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 57 static void usage(const char *name) 58 { 59 (printf) ( 60 "Usage: %s [OPTIONS] FILE\n" 61 "QEMU Disk Network Block Device Server\n" 62 "\n" 63 " -h, --help display this help and exit\n" 64 " -V, --version output version information and exit\n" 65 "\n" 66 "Connection properties:\n" 67 " -p, --port=PORT port to listen on (default `%d')\n" 68 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" 69 " -k, --socket=PATH path to the unix socket\n" 70 " (default '"SOCKET_PATH"')\n" 71 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" 72 " -t, --persistent don't exit on the last connection\n" 73 " -v, --verbose display extra debugging information\n" 74 "\n" 75 "Exposing part of the image:\n" 76 " -o, --offset=OFFSET offset into the image\n" 77 " -P, --partition=NUM only expose partition NUM\n" 78 "\n" 79 #ifdef __linux__ 80 "Kernel NBD client support:\n" 81 " -c, --connect=DEV connect FILE to the local NBD device DEV\n" 82 " -d, --disconnect disconnect the specified device\n" 83 "\n" 84 #endif 85 "\n" 86 "Block device options:\n" 87 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n" 88 " -r, --read-only export read-only\n" 89 " -s, --snapshot use FILE as an external snapshot, create a temporary\n" 90 " file with backing_file=FILE, redirect the write to\n" 91 " the temporary one\n" 92 " -l, --load-snapshot=SNAPSHOT_PARAM\n" 93 " load an internal snapshot inside FILE and export it\n" 94 " as an read-only device, SNAPSHOT_PARAM format is\n" 95 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n" 96 " '[ID_OR_NAME]'\n" 97 " -n, --nocache disable host cache\n" 98 " --cache=MODE set cache mode (none, writeback, ...)\n" 99 #ifdef CONFIG_LINUX_AIO 100 " --aio=MODE set AIO mode (native or threads)\n" 101 #endif 102 " --discard=MODE set discard mode (ignore, unmap)\n" 103 " --detect-zeroes=MODE set detect-zeroes mode (off, on, discard)\n" 104 "\n" 105 "Report bugs to <qemu-devel@nongnu.org>\n" 106 , name, NBD_DEFAULT_PORT, "DEVICE"); 107 } 108 109 static void version(const char *name) 110 { 111 printf( 112 "%s version 0.0.1\n" 113 "Written by Anthony Liguori.\n" 114 "\n" 115 "Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n" 116 "This is free software; see the source for copying conditions. There is NO\n" 117 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 118 , name); 119 } 120 121 struct partition_record 122 { 123 uint8_t bootable; 124 uint8_t start_head; 125 uint32_t start_cylinder; 126 uint8_t start_sector; 127 uint8_t system; 128 uint8_t end_head; 129 uint8_t end_cylinder; 130 uint8_t end_sector; 131 uint32_t start_sector_abs; 132 uint32_t nb_sectors_abs; 133 }; 134 135 static void read_partition(uint8_t *p, struct partition_record *r) 136 { 137 r->bootable = p[0]; 138 r->start_head = p[1]; 139 r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); 140 r->start_sector = p[2] & 0x3f; 141 r->system = p[4]; 142 r->end_head = p[5]; 143 r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); 144 r->end_sector = p[6] & 0x3f; 145 146 r->start_sector_abs = le32_to_cpup((uint32_t *)(p + 8)); 147 r->nb_sectors_abs = le32_to_cpup((uint32_t *)(p + 12)); 148 } 149 150 static int