source3/lib/server_prefork.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Common server globals
   4
   5    Copyright (C) Simo Sorce <idra@samba.org> 2011
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "system/time.h"
  23 #include "system/shmem.h"
  24 #include "system/filesys.h"
  25 #include "server_prefork.h"
  26 #include "../lib/util/util.h"
  27 #include "../lib/util/tevent_unix.h"
  28
  29 struct prefork_pool {
  30
  31         int listen_fd_size;
  32         int *listen_fds;
  33
  34         int lock_fd;
  35
  36         prefork_main_fn_t *main_fn;
  37         void *private_data;
  38
  39         int pool_size;
  40         struct pf_worker_data *pool;
  41
  42         int allowed_clients;
  43 };
  44
  45 int prefork_pool_destructor(struct prefork_pool *pfp)
  46 {
  47         munmap(pfp->pool, pfp->pool_size * sizeof(struct pf_worker_data));
  48         return 0;
  49 }
  50
  51 bool prefork_create_pool(struct tevent_context *ev_ctx, TALLOC_CTX *mem_ctx,
  52                          int listen_fd_size, int *listen_fds,
  53                          int min_children, int max_children,
  54                          prefork_main_fn_t *main_fn, void *private_data,
  55                          struct prefork_pool **pf_pool)
  56 {
  57         struct prefork_pool *pfp;
  58         pid_t pid;
  59         time_t now = time(NULL);
  60         size_t data_size;
  61         int ret;
  62         int i;
  63
  64         pfp = talloc(mem_ctx, struct prefork_pool);
  65         if (!pfp) {
  66                 DEBUG(1, ("Out of memory!\n"));
  67                 return false;
  68         }
  69         pfp->listen_fd_size = listen_fd_size;
  70         pfp->listen_fds = talloc_array(pfp, int, listen_fd_size);
  71         if (!pfp->listen_fds) {
  72                 DEBUG(1, ("Out of memory!\n"));
  73                 return false;
  74         }
  75         for (i = 0; i < listen_fd_size; i++) {
  76                 pfp->listen_fds[i] = listen_fds[i];
  77         }
  78         pfp->main_fn = main_fn;
  79         pfp->private_data = private_data;
  80
  81         pfp->lock_fd = create_unlink_tmp(NULL);
  82         if (pfp->lock_fd == -1) {
  83                 DEBUG(1, ("Failed to create prefork lock fd!\n"));
  84                 talloc_free(pfp);
  85                 return false;
  86         }
  87
  88         pfp->pool_size = max_children;
  89         data_size = sizeof(struct pf_worker_data) * max_children;
  90
  91         pfp->pool = mmap(NULL, data_size, PROT_READ|PROT_WRITE,
  92                          MAP_SHARED|MAP_ANONYMOUS, -1, 0);
  93         if (pfp->pool == MAP_FAILED) {
  94                 DEBUG(1, ("Failed to mmap memory for prefork pool!\n"));
  95                 talloc_free(pfp);
  96                 return false;
  97         }
  98         talloc_set_destructor(pfp, prefork_pool_destructor);
  99
 100         for (i = 0; i < min_children; i++) {
 101
 102                 pfp->pool[i].allowed_clients = 1;
 103                 pfp->pool[i].started = now;
 104
 105                 pid = sys_fork();
 106                 switch (pid) {
 107                 case -1:
 108                         DEBUG(1, ("Failed to prefork child n. %d !\n", i));
 109                         break;
 110
 111                 case 0: /* THE CHILD */
 112
 113                         pfp->pool[i].status = PF_WORKER_IDLE;
 114                         ret = pfp->main_fn(ev_ctx, &pfp->pool[i],
 115                                            pfp->listen_fd_size,
 116                                            pfp->listen_fds,
 117                                            pfp->lock_fd,
 118                                            pfp->private_data);
 119                         exit(ret);
 120
 121                 default: /* THE PARENT */
 122                         pfp->pool[i].pid = pid;
 123                         break;
 124                 }
 125         }
 126
 127         *pf_pool = pfp;
 128         return true;
 129 }
 130
 131 /* Provide the new max children number in new_max
 132  * (must be larger than current max).
