X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=qemu-nbd.c;h=d91c02ce4976cc196ce9c3a97d5ce8b86dfc4684;hb=ea0e541812c515e0bbdf598d3237d6f0bee3fbbf;hp=3fb3d0c70d7e98d69a3aedb849427808a1980091;hpb=7a5ca8648b6a3ecd359bc3029b2988de452494e9;p=qemu.git diff --git a/qemu-nbd.c b/qemu-nbd.c index 3fb3d0c70..d91c02ce4 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -1,4 +1,4 @@ -/*\ +/* * Copyright (C) 2005 Anthony Liguori * * Network Block Device @@ -13,25 +13,30 @@ * 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, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * along with this program; if not, see . */ #include #include "block_int.h" #include "nbd.h" -#include #include #include #include #include +#include #include #include #include #include +#include +#include -int verbose; +#define SOCKET_PATH "/var/lock/qemu-nbd-%s" + +#define NBD_BUFFER_SIZE (1024*1024) + +static int verbose; static void usage(const char *name) { @@ -39,29 +44,37 @@ static void usage(const char *name) "Usage: %s [OPTIONS] FILE\n" "QEMU Disk Network Block Device Server\n" "\n" -" -p, --port=PORT port to listen on (default `1024')\n" +" -p, --port=PORT port to listen on (default `%d')\n" " -o, --offset=OFFSET offset into the image\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" " -r, --read-only export read-only\n" " -P, --partition=NUM only expose partition NUM\n" +" -s, --snapshot use snapshot file\n" +" -n, --nocache disable host cache\n" +" -c, --connect=DEV connect FILE to the local NBD device DEV\n" +" -d, --disconnect disconnect the specified device\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" " -h, --help display this help and exit\n" " -V, --version output version information and exit\n" "\n" "Report bugs to \n" - , name); + , name, NBD_DEFAULT_PORT, "DEVICE"); } static void version(const char *name) { printf( -"qemu-nbd version 0.0.1\n" +"%s version 0.0.1\n" "Written by Anthony Liguori.\n" "\n" "Copyright (C) 2006 Anthony Liguori .\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); } struct partition_record @@ -99,9 +112,12 @@ static int find_partition(BlockDriverState *bs, int partition, uint8_t data[512]; int i; int ext_partnum = 4; + int ret; - if (bdrv_read(bs, 0, data, 1)) - errx(EINVAL, "error while reading"); + if ((ret = bdrv_read(bs, 0, data, 1)) < 0) { + errno = -ret; + err(EXIT_FAILURE, "error while reading"); + } if (data[510] != 0x55 || data[511] != 0xaa) { errno = -EINVAL; @@ -119,8 +135,10 @@ static int find_partition(BlockDriverState *bs, int partition, uint8_t data1[512]; int j; - if (bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) - errx(EINVAL, "error while reading"); + if ((ret = bdrv_read(bs, mbr[i].start_sector_abs, data1, 1)) < 0) { + errno = -ret; + err(EXIT_FAILURE, "error while reading"); + } for (j = 0; j < 4; j++) { read_partition(&data1[446 + 16 * j], &ext[j]); @@ -145,41 +163,82 @@ static int find_partition(BlockDriverState *bs, int partition, return -1; } +static void show_parts(const char *device) +{ + if (fork() == 0) { + 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 != -1) + close(nbd); + exit(0); + } +} + int main(int argc, char **argv) { BlockDriverState *bs; off_t dev_offset = 0; off_t offset = 0; bool readonly = false; + bool disconnect = false; const char *bindto = "0.0.0.0"; - int port = 1024; - int sock, csock; + int port = NBD_DEFAULT_PORT; struct sockaddr_in addr; socklen_t addr_len = sizeof(addr); off_t fd_size; - const char *sopt = "hVbo:p:rsP:v"; + char *device = NULL; + char *socket = NULL; + char sockpath[128]; + const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t"; struct