1 /* 2 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws> 3 * 4 * Network Block Device 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; under version 2 of the License. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include "qemu-common.h" 20 #include "sysemu/block-backend.h" 21 #include "block/block_int.h" 22 #include "block/nbd.h" 23 #include "qemu/main-loop.h" 24 #include "qemu/sockets.h" 25 #include "qemu/error-report.h" 26 #include "block/snapshot.h" 27 #include "qapi/util.h" 28 29 #include <stdarg.h> 30 #include <stdio.h> 31 #include <getopt.h> 32 #include <err.h> 33 #include <sys/types.h> 34 #include <sys/socket.h> 35 #include <netinet/in.h> 36 #include <netinet/tcp.h> 37 #include <arpa/inet.h> 38 #include <signal.h> 39 #include <libgen.h> 40 #include <pthread.h> 41 42 #define SOCKET_PATH "/var/lock/qemu-nbd-%s" 43 #define QEMU_NBD_OPT_CACHE 1 44 #define QEMU_NBD_OPT_AIO 2 45 #define QEMU_NBD_OPT_DISCARD 3 46 #define QEMU_NBD_OPT_DETECT_ZEROES 4 47 48 static NBDExport *exp; 49 static int verbose; 50 static char *srcpath; 51 static char *sockpath; 52 static int persistent = 0; 53 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state; 54 static int shared = 1; 55 static int nb_fds; 56 static int server_fd; 57 58 static void usage(const char *name) 59 { 60 (printf) ( 61 "Usage: %s [OPTIONS] FILE\n" 62 "QEMU Disk Network Block Device Server\n" 63 "\n" 64 " -h, --help display this help and exit\n" 65 " -V, --version output version information and exit\n" 66 "\n" 67 "Connection properties:\n" 68 " -p, --port=PORT port to listen on (default `%d')\n" 69 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" 70 " -k, --socket=PATH path to the unix socket\n" 71 " (default '"SOCKET_PATH"')\n" 72 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" 73 " -t, --persistent don't exit on the last connection\n" 74 " -v, --verbose display extra debugging information\n" 75 "\n" 76 "Exposing part of the image:\n" 77 " -o, --offset=OFFSET offset into the image\n" 78 " -P, --partition=NUM only expose partition NUM\n" 79 "\n" 80 #ifdef __linux__ 81 "Kernel NBD client support:\n" 82 " -c, --connect=DEV connect FILE to the local NBD device DEV\n" 83 " -d, --disconnect disconnect the specified device\n" 84 "\n" 85 #endif 86 "\n" 87 "Block device options:\n" 88 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n" 89 " -r, --read-only export read-only\n" 90 " -s, --snapshot use FILE as an external snapshot, create a temporary\n" 91 " file with backing_file=FILE, redirect the write to\n" 92 " the temporary one\n" 93 " -l, --load-snapshot=SNAPSHOT_PARAM\n" 94 " load an internal snapshot inside FILE and export it\n" 95 " as an read-only device, SNAPSHOT_PARAM format is\n" 96 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n" 97 " '[ID_OR_NAME]'\n" 98 " -n, --nocache disable host cache\n" 99 " --cache=MODE set cache mode (none, writeback, ...)\n" 100 #ifdef CONFIG_LINUX_AIO 101 " --aio=MODE set AIO mode (native or threads)\n" 102 #endif 103 " --discard=MODE set discard mode (ignore, unmap)\n" 104 " --detect-zeroes=MODE set detect-zeroes mode (off, on, discard)\n" 105 "\n" 106 "Report bugs to <qemu-devel@nongnu.org>\n" 107 , name, NBD_DEFAULT_PORT, "DEVICE"); 108 } 109 110 static void version(const char *name) 111 { 112 printf( 113 "%s version 0.0.1\n" 114 "Written by Anthony Liguori.