root / qemu-nbd.c @ 57f45b62
History | View | Annotate | Download (20.7 kB)
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 "block/block.h" |
21 |
#include "block/nbd.h" |
22 |
#include "qemu/main-loop.h" |
23 |
#include "qemu/sockets.h" |
24 |
#include "qemu/error-report.h" |
25 |
#include "block/snapshot.h" |
26 |
|
27 |
#include <stdarg.h> |
28 |
#include <stdio.h> |
29 |
#include <getopt.h> |
30 |
#include <err.h> |
31 |
#include <sys/types.h> |
32 |
#include <sys/socket.h> |
33 |
#include <netinet/in.h> |
34 |
#include <netinet/tcp.h> |
35 |
#include <arpa/inet.h> |
36 |
#include <signal.h> |
37 |
#include <libgen.h> |
38 |
#include <pthread.h> |
39 |
|
40 |
#define SOCKET_PATH "/var/lock/qemu-nbd-%s" |
41 |
#define QEMU_NBD_OPT_CACHE 1 |
42 |
#define QEMU_NBD_OPT_AIO 2 |
43 |
#define QEMU_NBD_OPT_DISCARD 3 |
44 |
|
45 |
static NBDExport *exp;
|
46 |
static int verbose; |
47 |
static char *srcpath; |
48 |
static char *sockpath; |
49 |
static int persistent = 0; |
50 |
static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state; |
51 |
static int shared = 1; |
52 |
static int nb_fds; |
53 |
|
54 |
static void usage(const char *name) |
55 |
{ |
56 |
(printf) ( |
57 |
"Usage: %s [OPTIONS] FILE\n"
|
58 |
"QEMU Disk Network Block Device Server\n"
|
59 |
"\n"
|
60 |
" -h, --help display this help and exit\n"
|
61 |
" -V, --version output version information and exit\n"
|
62 |
"\n"
|
63 |
"Connection properties:\n"
|
64 |
" -p, --port=PORT port to listen on (default `%d')\n"
|
65 |
" -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
|
66 |
" -k, --socket=PATH path to the unix socket\n"
|
67 |
" (default '"SOCKET_PATH"')\n" |
68 |
" -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
|
69 |
" -t, --persistent don't exit on the last connection\n"
|
70 |
" -v, --verbose display extra debugging information\n"
|
71 |
"\n"
|
72 |
"Exposing part of the image:\n"
|
73 |
" -o, --offset=OFFSET offset into the image\n"
|
74 |
" -P, --partition=NUM only expose partition NUM\n"
|
75 |
"\n"
|
76 |
#ifdef __linux__
|
77 |
"Kernel NBD client support:\n"
|
78 |
" -c, --connect=DEV connect FILE to the local NBD device DEV\n"
|
79 |
" -d, --disconnect disconnect the specified device\n"
|
80 |
"\n"
|
81 |
#endif
|
82 |
"\n"
|
83 |
"Block device options:\n"
|
84 |
" -f, --format=FORMAT set image format (raw, qcow2, ...)\n"
|
85 |
" -r, --read-only export read-only\n"
|
86 |
" -s, --snapshot use FILE as an external snapshot, create a temporary\n"
|
87 |
" file with backing_file=FILE, redirect the write to\n"
|
88 |
" the temporary one\n"
|
89 |
" -l, --load-snapshot=SNAPSHOT_PARAM\n"
|
90 |
" load an internal snapshot inside FILE and export it\n"
|
91 |
" as an read-only device, SNAPSHOT_PARAM format is\n"
|
92 |
" 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
|
93 |
" '[ID_OR_NAME]'\n"
|
94 |
" -n, --nocache disable host cache\n"
|
95 |
" --cache=MODE set cache mode (none, writeback, ...)\n"
|
96 |
#ifdef CONFIG_LINUX_AIO
|
97 |
" --aio=MODE set AIO mode (native or threads)\n"
|
98 |
#endif
|
99 |
"\n"
|
100 |
"Report bugs to <qemu-devel@nongnu.org>\n"
|
101 |
