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 #include "qapi/qmp/qstring.h" 29 30 #include <stdarg.h> 31 #include <stdio.h> 32 #include <getopt.h> 33 #include <err.h> 34 #include <sys/types.h> 35 #include <sys/socket.h> 36 #include <netinet/in.h> 37 #include <netinet/tcp.h> 38 #include <arpa/inet.h> 39 #include <signal.h> 40 #include <libgen.h> 41 #include <pthread.h> 42 43 #define SOCKET_PATH "/var/lock/qemu-nbd-%s" 44 #define QEMU_NBD_OPT_CACHE 1 45 #define QEMU_NBD_OPT_AIO 2 46 #define QEMU_NBD_OPT_DISCARD 3 47 #define QEMU_NBD_OPT_DETECT_ZEROES 4 48 49 static NBDExport *exp; 50 static int verbose; 51 static char *srcpath; 52 static char *sockpath; 53 static int persistent = 0; 54 static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state; 55 static int shared = 1; 56 static int nb_fds; 57 static int server_fd; 58 59 static void usage(const char *name) 60 { 61 (printf) ( 62 "Usage: %s [OPTIONS] FILE\n" 63 "QEMU Disk Network Block Device Server\n" 64 "\n" 65 " -h, --help display this help and exit\n" 66 " -V, --version output version information and exit\n" 67 "\n" 68 "Connection properties:\n" 69 " -p, --port=PORT port to listen on (default `%d')\n" 70 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" 71 " -k, --socket=PATH path to the unix socket\n" 72 " (default '"SOCKET_PATH"')\n" 73 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" 74 " -t, --persistent don't exit on the last connection\n" 75 " -v, --verbose display extra debugging information\n" 76 "\n" 77 "Exposing part of the image:\n" 78 " -o, --offset=OFFSET offset into the image\n" 79 " -P, --partition=NUM only expose partition NUM\n" 80 "\n" 81 #ifdef __linux__ 82 "Kernel NBD client support:\n" 83 " -c, --connect=DEV connect FILE to the local NBD device DEV\n" 84 " -d, --disconnect disconnect the specified device\n" 85 "\n" 86 #endif 87 "\n" 88 "Block device options:\n" 89 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n" 90 " -r, --read-only export read-only\n" 91 " -s, --snapshot use FILE as an external snapshot, create a temporary\n" 92 " file with backing_file=FILE, redirect the write to\n" 93 " the temporary one\n" 94 " -l, --load-snapshot=SNAPSHOT_PARAM\n" 95 " load an internal snapshot inside FILE and export it\n" 96 " as an read-only device, SNAPSHOT_PARAM format is\n" 97 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n" 98 " '[ID_OR_NAME]'\n" 99 " -n, --nocache disable host cache\n" 100 " --cache=MODE set cache mode (none, writeback, ...)\n" 101 #ifdef CONFIG_LINUX_AIO 102 " --aio=MODE set AIO mode (native or threads)\n" 103 #endif 104 " --discard=MODE set discard mode (ignore, unmap)\n" 105 " --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n" 106 "\n" 107 "Report bugs to <qemu-devel@nongnu.org>\n" 108 , name, NBD_DEFAULT_PORT, "DEVICE"); 109 } 110 111 static void version(const char *name) 112 { 113 printf( 114 "%s version 0.0.1\n" 115 "Written by Anthony Liguori.\n" 116 "\n" 117 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n" 118 "This is free software; see the source for copying conditions. There is NO\n" 119 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 120 , name); 121 } 122 123 struct partition_record 124 { 125 uint8_t bootable; 126 uint8_t start_head; 127 uint32_t start_cylinder; 128 uint8_t start_sector; 129 uint8_t system; 130 uint8_t end_head; 131 uint8_t end_cylinder; 132 uint8_t end_sector; 133 uint32_t start_sector_abs; 134 uint32_t nb_sectors_abs; 135 }; 136 137 static void read_partition(uint8_t *p, struct partition_record *r) 138 { 139 r->bootable = p[0]; 140 r->start_head = p[1]; 141 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); 142 r->start_sector = p[2] & 0x3f; 143 r->system = p[4]; 144 r->end_head = p[5]; 145 