option lopt[] = { - { "help", 0, 0, 'h' }, - { "version", 0, 0, 'V' }, - { "bind", 1, 0, 'b' }, - { "port", 1, 0, 'p' }, - { "offset", 1, 0, 'o' }, - { "read-only", 0, 0, 'r' }, - { "partition", 1, 0, 'P' }, - { "snapshot", 0, 0, 's' }, - { "verbose", 0, 0, 'v' }, + { "help", 0, NULL, 'h' }, + { "version", 0, NULL, 'V' }, + { "bind", 1, NULL, 'b' }, + { "port", 1, NULL, 'p' }, + { "socket", 1, NULL, 'k' }, + { "offset", 1, NULL, 'o' }, + { "read-only", 0, NULL, 'r' }, + { "partition", 1, NULL, 'P' }, + { "connect", 1, NULL, 'c' }, + { "disconnect", 0, NULL, 'd' }, + { "snapshot", 0, NULL, 's' }, + { "nocache", 0, NULL, 'n' }, + { "shared", 1, NULL, 'e' }, + { "persistent", 0, NULL, 't' }, + { "verbose", 0, NULL, 'v' }, + { NULL, 0, NULL, 0 } }; int ch; int opt_ind = 0; int li; char *end; - bool snapshot = false; + int flags = BDRV_O_RDWR; int partition = -1; + int ret; + int shared = 1; + uint8_t *data; + fd_set fds; + int *sharing_fds; + int fd; + int i; + int nb_fds = 0; + int max_fd; + int persistent = 0; + uint32_t nbdflags; while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { switch (ch) { case 's': - snapshot = true; + flags |= BDRV_O_SNAPSHOT; + break; + case 'n': + flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; break; case 'b': bindto = optarg; @@ -187,32 +246,56 @@ int main(int argc, char **argv) case 'p': li = strtol(optarg, &end, 0); if (*end) { - errx(EINVAL, "Invalid port `%s'", optarg); + errx(EXIT_FAILURE, "Invalid port `%s'", optarg); } if (li < 1 || li > 65535) { - errx(EINVAL, "Port out of range `%s'", optarg); + errx(EXIT_FAILURE, "Port out of range `%s'", optarg); } port = (uint16_t)li; break; case 'o': dev_offset = strtoll (optarg, &end, 0); if (*end) { - errx(EINVAL, "Invalid offset `%s'", optarg); + errx(EXIT_FAILURE, "Invalid offset `%s'", optarg); } if (dev_offset < 0) { - errx(EINVAL, "Offset must be positive `%s'", optarg); + errx(EXIT_FAILURE, "Offset must be positive `%s'", optarg); } break; case 'r': readonly = true; + flags &= ~BDRV_O_RDWR; break; case 'P': partition = strtol(optarg, &end, 0); if (*end) - errx(EINVAL, "Invalid partition `%s'", optarg); + errx(EXIT_FAILURE, "Invalid partition `%s'", optarg); if (partition < 1 || partition > 8) - errx(EINVAL, "Invalid partition %d", partition); + errx(EXIT_FAILURE, "Invalid partition %d", partition); + break; + case 'k': + socket = optarg; + if (socket[0] != '/') + errx(EXIT_FAILURE, "socket path must be absolute\n"); break; + case 'd': + disconnect = true; + break; + case 'c': + device = optarg; + break; + case 'e': + shared = strtol(optarg, &end, 0); + if (*end) { + errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg); + } + if (shared < 1) { + errx(EXIT_FAILURE, "Shared device number must be greater than 0\n"); + } + break; + case 't': + persistent = 1; + break; case 'v': verbose = 1; break; @@ -225,51 +308,192 @@ int main(int argc, char **argv) exit(0); break; case '?': - errx(EINVAL, "Try `%s --help' for more information.", + errx(EXIT_FAILURE, "Try `%s --help' for more information.", argv[0]); } } if ((argc - optind) != 1) { - errx(EINVAL, "Invalid number of argument.\n" + errx(EXIT_FAILURE, "Invalid number of argument.