 133  * Returns: 0 if all fine
 134  *          ENOSPC if mremap fails to expand
 135  *          EINVAL if new_max is invalid
 136  */
 137 int prefork_expand_pool(struct prefork_pool *pfp, int new_max)
 138 {
 139         struct pf_worker_data *pool;
 140         size_t old_size;
 141         size_t new_size;
 142
 143         if (new_max <= pfp->pool_size) {
 144                 return EINVAL;
 145         }
 146
 147         old_size = sizeof(struct pf_worker_data) * pfp->pool_size;
 148         new_size = sizeof(struct pf_worker_data) * new_max;
 149
 150         pool = mremap(pfp->pool, old_size, new_size, 0);
 151         if (pool == MAP_FAILED) {
 152                 DEBUG(3, ("Failed to mremap memory for prefork pool!\n"));
 153                 return ENOSPC;
 154         }
 155
 156         memset(&pool[pfp->pool_size], 0, new_size - old_size);
 157
 158         pfp->pool_size = new_max;
 159
 160         return 0;
 161 }
 162
 163 int prefork_add_children(struct tevent_context *ev_ctx,
 164                          struct prefork_pool *pfp,
 165                          int num_children)
 166 {
 167         pid_t pid;
 168         time_t now = time(NULL);
 169         int ret;
 170         int i, j;
 171
 172         for (i = 0, j = 0; i < pfp->pool_size && j < num_children; i++) {
 173
 174                 if (pfp->pool[i].status != PF_WORKER_NONE) {
 175                         continue;
 176                 }
 177
 178                 pfp->pool[i].allowed_clients = 1;
 179                 pfp->pool[i].started = now;
 180
 181                 pid = sys_fork();
 182                 switch (pid) {
 183                 case -1:
 184                         DEBUG(1, ("Failed to prefork child n. %d !\n", j));
 185                         break;
 186
 187                 case 0: /* THE CHILD */
 188
 189                         pfp->pool[i].status = PF_WORKER_IDLE;
 190                         ret = pfp->main_fn(ev_ctx, &pfp->pool[i],
 191                                            pfp->listen_fd_size,
 192                                            pfp->listen_fds,
 193                                            pfp->lock_fd,
 194                                            pfp->private_data);
 195
 196                         pfp->pool[i].status = PF_WORKER_EXITING;
 197                         exit(ret);
 198
 199                 default: /* THE PARENT */
 200                         pfp->pool[i].pid = pid;
 201                         j++;
 202                         break;
 203                 }
 204         }
 205
 206         DEBUG(5, ("Added %d children!\n", j));
 207
 208         return j;
 209 }
 210
 211 struct prefork_oldest {
 212         int num;
 213         time_t started;
 214 };
 215
 216 /* sort in inverse order */
 217 static int prefork_sort_oldest(const void *ap, const void *bp)
 218 {
 219         struct prefork_oldest *a = (struct prefork_oldest *)ap;
 220         struct prefork_oldest *b = (struct prefork_oldest *)bp;
 221
 222         if (a->started == b->started) {
 223                 return 0;
 224         }
 225         if (a->started < b->started) {
 226                 return 1;
 227         }
 228         return -1;
 229 }
 230
 231 int prefork_retire_children(struct prefork_pool *pfp,
 232                             int num_children, time_t age_limit)
 233 {
 234         time_t now = time(NULL);
 235         struct prefork_oldest *oldest;
 236         int i, j;
 237
 238         oldest = talloc_array(pfp, struct prefork_oldest, pfp->pool_size);
 239         if (!oldest) {
 240                 return -1;
 241         }
 242
 243         for (i = 0; i < pfp->pool_size; i++) {
 244                 oldest[i].num = i;
 245                 if (pfp->pool[i].status == PF_WORKER_IDLE) {
 246                         oldest[i].started = pfp->pool[i].started;
 247                 } else {
 248                         oldest[i].started = now;
 249                 }
 250         }
 251
 252         qsort(oldest, pfp->pool_size,
 253                 sizeof(struct prefork_oldest),
 254                 prefork_sort_oldest);
 255
 256         for (i = 0, j = 0; i < pfp->pool_size && j < num_children; i++) {
 257                 if (pfp->pool[i].status == PF_WORKER_IDLE &&
 258                     pfp->pool[i].started <= age_limit) {
 259                         /* tell the child it's time to give up */
 260                         DEBUG(5, ("Retiring pid %d!\n", pfp->pool[i].pid));