, name, NBD_DEFAULT_PORT, "DEVICE");
|
102 |
} |
103 |
|
104 |
static void version(const char *name) |
105 |
{ |
106 |
printf( |
107 |
"%s version 0.0.1\n"
|
108 |
"Written by Anthony Liguori.\n"
|
109 |
"\n"
|
110 |
"Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.\n"
|
111 |
"This is free software; see the source for copying conditions. There is NO\n"
|
112 |
"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
|
113 |
, name); |
114 |
} |
115 |
|
116 |
struct partition_record
|
117 |
{ |
118 |
uint8_t bootable; |
119 |
uint8_t start_head; |
120 |
uint32_t start_cylinder; |
121 |
uint8_t start_sector; |
122 |
uint8_t system; |
123 |
uint8_t end_head; |
124 |
uint8_t end_cylinder; |
125 |
uint8_t end_sector; |
126 |
uint32_t start_sector_abs; |
127 |
uint32_t nb_sectors_abs; |
128 |
}; |
129 |
|
130 |
static void read_partition(uint8_t *p, struct partition_record *r) |
131 |
{ |
132 |
r->bootable = p[0];
|
133 |
r->start_head = p[1];
|
134 |
r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); |
135 |
r->start_sector = p[2] & 0x3f; |
136 |
r->system = p[4];
|
137 |
r->end_head = p[5];
|
138 |
r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); |
139 |
r->end_sector = p[6] & 0x3f; |
140 |
r->start_sector_abs = p[8] | p[9] << 8 | p[10] << 16 | p[11] << 24; |
141 |
r->nb_sectors_abs = p[12] | p[13] << 8 | p[14] << 16 | p[15] << 24; |
142 |
} |
143 |
|
144 |
static int find_partition(BlockDriverState *bs, int partition, |
145 |
off_t *offset, off_t *size) |
146 |
{ |
147 |
struct partition_record mbr[4]; |
148 |
uint8_t data[512];
|
149 |
int i;
|
150 |
int ext_partnum = 4; |
151 |
int ret;
|
152 |
|
153 |
if ((ret = bdrv_read(bs, 0, data, 1)) < 0) { |
154 |
errno = -ret; |
155 |
err(EXIT_FAILURE, "error while reading");
|
156 |
} |
157 |
|
158 |
if (data[510] != 0x55 || data[511] != 0xaa) { |
159 |
return -EINVAL;
|
160 |
} |
161 |
|
162 |
for (i = 0; i < 4; i++) { |
163 |
read_partition(&data[446 + 16 * i], &mbr[i]); |
164 |
|
165 |
if (!mbr[i].nb_sectors_abs)
|
166 |
continue;
|
167 |
|
168 |
if (mbr[i].system == 0xF || mbr[i].system == 0x5) { |
169 |
struct partition_record ext[4]; |
170 |
uint8_t data1[512];
|
171 |
int j;
|
172 |
|
173 |
if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) { |
174 |
errno = -ret; |
175 |
err(EXIT_FAILURE, "error while reading");
|
176 |
} |
177 |
|
178 |
for (j = 0; j < 4; j++) { |
179 |
read_partition(&data1[446 + 16 * j], &ext[j]); |
180 |
if (!ext[j].nb_sectors_abs)
|
181 |
continue;
|
182 |
|
183 |
if ((ext_partnum + j + 1) == partition) { |
184 |
*offset = (uint64_t)ext[j].start_sector_abs << 9;
|
185 |
*size = (uint64_t)ext[j].nb_sectors_abs << 9;
|
186 |
return 0; |
187 |
} |
188 |
} |
189 |
ext_partnum += 4;
|
190 |
} else if ((i + 1) == partition) { |
191 |
*offset = (uint64_t)mbr[i].start_sector_abs << 9;
|
192 |
*size = (uint64_t)mbr[i].nb_sectors_abs << 9;
|
193 |
return 0; |
194 |
} |
195 |
} |
196 |
|
197 |
return -ENOENT;
|
198 |
} |
199 |
|
200 |
static void termsig_handler(int signum) |
201 |
{ |
202 |
state = TERMINATE; |
203 |
qemu_notify_event(); |
204 |
} |
205 |
|
206 |
