2 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
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.
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.
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/>.
19 #include "qemu/osdep.h"
24 #include "qapi/error.h"
25 #include "qemu/cutils.h"
26 #include "sysemu/block-backend.h"
27 #include "block/block_int.h"
28 #include "block/nbd.h"
29 #include "qemu/main-loop.h"
30 #include "qemu/option.h"
31 #include "qemu/error-report.h"
32 #include "qemu/config-file.h"
33 #include "qemu/bswap.h"
35 #include "qemu/systemd.h"
36 #include "block/snapshot.h"
37 #include "qapi/qmp/qdict.h"
38 #include "qapi/qmp/qstring.h"
39 #include "qom/object_interfaces.h"
40 #include "io/channel-socket.h"
41 #include "io/net-listener.h"
42 #include "crypto/init.h"
43 #include "trace/control.h"
44 #include "qemu-version.h"
46 #define SOCKET_PATH "/var/lock/qemu-nbd-%s"
47 #define QEMU_NBD_OPT_CACHE 256
48 #define QEMU_NBD_OPT_AIO 257
49 #define QEMU_NBD_OPT_DISCARD 258
50 #define QEMU_NBD_OPT_DETECT_ZEROES 259
51 #define QEMU_NBD_OPT_OBJECT 260
52 #define QEMU_NBD_OPT_TLSCREDS 261
53 #define QEMU_NBD_OPT_IMAGE_OPTS 262
54 #define QEMU_NBD_OPT_FORK 263
58 static NBDExport
*exp
;
62 static SocketAddress
*saddr
;
63 static int persistent
= 0;
64 static enum { RUNNING
, TERMINATE
, TERMINATING
, TERMINATED
} state
;
65 static int shared
= 1;
67 static QIONetListener
*server
;
68 static QCryptoTLSCreds
*tlscreds
;
70 static void usage(const char *name
)
73 "Usage: %s [OPTIONS] FILE\n"
74 "QEMU Disk Network Block Device Server\n"
76 " -h, --help display this help and exit\n"
77 " -V, --version output version information and exit\n"
79 "Connection properties:\n"
80 " -p, --port=PORT port to listen on (default `%d')\n"
81 " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"
82 " -k, --socket=PATH path to the unix socket\n"
83 " (default '"SOCKET_PATH
"')\n"
84 " -e, --shared=NUM device can be shared by NUM clients (default '1')\n"
85 " -t, --persistent don't exit on the last connection\n"
86 " -v, --verbose display extra debugging information\n"
87 " -x, --export-name=NAME expose export by name\n"
88 " -D, --description=TEXT with -x, also export a human-readable description\n"
90 "Exposing part of the image:\n"
91 " -o, --offset=OFFSET offset into the image\n"
92 " -P, --partition=NUM only expose partition NUM\n"
94 "General purpose options:\n"
95 " --object type,id=ID,... define an object such as 'secret' for providing\n"
96 " passwords and/or encryption keys\n"
97 " -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
98 " specify tracing options\n"
99 " --fork fork off the server process and exit the parent\n"
100 " once the server is running\n"
102 "Kernel NBD client support:\n"
103 " -c, --connect=DEV connect FILE to the local NBD device DEV\n"
104 " -d, --disconnect disconnect the specified device\n"
108 "Block device options:\n"
109 " -f, --format=FORMAT set image format (raw, qcow2, ...)\n"
110 " -r, --read-only export read-only\n"
111 " -s, --snapshot use FILE as an external snapshot, create a temporary\n"
112 " file with backing_file=FILE, redirect the write to\n"
113 " the temporary one\n"
114 " -l, --load-snapshot=SNAPSHOT_PARAM\n"
115 " load an internal snapshot inside FILE and export it\n"