 261                         pfp->pool[i].cmds = PF_SRV_MSG_EXIT;
 262                         kill(pfp->pool[i].pid, SIGHUP);
 263                         j++;
 264                 }
 265         }
 266
 267         return j;
 268 }
 269
 270 int prefork_count_active_children(struct prefork_pool *pfp, int *total)
 271 {
 272         int i, a, t;
 273
 274         a = 0;
 275         t = 0;
 276         for (i = 0; i < pfp->pool_size; i++) {
 277                 if (pfp->pool[i].status == PF_WORKER_NONE) {
 278                         continue;
 279                 }
 280
 281                 t++;
 282
 283                 if (pfp->pool[i].num_clients == 0) {
 284                         continue;
 285                 }
 286
 287                 a++;
 288         }
 289
 290         *total = t;
 291         return a;
 292 }
 293
 294 /* to be used to finally mark a children as dead, so that it's slot can
 295  * be reused */
 296 bool prefork_mark_pid_dead(struct prefork_pool *pfp, pid_t pid)
 297 {
 298         int i;
 299
 300         for (i = 0; i < pfp->pool_size; i++) {
 301                 if (pfp->pool[i].pid == pid) {
 302                         if (pfp->pool[i].status != PF_WORKER_EXITING) {
 303                                 DEBUG(2, ("pid %d terminated abnormally!\n",
 304                                           (int)pid));
 305                         }
 306
 307                         /* reset all fields,
 308                          * this makes status = PF_WORK_NONE */
 309                         memset(&pfp->pool[i], 0,
 310                                 sizeof(struct pf_worker_data));
 311
 312                         return true;
 313                 }
 314         }
 315
 316         return false;
 317 }
 318
 319 void prefork_increase_allowed_clients(struct prefork_pool *pfp, int max)
 320 {
 321         int i;
 322
 323         for (i = 0; i < pfp->pool_size; i++) {
 324                 if (pfp->pool[i].status == PF_WORKER_NONE) {
 325                         continue;
 326                 }
 327
 328                 if (pfp->pool[i].allowed_clients < max) {
 329                         pfp->pool[i].allowed_clients++;
 330                 }
 331         }
 332 }
 333
 334 void prefork_reset_allowed_clients(struct prefork_pool *pfp)
 335 {
 336         int i;
 337
 338         for (i = 0; i < pfp->pool_size; i++) {
 339                 pfp->pool[i].allowed_clients = 1;
 340         }
 341 }
 342
 343 void prefork_send_signal_to_all(struct prefork_pool *pfp, int signal_num)
 344 {
 345         int i;
 346
 347         for (i = 0; i < pfp->pool_size; i++) {
 348                 if (pfp->pool[i].status == PF_WORKER_NONE) {
 349                         continue;
 350                 }
 351
 352                 kill(pfp->pool[i].pid, signal_num);
 353         }
 354 }
 355
 356
 357 /* ==== Functions used by children ==== */
 358
 359 static SIG_ATOMIC_T pf_alarm;
 360
 361 static void pf_alarm_cb(int signum)
 362 {
 363         pf_alarm = 1;
 364 }
 365
 366
 367 /*
 368  * Parameters:
 369  * pf - the worker shared data structure
 370  * lock_fd - the file descriptor used for locking
 371  * timeout - expressed in seconds:
 372  *              -1 never timeouts,
 373  *              0 timeouts immediately
 374  *              N seconds before timing out
 375  *
 376  * Returns values:
 377  * negative errno on fatal error
 378  * 0 on success to acquire lock
 379  * -1 on timeout/lock held by other
 380  * -2 on server msg to terminate
 381  * ERRNO on other errors
 382  */
 383
 384 static int prefork_grab_lock(struct pf_worker_data *pf,
 385                              int lock_fd, int timeout)
 386 {
 387         struct flock lock;
 388         int op;
 389         int ret;
 390
 391         if (pf->cmds == PF_SRV_MSG_EXIT) {
 392                 return -2;
 393         }
 394
 395         pf_alarm = 0;
 396
 397         if (timeout > 0) {
 398                 CatchSignal(SIGALRM, pf_alarm_cb);
 399                 alarm(timeout);
 400         }
 401
 402         if (timeout == 0) {
 403                 op = F_SETLK;
 404         } else {
 405                 op = F_SETLKW;
 406         }
 407
 408         ret = 0;
 409         do {
 410                 ZERO_STRUCT(lock);
 411                 lock.l_type = F_WRLCK;
 412                 lock.l_whence = SEEK_SET;
 413
 414                 ret = fcntl(lock_fd, op, &lock);
 415                 if (ret == 0) break;
 416
 417                 ret = errno;
 418