static void combine_addr(char *buf, size_t len, const char* address, |
207 |
uint16_t port) |
208 |
{ |
209 |
/* If the address-part contains a colon, it's an IPv6 IP so needs [] */
|
210 |
if (strstr(address, ":")) { |
211 |
snprintf(buf, len, "[%s]:%u", address, port);
|
212 |
} else {
|
213 |
snprintf(buf, len, "%s:%u", address, port);
|
214 |
} |
215 |
} |
216 |
|
217 |
static int tcp_socket_incoming(const char *address, uint16_t port) |
218 |
{ |
219 |
char address_and_port[128]; |
220 |
Error *local_err = NULL;
|
221 |
|
222 |
combine_addr(address_and_port, 128, address, port);
|
223 |
int fd = inet_listen(address_and_port, NULL, 0, SOCK_STREAM, 0, &local_err); |
224 |
|
225 |
if (local_err != NULL) { |
226 |
qerror_report_err(local_err); |
227 |
error_free(local_err); |
228 |
} |
229 |
return fd;
|
230 |
} |
231 |
|
232 |
static int unix_socket_incoming(const char *path) |
233 |
{ |
234 |
Error *local_err = NULL;
|
235 |
int fd = unix_listen(path, NULL, 0, &local_err); |
236 |
|
237 |
if (local_err != NULL) { |
238 |
qerror_report_err(local_err); |
239 |
error_free(local_err); |
240 |
} |
241 |
return fd;
|
242 |
} |
243 |
|
244 |
static int unix_socket_outgoing(const char *path) |
245 |
{ |
246 |
Error *local_err = NULL;
|
247 |
int fd = unix_connect(path, &local_err);
|
248 |
|
249 |
if (local_err != NULL) { |
250 |
qerror_report_err(local_err); |
251 |
error_free(local_err); |
252 |
} |
253 |
return fd;
|
254 |
} |
255 |
|
256 |
static void *show_parts(void *arg) |
257 |
{ |
258 |
char *device = arg;
|
259 |
int nbd;
|
260 |
|
261 |
/* linux just needs an open() to trigger
|
262 |
* the partition table update
|
263 |
* but remember to load the module with max_part != 0 :
|
264 |
* modprobe nbd max_part=63
|
265 |
*/
|
266 |
nbd = open(device, O_RDWR); |
267 |
if (nbd >= 0) { |
268 |
close(nbd); |
269 |
} |
270 |
return NULL; |
271 |
} |
272 |
|
273 |
static void *nbd_client_thread(void *arg) |
274 |
{ |
275 |
char *device = arg;
|
276 |
off_t size; |
277 |
size_t blocksize; |
278 |
uint32_t nbdflags; |
279 |
int fd, sock;
|
280 |
int ret;
|
281 |
pthread_t show_parts_thread; |
282 |
|
283 |
sock = unix_socket_outgoing(sockpath); |
284 |
if (sock < 0) { |
285 |
goto out;
|
286 |
} |
287 |
|
288 |
ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
|
289 |
&size, &blocksize); |
290 |
if (ret < 0) { |
291 |
goto out;
|
292 |
} |
293 |
|
294 |
fd = open(device, O_RDWR); |
295 |
if (fd < 0) { |
296 |
/* Linux-only, we can use %m in printf. */
|
297 |
fprintf(stderr, "Failed to open %s: %m", device);
|
298 |
goto out;
|
299 |
} |
300 |
|
301 |
ret = nbd_init(fd, sock, nbdflags, size, blocksize); |
302 |
if (ret < 0) { |
303 |
goto out;
|
304 |
} |
305 |
|
306 |
/* update partition table */
|
307 |
pthread_create(&show_parts_thread, NULL, show_parts, device);
|
308 |
|
309 |
if (verbose) {
|
310 |
fprintf(stderr, "NBD device %s is now connected to %s\n",
|
311 |
device, srcpath); |
312 |
} else {
|
313 |
/* Close stderr so that the qemu-nbd process exits. */
|
314 |
dup2(STDOUT_FILENO, STDERR_FILENO); |
315 |
} |
316 |
|
317 |
ret = nbd_client(fd); |
318 |
if (ret) {
|
319 |
goto out;
|
320 |
} |