\n" 115 "\n" 116 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n" 117 "This is free software; see the source for copying conditions. There is NO\n" 118 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 119 , name); 120 } 121 122 struct partition_record 123 { 124 uint8_t bootable; 125 uint8_t start_head; 126 uint32_t start_cylinder; 127 uint8_t start_sector; 128 uint8_t system; 129 uint8_t end_head; 130 uint8_t end_cylinder; 131 uint8_t end_sector; 132 uint32_t start_sector_abs; 133 uint32_t nb_sectors_abs; 134 }; 135 136 static void read_partition(uint8_t *p, struct partition_record *r) 137 { 138 r->bootable = p[0]; 139 r->start_head = p[1]; 140 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); 141 r->start_sector = p[2] & 0x3f; 142 r->system = p[4]; 143 r->end_head = p[5]; 144 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); 145 r->end_sector = p[6] & 0x3f; 146 147 r->start_sector_abs = le32_to_cpup((uint32_t *)(p + 8)); 148 r->nb_sectors_abs = le32_to_cpup((uint32_t *)(p + 12)); 149 } 150 151 static int find_partition(BlockBackend *blk, int partition, 152 off_t *offset, off_t *size) 153 { 154 struct partition_record mbr[4]; 155 uint8_t data[512]; 156 int i; 157 int ext_partnum = 4; 158 int ret; 159 160 if ((ret = blk_read(blk, 0, data, 1)) < 0) { 161 errno = -ret; 162 err(EXIT_FAILURE, "error while reading"); 163 } 164 165 if (data[510] != 0x55 || data[511] != 0xaa) { 166 return -EINVAL; 167 } 168 169 for (i = 0; i < 4; i++) { 170 read_partition(&data[446 + 16 * i], &mbr[i]); 171 172 if (!mbr[i].system || !mbr[i].nb_sectors_abs) { 173 continue; 174 } 175 176 if (mbr[i].system == 0xF || mbr[i].system == 0x5) { 177 struct partition_record ext[4]; 178 uint8_t data1[512]; 179 int j; 180 181 if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) { 182 errno = -ret; 183 err(EXIT_FAILURE, "error while reading"); 184 } 185 186 for (j = 0; j < 4; j++) { 187 read_partition(&data1[446 + 16 * j], &ext[j]); 188 if (!ext[j].system || !ext[j].nb_sectors_abs) { 189 continue; 190 } 191 192 if ((ext_partnum + j + 1) == partition) { 193 *offset = (uint64_t)ext[j].start_sector_abs << 9; 194 *size = (uint64_t)ext[j].nb_sectors_abs << 9; 195 return 0; 196 } 197 } 198 ext_partnum += 4; 199 } else if ((i + 1) == partition) { 200 *offset = (uint64_t)mbr[i].start_sector_abs << 9; 201 *size = (uint64_t)mbr[i].nb_sectors_abs << 9; 202 return 0; 203 } 204 } 205 206 return -ENOENT; 207 } 208 209 static void termsig_handler(int signum) 210 { 211 state = TERMINATE; 212 qemu_notify_event(); 213 } 214 215 static void combine_addr(char *buf, size_t len, const char* address, 216 uint16_t port) 217 { 218 /* If the address-part contains a colon, it's an IPv6 IP so needs [] */ 219 if (strstr(address, ":")) { 220 snprintf(buf, len, "[%s]:%u", address, port); 221 } else { 222 snprintf(buf, len, "%s:%u", address, port); 223 } 224 } 225 226 static int tcp_socket_incoming(const char *address, uint16_t port) 227 { 228 char address_and_port[128]; 229 Error *local_err = NULL; 230 231 combine_addr(address_and_port, 128, address, port); 232 int fd = inet_listen(address_and_port, NULL, 0, SOCK_STREAM, 0, &local_err); 233 234 if (local_err != NULL) { 235 error_report_err(local_err); 236 } 237 return fd; 238 } 239 240 static int unix_socket_incoming(const char *path) 241 { 242 Error *local_err = NULL; 243 int fd = unix_listen(path, NULL, 0, &local_err); 244 245 if (local_err != NULL) { 246 error_report_err(local_err); 247 } 248 return fd; 249 } 250 251 static int unix_socket_outgoing(const char *path) 252 { 253 Error *local_err = NULL; 254 int fd = unix_connect(path, &local_err); 255 256 if (local_err != NULL) { 257 error_report_err(local_err); 258 } 259 return fd; 260 } 261 262 static void *show_parts(void *arg) 263 { 264 char *device = arg; 265 int nbd; 266 267 /* linux just needs an open() to trigger 268 * the partition table update 269 * but remember to load the module with max_part != 0 : 270 * modprobe nbd max_part=63 271 */ 272 nbd = open(device, O_RDWR); 273 if (nbd >= 0) { 274 close(nbd); 275 } 276 return NULL; 277 } 278 279 static void *nbd_client_thread(void *arg) 280 { 281 char *device = arg; 282 off_t size; 283 uint32_t nbdflags; 284 int fd, sock; 285 int ret; 286 pthread_t show_parts_thread; 287 Error *local_error = NULL; 288 289 sock = unix_socket_outgoing(sockpath); 290 if (sock < 0) { 291 goto out; 292 } 293 294 ret = nbd_receive_negotiate(sock, NULL, &nbdflags, 295 &size, &local_error); 296 if (ret < 0) { 297 if (local_error) { 298 fprintf(stderr, "%s\n", error_get_pretty(local_error)); 299 error_free(local_error); 300 } 301 goto out_socket; 302 } 303 304 fd = open(device, O_RDWR); 305 if (fd < 0) { 306 /* Linux-only, we can use %m in printf. */ 307 fprintf(stderr, "Failed to open %s: %m\n", device); 308 goto out_socket; 309 } 310 311 ret = nbd_init(fd, sock, nbdflags, size); 312 if (ret < 0) { 313 goto out_fd; 314 } 315 316 /* update partition table */ 317 pthread_create(&show_parts_thread, NULL, show_parts, device); 318 319 if (verbose) { 320 fprintf(stderr, "NBD device %s is now connected to %s\n", 321 device, srcpath); 322 } else { 323 /* Close stderr so that the qemu-nbd process exits. */ 324 dup2(STDOUT_FILENO, STDERR_FILENO); 325 } 326 327 ret = nbd_client(fd); 328 if (ret) { 329 goto out_fd; 330 } 331 close(fd); 332 kill(getpid(), SIGTERM); 333 return (void *) EXIT_SUCCESS; 334 335 out_fd: 336 close(fd); 337 out_socket: 338 closesocket(sock); 339 out: 340 kill(getpid(), SIGTERM); 341 return (void *) EXIT_FAILURE; 342 } 343 344 static int nbd_can_accept(void) 345 { 346 return nb_fds < shared; 347 } 348 349 static void nbd_export_closed(NBDExport *exp) 350 { 351 assert(state == TERMINATING); 352 state = TERMINATED; 353 } 354 355 static void nbd_update_server_fd_handler(int fd); 356 357 static void nbd_client_closed(NBDClient *client) 358 { 359 nb_fds--; 360 if (nb_fds == 0 && !persistent && state == RUNNING) { 361 state = TERMINATE; 362 } 363 nbd_update_server_fd_handler(server_fd); 364 qemu_notify_event(); 365 nbd_client_put(client); 366 } 367 368 static void nbd_accept(void *opaque) 369 { 370 struct sockaddr_in addr; 371 socklen_t addr_len = sizeof(addr); 372 373 int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len); 374 if (fd < 0) { 375 perror("accept"); 376 return; 377 } 378 379 if (state >= TERMINATE) { 380 close(fd); 381 return; 382 } 383 384 if (nbd_client_new(exp, fd, nbd_client_closed)) { 385 nb_fds++; 386 nbd_update_server_fd_handler(server_fd); 387 } else { 388 shutdown(fd, 2); 389 close(fd); 390 } 391 } 392 393 static void nbd_update_server_fd_handler(int fd) 394 { 395 if (nbd_can_accept()) { 396 qemu_set_fd_handler(fd, nbd_accept, NULL, (void *)(uintptr_t)fd); 397 } else { 398 qemu_set_fd_handler(fd, NULL, NULL, NULL); 399 } 400 } 401 402 int main(int argc, char **argv) 403 { 404 BlockBackend *blk; 405 BlockDriverState *bs; 406 off_t dev_offset = 0; 407 uint32_t nbdflags = 0; 408 bool disconnect = false; 409 const char *bindto = "0.0.0.0"; 410 char *device = NULL; 