 419                 if (pf->cmds == PF_SRV_MSG_EXIT) {
 420                         ret = -2;
 421                         goto done;
 422                 }
 423
 424                 switch (ret) {
 425                 case EINTR:
 426                         break;
 427
 428                 case EACCES:
 429                 case EAGAIN:
 430                         /* lock held by other proc */
 431                         ret = -1;
 432                         goto done;
 433                 default:
 434                         goto done;
 435                 }
 436
 437                 if (pf_alarm == 1) {
 438                         /* timed out */
 439                         ret = -1;
 440                         goto done;
 441                 }
 442         } while (timeout != 0);
 443
 444         if (ret != 0) {
 445                 /* We have the Lock */
 446                 pf->status = PF_WORKER_ACCEPTING;
 447         }
 448
 449 done:
 450         if (timeout > 0) {
 451                 alarm(0);
 452                 CatchSignal(SIGALRM, SIG_IGN);
 453         }
 454
 455         if (ret > 0) {
 456                 DEBUG(1, ("Failed to get lock (%d, %s)!\n",
 457                           ret, strerror(ret)));
 458         }
 459         return ret;
 460 }
 461
 462 /*
 463  * Parameters:
 464  * pf - the worker shared data structure
 465  * lock_fd - the file descriptor used for locking
 466  * timeout - expressed in seconds:
 467  *              -1 never timeouts,
 468  *              0 timeouts immediately
 469  *              N seconds before timing out
 470  *
 471  * Returns values:
 472  * negative errno on fatal error
 473  * 0 on success to release lock
 474  * -1 on timeout
 475  * ERRNO on error
 476  */
 477
 478 static int prefork_release_lock(struct pf_worker_data *pf,
 479                                 int lock_fd, int timeout)
 480 {
 481         struct flock lock;
 482         int op;
 483         int ret;
 484
 485         pf_alarm = 0;
 486
 487         if (timeout > 0) {
 488                 CatchSignal(SIGALRM, pf_alarm_cb);
 489                 alarm(timeout);
 490         }
 491
 492         if (timeout == 0) {
 493                 op = F_SETLK;
 494         } else {
 495                 op = F_SETLKW;
 496         }
 497
 498         do {
 499                 ZERO_STRUCT(lock);
 500                 lock.l_type = F_UNLCK;
 501                 lock.l_whence = SEEK_SET;
 502
 503                 ret = fcntl(lock_fd, op, &lock);
 504                 if (ret == 0) break;
 505
 506                 ret = errno;
 507
 508                 if (ret != EINTR) {
 509                         goto done;
 510                 }
 511
 512                 if (pf_alarm == 1) {
 513                         /* timed out */
 514                         ret = -1;
 515                         goto done;
 516                 }
 517         } while (timeout != 0);
 518
 519 done:
 520         if (timeout > 0) {
 521                 alarm(0);
 522                 CatchSignal(SIGALRM, SIG_IGN);
 523         }
 524
 525         if (ret > 0) {
 526                 DEBUG(1, ("Failed to release lock (%d, %s)!\n",
 527                           ret, strerror(ret)));
 528         }
 529         return ret;
 530 }
 531
 532 /* ==== async code ==== */
 533
 534 #define PF_ASYNC_LOCK_GRAB      0x01
 535 #define PF_ASYNC_LOCK_RELEASE   0x02
 536 #define PF_ASYNC_ACTION_MASK    0x03
 537 #define PF_ASYNC_LOCK_DONE      0x04
 538
 539 struct pf_lock_state {
 540         struct pf_worker_data *pf;
 541         int lock_fd;
 542         int flags;
 543 };
 544
 545 static void prefork_lock_handler(struct tevent_context *ev,
 546                                         struct tevent_timer *te,
 547                                         struct timeval curtime, void *pvt);
 548
 549 static struct tevent_req *prefork_lock_send(TALLOC_CTX *mem_ctx,
 550                                                 struct tevent_context *ev,
 551                                                 struct pf_worker_data *pf,
 552                                                 int lock_fd, int action)
 553 {
 554         struct tevent_req *req;
 555         struct pf_lock_state *state;
 556
 557         req = tevent_req_create(mem_ctx, &state, struct pf_lock_state);
 558         if (!req) {
 559                 return NULL;
 560         }
 561
 562         state->pf = pf;
 563         state->lock_fd = lock_fd;
 564         state->flags = action;
 565