116 " as an read-only device, SNAPSHOT_PARAM format is\n"
117 " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"
119 " -n, --nocache disable host cache\n"
120 " --cache=MODE set cache mode (none, writeback, ...)\n"
121 " --aio=MODE set AIO mode (native or threads)\n"
122 " --discard=MODE set discard mode (ignore, unmap)\n"
123 " --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n"
124 " --image-opts treat FILE as a full set of image options\n"
126 QEMU_HELP_BOTTOM
"\n"
127 , name
, NBD_DEFAULT_PORT
, "DEVICE");
130 static void version(const char *name
)
133 "%s " QEMU_FULL_VERSION
"\n"
134 "Written by Anthony Liguori.\n"
137 "This is free software; see the source for copying conditions. There is NO\n"
138 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
142 struct partition_record
146 uint32_t start_cylinder
;
147 uint8_t start_sector
;
150 uint8_t end_cylinder
;
152 uint32_t start_sector_abs
;
153 uint32_t nb_sectors_abs
;
156 static void read_partition(uint8_t *p
, struct partition_record
*r
)
159 r
->start_head
= p
[1];
160 r
->start_cylinder
= p
[3] | ((p
[2] << 2) & 0x0300);
161 r
->start_sector
= p
[2] & 0x3f;
164 r
->end_cylinder
= p
[7] | ((p
[6] << 2) & 0x300);
165 r
->end_sector
= p
[6] & 0x3f;
167 r
->start_sector_abs
= ldl_le_p(p
+ 8);
168 r
->nb_sectors_abs
= ldl_le_p(p
+ 12);
171 static int find_partition(BlockBackend
*blk
, int partition
,
172 off_t
*offset
, off_t
*size
)
174 struct partition_record mbr
[4];
175 uint8_t data
[MBR_SIZE
];
180 ret
= blk_pread(blk
, 0, data
, sizeof(data
));
182 error_report("error while reading: %s", strerror(-ret
));
186 if (data
[510] != 0x55 || data
[511] != 0xaa) {
190 for (i
= 0; i
< 4; i
++) {
191 read_partition(&data
[446 + 16 * i
], &mbr
[i
]);
193 if (!mbr
[i
].system
|| !mbr
[i
].nb_sectors_abs
) {
197 if (mbr
[i
].system
== 0xF || mbr
[i
].system
== 0x5) {
198 struct partition_record ext
[4];
199 uint8_t data1
[MBR_SIZE
];
202 ret
= blk_pread(blk
, mbr
[i
].start_sector_abs
* MBR_SIZE
,
203 data1
, sizeof(data1
));
205 error_report("error while reading: %s", strerror(-ret
));
209 for (j
= 0; j
< 4; j
++) {
210 read_partition(&data1
[446 + 16 * j
], &ext
[j
]);
211 if (!ext
[j
].system
|| !ext
[j
].nb_sectors_abs
) {
215 if ((ext_partnum
+ j
+ 1) == partition
) {
216 *offset
= (uint64_t)ext
[j
].start_sector_abs
<< 9;
217 *size
= (uint64_t)ext
[j
].nb_sectors_abs
<< 9;
222 } else if ((i
+ 1) == partition
) {
223 *offset
= (uint64_t)mbr
[i
].start_sector_abs
<< 9;
224 *size
= (uint64_t)mbr
[i
].nb_sectors_abs
<< 9;
232 static void termsig_handler(int signum
)
234 atomic_cmpxchg(&state
, RUNNING
, TERMINATE
);
239 static void *show_parts(void *arg
)
244 /* linux just needs an open() to trigger
245 * the partition table update
246 * but remember to load the module with max_part != 0 :
247 * modprobe nbd max_part=63
249 nbd
= open(device
, O_RDWR
);
256 static void *nbd_client_thread(void *arg
)
259 NBDExportInfo info
= { .request_sizes
= false, };
260 QIOChannelSocket
*sioc
;
263 pthread_t show_parts_thread
;
264 Error
*local_error
= NULL
;
266 sioc
= qio_channel_socket_new();
267 if (qio_channel_socket_connect_sync(sioc
,
270 error_report_err(local_error
);
274 ret
= nbd_receive_negotiate(QIO_CHANNEL(sioc