321 |
close(fd); |
322 |
kill(getpid(), SIGTERM); |
323 |
return (void *) EXIT_SUCCESS; |
324 |
|
325 |
out:
|
326 |
kill(getpid(), SIGTERM); |
327 |
return (void *) EXIT_FAILURE; |
328 |
} |
329 |
|
330 |
static int nbd_can_accept(void *opaque) |
331 |
{ |
332 |
return nb_fds < shared;
|
333 |
} |
334 |
|
335 |
static void nbd_export_closed(NBDExport *exp) |
336 |
{ |
337 |
assert(state == TERMINATING); |
338 |
state = TERMINATED; |
339 |
} |
340 |
|
341 |
static void nbd_client_closed(NBDClient *client) |
342 |
{ |
343 |
nb_fds--; |
344 |
if (nb_fds == 0 && !persistent && state == RUNNING) { |
345 |
state = TERMINATE; |
346 |
} |
347 |
qemu_notify_event(); |
348 |
nbd_client_put(client); |
349 |
} |
350 |
|
351 |
static void nbd_accept(void *opaque) |
352 |
{ |
353 |
int server_fd = (uintptr_t) opaque;
|
354 |
struct sockaddr_in addr;
|
355 |
socklen_t addr_len = sizeof(addr);
|
356 |
|
357 |
int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len); |
358 |
if (state >= TERMINATE) {
|
359 |
close(fd); |
360 |
return;
|
361 |
} |
362 |
|
363 |
if (fd >= 0 && nbd_client_new(exp, fd, nbd_client_closed)) { |
364 |
nb_fds++; |
365 |
} |
366 |
} |
367 |
|
368 |
int main(int argc, char **argv) |
369 |
{ |
370 |
BlockDriverState *bs; |
371 |
BlockDriver *drv; |
372 |
off_t dev_offset = 0;
|
373 |
uint32_t nbdflags = 0;
|
374 |
bool disconnect = false; |
375 |
const char *bindto = "0.0.0.0"; |
376 |
char *device = NULL; |
377 |
int port = NBD_DEFAULT_PORT;
|
378 |
off_t fd_size; |
379 |
QemuOpts *sn_opts = NULL;
|
380 |
const char *sn_id_or_name = NULL; |
381 |
const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:"; |
382 |
struct option lopt[] = {
|
383 |
{ "help", 0, NULL, 'h' }, |
384 |
{ "version", 0, NULL, 'V' }, |
385 |
{ "bind", 1, NULL, 'b' }, |
386 |
{ "port", 1, NULL, 'p' }, |
387 |
{ "socket", 1, NULL, 'k' }, |
388 |
{ "offset", 1, NULL, 'o' }, |
389 |
{ "read-only", 0, NULL, 'r' }, |
390 |
{ "partition", 1, NULL, 'P' }, |
391 |
{ "connect", 1, NULL, 'c' }, |
392 |
{ "disconnect", 0, NULL, 'd' }, |
393 |
{ "snapshot", 0, NULL, 's' }, |
394 |
{ "load-snapshot", 1, NULL, 'l' }, |
395 |
{ "nocache", 0, NULL, 'n' }, |
396 |
{ "cache", 1, NULL, QEMU_NBD_OPT_CACHE }, |
397 |
#ifdef CONFIG_LINUX_AIO
|
398 |
{ "aio", 1, NULL, QEMU_NBD_OPT_AIO }, |
399 |
#endif
|
400 |
{ "discard", 1, NULL, QEMU_NBD_OPT_DISCARD }, |
401 |
{ "shared", 1, NULL, 'e' }, |
402 |
{ "format", 1, NULL, 'f' }, |
403 |
{ "persistent", 0, NULL, 't' }, |
404 |
{ "verbose", 0, NULL, 'v' }, |
405 |
{ NULL, 0, NULL, 0 } |
406 |
}; |
407 |
int ch;
|
408 |
int opt_ind = 0; |
409 |
int li;
|
410 |
char *end;
|
411 |
int flags = BDRV_O_RDWR;
|
412 |
int partition = -1; |
413 |
int ret;
|
414 |
int fd;
|
415 |
bool seen_cache = false; |
416 |
bool seen_discard = false; |
417 |
#ifdef CONFIG_LINUX_AIO
|
418 |
bool seen_aio = false; |
419 |
#endif
|
420 |
pthread_t client_thread; |
421 |
const char *fmt = NULL; |
422 |
Error *local_err = NULL;
|
423 |
|
424 |
/* The client thread uses SIGTERM to interrupt the server. A signal
|
425 |
* handler ensures that "qemu-nbd -v -c" exits with a nice status code.