411 int port = NBD_DEFAULT_PORT; 412 off_t fd_size; 413 QemuOpts *sn_opts = NULL; 414 const char *sn_id_or_name = NULL; 415 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:"; 416 struct option lopt[] = { 417 { "help", 0, NULL, 'h' }, 418 { "version", 0, NULL, 'V' }, 419 { "bind", 1, NULL, 'b' }, 420 { "port", 1, NULL, 'p' }, 421 { "socket", 1, NULL, 'k' }, 422 { "offset", 1, NULL, 'o' }, 423 { "read-only", 0, NULL, 'r' }, 424 { "partition", 1, NULL, 'P' }, 425 { "connect", 1, NULL, 'c' }, 426 { "disconnect", 0, NULL, 'd' }, 427 { "snapshot", 0, NULL, 's' }, 428 { "load-snapshot", 1, NULL, 'l' }, 429 { "nocache", 0, NULL, 'n' }, 430 { "cache", 1, NULL, QEMU_NBD_OPT_CACHE }, 431 #ifdef CONFIG_LINUX_AIO 432 { "aio", 1, NULL, QEMU_NBD_OPT_AIO }, 433 #endif 434 { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD }, 435 { "detect-zeroes", 1, NULL, QEMU_NBD_OPT_DETECT_ZEROES }, 436 { "shared", 1, NULL, 'e' }, 437 { "format", 1, NULL, 'f' }, 438 { "persistent", 0, NULL, 't' }, 439 { "verbose", 0, NULL, 'v' }, 440 { NULL, 0, NULL, 0 } 441 }; 442 int ch; 443 int opt_ind = 0; 444 int li; 445 char *end; 446 int flags = BDRV_O_RDWR; 447 int partition = -1; 448 int ret = 0; 449 int fd; 450 bool seen_cache = false; 451 bool seen_discard = false; 452 #ifdef CONFIG_LINUX_AIO 453 bool seen_aio = false; 454 #endif 455 pthread_t client_thread; 456 const char *fmt = NULL; 457 Error *local_err = NULL; 458 BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF; 459 QDict *options = NULL; 460 461 /* The client thread uses SIGTERM to interrupt the server. A signal 462 * handler ensures that "qemu-nbd -v -c" exits with a nice status code. 463 */ 464 struct sigaction sa_sigterm; 465 memset(&sa_sigterm, 0, sizeof(sa_sigterm)); 466 sa_sigterm.sa_handler = termsig_handler; 467 sigaction(SIGTERM, &sa_sigterm, NULL); 468 qemu_init_exec_dir(argv[0]); 469 470 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { 471 switch (ch) { 472 case 's': 473 flags |= BDRV_O_SNAPSHOT; 474 break; 475 case 'n': 476 optarg = (char *) "none"; 477 /* fallthrough */ 478 case QEMU_NBD_OPT_CACHE: 479 if (seen_cache) { 480 errx(EXIT_FAILURE, "-n and --cache can only be specified once"); 481 } 482 seen_cache = true; 483 if (bdrv_parse_cache_flags(optarg, &flags) == -1) { 484 errx(EXIT_FAILURE, "Invalid cache mode `%s'", optarg); 485 } 486 break; 487 #ifdef CONFIG_LINUX_AIO 488 case QEMU_NBD_OPT_AIO: 489 if (seen_aio) { 490 errx(EXIT_FAILURE, "--aio can only be specified once"); 491 } 492 seen_aio = true; 493 if (!strcmp(optarg, "native")) { 494 flags |= BDRV_O_NATIVE_AIO; 495 } else if (!strcmp(optarg, "threads")) { 496 /* this is the default */ 497 } else { 498 errx(EXIT_FAILURE, "invalid aio mode `%s'", optarg); 499 } 500 break; 501 #endif 502 case QEMU_NBD_OPT_DISCARD: 503 if (seen_discard) { 504 errx(EXIT_FAILURE, "--discard can only be specified once"); 505 } 506 seen_discard = true; 507 if (bdrv_parse_discard_flags(optarg, &flags) == -1) { 508 errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg); 509 } 510 break; 511 case QEMU_NBD_OPT_DETECT_ZEROES: 512 detect_zeroes = 513 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup, 514 optarg, 515 BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX, 516 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, 517 &local_err); 518 if (local_err) { 519 errx(EXIT_FAILURE, "Failed to parse detect_zeroes mode: %s", 520 error_get_pretty(local_err)); 521 } 522 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && 523 !