), NULL
,
275 NULL
, NULL
, NULL
, &info
, &local_error
);
278 error_report_err(local_error
);
283 fd
= open(device
, O_RDWR
);
285 /* Linux-only, we can use %m in printf. */
286 error_report("Failed to open %s: %m", device
);
290 ret
= nbd_init(fd
, sioc
, &info
, &local_error
);
292 error_report_err(local_error
);
296 /* update partition table */
297 pthread_create(&show_parts_thread
, NULL
, show_parts
, device
);
300 fprintf(stderr
, "NBD device %s is now connected to %s\n",
303 /* Close stderr so that the qemu-nbd process exits. */
304 dup2(STDOUT_FILENO
, STDERR_FILENO
);
307 ret
= nbd_client(fd
);
312 object_unref(OBJECT(sioc
));
313 kill(getpid(), SIGTERM
);
314 return (void *) EXIT_SUCCESS
;
319 object_unref(OBJECT(sioc
));
321 kill(getpid(), SIGTERM
);
322 return (void *) EXIT_FAILURE
;
325 static int nbd_can_accept(void)
327 return state
== RUNNING
&& nb_fds
< shared
;
330 static void nbd_export_closed(NBDExport
*exp
)
332 assert(state
== TERMINATING
);
336 static void nbd_update_server_watch(void);
338 static void nbd_client_closed(NBDClient
*client
, bool negotiated
)
341 if (negotiated
&& nb_fds
== 0 && !persistent
&& state
== RUNNING
) {
344 nbd_update_server_watch();
345 nbd_client_put(client
);
348 static void nbd_accept(QIONetListener
*listener
, QIOChannelSocket
*cioc
,
351 if (state
>= TERMINATE
) {
356 nbd_update_server_watch();
357 nbd_client_new(newproto
? NULL
: exp
, cioc
,
358 tlscreds
, NULL
, nbd_client_closed
);
361 static void nbd_update_server_watch(void)
363 if (nbd_can_accept()) {
364 qio_net_listener_set_client_func(server
, nbd_accept
, NULL
, NULL
);
366 qio_net_listener_set_client_func(server
, NULL
, NULL
, NULL
);
371 static SocketAddress
*nbd_build_socket_address(const char *sockpath
,
375 SocketAddress
*saddr
;
377 saddr
= g_new0(SocketAddress
, 1);
379 saddr
->type
= SOCKET_ADDRESS_TYPE_UNIX
;
380 saddr
->u
.q_unix
.path
= g_strdup(sockpath
);
382 InetSocketAddress
*inet
;
383 saddr
->type
= SOCKET_ADDRESS_TYPE_INET
;
384 inet
= &saddr
->u
.inet
;
385 inet
->host
= g_strdup(bindto
);
387 inet
->port
= g_strdup(port
);
389 inet
->port
= g_strdup_printf("%d", NBD_DEFAULT_PORT
);
397 static QemuOptsList file_opts
= {
399 .implied_opt_name
= "file",
400 .head
= QTAILQ_HEAD_INITIALIZER(file_opts
.head
),
402 /* no elements => accept any params */
403 { /* end of list */ }
407 static QemuOptsList qemu_object_opts
= {
409 .implied_opt_name
= "qom-type",
410 .head
= QTAILQ_HEAD_INITIALIZER(qemu_object_opts
.head
),
418 static QCryptoTLSCreds
*nbd_get_tls_creds(const char *id
, Error
**errp
)
421 QCryptoTLSCreds
*creds
;
423 obj
= object_resolve_path_component(
424 object_get_objects_root(), id
);
426 error_setg(errp
, "No TLS credentials with id '%s'",
430 creds
= (QCryptoTLSCreds
*)
431 object_dynamic_cast(obj
, TYPE_QCRYPTO_TLS_CREDS
);
433 error_setg(errp
, "Object with id '%s' is not TLS credentials",
438 if (creds
->endpoint
!= QCRYPTO_TLS_CREDS_ENDPOINT_SERVER
) {
440 "Expecting TLS credentials with a server endpoint");
447 static void setup_address_and_port(const char **address
, const char **port
)
449 if (*address
== NULL
) {
450 *address
= "0.0.0.0";
454 *port
= stringify(NBD_DEFAULT_PORT
);
459 * Check socket parameters compatibility when socket activation is used.