 566         /* try once immediately */
 567         prefork_lock_handler(ev, NULL, tevent_timeval_zero(), req);
 568         if (state->flags & PF_ASYNC_LOCK_DONE) {
 569                 tevent_req_post(req, ev);
 570         }
 571
 572         return req;
 573 }
 574
 575 static void prefork_lock_handler(struct tevent_context *ev,
 576                                  struct tevent_timer *te,
 577                                  struct timeval curtime, void *pvt)
 578 {
 579         struct tevent_req *req;
 580         struct pf_lock_state *state;
 581         int ret;
 582
 583         req = talloc_get_type_abort(pvt, struct tevent_req);
 584         state = tevent_req_data(req, struct pf_lock_state);
 585
 586         switch (state->flags & PF_ASYNC_ACTION_MASK) {
 587         case PF_ASYNC_LOCK_GRAB:
 588                 ret = prefork_grab_lock(state->pf, state->lock_fd, 0);
 589                 break;
 590         case PF_ASYNC_LOCK_RELEASE:
 591                 ret = prefork_release_lock(state->pf, state->lock_fd, 0);
 592                 break;
 593         default:
 594                 ret = EINVAL;
 595                 break;
 596         }
 597
 598         switch (ret) {
 599         case 0:
 600                 state->flags |= PF_ASYNC_LOCK_DONE;
 601                 tevent_req_done(req);
 602                 return;
 603         case -1:
 604                 te = tevent_add_timer(ev, state,
 605                                         tevent_timeval_current_ofs(1, 0),
 606                                         prefork_lock_handler, req);
 607                 tevent_req_nomem(te, req);
 608                 return;
 609         case -2:
 610                 /* server tells us to stop */
 611                 state->flags |= PF_ASYNC_LOCK_DONE;
 612                 tevent_req_error(req, -2);
 613                 return;
 614         default:
 615                 state->flags |= PF_ASYNC_LOCK_DONE;
 616                 tevent_req_error(req, ret);
 617                 return;
 618         }
 619 }
 620
 621 static int prefork_lock_recv(struct tevent_req *req)
 622 {
 623         int ret;
 624
 625         if (!tevent_req_is_unix_error(req, &ret)) {
 626                 ret = 0;
 627         }
 628
 629         tevent_req_received(req);
 630         return ret;
 631 }
 632
 633 struct pf_listen_state {
 634         struct tevent_context *ev;
 635         struct pf_worker_data *pf;
 636
 637         int listen_fd_size;
 638         int *listen_fds;
 639
 640         int lock_fd;
 641
 642         struct sockaddr *addr;
 643         socklen_t *addrlen;
 644
 645         int accept_fd;
 646
 647         int error;
 648 };
 649
 650 static void prefork_listen_lock_done(struct tevent_req *subreq);
 651 static void prefork_listen_accept_handler(struct tevent_context *ev,
 652                                           struct tevent_fd *fde,
 653                                           uint16_t flags, void *pvt);
 654 static void prefork_listen_release_done(struct tevent_req *subreq);
 655
 656 struct tevent_req *prefork_listen_send(TALLOC_CTX *mem_ctx,
 657                                         struct tevent_context *ev,
 658                                         struct pf_worker_data *pf,
 659                                         int listen_fd_size,
 660                                         int *listen_fds,
 661                                         int lock_fd,
 662                                         struct sockaddr *addr,
 663                                         socklen_t *addrlen)
 664 {
 665         struct tevent_req *req, *subreq;
 666         struct pf_listen_state *state;
 667
 668         req = tevent_req_create(mem_ctx, &state, struct pf_listen_state);
 669         if (!req) {
 670                 return NULL;
 671         }
 672
 673         state->ev = ev;
 674         state->pf = pf;
 675         state->lock_fd = lock_fd;
 676         state->listen_fd_size = listen_fd_size;
 677         state->listen_fds = listen_fds;
 678         state->addr = addr;
 679         state->addrlen = addrlen;
 680         state->accept_fd = -1;
 681         state->error = 0;
 682
 683         subreq = prefork_lock_send(state, state->ev, state->pf,
 684                                    state->lock_fd, PF_ASYNC_LOCK_GRAB);
 685         if (tevent_req_nomem(subreq, req)) {
 686                 return tevent_req_post(req, ev);
 687         }
 688
 689         tevent_req_set_callback(subreq, prefork_listen_lock_done, req);