(flags & BDRV_O_UNMAP)) { 524 errx(EXIT_FAILURE, "setting detect-zeroes to unmap is not allowed " 525 "without setting discard operation to unmap"); 526 } 527 break; 528 case 'b': 529 bindto = optarg; 530 break; 531 case 'p': 532 li = strtol(optarg, &end, 0); 533 if (*end) { 534 errx(EXIT_FAILURE, "Invalid port `%s'", optarg); 535 } 536 if (li < 1 || li > 65535) { 537 errx(EXIT_FAILURE, "Port out of range `%s'", optarg); 538 } 539 port = (uint16_t)li; 540 break; 541 case 'o': 542 dev_offset = strtoll (optarg, &end, 0); 543 if (*end) { 544 errx(EXIT_FAILURE, "Invalid offset `%s'", optarg); 545 } 546 if (dev_offset < 0) { 547 errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg); 548 } 549 break; 550 case 'l': 551 if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { 552 sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0); 553 if (!sn_opts) { 554 errx(EXIT_FAILURE, "Failed in parsing snapshot param `%s'", 555 optarg); 556 } 557 } else { 558 sn_id_or_name = optarg; 559 } 560 /* fall through */ 561 case 'r': 562 nbdflags |= NBD_FLAG_READ_ONLY; 563 flags &= ~BDRV_O_RDWR; 564 break; 565 case 'P': 566 partition = strtol(optarg, &end, 0); 567 if (*end) { 568 errx(EXIT_FAILURE, "Invalid partition `%s'", optarg); 569 } 570 if (partition < 1 || partition > 8) { 571 errx(EXIT_FAILURE, "Invalid partition %d", partition); 572 } 573 break; 574 case 'k': 575 sockpath = optarg; 576 if (sockpath[0] != '/') { 577 errx(EXIT_FAILURE, "socket path must be absolute\n"); 578 } 579 break; 580 case 'd': 581 disconnect = true; 582 break; 583 case 'c': 584 device = optarg; 585 break; 586 case 'e': 587 shared = strtol(optarg, &end, 0); 588 if (*end) { 589 errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg); 590 } 591 if (shared < 1) { 592 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n"); 593 } 594 break; 595 case 'f': 596 fmt = optarg; 597 break; 598 case 't': 599 persistent = 1; 600 break; 601 case 'v': 602 verbose = 1; 603 break; 604 case 'V': 605 version(argv[0]); 606 exit(0); 607 break; 608 case 'h': 609 usage(argv[0]); 610 exit(0); 611 break; 612 case '?': 613 errx(EXIT_FAILURE, "Try `%s --help' for more information.", 614 argv[0]); 615 } 616 } 617 618 if ((argc - optind) != 1) { 619 errx(EXIT_FAILURE, "Invalid number of argument.\n" 620 "Try `%s --help' for more information.", 621 argv[0]); 622 } 623 624 if (disconnect) { 625 fd = open(argv[optind], O_RDWR); 626 if (fd < 0) { 627 err(EXIT_FAILURE, "Cannot open %s", argv[optind]); 628 } 629 nbd_disconnect(fd); 630 631 close(fd); 632 633 printf("%s disconnected\n", argv[optind]); 634 635 return 0; 636 } 637 638 if (device && !verbose) { 639 int stderr_fd[2]; 640 pid_t pid; 641 int ret; 642 643 if (qemu_pipe(stderr_fd) < 0) { 644 err(EXIT_FAILURE, "Error setting up communication pipe"); 645 } 646 647 /* Now daemonize, but keep a communication channel open to 648 * print errors and exit with the proper status code. 649 */ 650 pid = fork(); 651 if (pid < 0) { 652 err(EXIT_FAILURE, "Failed to fork"); 653 } else if (pid == 0) { 654 close(stderr_fd[0]); 655 ret = qemu_daemon(1, 0); 656 657 /* Temporarily redirect stderr to the parent's pipe... */ 658 dup2(stderr_fd[1], STDERR_FILENO); 659 if (ret < 0) { 660 err(EXIT_FAILURE, "Failed to daemonize"); 661 } 662 663 /* ... close the descriptor we inherited and go on. */ 664 close(stderr_fd[1]); 665 } else { 666 bool errors = false; 667 char *buf; 668 669 /* In the parent. Print error messages from the child until 670 * it closes the pipe. 671 */ 672 close(stderr_fd[1]); 673 buf = g_malloc(1024); 674 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { 675 errors = true; 676 ret = qemu_write_full(STDERR_FILENO, buf, ret); 677 if (ret < 0) { 678 exit(EXIT_FAILURE); 679 } 680 } 681 if (ret < 0) { 682 err(EXIT_FAILURE, "Cannot read from daemon"); 683 } 684 685 /* Usually the daemon should not print any message. 