Provide the missing LIBUSB_LOG_LEVEL_* for older libusb or FreeBSD. Providing just...
[qemu.git] / qemu-nbd.c
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 r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24;
146 r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24;
147 }
148
149 static int find_partition(BlockDriverState *bs, int partition,
150 off_t *offset, off_t *size)
151 {
152 struct partition_record mbr[4];
153 uint8_t data[512];
154 int i;
155 int ext_partnum = 4;
156 int ret;
157
158 if ((ret = bdrv_read(bs, 0, data, 1)) < 0) {
159 errno = -ret;
160 err(EXIT_FAILURE, "error while reading");
161 }
162
163 if (data[510] != 0x55 || data[511] != 0xaa) {
164 return -EINVAL;
165 }
166
167 for (i = 0; i < 4; i++) {
168 read_partition(&data[446 + 16 * i], &mbr[i]);
169
170 if (!mbr[i].nb_sectors_abs)
171 continue;
172
173 if (mbr[i].system == 0xF || mbr[i].system == 0x5) {
174 struct partition_record ext[4];
175 uint8_t data1[512];
176 int j;
177
178 if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) {
179 errno = -ret;
180 err(EXIT_FAILURE, "error while reading");
181 }
182
183 for (j = 0; j < 4; j++) {
184 read_partition(&data1[446 + 16 * j], &ext[j]);
185 if (!ext[j].nb_sectors_abs)
186 continue;
187
188 if ((ext_partnum + j + 1) == partition) {
189 *offset = (uint64_t)ext[j].start_sector_abs << 9;
190 *size = (uint64_t)ext[j].nb_sectors_abs << 9;
191 return 0;
192 }
193 }
194 ext_partnum += 4;
195 } else if ((i + 1) == partition) {
196 *offset = (uint64_t)mbr[i].start_sector_abs << 9;
197 *size = (uint64_t)mbr[i].nb_sectors_abs << 9;
198 return 0;
199 }
200 }
201
202 return -ENOENT;
203 }
204
205 static void termsig_handler(int signum)
206 {
207 state = TERMINATE;
208 qemu_notify_event();
209 }
210
211 static void combine_addr(char *buf, size_t len, const char* address,
212 uint16_t port)
213 {
214 /* If the address-part contains a colon, it's an IPv6 IP so needs [] */
215 if (strstr(address, ":")) {
216 snprintf(buf, len, "[%s]:%u", address, port);
217 } else {
218 snprintf(buf, len, "%s:%u", address, port);
219 }
220 }
221
222 static int tcp_socket_incoming(const char *address, uint16_t port)
223 {
224 char address_and_port[128];
225 Error *local_err = NULL;
226
227 combine_addr(address_and_port, 128, address, port);
228 int fd = inet_listen(address_and_port, NULL, 0, SOCK_STREAM, 0, &local_err);
229
230 if (local_err != NULL) {
231 error_report("%s", error_get_pretty(local_err));
232 error_free(local_err);
233 }
234 return fd;
235 }
236
237 static int unix_socket_incoming(const char *path)
238 {
239 Error *local_err = NULL;
240 int fd = unix_listen(path, NULL, 0, &local_err);
241
242 if (local_err != NULL) {
243 error_report("%s", error_get_pretty(local_err));
244 error_free(local_err);
245 }
246 return fd;
247 }
248
249 static int unix_socket_outgoing(const char *path)
250 {
251 Error *local_err = NULL;
252 int fd = unix_connect(path, &local_err);
253
254 if (local_err != NULL) {
255 error_report("%s", error_get_pretty(local_err));
256 error_free(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 size_t blocksize;
283 uint32_t nbdflags;
284 int fd, sock;
285 int ret;
286 pthread_t show_parts_thread;
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, &blocksize);
295 if (ret < 0) {
296 goto out_socket;
297 }
298
299 fd = open(device, O_RDWR);
300 if (fd < 0) {
301 /* Linux-only, we can use %m in printf. */
302 fprintf(stderr, "Failed to open %s: %m\n", device);
303 goto out_socket;
304 }
305
306 ret = nbd_init(fd, sock, nbdflags, size, blocksize);
307 if (ret < 0) {
308 goto out_fd;
309 }
310
311 /* update partition table */
312 pthread_create(&show_parts_thread, NULL, show_parts, device);
313
314 if (verbose) {
315 fprintf(stderr, "NBD device %s is now connected to %s\n",
316 device, srcpath);
317 } else {
318 /* Close stderr so that the qemu-nbd process exits. */
319 dup2(STDOUT_FILENO, STDERR_FILENO);