 690         return req;
 691 }
 692
 693 struct pf_listen_ctx {
 694         TALLOC_CTX *fde_ctx;
 695         struct tevent_req *req;
 696         int listen_fd;
 697 };
 698
 699 static void prefork_listen_lock_done(struct tevent_req *subreq)
 700 {
 701         struct tevent_req *req;
 702         struct pf_listen_state *state;
 703         struct pf_listen_ctx *ctx;
 704         struct tevent_fd *fde;
 705         TALLOC_CTX *fde_ctx;
 706         int ret;
 707         int i;
 708
 709         req = tevent_req_callback_data(subreq, struct tevent_req);
 710         state = tevent_req_data(req, struct pf_listen_state);
 711
 712         ret = prefork_lock_recv(subreq);
 713         if (ret != 0) {
 714                 tevent_req_error(req, ret);
 715                 return;
 716         }
 717
 718         fde_ctx = talloc_new(state);
 719         if (tevent_req_nomem(fde_ctx, req)) {
 720                 return;
 721         }
 722
 723         /* next step, accept */
 724         for (i = 0; i < state->listen_fd_size; i++) {
 725                 ctx = talloc(fde_ctx, struct pf_listen_ctx);
 726                 if (tevent_req_nomem(ctx, req)) {
 727                         return;
 728                 }
 729                 ctx->fde_ctx = fde_ctx;
 730                 ctx->req = req;
 731                 ctx->listen_fd = state->listen_fds[i];
 732
 733                 fde = tevent_add_fd(state->ev, fde_ctx,
 734                                     ctx->listen_fd, TEVENT_FD_READ,
 735                                     prefork_listen_accept_handler, ctx);
 736                 if (tevent_req_nomem(fde, req)) {
 737                         return;
 738                 }
 739         }
 740 }
 741
 742 static void prefork_listen_accept_handler(struct tevent_context *ev,
 743                                           struct tevent_fd *fde,
 744                                           uint16_t flags, void *pvt)
 745 {
 746         struct pf_listen_state *state;
 747         struct tevent_req *req, *subreq;
 748         struct pf_listen_ctx *ctx;
 749         int err = 0;
 750         int sd = -1;
 751
 752         ctx = talloc_get_type_abort(pvt, struct pf_listen_ctx);
 753         state = tevent_req_data(ctx->req, struct pf_listen_state);
 754
 755         sd = accept(ctx->listen_fd, state->addr, state->addrlen);
 756         if (sd == -1) {
 757                 if (errno == EINTR) {
 758                         /* keep trying */
 759                         return;
 760                 }
 761                 err = errno;
 762                 DEBUG(6, ("Accept failed! (%d, %s)\n", err, strerror(err)));
 763
 764         }
 765
 766         /* do not track the listen fds anymore */
 767         req = ctx->req;
 768         talloc_free(ctx->fde_ctx);
 769         ctx = NULL;
 770         if (err) {
 771                 tevent_req_error(req, err);
 772                 return;
 773         }
 774
 775         state->accept_fd = sd;
 776
 777         /* release lock now */
 778         subreq = prefork_lock_send(state, state->ev, state->pf,
 779                                    state->lock_fd, PF_ASYNC_LOCK_RELEASE);
 780         if (tevent_req_nomem(subreq, req)) {
 781                 return;
 782         }
 783         tevent_req_set_callback(subreq, prefork_listen_release_done, req);
 784 }
 785
 786 static void prefork_listen_release_done(struct tevent_req *subreq)
 787 {
 788         struct tevent_req *req;
 789         int ret;
 790
 791         req = tevent_req_callback_data(subreq, struct tevent_req);
 792
 793         ret = prefork_lock_recv(subreq);
 794         if (ret != 0) {
 795                 tevent_req_error(req, ret);
 796                 return;
 797         }
 798
 799         tevent_req_done(req);
 800 }
 801
 802 int prefork_listen_recv(struct tevent_req *req, int *fd)
 803 {
 804         struct pf_listen_state *state;
 805         int ret;
 806
 807         state = tevent_req_data(req, struct pf_listen_state);
 808
 809         if (tevent_req_is_unix_error(req, &ret)) {
 810                 if (state->accept_fd != -1) {
 811                         close(state->accept_fd);
 812                 }
 813         } else {
 814                 *fd = state->accept_fd;
 815                 ret = 0;
 816                 state->pf->status = PF_WORKER_BUSY;
 817                 state->pf->num_clients++;
 818         }
 819
 820         tevent_req_received(req);
 821         return ret;
 822 }