\n" "Try `%s --help' for more information.", argv[0]); } + if (disconnect) { + fd = open(argv[optind], O_RDWR); + if (fd == -1) + err(EXIT_FAILURE, "Cannot open %s", argv[optind]); + + nbd_disconnect(fd); + + close(fd); + + printf("%s disconnected\n", argv[optind]); + + return 0; + } + bdrv_init(); bs = bdrv_new("hda"); - if (bs == NULL) - return 1; - if (bdrv_open(bs, argv[optind], snapshot) == -1) - return 1; + if ((ret = bdrv_open(bs, argv[optind], flags, NULL)) < 0) { + errno = -ret; + err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]); + } fd_size = bs->total_sectors * 512; if (partition != -1 && find_partition(bs, partition, &dev_offset, &fd_size)) - errx(errno, "Could not find partition %d", partition); + err(EXIT_FAILURE, "Could not find partition %d", partition); - sock = tcp_socket_incoming(bindto, port); - if (sock == -1) - return 1; + if (device) { + pid_t pid; + int sock; - csock = accept(sock, - (struct sockaddr *)&addr, - &addr_len); - if (csock == -1) - return 1; + /* want to fail before daemonizing */ + if (access(device, R_OK|W_OK) == -1) { + err(EXIT_FAILURE, "Could not access '%s'", device); + } + + if (!verbose) { + /* detach client and server */ + if (qemu_daemon(0, 0) == -1) { + err(EXIT_FAILURE, "Failed to daemonize"); + } + } - /* new fd_size is calculated by find_partition */ - if (nbd_negotiate(bs, csock, fd_size) == -1) + if (socket == NULL) { + snprintf(sockpath, sizeof(sockpath), SOCKET_PATH, + basename(device)); + socket = sockpath; + } + + pid = fork(); + if (pid < 0) + return 1; + if (pid != 0) { + off_t size; + size_t blocksize; + + ret = 0; + bdrv_close(bs); + + do { + sock = unix_socket_outgoing(socket); + if (sock == -1) { + if (errno != ENOENT && errno != ECONNREFUSED) { + ret = 1; + goto out; + } + sleep(1); /* wait children */ + } + } while (sock == -1); + + fd = open(device, O_RDWR); + if (fd == -1) { + ret = 1; + goto out; + } + + ret = nbd_receive_negotiate(sock, NULL, &nbdflags, + &size, &blocksize); + if (ret == -1) { + ret = 1; + goto out; + } + + ret = nbd_init(fd, sock, size, blocksize); + if (ret == -1) { + ret = 1; + goto out; + } + + printf("NBD device %s is now connected to file %s\n", + device, argv[optind]); + + /* update partition table */ + + show_parts(device); + + ret = nbd_client(fd); + if (ret) { + ret = 1; + } + close(fd); + out: + kill(pid, SIGTERM); + unlink(socket); + + return ret; + } + /* children */ + } + + sharing_fds = qemu_malloc((shared + 1) * sizeof(int)); + + if (socket) { + sharing_fds[0] = unix_socket_incoming(socket); + } else { + sharing_fds[0] = tcp_socket_incoming(bindto, port); + } + + if (sharing_fds[0] == -1) return 1; + max_fd = sharing_fds[0]; + nb_fds++; + + data = qemu_blockalign(bs, NBD_BUFFER_SIZE); + if (data == NULL) + errx(EXIT_FAILURE, "Cannot allocate data buffer"); + + do { + + FD_ZERO(&fds); + for (i = 0; i < nb_fds; i++) + FD_SET(sharing_fds[i], &fds); - while (nbd_trip(bs, csock, fd_size, dev_offset, &offset, readonly) == 0); + ret = select(max_fd + 1, &fds, NULL, NULL, NULL); + if (ret == -1) + break; + + if (FD_ISSET(sharing_fds[0], &fds)) + ret--; + for (i = 1; i < nb_fds && ret; i++) { + if (FD_ISSET(sharing_fds[i], &fds)) { + if (nbd_trip(bs, sharing_fds[i], fd_size, dev_offset, + &offset, readonly, data, NBD_BUFFER_SIZE) != 0) { + close(sharing_fds[i]); + nb_fds--; + sharing_fds[i] = sharing_fds[nb_fds]; + i--; + } + ret--; + } + } + /* new connection ? */ + if (FD_ISSET(sharing_fds[0], &fds)) { + if (nb_fds < shared + 1) { + sharing_fds[nb_fds] = accept(sharing_fds[0], + (struct sockaddr *)&addr, + &addr_len); + if (sharing_fds[nb_fds] != -1 && + nbd_negotiate(sharing_fds[nb_fds], fd_size) != -1) { + if (sharing_fds[nb_fds] > max_fd) + max_fd = sharing_fds[nb_fds]; + nb_fds++; + } + } + } + } while (persistent || nb_fds > 1); + qemu_vfree(data); - close(csock); - close(sock); + close(sharing_fds[0]); bdrv_close(bs); + qemu_free(sharing_fds); + if (socket) + unlink(socket); return 0; }