320 }
321
322 ret = nbd_client(fd);
323 if (ret) {
324 goto out_fd;
325 }
326 close(fd);
327 kill(getpid(), SIGTERM);
328 return (void *) EXIT_SUCCESS;
329
330 out_fd:
331 close(fd);
332 out_socket:
333 closesocket(sock);
334 out:
335 kill(getpid(), SIGTERM);
336 return (void *) EXIT_FAILURE;
337 }
338
339 static int nbd_can_accept(void *opaque)
340 {
341 return nb_fds < shared;
342 }
343
344 static void nbd_export_closed(NBDExport *exp)
345 {
346 assert(state == TERMINATING);
347 state = TERMINATED;
348 }
349
350 static void nbd_client_closed(NBDClient *client)
351 {
352 nb_fds--;
353 if (nb_fds == 0 && !persistent && state == RUNNING) {
354 state = TERMINATE;
355 }
356 qemu_notify_event();
357 nbd_client_put(client);
358 }
359
360 static void nbd_accept(void *opaque)
361 {
362 int server_fd = (uintptr_t) opaque;
363 struct sockaddr_in addr;
364 socklen_t addr_len = sizeof(addr);
365
366 int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
367 if (fd < 0) {
368 perror("accept");
369 return;
370 }
371
372 if (state >= TERMINATE) {
373 close(fd);
374 return;
375 }
376
377 if (nbd_client_new(exp, fd, nbd_client_closed)) {
378 nb_fds++;
379 } else {
380 shutdown(fd, 2);
381 close(fd);
382 }
383 }
384
385 int main(int argc, char **argv)
386 {
387 BlockBackend *blk;
388 BlockDriverState *bs;
389 BlockDriver *drv;
390 off_t dev_offset = 0;
391 uint32_t nbdflags = 0;
392 bool disconnect = false;
393 const char *bindto = "0.0.0.0";
394 char *device = NULL;
395 int port = NBD_DEFAULT_PORT;
396 off_t fd_size;
397 QemuOpts *sn_opts = NULL;
398 const char *sn_id_or_name = NULL;
399 const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:";
400 struct option lopt[] = {
401 { "help", 0, NULL, 'h' },
402 { "version", 0, NULL, 'V' },
403 { "bind", 1, NULL, 'b' },
404 { "port", 1, NULL, 'p' },
405 { "socket", 1, NULL, 'k' },
406 { "offset", 1, NULL, 'o' },
407 { "read-only", 0, NULL, 'r' },
408 { "partition", 1, NULL, 'P' },
409 { "connect", 1, NULL, 'c' },
410 { "disconnect", 0, NULL, 'd' },
411 { "snapshot", 0, NULL, 's' },
412 { "load-snapshot", 1, NULL, 'l' },
413 { "nocache", 0, NULL, 'n' },
414 { "cache", 1, NULL, QEMU_NBD_OPT_CACHE },
415 #ifdef CONFIG_LINUX_AIO
416 { "aio", 1, NULL, QEMU_NBD_OPT_AIO },
417 #endif
418 { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD },
419 { "detect-zeroes", 1, NULL, QEMU_NBD_OPT_DETECT_ZEROES },
420 { "shared", 1, NULL, 'e' },
421 { "format", 1, NULL, 'f' },
422 { "persistent", 0, NULL, 't' },
423 { "verbose", 0, NULL, 'v' },
424 { NULL, 0, NULL, 0 }
425 };
426 int ch;
427 int opt_ind = 0;
428 int li;
429 char *end;
430 int flags = BDRV_O_RDWR;
431 int partition = -1;
432 int ret;
433 int fd;
434 bool seen_cache = false;
435 bool seen_discard = false;
436 #ifdef CONFIG_LINUX_AIO
437 bool seen_aio = false;
438 #endif
439 pthread_t client_thread;
440 const char *fmt = NULL;
441 Error *local_err = NULL;
442 BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
443
444 /* The client thread uses SIGTERM to interrupt the server. A signal
445 * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
446 */
447 struct sigaction sa_sigterm;
448 memset(&sa_sigterm, 0, sizeof(sa_sigterm));
449 sa_sigterm.sa_handler = termsig_handler;
450 sigaction(SIGTERM, &sa_sigterm, NULL);
451 qemu_init_exec_dir(argv[0]);
452
453 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
454 switch (ch) {
455 case 's':
456 flags |= BDRV_O_SNAPSHOT;
457 break;
458 case 'n':
459 optarg = (char *) "none";
460 /* fallthrough */
461 case QEMU_NBD_OPT_CACHE:
462 if (seen_cache) {
463 errx(EXIT_FAILURE, "-n and --cache can only be specified once");
464 }
465 seen_cache = true;
466 if (bdrv_parse_cache_flags(optarg, &flags) == -1) {
467 errx(EXIT_FAILURE, "Invalid cache mode `%s'", optarg);
468 }
469 break;
470 #ifdef CONFIG_LINUX_AIO
471 case QEMU_NBD_OPT_AIO:
472 if (seen_aio) {
473 errx(EXIT_FAILURE, "--aio can only be specified once");