|
426 |
*/
|
427 |
struct sigaction sa_sigterm;
|
428 |
memset(&sa_sigterm, 0, sizeof(sa_sigterm)); |
429 |
sa_sigterm.sa_handler = termsig_handler; |
430 |
sigaction(SIGTERM, &sa_sigterm, NULL);
|
431 |
qemu_init_exec_dir(argv[0]);
|
432 |
|
433 |
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { |
434 |
switch (ch) {
|
435 |
case 's': |
436 |
flags |= BDRV_O_SNAPSHOT; |
437 |
break;
|
438 |
case 'n': |
439 |
optarg = (char *) "none"; |
440 |
/* fallthrough */
|
441 |
case QEMU_NBD_OPT_CACHE:
|
442 |
if (seen_cache) {
|
443 |
errx(EXIT_FAILURE, "-n and --cache can only be specified once");
|
444 |
} |
445 |
seen_cache = true;
|
446 |
if (bdrv_parse_cache_flags(optarg, &flags) == -1) { |
447 |
errx(EXIT_FAILURE, "Invalid cache mode `%s'", optarg);
|
448 |
} |
449 |
break;
|
450 |
#ifdef CONFIG_LINUX_AIO
|
451 |
case QEMU_NBD_OPT_AIO:
|
452 |
if (seen_aio) {
|
453 |
errx(EXIT_FAILURE, "--aio can only be specified once");
|
454 |
} |
455 |
seen_aio = true;
|
456 |
if (!strcmp(optarg, "native")) { |
457 |
flags |= BDRV_O_NATIVE_AIO; |
458 |
} else if (!strcmp(optarg, "threads")) { |
459 |
/* this is the default */
|
460 |
} else {
|
461 |
errx(EXIT_FAILURE, "invalid aio mode `%s'", optarg);
|
462 |
} |
463 |
break;
|
464 |
#endif
|
465 |
case QEMU_NBD_OPT_DISCARD:
|
466 |
if (seen_discard) {
|
467 |
errx(EXIT_FAILURE, "--discard can only be specified once");
|
468 |
} |
469 |
seen_discard = true;
|
470 |
if (bdrv_parse_discard_flags(optarg, &flags) == -1) { |
471 |
errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg);
|
472 |
} |
473 |
break;
|
474 |
case 'b': |
475 |
bindto = optarg; |
476 |
break;
|
477 |
case 'p': |
478 |
li = strtol(optarg, &end, 0);
|
479 |
if (*end) {
|
480 |
errx(EXIT_FAILURE, "Invalid port `%s'", optarg);
|
481 |
} |
482 |
if (li < 1 || li > 65535) { |
483 |
errx(EXIT_FAILURE, "Port out of range `%s'", optarg);
|
484 |
} |
485 |
port = (uint16_t)li; |
486 |
break;
|
487 |
case 'o': |
488 |
dev_offset = strtoll (optarg, &end, 0);
|
489 |
if (*end) {
|
490 |
errx(EXIT_FAILURE, "Invalid offset `%s'", optarg);
|
491 |
} |
492 |
if (dev_offset < 0) { |
493 |
errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg);
|
494 |
} |
495 |
break;
|
496 |
case 'l': |
497 |
if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { |
498 |
sn_opts = qemu_opts_parse(&internal_snapshot_opts, optarg, 0);
|
499 |
if (!sn_opts) {
|
500 |
errx(EXIT_FAILURE, "Failed in parsing snapshot param `%s'",
|
501 |
optarg); |
502 |
} |
503 |
} else {
|
504 |
sn_id_or_name = optarg; |
505 |
} |
506 |
/* fall through */
|
507 |
case 'r': |
508 |
nbdflags |= NBD_FLAG_READ_ONLY; |
509 |
flags &= ~BDRV_O_RDWR; |
510 |
break;
|
511 |
case 'P': |
512 |
partition = strtol(optarg, &end, 0);
|
513 |
if (*end)
|
514 |
errx(EXIT_FAILURE, "Invalid partition `%s'", optarg);
|
515 |
if (partition < 1 || partition > 8) |
516 |
errx(EXIT_FAILURE, "Invalid partition %d", partition);
|
517 |
break;