find_partition(BlockBackend *blk, int partition, 151 off_t *offset, off_t *size) 152 { 153 struct partition_record mbr[4]; 154 uint8_t data[512]; 155 int i; 156 int ext_partnum = 4; 157 int ret; 158 159 if ((ret = blk_read(blk, 0, data, 1)) < 0) { 160 errno = -ret; 161 err(EXIT_FAILURE, "error while reading"); 162 } 163 164 if (data[510] != 0x55 || data[511] != 0xaa) { 165 return -EINVAL; 166 } 167 168 for (i = 0; i < 4; i++) { 169 read_partition(&data[446 + 16 * i], &mbr[i]); 170 171 if (!mbr[i].system || !mbr[i].nb_sectors_abs) { 172 continue; 173 } 174 175 if (mbr[i].system == 0xF || mbr[i].system == 0x5) { 176 struct partition_record ext[4]; 177 uint8_t data1[512]; 178 int j; 179 180 if ((ret = blk_read(blk, mbr[i].start_sector_abs, data1, 1)) < 0) { 181 errno = -ret; 182 err(EXIT_FAILURE, "error while reading"); 183 } 184 185 for (j = 0; j < 4; j++) { 186 read_partition(&data1[446 + 16 * j], &ext[j]); 187 if (!ext[j].system || !ext[j].nb_sectors_abs) { 188 continue; 189 } 190 191 if ((ext_partnum + j + 1) == partition) { 192 *offset = (uint64_t)ext[j].start_sector_abs << 9; 193 *size = (uint64_t)ext[j].nb_sectors_abs << 9; 194 return 0; 195 } 196 } 197 ext_partnum += 4; 198 } else if ((i + 1) == partition) { 199 *offset = (uint64_t)mbr[i].start_sector_abs << 9; 200 *size = (uint64_t)mbr[i].nb_sectors_abs << 9; 201 return 0; 202 } 203 } 204 205 return -ENOENT; 206 } 207 208 static void termsig_handler(int signum) 209 { 210 state = TERMINATE; 211 qemu_notify_event(); 212 } 213 214 static void combine_addr(char *buf, size_t len, const char* address, 215 uint16_t port) 216 { 217 /* If the address-part contains a colon, it's an IPv6 IP so needs [] */ 218 if (strstr(address, ":")) { 219 snprintf(buf, len, "[%s]:%u", address, port); 220 } else { 221 snprintf(buf, len, "%s:%u", address, port); 222 } 223 } 224 225 static int tcp_socket_incoming(const char *address, uint16_t port) 226 { 227 char address_and_port[128]; 228 Error *local_err = NULL; 229 230 combine_addr(address_and_port, 128, address, port); 231 int fd = inet_listen(address_and_port, NULL, 0, SOCK_STREAM, 0, &local_err); 232 233 if (local_err != NULL) { 234 error_report_err(local_err); 235 } 236 return fd; 237 } 238 239 static int unix_socket_incoming(const char *path) 240 { 241 Error *local_err = NULL; 242 int fd = unix_listen(path, NULL, 0, &local_err); 243 244 if (local_err != NULL) { 245 error_report_err(local_err); 246 } 247 return fd; 248 } 249 250 static int unix_socket_outgoing(const char *path) 251 { 252 Error *local_err = NULL; 253 int fd = unix_connect(path, &local_err); 254 255 if (local_err != NULL) { 256 error_report_err(local_err); 257 } 258 return fd; 259 } 260 261 static void *show_parts(void *arg) 262 { 263 char *device = arg; 264 int nbd; 265 266 /* linux just needs an open() to trigger 267 * the partition table update 268 * but remember to load the module with max_part != 0 : 269 * modprobe nbd max_part=63 270 */ 271 nbd = open(device, O_RDWR); 272 if (nbd >= 0) { 273 close(nbd); 274 } 275 return NULL; 276 } 277 278 static void *nbd_client_thread(void *arg) 279 { 280 char *device = arg; 281 off_t size; 282 uint32_t nbdflags; 283 int fd, sock; 284 int ret; 285 pthread_t show_parts_thread; 