474 }
475 seen_aio = true;
476 if (!strcmp(optarg, "native")) {
477 flags |= BDRV_O_NATIVE_AIO;
478 } else if (!strcmp(optarg, "threads")) {
479 /* this is the default */
480 } else {
481 errx(EXIT_FAILURE, "invalid aio mode `%s'", optarg);
482 }
483 break;
484 #endif
485 case QEMU_NBD_OPT_DISCARD:
486 if (seen_discard) {
487 errx(EXIT_FAILURE, "--discard can only be specified once");
488 }
489 seen_discard = true;
490 if (bdrv_parse_discard_flags(optarg, &flags) == -1) {
491 errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg);
492 }
493 break;
494 case QEMU_NBD_OPT_DETECT_ZEROES:
495 detect_zeroes =
496 qapi_enum_parse(BlockdevDetectZeroesOptions_lookup,
497 optarg,
498 BLOCKDEV_DETECT_ZEROES_OPTIONS_MAX,
499 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
500 &local_err);
501 if (local_err) {
502 errx(EXIT_FAILURE, "Failed to parse detect_zeroes mode: %s",
503 error_get_pretty(local_err));
504 }
505 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
506 !(flags & BDRV_O_UNMAP)) {
507 errx(EXIT_FAILURE, "setting detect-zeroes to unmap is not allowed "
508 "without setting discard operation to unmap");
509 }
510 break;
511 case 'b':
512 bindto = optarg;
513 break;
514 case 'p':
515 li = strtol(optarg, &end, 0);
516 if (*end) {
517 errx(EXIT_FAILURE, "Invalid port `%s'", optarg);
518 }
519 if (li < 1 || li > 65535) {
520 errx(EXIT_FAILURE, "Port out of range `%s'", optarg);
521 }
522 port = (uint16_t)li;
523 break;
524 case 'o':
525 dev_offset = strtoll (optarg, &end, 0);
526 if (*end) {
527 errx(EXIT_FAILURE, "Invalid offset `%s'", optarg);
528 }
529 if (dev_offset < 0) {
530 errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg);
531 }
532 break;
533 case 'l':
534 if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
535 sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0);
536 if (!sn_opts) {
537 errx(EXIT_FAILURE, "Failed in parsing snapshot param `%s'",
538 optarg);
539 }
540 } else {
541 sn_id_or_name = optarg;
542 }
543 /* fall through */
544 case 'r':
545 nbdflags |= NBD_FLAG_READ_ONLY;
546 flags &= ~BDRV_O_RDWR;
547 break;
548 case 'P':
549 partition = strtol(optarg, &end, 0);
550 if (*end) {
551 errx(EXIT_FAILURE, "Invalid partition `%s'", optarg);
552 }
553 if (partition < 1 || partition > 8) {
554 errx(EXIT_FAILURE, "Invalid partition %d", partition);
555 }
556 break;
557 case 'k':
558 sockpath = optarg;
559 if (sockpath[0] != '/') {
560 errx(EXIT_FAILURE, "socket path must be absolute\n");
561 }
562 break;
563 case 'd':
564 disconnect = true;
565 break;
566 case 'c':
567 device = optarg;
568 break;
569 case 'e':
570 shared = strtol(optarg, &end, 0);
571 if (*end) {
572 errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg);
573 }
574 if (shared < 1) {
575 errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
576 }
577 break;
578 case 'f':
579 fmt = optarg;
580 break;
581 case 't':
582 persistent = 1;
583 break;
584 case 'v':
585 verbose = 1;
586 break;
587 case 'V':
588 version(argv[0]);
589 exit(0);
590 break;
591 case 'h':
592 usage(argv[0]);
593 exit(0);
594 break;
595 case '?':
596 errx(EXIT_FAILURE, "Try `%s --help' for more information.",
597 argv[0]);
598 }
599 }
600
601 if ((argc - optind) != 1) {
602 errx(EXIT_FAILURE, "Invalid number of argument.\n"
603 "Try `%s --help' for more information.",
604 argv[0]);
605 }
606
607 if (disconnect) {
608 fd = open(argv[optind], O_RDWR);
609 if (fd < 0) {
610 err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
611 }
612 nbd_disconnect(fd);
613
614 close(fd);
615
616 printf("%s disconnected\n", argv[optind]);
617
618 return 0;
619 }
620
621 if (device && !verbose) {
622 int stderr_fd[2];
623 pid_t pid;
624 int ret;
625
626 if (qemu_pipe(stderr_fd) < 0) {
627 err(EXIT_FAILURE, "Error setting up communication pipe");
628 }
629
630 /* Now daemonize, but keep a communication channel open to
631 * print errors and exit with the proper status code.