461 static const char *socket_activation_validate_opts(const char *device
,
462 const char *sockpath
,
466 if (device
!= NULL
) {
467 return "NBD device can't be set when using socket activation";
470 if (sockpath
!= NULL
) {
471 return "Unix socket can't be set when using socket activation";
474 if (address
!= NULL
) {
475 return "The interface can't be set when using socket activation";
479 return "TCP port number can't be set when using socket activation";
485 int main(int argc
, char **argv
)
488 BlockDriverState
*bs
;
489 off_t dev_offset
= 0;
490 uint16_t nbdflags
= 0;
491 bool disconnect
= false;
492 const char *bindto
= NULL
;
493 const char *port
= NULL
;
494 char *sockpath
= NULL
;
497 QemuOpts
*sn_opts
= NULL
;
498 const char *sn_id_or_name
= NULL
;
499 const char *sopt
= "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:";
500 struct option lopt
[] = {
501 { "help", no_argument
, NULL
, 'h' },
502 { "version", no_argument
, NULL
, 'V' },
503 { "bind", required_argument
, NULL
, 'b' },
504 { "port", required_argument
, NULL
, 'p' },
505 { "socket", required_argument
, NULL
, 'k' },
506 { "offset", required_argument
, NULL
, 'o' },
507 { "read-only", no_argument
, NULL
, 'r' },
508 { "partition", required_argument
, NULL
, 'P' },
509 { "connect", required_argument
, NULL
, 'c' },
510 { "disconnect", no_argument
, NULL
, 'd' },
511 { "snapshot", no_argument
, NULL
, 's' },
512 { "load-snapshot", required_argument
, NULL
, 'l' },
513 { "nocache", no_argument
, NULL
, 'n' },
514 { "cache", required_argument
, NULL
, QEMU_NBD_OPT_CACHE
},
515 { "aio", required_argument
, NULL
, QEMU_NBD_OPT_AIO
},
516 { "discard", required_argument
, NULL
, QEMU_NBD_OPT_DISCARD
},
517 { "detect-zeroes", required_argument
, NULL
,
518 QEMU_NBD_OPT_DETECT_ZEROES
},
519 { "shared", required_argument
, NULL
, 'e' },
520 { "format", required_argument
, NULL
, 'f' },
521 { "persistent", no_argument
, NULL
, 't' },
522 { "verbose", no_argument
, NULL
, 'v' },
523 { "object", required_argument
, NULL
, QEMU_NBD_OPT_OBJECT
},
524 { "export-name", required_argument
, NULL
, 'x' },
525 { "description", required_argument
, NULL
, 'D' },
526 { "tls-creds", required_argument
, NULL
, QEMU_NBD_OPT_TLSCREDS
},
527 { "image-opts", no_argument
, NULL
, QEMU_NBD_OPT_IMAGE_OPTS
},
528 { "trace", required_argument
, NULL
, 'T' },
529 { "fork", no_argument
, NULL
, QEMU_NBD_OPT_FORK
},
535 int flags
= BDRV_O_RDWR
;
538 bool seen_cache
= false;
539 bool seen_discard
= false;
540 bool seen_aio
= false;
541 pthread_t client_thread
;
542 const char *fmt
= NULL
;
543 Error
*local_err
= NULL
;
544 BlockdevDetectZeroesOptions detect_zeroes
= BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
;
545 QDict
*options
= NULL
;
546 const char *export_name
= NULL
;
547 const char *export_description
= NULL
;
548 const char *tlscredsid
= NULL
;
549 bool imageOpts
= false;
550 bool writethrough
= true;
551 char *trace_file
= NULL
;
552 bool fork_process
= false;
554 unsigned socket_activation
;
556 /* The client thread uses SIGTERM to interrupt the server. A signal
557 * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
559 struct sigaction sa_sigterm
;
560 memset(&sa_sigterm
, 0, sizeof(sa_sigterm
));
561 sa_sigterm
.sa_handler
= termsig_handler
;
562 sigaction(SIGTERM
, &sa_sigterm
, NULL
);
565 signal(SIGPIPE
, SIG_IGN
);
568 module_call_init(MODULE_INIT_TRACE
);
569 qcrypto_init(&error_fatal
);
571 module_call_init(MODULE_INIT_QOM
);
572 qemu_add_opts(&qemu_object_opts
);
573 qemu_add_opts(&qemu_trace_opts
);
574 qemu_init_exec_dir(argv
[0]);
576 while ((ch
= getopt_long(argc
, argv
, sopt
, lopt
, &opt_ind
)) != -1) {
579 flags
|= BDRV_O_SNAPSHOT
;
582 optarg
= (char *) "none";
584 case QEMU_NBD_OPT_CACHE
:
586 error_report("-n and --cache can only be specified once");
590 if (bdrv_parse_cache_mode(optarg
, &flags
, &writethrough
) == -1) {
591 error_report("Invalid cache mode `%s'", optarg
);
595 case QEMU_NBD_OPT_AIO
:
597 error_report("--aio can only be specified once");
601 if (!strcmp(optarg
, "native")) {
602 flags
|= BDRV_O_NATIVE_AIO
;
603 } else if (!strcmp(optarg
, "threads")) {
604 /* this is the default */
606 error_report("invalid aio mode `%s'", optarg
);
610 case QEMU_NBD_OPT_DISCARD
:
