/* * Copyright (C) 2005 Anthony Liguori * * Network Block Device * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; under version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . */ #include "qemu/osdep.h" #include #include #include #include "qemu-common.h" #include "qapi/error.h" #include "qemu/cutils.h" #include "sysemu/block-backend.h" #include "sysemu/runstate.h" /* for qemu_system_killed() prototype */ #include "block/block_int.h" #include "block/nbd.h" #include "qemu/main-loop.h" #include "qemu/module.h" #include "qemu/option.h" #include "qemu/error-report.h" #include "qemu/config-file.h" #include "qemu/bswap.h" #include "qemu/log.h" #include "qemu/systemd.h" #include "block/snapshot.h" #include "qapi/qmp/qdict.h" #include "qapi/qmp/qstring.h" #include "qom/object_interfaces.h" #include "io/channel-socket.h" #include "io/net-listener.h" #include "crypto/init.h" #include "trace/control.h" #include "qemu-version.h" #ifdef __linux__ #define HAVE_NBD_DEVICE 1 #else #define HAVE_NBD_DEVICE 0 #endif #define SOCKET_PATH "/var/lock/qemu-nbd-%s" #define QEMU_NBD_OPT_CACHE 256 #define QEMU_NBD_OPT_AIO 257 #define QEMU_NBD_OPT_DISCARD 258 #define QEMU_NBD_OPT_DETECT_ZEROES 259 #define QEMU_NBD_OPT_OBJECT 260 #define QEMU_NBD_OPT_TLSCREDS 261 #define QEMU_NBD_OPT_IMAGE_OPTS 262 #define QEMU_NBD_OPT_FORK 263 #define QEMU_NBD_OPT_TLSAUTHZ 264 #define QEMU_NBD_OPT_PID_FILE 265 #define MBR_SIZE 512 static int verbose; static char *srcpath; static SocketAddress *saddr; static int persistent = 0; static enum { RUNNING, TERMINATE, TERMINATED } state; static int shared = 1; static int nb_fds; static QIONetListener *server; static QCryptoTLSCreds *tlscreds; static const char *tlsauthz; static void usage(const char *name) { (printf) ( "Usage: %s [OPTIONS] FILE\n" " or: %s -L [OPTIONS]\n" "QEMU Disk Network Block Device Utility\n" "\n" " -h, --help display this help and exit\n" " -V, --version output version information and exit\n" "\n" "Connection properties:\n" " -p, --port=PORT port to listen on (default `%d')\n" " -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n" " -k, --socket=PATH path to the unix socket\n" " (default '"SOCKET_PATH"')\n" " -e, --shared=NUM device can be shared by NUM clients (default '1')\n" " -t, --persistent don't exit on the last connection\n" " -v, --verbose display extra debugging information\n" " -x, --export-name=NAME expose export by name (default is empty string)\n" " -D, --description=TEXT export a human-readable description\n" "\n" "Exposing part of the image:\n" " -o, --offset=OFFSET offset into the image\n" " -A, --allocation-depth expose the allocation depth\n" " -B, --bitmap=NAME expose a persistent dirty bitmap\n" "\n" "General purpose options:\n" " -L, --list list exports available from another NBD server\n" " --object type,id=ID,... define an object such as 'secret' for providing\n" " passwords and/or encryption keys\n" " --tls-creds=ID use id of an earlier --object to provide TLS\n" " --tls-authz=ID use id of an earlier --object to provide\n" " authorization\n" " -T, --trace [[enable=]][,events=][,file=]\n" " specify tracing options\n" " --fork fork off the server process and exit the parent\n" " once the server is running\n" " --pid-file=PATH store the server's process ID in the given file\n" #if HAVE_NBD_DEVICE "\n" "Kernel NBD client support:\n" " -c, --connect=DEV connect FILE to the local NBD device DEV\n" " -d, --disconnect disconnect the specified device\n" #endif "\n" "Block device options:\n" " -f, --format=FORMAT set image format (raw, qcow2, ...)