286 Error *local_error = NULL; 287 288 sock = unix_socket_outgoing(sockpath); 289 if (sock < 0) { 290 goto out; 291 } 292 293 ret = nbd_receive_negotiate(sock, NULL, &nbdflags, 294 &size, &local_error); 295 if (ret < 0) { 296 if (local_error) { 297 fprintf(stderr, "%s\n", error_get_pretty(local_error)); 298 error_free(local_error); 299 } 300 goto out_socket; 301 } 302 303 fd = open(device, O_RDWR); 304 if (fd < 0) { 305 /* Linux-only, we can use %m in printf. */ 306 fprintf(stderr, "Failed to open %s: %m\n", device); 307 goto out_socket; 308 } 309 310 ret = nbd_init(fd, sock, nbdflags, size); 311 if (ret < 0) { 312 goto out_fd; 313 } 314 315 /* update partition table */ 316 pthread_create(&show_parts_thread, NULL, show_parts, device); 317 318 if (verbose) { 319 fprintf(stderr, "NBD device %s is now connected to %s\n", 320 device, srcpath); 321 } else { 322 /* Close stderr so that the qemu-nbd process exits. */ 323 dup2(STDOUT_FILENO, STDERR_FILENO); 324 } 325 326 ret = nbd_client(fd); 327 if (ret) { 328 goto out_fd; 329 } 330 close(fd); 331 kill(getpid(), SIGTERM); 332 return (void *) EXIT_SUCCESS; 333 334 out_fd: 335 close(fd); 336 out_socket: 337 closesocket(sock); 338 out: 339 kill(getpid(), SIGTERM); 340 return (void *) EXIT_FAILURE; 341 } 342 343 static int nbd_can_accept(void *opaque) 344 { 345 return nb_fds < shared; 346 } 347 348 static void nbd_export_closed(NBDExport *exp) 349 { 350 assert(state == TERMINATING); 351 state = TERMINATED; 352 } 353 354 static void nbd_client_closed(NBDClient *client) 355 { 356 nb_fds--; 357 if (nb_fds == 0 && !persistent && state == RUNNING) { 358 state = TERMINATE; 359 } 360 qemu_notify_event(); 361 nbd_client_put(client); 362 } 363 364 static void nbd_accept(void *opaque) 365 { 366 int server_fd = (uintptr_t) opaque; 367 struct sockaddr_in addr; 368 socklen_t addr_len = sizeof(addr); 369 370 int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len); 371 if (fd < 0) { 372 perror("accept"); 373 return; 374 } 375 376 if (state >= TERMINATE) { 377 close(fd); 378 return; 379 } 380 381 if (nbd_client_new(exp, fd, nbd_client_closed)) { 382 nb_fds++; 383 } else { 384 shutdown(fd, 2); 385 close(fd); 386 } 387 } 388 389 int main(int argc, char **argv) 390 { 391 BlockBackend *blk; 392 BlockDriverState *bs; 393 off_t dev_offset = 0; 394 uint32_t nbdflags = 0; 395 bool disconnect = false; 396 const char *bindto = "0.0.0.0"; 397 char *device = NULL; 398 int port = NBD_DEFAULT_PORT; 399 off_t fd_size; 400 QemuOpts *sn_opts = NULL; 401 const char *sn_id_or_name = NULL; 402 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:"; 403 struct option lopt[] = { 404 { "help", 0, NULL, 'h' }, 405 { "version", 0, NULL, 'V' }, 406 { "bind", 1, NULL, 'b' }, 407 { "port", 1, NULL, 'p' }, 408 { "socket", 1, NULL, 'k' }, 409 { "offset", 1, NULL, 'o' }, 410 { "read-only", 0, NULL, 'r' }, 411 { "partition", 1, NULL, 'P' }, 412 { "connect", 1, NULL, 'c' }, 413 { "disconnect", 0, NULL, 'd' }, 414 { "snapshot", 0, NULL, 's' }, 415 { "load-snapshot", 1, NULL, 'l' }, 416 { "nocache", 0, NULL, 'n' }, 417 { "cache", 1, NULL, QEMU_NBD_OPT_CACHE }, 418 #ifdef CONFIG_LINUX_AIO 419 { "aio", 1, NULL, QEMU_NBD_OPT_AIO }, 420 #endif 421 { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD }, 422 { "detect-zeroes", 1, NULL, QEMU_NBD_OPT_DETECT_ZEROES }, 423 { "shared", 1, NULL, 'e' }, 424 { "format", 1, NULL, 'f' }, 425 { "persistent", 0, NULL, 't' }, 426 { "verbose", 0, NULL, 'v' }, 427 { NULL, 0, NULL, 0 } 428 }; 429 int ch; 430 int opt_ind = 0; 431 int li; 432 char *end; 433 int flags = BDRV_O_RDWR; 434 int partition = -1; 435 int ret = 0; 436 int fd; 437 bool seen_cache = false; 438 bool seen_discard = false; 439 #ifdef CONFIG_LINUX_AIO 440 bool seen_aio = false; 441 #endif 442 pthread_t client_thread; 443 const char *fmt = NULL; 444 Error *local_err = NULL; 445 BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF; 446 QDict *options = NULL; 447 448 /* The client thread uses SIGTERM to interrupt the server. A signal 449 * handler ensures that "qemu-nbd -v -c" exits with a nice status code. 450 */ 451 struct sigaction sa_sigterm; 452 memset(&sa_sigterm, 0, sizeof(sa_sigterm)); 453 sa_sigterm.sa_handler = termsig_handler; 454 sigaction(SIGTERM, &sa_sigterm, NULL); 455 qemu_init_exec_dir(argv[0]); 456 457 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { 458 switch (ch) { 459 case 's': 460 flags |= BDRV_O_SNAPSHOT; 461 break; 462 case 'n': 463 optarg = (char *) "none"; 464 /* fallthrough */ 465 case QEMU_NBD_OPT_CACHE: 466 if (seen_cache) { 467 errx(EXIT_FAILURE, "-n and --cache can only be specified once"); 468 } 469 seen_cache = true; 470 if (bdrv_parse_cache_flags(optarg, &flags) == -1) { 471 errx(EXIT_FAILURE, "Invalid cache mode `%s'", optarg); 472 } 473 break; 474 #ifdef CONFIG_LINUX_AIO 475 case QEMU_NBD_OPT_AIO: 476 if (seen_aio) { 477 errx(EXIT_FAILURE, "--aio can only be specified once"); 478 } 479 seen_aio = true; 480 if (!strcmp(optarg, "native")) { 481 flags |= BDRV_O_NATIVE_AIO; 482 } else if (!strcmp(optarg, "threads")) { 483 /* this is the default */ 484 } else { 485 errx(EXIT_FAILURE, "invalid aio mode `%s'", optarg); 486 } 487 break; 488 #endif 489 case QEMU_NBD_OPT_DISCARD: 490 if (seen_discard) { 491 errx(EXIT_FAILURE, "--discard can only be specified once"); 492 } 493 seen_discard = true; 494 if (bdrv_parse_discard_flags(optarg, &flags) == -1) { 495 errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg); 496 } 497 break; 498 case QEMU_NBD_OPT_DETECT_ZEROES: 499 detect_zeroes = 500 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup, 501 optarg, 502 BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX, 503 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, 504 &local_err); 505 if (local_err) { 506 errx(EXIT_FAILURE, "Failed to parse detect_zeroes mode: %s", 507 error_get_pretty(local_err)); 508 } 509 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && 510 !(flags & BDRV_O_UNMAP)) { 511 errx(EXIT_FAILURE, "setting detect-zeroes to unmap is not allowed " 512 "without setting discard operation to unmap"); 513 } 514 break; 515 case 'b': 516 bindto = optarg; 517 break; 518 case 'p': 519 li = strtol(optarg, &end, 0); 520 if (*end) { 521 errx(EXIT_FAILURE, "Invalid port `%s'", optarg); 522 } 523 if (li < 1 || li > 65535) { 524 errx(EXIT_FAILURE, "Port out of range `%s'", optarg); 525 } 526 port = (uint16_t)li; 527 break; 528 case 'o': 529 dev_offset = strtoll (optarg, &end, 0); 530 if (*end) { 531 errx(EXIT_FAILURE, "Invalid offset `%s'", optarg); 532 } 533 if (dev_offset < 0) { 534 errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg); 535 } 536 break; 537 case 'l': 538 if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { 539 sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0); 540 if (!sn_opts) { 541 errx(EXIT_FAILURE, "Failed in parsing snapshot param `%s'", 542 optarg); 543 } 544 } else { 545 sn_id_or_name = optarg; 546 } 547 /* fall through */ 548 case 'r': 549 nbdflags |= NBD_FLAG_READ_ONLY; 550 flags &= ~BDRV_O_RDWR; 551 break; 552 case 'P': 553 partition = strtol(optarg, &end, 0); 554 if (*end) { 555 errx(EXIT_FAILURE, "Invalid partition `%s'", optarg); 556 } 557 if (partition < 1 || partition > 8) { 558 errx(EXIT_FAILURE, "Invalid partition %d", partition); 559 } 560 break; 561 case 'k': 562 sockpath = optarg; 563 if (sockpath[0] != '/') { 564 errx(EXIT_FAILURE, "socket path must be absolute\n"); 565 } 566 break; 567 case 'd': 568 disconnect = true; 569 break; 570 case 'c': 571 device = optarg; 572 break; 573 case 'e': 574 shared = strtol(optarg, &end, 0); 575 if (*end) { 576 errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg); 577 } 578 if (shared < 1) { 579 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n"); 580 } 581 break; 582 case 'f': 583 fmt = optarg; 584 break; 585 case 't': 586 persistent = 1; 587 break; 588 case 'v': 589 verbose = 1; 590 break; 591 case 'V': 592 version(argv[0]); 593 exit(0); 594 break; 595 case 'h': 596 usage(argv[0]); 597 exit(0); 598 break; 599 case '?': 600 errx(EXIT_FAILURE, "Try `%s --help' for more information.", 601 argv[0]); 602 } 603 } 604 605 if ((argc - optind) != 1) { 606 errx(EXIT_FAILURE, "Invalid number of argument.\n" 607 "Try `%s --help' for more information.", 608 argv[0]); 609 } 610 611 if (disconnect) { 612 fd = open(argv[optind], O_RDWR); 613 if (fd < 0) { 614 err(EXIT_FAILURE, "Cannot open %s", argv[optind]); 615 } 616 nbd_disconnect(fd); 617 618 close(fd); 619 620 printf("%s disconnected\n", argv[optind]); 621 622 return 0; 623 } 624 625 if (device && !verbose) { 626 int stderr_fd[2]; 627 pid_t pid; 628 int ret; 629 630 if (qemu_pipe(stderr_fd) < 0) { 631 err(EXIT_FAILURE, "Error setting up communication pipe"); 632 } 633 634 /* Now daemonize, but keep a communication channel open to 635 * print errors and exit with the proper status code. 636 */ 637 pid = fork(); 638 if (pid < 0) { 639 err(EXIT_FAILURE, "Failed to fork"); 640 } else if (pid == 0) { 641 close(stderr_fd[0]); 642 ret = qemu_daemon(1, 0); 643 644 /* Temporarily redirect stderr to the parent's pipe... */ 645 dup2(stderr_fd[1], STDERR_FILENO); 646 if (ret < 0) { 647 err(EXIT_FAILURE, "Failed to daemonize"); 648 } 649 650 /* ... close the descriptor we inherited and go on. */ 651 close(stderr_fd[1]); 652 } else { 653 bool errors = false; 654 char *buf; 655 656 /* In the parent. Print error messages from the child until 657 * it closes the pipe. 658 */ 659 close(stderr_fd[1]); 660 buf = g_malloc(1024); 661 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { 662 errors = true; 663 ret = qemu_write_full(STDERR_FILENO, buf, ret); 664 if (ret < 0) { 665 exit(EXIT_FAILURE); 666 } 667 } 668 if (ret < 0) { 669 err(EXIT_FAILURE, "Cannot read from daemon"); 670 } 671 672 /* Usually the daemon should not print any message. 