632 */
633 pid = fork();
634 if (pid == 0) {
635 close(stderr_fd[0]);
636 ret = qemu_daemon(1, 0);
637
638 /* Temporarily redirect stderr to the parent's pipe... */
639 dup2(stderr_fd[1], STDERR_FILENO);
640 if (ret < 0) {
641 err(EXIT_FAILURE, "Failed to daemonize");
642 }
643
644 /* ... close the descriptor we inherited and go on. */
645 close(stderr_fd[1]);
646 } else {
647 bool errors = false;
648 char *buf;
649
650 /* In the parent. Print error messages from the child until
651 * it closes the pipe.
652 */
653 close(stderr_fd[1]);
654 buf = g_malloc(1024);
655 while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {
656 errors = true;
657 ret = qemu_write_full(STDERR_FILENO, buf, ret);
658 if (ret < 0) {
659 exit(EXIT_FAILURE);
660 }
661 }
662 if (ret < 0) {
663 err(EXIT_FAILURE, "Cannot read from daemon");
664 }
665
666 /* Usually the daemon should not print any message.
667 * Exit with zero status in that case.
668 */
669 exit(errors);
670 }
671 }
672
673 if (device != NULL && sockpath == NULL) {
674 sockpath = g_malloc(128);
675 snprintf(sockpath, 128, SOCKET_PATH, basename(device));
676 }
677
678 if (qemu_init_main_loop(&local_err)) {
679 error_report("%s", error_get_pretty(local_err));
680 error_free(local_err);
681 exit(EXIT_FAILURE);
682 }
683 bdrv_init();
684 atexit(bdrv_close_all);
685
686 if (fmt) {
687 drv = bdrv_find_format(fmt);
688 if (!drv) {
689 errx(EXIT_FAILURE, "Unknown file format '%s'", fmt);
690 }
691 } else {
692 drv = NULL;
693 }
694
695 blk = blk_new_with_bs("hda", &error_abort);
696 bs = blk_bs(blk);
697
698 srcpath = argv[optind];
699 ret = bdrv_open(&bs, srcpath, NULL, NULL, flags, drv, &local_err);
700 if (ret < 0) {
701 errno = -ret;
702 err(EXIT_FAILURE, "Failed to bdrv_open '%s': %s", argv[optind],
703 error_get_pretty(local_err));
704 }
705
706 if (sn_opts) {
707 ret = bdrv_snapshot_load_tmp(bs,
708 qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
709 qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
710 &local_err);
711 } else if (sn_id_or_name) {
712 ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,
713 &local_err);
714 }
715 if (ret < 0) {
716 errno = -ret;
717 err(EXIT_FAILURE,
718 "Failed to load snapshot: %s",
719 error_get_pretty(local_err));
720 }
721
722 bs->detect_zeroes = detect_zeroes;
723 fd_size = bdrv_getlength(bs);
724
725 if (partition != -1) {
726 ret = find_partition(bs, partition, &dev_offset, &fd_size);
727 if (ret < 0) {
728 errno = -ret;
729 err(EXIT_FAILURE, "Could not find partition %d", partition);
730 }
731 }
732
733 exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed);
734
735 if (sockpath) {
736 fd = unix_socket_incoming(sockpath);
737 } else {
738 fd = tcp_socket_incoming(bindto, port);
739 }
740
741 if (fd < 0) {
742 return 1;
743 }
744
745 if (device) {
746 int ret;
747
748 ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
749 if (ret != 0) {
750 errx(EXIT_FAILURE, "Failed to create client thread: %s",
751 strerror(ret));
752 }
753 } else {
754 /* Shut up GCC warnings. */
755 memset(&client_thread, 0, sizeof(client_thread));
756 }
757
758 qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
759 (void *)(uintptr_t)fd);
760
761 /* now when the initialization is (almost) complete, chdir("/")
762 * to free any busy filesystems */
763 if (chdir("/") < 0) {
764 err(EXIT_FAILURE, "Could not chdir to root directory");
765 }
766
767 state = RUNNING;
768 do {
769 main_loop_wait(false);
770 if (state == TERMINATE) {
771 state = TERMINATING;
772 nbd_export_close(exp);
773 nbd_export_put(exp);
774 exp = NULL;
775 }
776 } while (state != TERMINATED);
777
778 blk_unref(blk);
779 if (sockpath) {
780 unlink(sockpath);
781 }
782
783 qemu_opts_del(sn_opts);
784
785 if (device) {
786 void *ret;
787 pthread_join(client_thread, &ret);
788 exit(ret != NULL);
789 } else {
790 exit(EXIT_SUCCESS);
791 }
792 }