\n" " -r, --read-only export read-only\n" " -s, --snapshot use FILE as an external snapshot, create a temporary\n" " file with backing_file=FILE, redirect the write to\n" " the temporary one\n" " -l, --load-snapshot=SNAPSHOT_PARAM\n" " load an internal snapshot inside FILE and export it\n" " as an read-only device, SNAPSHOT_PARAM format is\n" " 'snapshot.id=[ID],snapshot.name=[NAME]', or\n" " '[ID_OR_NAME]'\n" " -n, --nocache disable host cache\n" " --cache=MODE set cache mode (none, writeback, ...)\n" " --aio=MODE set AIO mode (native, io_uring or threads)\n" " --discard=MODE set discard mode (ignore, unmap)\n" " --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n" " --image-opts treat FILE as a full set of image options\n" "\n" QEMU_HELP_BOTTOM "\n" , name, name, NBD_DEFAULT_PORT, "DEVICE"); } static void version(const char *name) { printf( "%s " QEMU_FULL_VERSION "\n" "Written by Anthony Liguori.\n" "\n" QEMU_COPYRIGHT "\n" "This is free software; see the source for copying conditions. There is NO\n" "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" , name); } #ifdef CONFIG_POSIX /* * The client thread uses SIGTERM to interrupt the server. A signal * handler ensures that "qemu-nbd -v -c" exits with a nice status code. */ void qemu_system_killed(int signum, pid_t pid) { qatomic_cmpxchg(&state, RUNNING, TERMINATE); qemu_notify_event(); } #endif /* CONFIG_POSIX */ static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls, const char *hostname) { int ret = EXIT_FAILURE; int rc; Error *err = NULL; QIOChannelSocket *sioc; NBDExportInfo *list; int i, j; sioc = qio_channel_socket_new(); if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) { error_report_err(err); goto out; } rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list, &err); if (rc < 0) { if (err) { error_report_err(err); } goto out; } printf("exports available: %d\n", rc); for (i = 0; i < rc; i++) { printf(" export: '%s'\n", list[i].name); if (list[i].description && *list[i].description) { printf(" description: %s\n", list[i].description); } if (list[i].flags & NBD_FLAG_HAS_FLAGS) { static const char *const flag_names[] = { [NBD_FLAG_READ_ONLY_BIT] = "readonly", [NBD_FLAG_SEND_FLUSH_BIT] = "flush", [NBD_FLAG_SEND_FUA_BIT] = "fua", [NBD_FLAG_ROTATIONAL_BIT] = "rotational", [NBD_FLAG_SEND_TRIM_BIT] = "trim", [NBD_FLAG_SEND_WRITE_ZEROES_BIT] = "zeroes", [NBD_FLAG_SEND_DF_BIT] = "df", [NBD_FLAG_CAN_MULTI_CONN_BIT] = "multi", [NBD_FLAG_SEND_RESIZE_BIT] = "resize", [NBD_FLAG_SEND_CACHE_BIT] = "cache", [NBD_FLAG_SEND_FAST_ZERO_BIT] = "fast-zero", }; printf(" size: %" PRIu64 "\n", list[i].size); printf(" flags: 0x%x (", list[i].flags); for (size_t bit = 0; bit < ARRAY_SIZE(flag_names); bit++) { if (flag_names[bit] && (list[i].flags & (1 << bit))) { printf(" %s", flag_names[bit]); } } printf(" )\n"); } if (list[i].min_block) { printf(" min block: %u\n", list[i].min_block); printf(" opt block: %u\n", list[i].opt_block); printf(" max block: %u\n", list[i].max_block); } if (list[i].n_contexts) { printf(" available meta contexts: %d\n", list[i].n_contexts); for (j = 0; j < list[i].n_contexts; j++) { printf(" %s\n", list[i].contexts[j]); } } } nbd_free_export_list(list, rc); ret = EXIT_SUCCESS; out: object_unref(OBJECT(sioc)); return ret; } #if HAVE_NBD_DEVICE static void *show_parts(void *arg) { char *device = arg; int nbd; /* linux just needs an open() to trigger * the partition table update * but remember to load the module with max_part != 0 : * modprobe nbd max_part=63 */ nbd = open(device, O_RDWR); if (nbd >= 0) { close(nbd); } return NULL; } static void *nbd_client_thread(void *arg) { char *device = arg; NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") }; QIOChannelSocket *sioc; int fd = -1; int ret = EXIT_FAILURE; pthread_t show_parts_thread; Error *local_error = NULL; sioc = qio_channel_socket_new(); if (qio_channel_socket_connect_sync(sioc, saddr, &local_error) < 0) { error_report_err(local_error); goto