686 * Exit with zero status in that case. 687 */ 688 exit(errors); 689 } 690 } 691 692 if (device != NULL && sockpath == NULL) { 693 sockpath = g_malloc(128); 694 snprintf(sockpath, 128, SOCKET_PATH, basename(device)); 695 } 696 697 if (qemu_init_main_loop(&local_err)) { 698 error_report_err(local_err); 699 exit(EXIT_FAILURE); 700 } 701 bdrv_init(); 702 atexit(bdrv_close_all); 703 704 if (fmt) { 705 options = qdict_new(); 706 qdict_put(options, "driver", qstring_from_str(fmt)); 707 } 708 709 srcpath = argv[optind]; 710 blk = blk_new_open("hda", srcpath, NULL, options, flags, &local_err); 711 if (!blk) { 712 errx(EXIT_FAILURE, "Failed to blk_new_open '%s': %s", argv[optind], 713 error_get_pretty(local_err)); 714 } 715 bs = blk_bs(blk); 716 717 if (sn_opts) { 718 ret = bdrv_snapshot_load_tmp(bs, 719 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), 720 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), 721 &local_err); 722 } else if (sn_id_or_name) { 723 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name, 724 &local_err); 725 } 726 if (ret < 0) { 727 errno = -ret; 728 err(EXIT_FAILURE, 729 "Failed to load snapshot: %s", 730 error_get_pretty(local_err)); 731 } 732 733 bs->detect_zeroes = detect_zeroes; 734 fd_size = blk_getlength(blk); 735 if (fd_size < 0) { 736 errx(EXIT_FAILURE, "Failed to determine the image length: %s", 737 strerror(-fd_size)); 738 } 739 740 if (partition != -1) { 741 ret = find_partition(blk, partition, &dev_offset, &fd_size); 742 if (ret < 0) { 743 errno = -ret; 744 err(EXIT_FAILURE, "Could not find partition %d", partition); 745 } 746 } 747 748 exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed, 749 &local_err); 750 if (!exp) { 751 errx(EXIT_FAILURE, "%s", error_get_pretty(local_err)); 752 } 753 754 if (sockpath) { 755 fd = unix_socket_incoming(sockpath); 756 } else { 757 fd = tcp_socket_incoming(bindto, port); 758 } 759 760 if (fd < 0) { 761 return 1; 762 } 763 764 if (device) { 765 int ret; 766 767 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device); 768 if (ret != 0) { 769 errx(EXIT_FAILURE, "Failed to create client thread: %s", 770 strerror(ret)); 771 } 772 } else { 773 /* Shut up GCC warnings. */ 774 memset(&client_thread, 0, sizeof(client_thread)); 775 } 776 777 server_fd = fd; 778 nbd_update_server_fd_handler(fd); 779 780 /* now when the initialization is (almost) complete, chdir("/") 781 * to free any busy filesystems */ 782 if (chdir("/") < 0) { 783 err(EXIT_FAILURE, "Could not chdir to root directory"); 784 } 785 786 state = RUNNING; 787 do { 788 main_loop_wait(false); 789 if (state == TERMINATE) { 790 state = TERMINATING; 791 nbd_export_close(exp); 792 nbd_export_put(exp); 793 exp = NULL; 794 } 795 } while (state != TERMINATED); 796 797 blk_unref(blk); 798 if (sockpath) { 799 unlink(sockpath); 800 } 801 802 qemu_opts_del(sn_opts); 803 804 if (device) { 805 void *ret; 806 pthread_join(client_thread, &ret); 807 exit(ret != NULL); 808 } else { 809 exit(EXIT_SUCCESS); 810 } 811 } 812