612 error_report("--discard can only be specified once");
616 if (bdrv_parse_discard_flags(optarg
, &flags
) == -1) {
617 error_report("Invalid discard mode `%s'", optarg
);
621 case QEMU_NBD_OPT_DETECT_ZEROES
:
623 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup
,
625 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF
,
628 error_reportf_err(local_err
,
629 "Failed to parse detect_zeroes mode: ");
632 if (detect_zeroes
== BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP
&&
633 !(flags
& BDRV_O_UNMAP
)) {
634 error_report("setting detect-zeroes to unmap is not allowed "
635 "without setting discard operation to unmap");
646 dev_offset
= strtoll (optarg
, &end
, 0);
648 error_report("Invalid offset `%s'", optarg
);
651 if (dev_offset
< 0) {
652 error_report("Offset must be positive `%s'", optarg
);
657 if (strstart(optarg
, SNAPSHOT_OPT_BASE
, NULL
)) {
658 sn_opts
= qemu_opts_parse_noisily(&internal_snapshot_opts
,
661 error_report("Failed in parsing snapshot param `%s'",
666 sn_id_or_name
= optarg
;
670 nbdflags
|= NBD_FLAG_READ_ONLY
;
671 flags
&= ~BDRV_O_RDWR
;
674 partition
= strtol(optarg
, &end
, 0);
676 error_report("Invalid partition `%s'", optarg
);
679 if (partition
< 1 || partition
> 8) {
680 error_report("Invalid partition %d", partition
);
686 if (sockpath
[0] != '/') {
687 error_report("socket path must be absolute");
698 shared
= strtol(optarg
, &end
, 0);
700 error_report("Invalid shared device number '%s'", optarg
);
704 error_report("Shared device number must be greater than 0");
715 export_name
= optarg
;
718 export_description
= optarg
;
732 error_report("Try `%s --help' for more information.", argv
[0]);
734 case QEMU_NBD_OPT_OBJECT
: {
736 opts
= qemu_opts_parse_noisily(&qemu_object_opts
,
742 case QEMU_NBD_OPT_TLSCREDS
:
745 case QEMU_NBD_OPT_IMAGE_OPTS
:
750 trace_file
= trace_opt_parse(optarg
);
752 case QEMU_NBD_OPT_FORK
:
758 if ((argc
- optind
) != 1) {
759 error_report("Invalid number of arguments");
760 error_printf("Try `%s --help' for more information.\n", argv
[0]);
764 if (qemu_opts_foreach(&qemu_object_opts
,
765 user_creatable_add_opts_foreach
,
770 if (!trace_init_backends()) {
773 trace_init_file(trace_file
);
774 qemu_set_log(LOG_TRACE
);
776 socket_activation
= check_socket_activation();
777 if (socket_activation
== 0) {
778 setup_address_and_port(&bindto
, &port
);
780 /* Using socket activation - check user didn't use -p etc. */
781 const char *err_msg
= socket_activation_validate_opts(device
, sockpath
,
783 if (err_msg
!= NULL
) {
784 error_report("%s", err_msg
);
788 /* qemu-nbd can only listen on a single socket. */
789 if (socket_activation
> 1) {
790 error_report("qemu-nbd does not support socket activation with %s > 1",
798 error_report("TLS is only supported with IPv4/IPv6");
802 error_report("TLS is not supported with a host device");
806 /* Set the default NBD protocol export name, since
807 * we *must* use new style protocol for TLS */
810 tlscreds
= nbd_get_tls_creds(tlscredsid
, &local_err
);
812 error_report("Failed to get TLS creds %s",
813 error_get_pretty(local_err
));
819 int nbdfd
= open(argv
[optind
], O_RDWR
);
821 error_report("Cannot open %s: %s", argv
[optind
],
825 nbd_disconnect(nbdfd
);
829 printf("%s disconnected\n", argv
[optind
]);
834 if ((device
&& !verbose
) || fork_process
) {
839 if (qemu_pipe(stderr_fd
) < 0) {
840 error_report("Error setting up communication pipe: %s",
845 /* Now daemonize, but keep a communication channel open to
846 * print errors and exit with the proper status code.
850 error_report("Failed to fork: %s", strerror(errno
));
852 } else if (pid
== 0) {
854 ret
= qemu_daemon(1, 0);
856 /* Temporarily redirect stderr to the parent's pipe... */
857 old_stderr
= dup(STDERR_FILENO
);
858 dup2(stderr_fd
[1], STDERR_FILENO
);
860 error_report("Failed to daemonize: %s", strerror(errno
));
864 /* ... close the descriptor we inherited and go on. */
870 /* In the parent. Print error messages from the child until
871 * it closes the pipe.
874 buf
= g_malloc(1024);
875 while ((ret
= read(stderr_fd
[0], buf
, 1024)) > 0) {
877 ret
= qemu_write_full(STDERR_FILENO
, buf
, ret
);
883 error_report("Cannot read from daemon: %s",
888 /* Usually the daemon should not print any message.