|
518 |
case 'k': |
519 |
sockpath = optarg; |
520 |
if (sockpath[0] != '/') |
521 |
errx(EXIT_FAILURE, "socket path must be absolute\n");
|
522 |
break;
|
523 |
case 'd': |
524 |
disconnect = true;
|
525 |
break;
|
526 |
case 'c': |
527 |
device = optarg; |
528 |
break;
|
529 |
case 'e': |
530 |
shared = strtol(optarg, &end, 0);
|
531 |
if (*end) {
|
532 |
errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg);
|
533 |
} |
534 |
if (shared < 1) { |
535 |
errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
|
536 |
} |
537 |
break;
|
538 |
case 'f': |
539 |
fmt = optarg; |
540 |
break;
|
541 |
case 't': |
542 |
persistent = 1;
|
543 |
break;
|
544 |
case 'v': |
545 |
verbose = 1;
|
546 |
break;
|
547 |
case 'V': |
548 |
version(argv[0]);
|
549 |
exit(0);
|
550 |
break;
|
551 |
case 'h': |
552 |
usage(argv[0]);
|
553 |
exit(0);
|
554 |
break;
|
555 |
case '?': |
556 |
errx(EXIT_FAILURE, "Try `%s --help' for more information.",
|
557 |
argv[0]);
|
558 |
} |
559 |
} |
560 |
|
561 |
if ((argc - optind) != 1) { |
562 |
errx(EXIT_FAILURE, "Invalid number of argument.\n"
|
563 |
"Try `%s --help' for more information.",
|
564 |
argv[0]);
|
565 |
} |
566 |
|
567 |
if (disconnect) {
|
568 |
fd = open(argv[optind], O_RDWR); |
569 |
if (fd < 0) { |
570 |
err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
|
571 |
} |
572 |
nbd_disconnect(fd); |
573 |
|
574 |
close(fd); |
575 |
|
576 |
printf("%s disconnected\n", argv[optind]);
|
577 |
|
578 |
return 0; |
579 |
} |
580 |
|
581 |
if (device && !verbose) {
|
582 |
int stderr_fd[2]; |
583 |
pid_t pid; |
584 |
int ret;
|
585 |
|
586 |
if (qemu_pipe(stderr_fd) < 0) { |
587 |
err(EXIT_FAILURE, "Error setting up communication pipe");
|
588 |
} |
589 |
|
590 |
/* Now daemonize, but keep a communication channel open to
|
591 |
* print errors and exit with the proper status code.
|
592 |
*/
|
593 |
pid = fork(); |
594 |
if (pid == 0) { |
595 |
close(stderr_fd[0]);
|
596 |
ret = qemu_daemon(1, 0); |
597 |
|
598 |
/* Temporarily redirect stderr to the parent's pipe... */
|
599 |
dup2(stderr_fd[1], STDERR_FILENO);
|
600 |
if (ret < 0) { |
601 |
err(EXIT_FAILURE, "Failed to daemonize");
|
602 |
} |
603 |
|
604 |
/* ... close the descriptor we inherited and go on. */
|
605 |
close(stderr_fd[1]);
|
606 |
} else {
|
607 |
bool errors = false; |
608 |
char *buf;
|
609 |
|
610 |
/* In the parent. Print error messages from the child until
|
611 |
* it closes the pipe.
|
612 |
*/
|
613 |
close(stderr_fd[1]);
|
614 |
buf = g_malloc(1024);
|
615 |
while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { |
616 |
errors = true;
|
617 |
ret = qemu_write_full(STDERR_FILENO, buf, ret); |
618 |
if (ret < 0) { |
619 |
exit(EXIT_FAILURE); |
620 |
} |
621 |
} |
622 |
if (ret < 0) { |
623 |
err(EXIT_FAILURE, "Cannot read from daemon");
|
624 |
} |
625 |
|
626 |
/* Usually the daemon should not print any message.
|
627 |
* Exit with zero status in that case.