673 * Exit with zero status in that case. 674 */ 675 exit(errors); 676 } 677 } 678 679 if (device != NULL && sockpath == NULL) { 680 sockpath = g_malloc(128); 681 snprintf(sockpath, 128, SOCKET_PATH, basename(device)); 682 } 683 684 if (qemu_init_main_loop(&local_err)) { 685 error_report_err(local_err); 686 exit(EXIT_FAILURE); 687 } 688 bdrv_init(); 689 atexit(bdrv_close_all); 690 691 if (fmt) { 692 options = qdict_new(); 693 qdict_put(options, "driver", qstring_from_str(fmt)); 694 } 695 696 srcpath = argv[optind]; 697 blk = blk_new_open("hda", srcpath, NULL, options, flags, &local_err); 698 if (!blk) { 699 errx(EXIT_FAILURE, "Failed to blk_new_open '%s': %s", argv[optind], 700 error_get_pretty(local_err)); 701 } 702 bs = blk_bs(blk); 703 704 if (sn_opts) { 705 ret = bdrv_snapshot_load_tmp(bs, 706 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), 707 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), 708 &local_err); 709 } else if (sn_id_or_name) { 710 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name, 711 &local_err); 712 } 713 if (ret < 0) { 714 errno = -ret; 715 err(EXIT_FAILURE, 716 "Failed to load snapshot: %s", 717 error_get_pretty(local_err)); 718 } 719 720 bs->detect_zeroes = detect_zeroes; 721 fd_size = blk_getlength(blk); 722 if (fd_size < 0) { 723 errx(EXIT_FAILURE, "Failed to determine the image length: %s", 724 strerror(-fd_size)); 725 } 726 727 if (partition != -1) { 728 ret = find_partition(blk, partition, &dev_offset, &fd_size); 729 if (ret < 0) { 730 errno = -ret; 731 err(EXIT_FAILURE, "Could not find partition %d", partition); 732 } 733 } 734 735 exp = nbd_export_new(blk, dev_offset, fd_size, nbdflags, nbd_export_closed, 736 &local_err); 737 if (!exp) { 738 errx(EXIT_FAILURE, "%s", error_get_pretty(local_err)); 739 } 740 741 if (sockpath) { 742 fd = unix_socket_incoming(sockpath); 743 } else { 744 fd = tcp_socket_incoming(bindto, port); 745 } 746 747 if (fd < 0) { 748 return 1; 749 } 750 751 if (device) { 752 int ret; 753 754 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device); 755 if (ret != 0) { 756 errx(EXIT_FAILURE, "Failed to create client thread: %s", 757 strerror(ret)); 758 } 759 } else { 760 /* Shut up GCC warnings. */ 761 memset(&client_thread, 0, sizeof(client_thread)); 762 } 763 764 qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL, 765 (void *)(uintptr_t)fd); 766 767 /* now when the initialization is (almost) complete, chdir("/") 768 * to free any busy filesystems */ 769 if (chdir("/") < 0) { 770 err(EXIT_FAILURE, "Could not chdir to root directory"); 771 } 772 773 state = RUNNING; 774 do { 775 main_loop_wait(false); 776 if (state == TERMINATE) { 777 state = TERMINATING; 778 nbd_export_close(exp); 779 nbd_export_put(exp); 780 exp = NULL; 781 } 782 } while (state != TERMINATED); 783 784 blk_unref(blk); 785 if (sockpath) { 786 unlink(sockpath); 787 } 788 789 qemu_opts_del(sn_opts); 790 791 if (device) { 792 void *ret; 793 pthread_join(client_thread, &ret); 794 exit(ret != NULL); 795 } else { 796 exit(EXIT_SUCCESS); 797 } 798 } 799