889 * Exit with zero status in that case.
895 if (device
!= NULL
&& sockpath
== NULL
) {
896 sockpath
= g_malloc(128);
897 snprintf(sockpath
, 128, SOCKET_PATH
, basename(device
));
900 server
= qio_net_listener_new();
901 if (socket_activation
== 0) {
902 saddr
= nbd_build_socket_address(sockpath
, bindto
, port
);
903 if (qio_net_listener_open_sync(server
, saddr
, &local_err
) < 0) {
904 object_unref(OBJECT(server
));
905 error_report_err(local_err
);
910 /* See comment in check_socket_activation above. */
911 for (i
= 0; i
< socket_activation
; i
++) {
912 QIOChannelSocket
*sioc
;
913 sioc
= qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD
+ i
,
916 object_unref(OBJECT(server
));
917 error_report("Failed to use socket activation: %s",
918 error_get_pretty(local_err
));
921 qio_net_listener_add(server
, sioc
);
922 object_unref(OBJECT(sioc
));
926 if (qemu_init_main_loop(&local_err
)) {
927 error_report_err(local_err
);
931 atexit(bdrv_close_all
);
933 srcpath
= argv
[optind
];
937 error_report("--image-opts and -f are mutually exclusive");
940 opts
= qemu_opts_parse_noisily(&file_opts
, srcpath
, true);
942 qemu_opts_reset(&file_opts
);
945 options
= qemu_opts_to_qdict(opts
, NULL
);
946 qemu_opts_reset(&file_opts
);
947 blk
= blk_new_open(NULL
, NULL
, options
, flags
, &local_err
);
950 options
= qdict_new();
951 qdict_put_str(options
, "driver", fmt
);
953 blk
= blk_new_open(srcpath
, NULL
, options
, flags
, &local_err
);
957 error_reportf_err(local_err
, "Failed to blk_new_open '%s': ",
963 blk_set_enable_write_cache(blk
, !writethrough
);
966 ret
= bdrv_snapshot_load_tmp(bs
,
967 qemu_opt_get(sn_opts
, SNAPSHOT_OPT_ID
),
968 qemu_opt_get(sn_opts
, SNAPSHOT_OPT_NAME
),
970 } else if (sn_id_or_name
) {
971 ret
= bdrv_snapshot_load_tmp_by_id_or_name(bs
, sn_id_or_name
,
975 error_reportf_err(local_err
, "Failed to load snapshot: ");
979 bs
->detect_zeroes
= detect_zeroes
;
980 fd_size
= blk_getlength(blk
);
982 error_report("Failed to determine the image length: %s",
987 if (dev_offset
>= fd_size
) {
988 error_report("Offset (%lld) has to be smaller than the image size "
990 (long long int)dev_offset
, (long long int)fd_size
);
993 fd_size
-= dev_offset
;
995 if (partition
!= -1) {
996 ret
= find_partition(blk
, partition
, &dev_offset
, &fd_size
);
998 error_report("Could not find partition %d: %s", partition
,
1004 exp
= nbd_export_new(bs
, dev_offset
, fd_size
, nbdflags
, nbd_export_closed
,
1005 writethrough
, NULL
, &local_err
);
1007 error_report_err(local_err
);
1011 nbd_export_set_name(exp
, export_name
);
1012 nbd_export_set_description(exp
, export_description
);
1014 } else if (export_description
) {
1015 error_report("Export description requires an export name");
1022 ret
= pthread_create(&client_thread
, NULL
, nbd_client_thread
, device
);
1024 error_report("Failed to create client thread: %s", strerror(ret
));
1028 /* Shut up GCC warnings. */
1029 memset(&client_thread
, 0, sizeof(client_thread
));
1032 nbd_update_server_watch();
1034 /* now when the initialization is (almost) complete, chdir("/")
1035 * to free any busy filesystems */
1036 if (chdir("/") < 0) {
1037 error_report("Could not chdir to root directory: %s",
1043 dup2(old_stderr
, STDERR_FILENO
);
1049 main_loop_wait(false);
1050 if (state
== TERMINATE
) {
1051 state
= TERMINATING
;
1052 nbd_export_close(exp
);
1053 nbd_export_put(exp
);
1056 } while (state
!= TERMINATED
);
1063 qemu_opts_del(sn_opts
);
1067 pthread_join(client_thread
, &ret
);