out; } if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc), NULL, NULL, NULL, &info, &local_error) < 0) { if (local_error) { error_report_err(local_error); } goto out; } fd = open(device, O_RDWR); if (fd < 0) { /* Linux-only, we can use %m in printf. */ error_report("Failed to open %s: %m", device); goto out; } if (nbd_init(fd, sioc, &info, &local_error) < 0) { error_report_err(local_error); goto out; } /* update partition table */ pthread_create(&show_parts_thread, NULL, show_parts, device); if (verbose) { fprintf(stderr, "NBD device %s is now connected to %s\n", device, srcpath); } else { /* Close stderr so that the qemu-nbd process exits. */ dup2(STDOUT_FILENO, STDERR_FILENO); } if (nbd_client(fd) < 0) { goto out; } ret = EXIT_SUCCESS; out: if (fd >= 0) { close(fd); } object_unref(OBJECT(sioc)); g_free(info.name); kill(getpid(), SIGTERM); return (void *) (intptr_t) ret; } #endif /* HAVE_NBD_DEVICE */ static int nbd_can_accept(void) { return state == RUNNING && (shared == 0 || nb_fds < shared); } static void nbd_update_server_watch(void); static void nbd_client_closed(NBDClient *client, bool negotiated) { nb_fds--; if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) { state = TERMINATE; } nbd_update_server_watch(); nbd_client_put(client); } static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, gpointer opaque) { if (state >= TERMINATE) { return; } nb_fds++; nbd_update_server_watch(); nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed); } static void nbd_update_server_watch(void) { if (nbd_can_accept()) { qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL); } else { qio_net_listener_set_client_func(server, NULL, NULL, NULL); } } static SocketAddress *nbd_build_socket_address(const char *sockpath, const char *bindto, const char *port) { SocketAddress *saddr; saddr = g_new0(SocketAddress, 1); if (sockpath) { saddr->type = SOCKET_ADDRESS_TYPE_UNIX; saddr->u.q_unix.path = g_strdup(sockpath); } else { InetSocketAddress *inet; saddr->type = SOCKET_ADDRESS_TYPE_INET; inet = &saddr->u.inet; inet->host = g_strdup(bindto); if (port) { inet->port = g_strdup(port); } else { inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT); } } return saddr; } static QemuOptsList file_opts = { .name = "file", .implied_opt_name = "file", .head = QTAILQ_HEAD_INITIALIZER(file_opts.head), .desc = { /* no elements => accept any params */ { /* end of list */ } }, }; static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list, Error **errp) { Object *obj; QCryptoTLSCreds *creds; obj = object_resolve_path_component( object_get_objects_root(), id); if (!obj) { error_setg(errp, "No TLS credentials with id '%s'", id); return NULL; } creds = (QCryptoTLSCreds *) object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); if (!creds) { error_setg(errp, "Object with id '%s' is not TLS credentials", id); return NULL; } if (list) { if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) { error_setg(errp, "Expecting TLS credentials with a client endpoint"); return NULL; } } else { if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) { error_setg(errp, "Expecting TLS credentials with a server endpoint"); return NULL; } } object_ref(obj); return creds; } static void setup_address_and_port(const char **address, const char **port) { if (*address == NULL) { *address = "0.0.0.0"; } if (*port == NULL) { *port = stringify(NBD_DEFAULT_PORT); } } /* * Check socket parameters compatibility when socket activation is used. */ static const char *socket_activation_validate_opts(const char *device, const char *sockpath, const char *address, const char *port, bool list) { if (device != NULL) { return "NBD device can't be set when using socket activation"; } if (sockpath != NULL) { return "Unix socket can't be set when using socket activation"; } if (address != NULL) { return "The interface can't be set when using socket activation"; } if (port != NULL) { return "TCP port number can't be set when using socket activation"; } if (list) { return "List mode is incompatible with socket activation"; } return NULL; } static void qemu_nbd_shutdown(void) { job_cancel_sync_all(); blk_exp_close_all(); bdrv_close_all(); } int main(int argc, char **argv) { BlockBackend *blk; BlockDriverState *bs; uint64_t dev_offset = 0; bool readonly = false; bool disconnect = false; const char *bindto = NULL; const char *port = NULL; char *sockpath = NULL; char *device = NULL; QemuOpts *sn_opts = NULL; const char *sn_id_or_name = NULL; const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:AB:L"; struct option lopt[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, 'V' }, { "bind", required_argument, NULL, 'b' }, { "port", required_argument, NULL, 'p' }, { "socket", required_argument, NULL, 'k' }, { "offset", required_argument, NULL, 'o' }, { "read-only", no_argument, NULL, 'r' }, { "allocation-depth", no_argument, NULL, 'A' }, { "bitmap", required_argument, NULL, 'B' }, { "connect", required_argument, NULL, 'c' }, { "disconnect", no_argument, NULL, 'd' }, { "list", no_argument, NULL, 'L' }, { "snapshot", no_argument, NULL, 's' }, { "load-snapshot", required_argument, NULL, 'l' }, { "nocache", no_argument, NULL, 'n' }, { "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE }, { "aio", required_argument, NULL, QEMU_NBD_OPT_AIO }, { "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD }, { "detect-zeroes", required_argument, NULL, QEMU_NBD_OPT_DETECT_ZEROES }, { "shared", required_argument, NULL, 'e' }, { "format", required_argument, NULL, 'f' }, { "persistent", no_argument, NULL, 't' }, { "verbose", no_argument, NULL, 'v' }, { "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT }, { "export-name", required_argument, NULL, 'x' }, { "description", required_argument, NULL, 'D' }, { "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS }, { "tls-authz", required_argument, NULL, QEMU_NBD_OPT_TLSAUTHZ }, { "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS }, { "trace", required_argument, NULL, 'T' }, { "fork", no_argument, NULL, QEMU_NBD_OPT_FORK }, { "pid-file", required_argument, NULL, QEMU_NBD_OPT_PID_FILE }, { NULL, 0, NULL, 0 } }; int ch; int opt_ind = 0; int flags = BDRV_O_RDWR; int ret = 0; bool seen_cache = false; bool seen_discard = false; bool seen_aio = false; pthread_t client_thread; const char *fmt = NULL; Error *local_err = NULL; BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF; QDict *options = NULL; const char *export_name = NULL; /* defaults to "" later for server mode */ const char *export_description = NULL; strList *bitmaps = NULL; bool alloc_depth = false; const char *tlscredsid = NULL; bool imageOpts = false; bool writethrough = true; bool fork_process = false; bool list = false; int old_stderr = -1; unsigned socket_activation; const char *pid_file_name = NULL; BlockExportOptions *export_opts; #ifdef CONFIG_POSIX os_setup_early_signal_handling(); os_setup_signal_handling(); #endif socket_init(); error_init(argv[0]); module_call_init(MODULE_INIT_TRACE); qcrypto_init(&error_fatal); module_call_init(MODULE_INIT_QOM); qemu_add_opts(&qemu_trace_opts); qemu_init_exec_dir(argv[0]); while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { switch (ch) { case 's': flags |= BDRV_O_SNAPSHOT; break; case 'n': optarg = (char *) "none"; /* fallthrough */ case QEMU_NBD_OPT_CACHE: if (seen_cache) { error_report("-n and --cache can only be specified once"); exit(EXIT_FAILURE); } seen_cache = true; if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) { error_report("Invalid cache mode `%s'", optarg); exit(EXIT_FAILURE); } break; case QEMU_NBD_OPT_AIO: if (seen_aio) { error_report("--aio can only be specified once"); exit(EXIT_FAILURE); } seen_aio = true; if (bdrv_parse_aio(optarg, &flags) < 0) { error_report("Invalid aio mode '%s'", optarg); exit(EXIT_FAILURE); } break; case QEMU_NBD_OPT_DISCARD: if (seen_discard) { error_report("--discard can only be specified once"); exit(EXIT_FAILURE); } seen_discard = true; if (bdrv_parse_discard_flags(optarg, &flags) == -1) { error_report("Invalid discard mode `%s'", optarg); exit(EXIT_FAILURE); } break; case QEMU_NBD_OPT_DETECT_ZEROES: detect_zeroes = qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, optarg, BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err); if (local_err) { error_reportf_err(local_err, "Failed to parse detect_zeroes mode: "); exit(EXIT_FAILURE); } if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && !(flags & BDRV_O_UNMAP)) { error_report("setting detect-zeroes to unmap is not allowed " "without setting discard operation to unmap"); exit(EXIT_FAILURE); } break; case 'b': bindto = optarg; break; case 'p': port = optarg; break; case 'o': if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) { error_report("Invalid offset '%s'", optarg); exit(EXIT_FAILURE); } break; case 'l': if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) { sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts, optarg, false); if (!sn_opts) { error_report("Failed in parsing snapshot param `%s'", optarg); exit(EXIT_FAILURE); } } else { sn_id_or_name = optarg; } /* fall through */ case 'r': readonly = true; flags &= ~BDRV_O_RDWR; break; case 'A': alloc_depth = true; break; case 'B': QAPI_LIST_PREPEND(bitmaps, g_strdup(optarg)); break; case 'k': sockpath = optarg; if (sockpath[0] != '/') { error_report("socket path must be absolute"); exit(EXIT_FAILURE); } break; case 'd': disconnect = true; break; case 'c': device = optarg; break; case 'e': if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 || shared < 0) { error_report("Invalid shared device number '%s'", optarg); exit(EXIT_FAILURE); } break; case 'f': fmt = optarg; break; case 't': persistent = 1; break; case 'x': export_name = optarg; if (strlen(export_name) > NBD_MAX_STRING_SIZE) { error_report("export name '%s' too long", export_name); exit(EXIT_FAILURE); } break; case 'D': export_description = optarg; if (strlen(export_description) > NBD_MAX_STRING_SIZE) { error_report("export description '%s' too long", export_description); exit(EXIT_FAILURE); } break; case 'v': verbose = 1; break; case 'V': version(argv[0]); exit(0); break; case 'h': usage(argv[0]); exit(0); break; case '?': error_report("Try `%s --help' for more information.", argv[0]); exit(EXIT_FAILURE); case QEMU_NBD_OPT_OBJECT: user_creatable_process_cmdline(optarg); break; case QEMU_NBD_OPT_TLSCREDS: tlscredsid = optarg; break; case QEMU_NBD_OPT_IMAGE_OPTS: imageOpts = true; break; case 'T': trace_opt_parse(optarg); break; case QEMU_NBD_OPT_TLSAUTHZ: tlsauthz = optarg; break; case QEMU_NBD_OPT_FORK: fork_process = true; break; case 'L': list = true; break; case QEMU_NBD_OPT_PID_FILE: pid_file_name = optarg; break; } } if (list) { if (argc != optind) { error_report("List mode is incompatible with a file name"); exit(EXIT_FAILURE); } if (export_name || export_description || dev_offset || device || disconnect || fmt || sn_id_or_name || bitmaps || alloc_depth || seen_aio || seen_discard || seen_cache) { error_report("List mode is incompatible with per-device settings"); exit(EXIT_FAILURE); } if (fork_process) { error_report("List mode is incompatible with forking"); exit(EXIT_FAILURE); } } else if ((argc - optind) != 1) { error_report("Invalid number of arguments"); error_printf("Try `%s --help' for more information.