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); 146 r->end_sector = p[6] & 0x3f; 147 148 r->start_sector_abs = le32_to_cpup((uint32_t *)(p + 8)); 149 r->nb_sectors_abs = le32_to_cpup((uint32_t *)(p + 12)); 150 } 151 152 static int find_partition(BlockBackend *blk, int partition, 153 off_t *offset, off_t *size) 154 { 155 struct partition_record mbr[4]; 156 uint8_t data[512]; 157 int i; 158 int ext_partnum = 4; 159 int ret; 160 161 if ((ret = blk_read(blk, 0, data, 1)) < 0) { 162 errno = -ret; 163 err(EXIT_FAILURE, "error while reading"); 164 } 165 166 if (data[510] != 0x55 || data[511] != 0xaa) { 167 return -EINVAL; 168 } 169 170 for (i = 0; i < 4; i++) { 171 read_partition(&data[446 + 16 * i], &mbr[i]); 172 173 if (!mbr[i].system || !mbr[i].nb_sectors_abs) { 174 continue; 175 } 176 177 if (mbr[i].system == 0xF || mbr[i].system == 0x5) { 178 struct partition_record ext[4]; 179 uint8_t data1[512]; 180 int j; 181 182 if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) { 183 errno = -ret; 184 err(EXIT_FAILURE, "error while reading"); 185 } 186 187 for (j = 0; j < 4; j++) { 188 read_partition(&data1[446 + 16 * j], &ext[j]); 189 if (!ext[j].system || !ext[j].nb_sectors_abs) { 190 continue; 191 } 192 193 if ((ext_partnum + j + 1) == partition) { 194 *offset = (uint64_t)ext[j].start_sector_abs << 9; 195 *size = (uint64_t)ext[j].nb_sectors_abs << 9; 196 return 0; 197 } 198 } 199 ext_partnum += 4; 200 } else if ((i + 1) == partition) { 201 *offset = (uint64_t)mbr[i].start_sector_abs << 9; 202 *size = (uint64_t)mbr[i].nb_sectors_abs << 9; 203 return 0; 204 } 205 } 206 207 return -ENOENT; 208 } 209 210 static void termsig_handler(int signum) 211 { 212 state = TERMINATE; 213 qemu_notify_event(); 214 } 215 216 static void combine_addr(char *buf, size_t len, const char* address, 217 uint16_t port) 218 { 219 /* If the address-part contains a colon, it's an IPv6 IP so needs [] */ 220 if (strstr(address, ":")) { 221 snprintf(buf, len, "[%s]:%u", address, port); 222 } else { 223 snprintf(buf, len, "%s:%u", address, port); 224 } 225 } 226 227 static int tcp_socket_incoming(const char *address, uint16_t port) 228 { 229 char address_and_port[128]; 230 Error *local_err = NULL; 231 232 combine_addr(address_and_port, 128, address, port); 233 int fd = inet_listen(address_and_port, NULL, 0, SOCK_STREAM, 0, &local_err); 234 235 if (local_err != NULL) { 236 error_report_err(local_err); 237 } 238 return fd; 239 } 240 241 static int unix_socket_incoming(const char *path) 242 { 243 Error *local_err = NULL; 244 int fd = unix_listen(path, NULL, 0, &local_err); 245 246 if (local_err != NULL) { 247 error_report_err(local_err); 248 } 249 return fd; 250 } 251 252 static int unix_socket_outgoing(const char *path) 253 { 254 Error *local_err = NULL; 255 int fd = unix_connect(path, &local_err); 256 257 if (local_err != NULL) { 258 error_report_err(local_err); 259 } 260 return fd; 261 } 262 263 static void *show_parts(void *arg) 264 { 265 char *device = arg; 266 int nbd; 267 268 /* linux just needs an open() to trigger 269 * the partition table update 270 * but remember to load the module with max_part != 0 : 271 * modprobe nbd max_part=63 272 */ 273 nbd = open(device, O_RDWR); 274 if (nbd >= 0) { 275 close(nbd); 276 } 277 return NULL; 278 } 279 280 static void *nbd_client_thread(void *arg) 281 { 282 char *device = arg; 283 off_t size; 284 uint32_t nbdflags; 285 int fd, sock; 286 int ret; 287 pthread_t show_parts_thread; 288 Error *local_error = NULL; 289 290 sock = unix_socket_outgoing(sockpath); 291 if (sock < 0) { 292 goto out; 293 } 294 295 ret = nbd_receive_negotiate(sock, NULL, &nbdflags, 296 &size, &local_error); 297 if (ret < 0) { 298 if (local_error) { 299 fprintf(stderr, "%s\n", error_get_pretty(local_error)); 300 error_free(local_error); 301 } 302 goto out_socket; 303 } 304 305 fd = open(device, O_RDWR); 306 if (fd < 0) { 307 /* Linux-only, we can use %m in printf. */ 308 fprintf(stderr, "Failed to open %s: %m\n", device); 309 goto out_socket; 310 } 311 312 ret = nbd_init(fd, sock, nbdflags, size); 313 if (ret < 0) { 314 goto out_fd; 315 } 316 317 /* update partition table */ 318 pthread_create(&show_parts_thread, NULL, show_parts, device); 319 320 if (verbose) { 321 fprintf(stderr, "NBD device %s is now connected to %s\n", 322 device, srcpath); 323 } else { 324 /* Close stderr so that the qemu-nbd process exits. */ 325 dup2(STDOUT_FILENO, STDERR_FILENO); 326 } 327 328 ret = nbd_client(fd); 329 if (ret) { 330 goto out_fd; 331 } 332 close(fd); 333 kill(getpid(), SIGTERM); 334 return (void *) EXIT_SUCCESS; 335 336 out_fd: 337 close(fd); 338 out_socket: 339 closesocket(sock); 340 out: 341 kill(getpid(), SIGTERM); 342 return (void *) EXIT_FAILURE; 343 } 344 345 static int nbd_can_accept(void) 346 { 347 return nb_fds < shared; 348 } 349 350 static void nbd_export_closed(NBDExport *exp) 351 { 352 assert(state == TERMINATING); 353 state = TERMINATED; 354 } 355 356 static void nbd_update_server_fd_handler(int fd); 357 358 static void nbd_client_closed(NBDClient *client) 359 { 360 nb_fds--; 361 if (nb_fds == 0 && !persistent && state == RUNNING) { 362 state = TERMINATE; 363 } 364 nbd_update_server_fd_handler(server_fd); 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_noisily(&internal_snapshot_opts, 553 optarg, false); 554 if (!sn_opts) { 555 errx(EXIT_FAILURE, "Failed in parsing snapshot param `%s'", 556 optarg); 557 } 558 } else { 559 sn_id_or_name = optarg; 560 } 561 /* fall through */ 562 case 'r': 563 nbdflags |= NBD_FLAG_READ_ONLY; 564 flags &= ~BDRV_O_RDWR; 565 break; 566 case 'P': 567 partition = strtol(optarg, &end, 0); 568 if (*end) { 569 errx(EXIT_FAILURE, "Invalid partition `%s'", optarg); 570 } 571 if (partition < 1 || partition > 8) { 572 errx(EXIT_FAILURE, "Invalid partition %d", partition); 573 } 574 break; 575 case 'k': 576 sockpath = optarg; 577 if (sockpath[0] != '/') { 578 errx(EXIT_FAILURE, "socket path must be absolute\n"); 579 } 580 break; 581 case 'd': 582 disconnect = true; 583 break; 584 case 'c': 585 device = optarg; 586 break; 587 case 'e': 588 shared = strtol(optarg, &end, 0); 589 if (*end) { 590 errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg); 591 } 592 if (shared < 1) { 593 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n"); 594 } 595 break; 596 case 'f': 597 fmt = optarg; 598 break; 599 case 't': 600 persistent = 1; 601 break; 602 case 'v': 603 verbose = 1; 604 break; 605 case 'V': 606 version(argv[0]); 607 exit(0); 608 break; 609 case 'h': 610 usage(argv[0]); 611 exit(0); 612 break; 613 case '?': 614 errx(EXIT_FAILURE, "Try `%s --help' for more information.", 615 argv[0]); 616 } 617 } 618 619 if ((argc - optind) != 1) { 620 errx(EXIT_FAILURE, "Invalid number of argument.\n" 621 "Try `%s --help' for more information.", 622 argv[0]); 623 } 624 625 if (disconnect) { 626 fd = open(argv[optind], O_RDWR); 627 if (fd < 0) { 628 err(EXIT_FAILURE, "Cannot open %s", argv[optind]); 629 } 630 nbd_disconnect(fd); 631 632 close(fd); 633 634 printf("%s disconnected\n", argv[optind]); 635 636 return 0; 637 } 638 639 if (device && !verbose) { 640 int stderr_fd[2]; 641 pid_t pid; 642 int ret; 643 644 if (qemu_pipe(stderr_fd) < 0) { 645 err(EXIT_FAILURE, "Error setting up communication pipe"); 646 } 647 648 /* Now daemonize, but keep a communication channel open to 649 * print errors and exit with the proper status code. 650 */ 651 pid = fork(); 652 if (pid < 0) { 653 err(EXIT_FAILURE, "Failed to fork"); 654 } else if (pid == 0) { 655 close(stderr_fd[0]); 656 ret = qemu_daemon(1, 0); 657 658 /* Temporarily