|
628 |
*/
|
629 |
exit(errors); |
630 |
} |
631 |
} |
632 |
|
633 |
if (device != NULL && sockpath == NULL) { |
634 |
sockpath = g_malloc(128);
|
635 |
snprintf(sockpath, 128, SOCKET_PATH, basename(device));
|
636 |
} |
637 |
|
638 |
qemu_init_main_loop(); |
639 |
bdrv_init(); |
640 |
atexit(bdrv_close_all); |
641 |
|
642 |
if (fmt) {
|
643 |
drv = bdrv_find_format(fmt); |
644 |
if (!drv) {
|
645 |
errx(EXIT_FAILURE, "Unknown file format '%s'", fmt);
|
646 |
} |
647 |
} else {
|
648 |
drv = NULL;
|
649 |
} |
650 |
|
651 |
bs = bdrv_new("hda");
|
652 |
srcpath = argv[optind]; |
653 |
ret = bdrv_open(&bs, srcpath, NULL, NULL, flags, drv, &local_err); |
654 |
if (ret < 0) { |
655 |
errno = -ret; |
656 |
err(EXIT_FAILURE, "Failed to bdrv_open '%s': %s", argv[optind],
|
657 |
error_get_pretty(local_err)); |
658 |
} |
659 |
|
660 |
if (sn_opts) {
|
661 |
ret = bdrv_snapshot_load_tmp(bs, |
662 |
qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), |
663 |
qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), |
664 |
&local_err); |
665 |
} else if (sn_id_or_name) { |
666 |
ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name, |
667 |
&local_err); |
668 |
} |
669 |
if (ret < 0) { |
670 |
errno = -ret; |
671 |
err(EXIT_FAILURE, |
672 |
"Failed to load snapshot: %s",
|
673 |
error_get_pretty(local_err)); |
674 |
} |
675 |
|
676 |
fd_size = bdrv_getlength(bs); |
677 |
|
678 |
if (partition != -1) { |
679 |
ret = find_partition(bs, partition, &dev_offset, &fd_size); |
680 |
if (ret < 0) { |
681 |
errno = -ret; |
682 |
err(EXIT_FAILURE, "Could not find partition %d", partition);
|
683 |
} |
684 |
} |
685 |
|
686 |
exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed); |
687 |
|
688 |
if (sockpath) {
|
689 |
fd = unix_socket_incoming(sockpath); |
690 |
} else {
|
691 |
fd = tcp_socket_incoming(bindto, port); |
692 |
} |
693 |
|
694 |
if (fd < 0) { |
695 |
return 1; |
696 |
} |
697 |
|
698 |
if (device) {
|
699 |
int ret;
|
700 |
|
701 |
ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
|
702 |
if (ret != 0) { |
703 |
errx(EXIT_FAILURE, "Failed to create client thread: %s",
|
704 |
strerror(ret)); |
705 |
} |
706 |
} else {
|
707 |
/* Shut up GCC warnings. */
|
708 |
memset(&client_thread, 0, sizeof(client_thread)); |
709 |
} |
710 |
|
711 |
qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
|
712 |
(void *)(uintptr_t)fd);
|
713 |
|
714 |
/* now when the initialization is (almost) complete, chdir("/")
|
715 |
* to free any busy filesystems */
|
716 |
if (chdir("/") < 0) { |
717 |
err(EXIT_FAILURE, "Could not chdir to root directory");
|
718 |
} |
719 |
|
720 |
state = RUNNING; |
721 |
do {
|
722 |
main_loop_wait(false);
|
723 |
if (state == TERMINATE) {
|
724 |
state = TERMINATING; |
725 |
nbd_export_close(exp); |
726 |
nbd_export_put(exp); |
727 |
exp = NULL;
|
728 |
} |
729 |
} while (state != TERMINATED);
|
730 |
|
731 |
bdrv_close(bs); |
732 |
if (sockpath) {
|
733 |
unlink(sockpath); |
734 |
} |
735 |
|
736 |
if (sn_opts) {
|
737 |
qemu_opts_del(sn_opts); |
738 |
} |
739 |
|
740 |
if (device) {
|
741 |
void *ret;
|
742 |
pthread_join(client_thread, &ret); |
743 |
exit(ret != NULL);
|
744 |
} else {
|
745 |
exit(EXIT_SUCCESS); |
746 |
} |
747 |
} |