\n", argv[0]); exit(EXIT_FAILURE); } else if (!export_name) { export_name = ""; } if (!trace_init_backends()) { exit(1); } trace_init_file(); qemu_set_log(LOG_TRACE); socket_activation = check_socket_activation(); if (socket_activation == 0) { setup_address_and_port(&bindto, &port); } else { /* Using socket activation - check user didn't use -p etc. */ const char *err_msg = socket_activation_validate_opts(device, sockpath, bindto, port, list); if (err_msg != NULL) { error_report("%s", err_msg); exit(EXIT_FAILURE); } /* qemu-nbd can only listen on a single socket. */ if (socket_activation > 1) { error_report("qemu-nbd does not support socket activation with %s > 1", "LISTEN_FDS"); exit(EXIT_FAILURE); } } if (tlscredsid) { if (sockpath) { error_report("TLS is only supported with IPv4/IPv6"); exit(EXIT_FAILURE); } if (device) { error_report("TLS is not supported with a host device"); exit(EXIT_FAILURE); } if (tlsauthz && list) { error_report("TLS authorization is incompatible with export list"); exit(EXIT_FAILURE); } tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err); if (local_err) { error_reportf_err(local_err, "Failed to get TLS creds: "); exit(EXIT_FAILURE); } } else { if (tlsauthz) { error_report("--tls-authz is not permitted without --tls-creds"); exit(EXIT_FAILURE); } } if (list) { saddr = nbd_build_socket_address(sockpath, bindto, port); return qemu_nbd_client_list(saddr, tlscreds, bindto); } #if !HAVE_NBD_DEVICE if (disconnect || device) { error_report("Kernel /dev/nbdN support not available"); exit(EXIT_FAILURE); } #else /* HAVE_NBD_DEVICE */ if (disconnect) { int nbdfd = open(argv[optind], O_RDWR); if (nbdfd < 0) { error_report("Cannot open %s: %s", argv[optind], strerror(errno)); exit(EXIT_FAILURE); } nbd_disconnect(nbdfd); close(nbdfd); printf("%s disconnected\n", argv[optind]); return 0; } #endif if ((device && !verbose) || fork_process) { #ifndef WIN32 int stderr_fd[2]; pid_t pid; int ret; if (qemu_pipe(stderr_fd) < 0) { error_report("Error setting up communication pipe: %s", strerror(errno)); exit(EXIT_FAILURE); } /* Now daemonize, but keep a communication channel open to * print errors and exit with the proper status code. */ pid = fork(); if (pid < 0) { error_report("Failed to fork: %s", strerror(errno)); exit(EXIT_FAILURE); } else if (pid == 0) { close(stderr_fd[0]); /* Remember parent's stderr if we will be restoring it. */ if (fork_process) { old_stderr = dup(STDERR_FILENO); } ret = qemu_daemon(1, 0); /* Temporarily redirect stderr to the parent's pipe... */ dup2(stderr_fd[1], STDERR_FILENO); if (ret < 0) { error_report("Failed to daemonize: %s", strerror(errno)); exit(EXIT_FAILURE); } /* ... close the descriptor we inherited and go on. */ close(stderr_fd[1]); } else { bool errors = false; char *buf; /* In the parent. Print error messages from the child until * it closes the pipe. */ close(stderr_fd[1]); buf = g_malloc(1024); while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { errors = true; ret = qemu_write_full(STDERR_FILENO, buf, ret); if (ret < 0) { exit(EXIT_FAILURE); } } if (ret < 0) { error_report("Cannot read from daemon: %s", strerror(errno)); exit(EXIT_FAILURE); } /* Usually the daemon should not print any message. * Exit with zero status in that case. */ exit(errors); } #else /* WIN32 */ error_report("Unable to fork into background on Windows hosts"); exit(EXIT_FAILURE); #endif /* WIN32 */ } if (device != NULL && sockpath == NULL) { sockpath = g_malloc(128); snprintf(sockpath, 128, SOCKET_PATH, basename(device)); } server = qio_net_listener_new(); if (socket_activation == 0) { int backlog; if (persistent || shared == 0) { backlog = SOMAXCONN; } else { backlog = MIN(shared, SOMAXCONN); } saddr = nbd_build_socket_address(sockpath, bindto, port); if (qio_net_listener_open_sync(server, saddr, backlog, &local_err) < 