redirect stderr to the parent's pipe... */ 659 dup2(stderr_fd[1], STDERR_FILENO); 660 if (ret < 0) { 661 err(EXIT_FAILURE, "Failed to daemonize"); 662 } 663 664 /* ... close the descriptor we inherited and go on. */ 665 close(stderr_fd[1]); 666 } else { 667 bool errors = false; 668 char *buf; 669 670 /* In the parent. Print error messages from the child until 671 * it closes the pipe. 672 */ 673 close(stderr_fd[1]); 674 buf = g_malloc(1024); 675 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { 676 errors = true; 677 ret = qemu_write_full(STDERR_FILENO, buf, ret); 678 if (ret < 0) { 679 exit(EXIT_FAILURE); 680 } 681 } 682 if (ret < 0) { 683 err(EXIT_FAILURE, "Cannot read from daemon"); 684 } 685 686 /* Usually the daemon should not print any message. 687 * Exit with zero status in that case. 688 */ 689 exit(errors); 690 } 691 } 692 693 if (device != NULL && sockpath == NULL) { 694 sockpath = g_malloc(128); 695 snprintf(sockpath, 128, SOCKET_PATH, basename(device)); 696 } 697 698 if (qemu_init_main_loop(&local_err)) { 699 error_report_err(local_err); 700 exit(EXIT_FAILURE); 701 } 702 bdrv_init(); 703 atexit(bdrv_close_all); 704 705 if (fmt) { 706 options = qdict_new(); 707 qdict_put(options, "driver", qstring_from_str(fmt)); 708 } 709 710 srcpath = argv[optind]; 711 blk = blk_new_open("hda", srcpath, NULL, options, flags, &local_err); 712 if (!blk) { 713 errx(EXIT_FAILURE, "Failed to blk_new_open '%s': %s", argv[optind], 714 error_get_pretty(local_err)); 715 } 716 bs = blk_bs(blk); 717 718 if (sn_opts) { 719 ret = bdrv_snapshot_load_tmp(bs, 720 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), 721 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), 722 &local_err); 723 } else if (sn_id_or_name) { 724 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name, 725 &local_err); 726 } 727 if (ret < 0) { 728 errno = -ret; 729 err(EXIT_FAILURE, 730 "Failed to load snapshot: %s", 731 error_get_pretty(local_err)); 732 } 733 734 bs->detect_zeroes = detect_zeroes; 735 fd_size = blk_getlength(blk); 736 if (fd_size < 0) { 737 errx(EXIT_FAILURE, "Failed to determine the image length: %s", 738 strerror(-fd_size)); 739 } 740 741 if (partition != -1) { 742 ret = find_partition(blk, partition, &dev_offset, &fd_size); 743 if (ret < 0) { 744 errno = -ret; 745 err(EXIT_FAILURE, "Could not find partition %d", partition); 746 } 747 } 748 749 exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed, 750 &local_err); 751 if (!exp) { 752 errx(EXIT_FAILURE, "%s", error_get_pretty(local_err)); 753 } 754 755 if (sockpath) { 756 fd = unix_socket_incoming(sockpath); 757 } else { 758 fd = tcp_socket_incoming(bindto, port); 759 } 760 761 if (fd < 0) { 762 return 1; 763 } 764 765 if (device) { 766 int ret; 767 768 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device); 769 if (ret != 0) { 770 errx(EXIT_FAILURE, "Failed to create client thread: %s", 771 strerror(ret)); 772 } 773 } else { 774 /* Shut up GCC warnings. */ 775 memset(&client_thread, 0, sizeof(client_thread)); 776 } 777 778 server_fd = fd; 779 nbd_update_server_fd_handler(fd); 780 781 /* now when the initialization is (almost) complete, chdir("/") 782 * to free any busy filesystems */ 783 if (chdir("/") < 0) { 784 err(EXIT_FAILURE, "Could not chdir to root directory"); 785 } 786 787 state = RUNNING; 788 do { 789 main_loop_wait(false); 790 if (state == TERMINATE) { 791 state = TERMINATING; 792 nbd_export_close(exp); 793 nbd_export_put(exp); 794 exp = NULL; 795 } 796 } while (state != TERMINATED); 797 798 blk_unref(blk); 799 if (sockpath) { 800 unlink(sockpath); 801 } 802 803 qemu_opts_del(sn_opts); 804 805 if (device) { 806 void *ret; 807 pthread_join(client_thread, &ret); 808 exit(ret != NULL); 809 } else { 810 exit(EXIT_SUCCESS); 811 } 812 } 813