                                     lockdep_is_held(&server->fs_lock));
 644                 rcu_assign_pointer(server->addresses, alist);
 645                 server->addr_version = alist->version;
 646                 write_unlock(&server->fs_lock);
 647         }
 648
 649         server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
 650         afs_put_addrlist(discard);
 651         _leave(" = t");
 652         return true;
 653 }
 654
 655 /*
 656  * See if a server's address list needs updating.
 657  */
 658 bool afs_check_server_record(struct afs_fs_cursor *fc, struct afs_server *server)
 659 {
 660         time64_t now = ktime_get_real_seconds();
 661         long diff;
 662         bool success;
 663         int ret, retries = 0;
 664
 665         _enter("");
 666
 667         ASSERT(server);
 668
 669 retry:
 670         diff = READ_ONCE(server->update_at) - now;
 671         if (diff > 0) {
 672                 _leave(" = t [not now %ld]", diff);
 673                 return true;
 674         }
 675
 676         if (!test_and_set_bit_lock(AFS_SERVER_FL_UPDATING, &server->flags)) {
 677                 success = afs_update_server_record(fc, server);
 678                 clear_bit_unlock(AFS_SERVER_FL_UPDATING, &server->flags);
 679                 wake_up_bit(&server->flags, AFS_SERVER_FL_UPDATING);
 680                 _leave(" = %d", success);
 681                 return success;
 682         }
 683
 684         ret = wait_on_bit(&server->flags, AFS_SERVER_FL_UPDATING,
 685                           TASK_INTERRUPTIBLE);
 686         if (ret == -ERESTARTSYS) {
 687                 fc->ac.error = ret;
 688                 _leave(" = f [intr]");
 689                 return false;
 690         }
 691
 692         retries++;
 693         if (retries == 4) {
 694                 _leave(" = f [stale]");
 695                 ret = -ESTALE;
 696                 return false;
 697         }
 698         goto retry;
 699 }