0) { object_unref(OBJECT(server)); error_report_err(local_err); exit(EXIT_FAILURE); } } else { size_t i; /* See comment in check_socket_activation above. */ for (i = 0; i < socket_activation; i++) { QIOChannelSocket *sioc; sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i, &local_err); if (sioc == NULL) { object_unref(OBJECT(server)); error_reportf_err(local_err, "Failed to use socket activation: "); exit(EXIT_FAILURE); } qio_net_listener_add(server, sioc); object_unref(OBJECT(sioc)); } } if (qemu_init_main_loop(&local_err)) { error_report_err(local_err); exit(EXIT_FAILURE); } bdrv_init(); atexit(qemu_nbd_shutdown); srcpath = argv[optind]; if (imageOpts) { QemuOpts *opts; if (fmt) { error_report("--image-opts and -f are mutually exclusive"); exit(EXIT_FAILURE); } opts = qemu_opts_parse_noisily(&file_opts, srcpath, true); if (!opts) { qemu_opts_reset(&file_opts); exit(EXIT_FAILURE); } options = qemu_opts_to_qdict(opts, NULL); qemu_opts_reset(&file_opts); blk = blk_new_open(NULL, NULL, options, flags, &local_err); } else { if (fmt) { options = qdict_new(); qdict_put_str(options, "driver", fmt); } blk = blk_new_open(srcpath, NULL, options, flags, &local_err); } if (!blk) { error_reportf_err(local_err, "Failed to blk_new_open '%s': ", argv[optind]); exit(EXIT_FAILURE); } bs = blk_bs(blk); if (dev_offset) { QDict *raw_opts = qdict_new(); qdict_put_str(raw_opts, "driver", "raw"); qdict_put_str(raw_opts, "file", bs->node_name); qdict_put_int(raw_opts, "offset", dev_offset); bs = bdrv_open(NULL, NULL, raw_opts, flags, &error_fatal); blk_remove_bs(blk); blk_insert_bs(blk, bs, &error_fatal); bdrv_unref(bs); } blk_set_enable_write_cache(blk, !writethrough); if (sn_opts) { ret = bdrv_snapshot_load_tmp(bs, qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID), qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME), &local_err); } else if (sn_id_or_name) { ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name, &local_err); } if (ret < 0) { error_reportf_err(local_err, "Failed to load snapshot: "); exit(EXIT_FAILURE); } bs->detect_zeroes = detect_zeroes; nbd_server_is_qemu_nbd(true); export_opts = g_new(BlockExportOptions, 1); *export_opts = (BlockExportOptions) { .type = BLOCK_EXPORT_TYPE_NBD, .id = g_strdup("qemu-nbd-export"), .node_name = g_strdup(bdrv_get_node_name(bs)), .has_writethrough = true, .writethrough = writethrough, .has_writable = true, .writable = !readonly, .u.nbd = { .has_name = true, .name = g_strdup(export_name), .has_description = !!export_description, .description = g_strdup(export_description), .has_bitmaps = !!bitmaps, .bitmaps = bitmaps, .has_allocation_depth = alloc_depth, .allocation_depth = alloc_depth, }, }; blk_exp_add(export_opts, &error_fatal); qapi_free_BlockExportOptions(export_opts); if (device) { #if HAVE_NBD_DEVICE int ret; ret = pthread_create(&client_thread, NULL, nbd_client_thread, device); if (ret != 0) { error_report("Failed to create client thread: %s", strerror(ret)); exit(EXIT_FAILURE); } #endif } else { /* Shut up GCC warnings. */ memset(&client_thread, 0, sizeof(client_thread)); } nbd_update_server_watch(); if (pid_file_name) { qemu_write_pidfile(pid_file_name, &error_fatal); } /* now when the initialization is (almost) complete, chdir("/") * to free any busy filesystems */ if (chdir("/") < 0) { error_report("Could not chdir to root directory: %s", strerror(errno)); exit(EXIT_FAILURE); } if (fork_process) { dup2(old_stderr, STDERR_FILENO); close(old_stderr); } state = RUNNING; do { main_loop_wait(false); if (state == TERMINATE) { blk_exp_close_all(); state = TERMINATED; } } while (state != TERMINATED); blk_unref(blk); if (sockpath) { unlink(sockpath); } qemu_opts_del(sn_opts); if (device) { void *ret; pthread_join(client_thread, &ret); exit(ret != NULL); } else { exit(EXIT_SUCCESS); } }