X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=qemu-nbd.c;h=c26c98ef1d97ae7b8a2b375572cdb2ba1e71213f;hb=8b7acc79b9adb4dda6cc867b90e3a1e873f4f7e8;hp=155b05840bd22ba50c11dd255ca24d669e0e3e2b;hpb=f3c6a169a39d188e98c17a0a0ebfa7f85e5aafdd;p=qemu.git diff --git a/qemu-nbd.c b/qemu-nbd.c index 155b05840..c26c98ef1 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -17,8 +17,9 @@ */ #include "qemu-common.h" -#include "block_int.h" -#include "nbd.h" +#include "block/block.h" +#include "block/nbd.h" +#include "qemu/main-loop.h" #include #include @@ -33,42 +34,59 @@ #include #include -#define SOCKET_PATH "/var/lock/qemu-nbd-%s" +#define SOCKET_PATH "/var/lock/qemu-nbd-%s" +#define QEMU_NBD_OPT_CACHE 1 +#define QEMU_NBD_OPT_AIO 2 +#define QEMU_NBD_OPT_DISCARD 3 static NBDExport *exp; static int verbose; -static char *device; static char *srcpath; static char *sockpath; -static bool sigterm_reported; -static bool nbd_started; +static int persistent = 0; +static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state; static int shared = 1; static int nb_fds; static void usage(const char *name) { - printf( + (printf) ( "Usage: %s [OPTIONS] FILE\n" "QEMU Disk Network Block Device Server\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" -" -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" +"Exposing part of the image:\n" +" -o, --offset=OFFSET offset into the image\n" +" -P, --partition=NUM only expose partition NUM\n" +"\n" +#ifdef __linux__ +"Kernel NBD client support:\n" +" -c, --connect=DEV connect FILE to the local NBD device DEV\n" +" -d, --disconnect disconnect the specified device\n" +"\n" +#endif +"\n" +"Block device options:\n" +" -r, --read-only export read-only\n" +" -s, --snapshot use snapshot file\n" +" -n, --nocache disable host cache\n" +" --cache=MODE set cache mode (none, writeback, ...)\n" +#ifdef CONFIG_LINUX_AIO +" --aio=MODE set AIO mode (native or threads)\n" +#endif +"\n" +"Report bugs to \n" , name, NBD_DEFAULT_PORT, "DEVICE"); } @@ -127,8 +145,7 @@ static int find_partition(BlockDriverState *bs, int partition, } if (data[510] != 0x55 || data[511] != 0xaa) { - errno = -EINVAL; - return -1; + return -EINVAL; } for (i = 0; i < 4; i++) { @@ -166,18 +183,18 @@ static int find_partition(BlockDriverState *bs, int partition, } } - errno = -ENOENT; - return -1; + return -ENOENT; } static void termsig_handler(int signum) { - sigterm_reported = true; + state = TERMINATE; qemu_notify_event(); } static void *show_parts(void *arg) { + char *device = arg; int nbd; /* linux just needs an open() to trigger @@ -186,7 +203,7 @@ static void *show_parts(void *arg) * modprobe nbd max_part=63 */ nbd = open(device, O_RDWR); - if (nbd != -1) { + if (nbd >= 0) { close(nbd); } return NULL; @@ -194,34 +211,39 @@ static void *show_parts(void *arg) static void *nbd_client_thread(void *arg) { - int fd = *(int *)arg; + char *device = arg; off_t size; size_t blocksize; uint32_t nbdflags; - int sock; + int fd, sock; int ret; pthread_t show_parts_thread; - do { - sock = unix_socket_outgoing(sockpath); - if (sock == -1) { - goto out; - } - } while (sock == -1); + sock = unix_socket_outgoing(sockpath); + if (sock < 0) { + goto out; + } ret = nbd_receive_negotiate(sock, NULL, &nbdflags, &size, &blocksize); - if (ret == -1) { + if (ret < 0) { + goto out; + } + + fd = open(device, O_RDWR); + if (fd < 0) { + /* Linux-only, we can use %m in printf. */ + fprintf(stderr, "Failed to open %s: %m", device); goto out; } ret = nbd_init(fd, sock, nbdflags, size, blocksize); - if (ret == -1) { + if (ret < 0) { goto out; } /* update partition table */ - pthread_create(&show_parts_thread, NULL, show_parts, NULL); + pthread_create(&show_parts_thread, NULL, show_parts, device); if (verbose) { fprintf(stderr, "NBD device %s is now connected to %s\n", @@ -249,10 +271,20 @@ static int nbd_can_accept(void *opaque) return nb_fds < shared; } +static void nbd_export_closed(NBDExport *exp) +{ + assert(state == TERMINATING); + state = TERMINATED; +} + static void nbd_client_closed(NBDClient *client) { nb_fds--; + if (nb_fds == 0 && !persistent && state == RUNNING) { + state = TERMINATE; + } qemu_notify_event(); + nbd_client_put(client); } static void nbd_accept(void *opaque) @@ -262,8 +294,12 @@ static void nbd_accept(void *opaque) socklen_t addr_len = sizeof(addr); int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len); - nbd_started = true; - if (fd != -1 && nbd_client_new(exp, fd, nbd_client_closed)) { + if (state >= TERMINATE) { + close(fd); + return; + } + + if (fd >= 0 && nbd_client_new(exp, fd, nbd_client_closed)) { nb_fds++; } } @@ -271,13 +307,15 @@ static void nbd_accept(void *opaque) int main(int argc, char **argv) { BlockDriverState *bs; + BlockDriver *drv; off_t dev_offset = 0; uint32_t nbdflags = 0; bool disconnect = false; const char *bindto = "0.0.0.0"; + char *device = NULL; int port = NBD_DEFAULT_PORT; off_t fd_size; - const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t"; + const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:t"; struct option lopt[] = { { "help", 0, NULL, 'h' }, { "version", 0, NULL, 'V' }, @@ -291,7 +329,13 @@ int main(int argc, char **argv) { "disconnect", 0, NULL, 'd' }, { "snapshot", 0, NULL, 's' }, { "nocache", 0, NULL, 'n' }, + { "cache", 1, NULL, QEMU_NBD_OPT_CACHE }, +#ifdef CONFIG_LINUX_AIO + { "aio", 1, NULL, QEMU_NBD_OPT_AIO }, +#endif + { "discard", 1, NULL, QEMU_NBD_OPT_DISCARD }, { "shared", 1, NULL, 'e' }, + { "format", 1, NULL, 'f' }, { "persistent", 0, NULL, 't' }, { "verbose", 0, NULL, 'v' }, { NULL, 0, NULL, 0 } @@ -304,8 +348,14 @@ int main(int argc, char **argv) int partition = -1; int ret; int fd; - int persistent = 0; + bool seen_cache = false; + bool seen_discard = false; +#ifdef CONFIG_LINUX_AIO + bool seen_aio = false; +#endif pthread_t client_thread; + const char *fmt = NULL; + Error *local_err = NULL; /* The client thread uses SIGTERM to interrupt the server. A signal * handler ensures that "qemu-nbd -v -c" exits with a nice status code. @@ -321,7 +371,40 @@ int main(int argc, char **argv) flags |= BDRV_O_SNAPSHOT; break; case 'n': - flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; + optarg = (char *) "none"; + /* fallthrough */ + case QEMU_NBD_OPT_CACHE: + if (seen_cache) { + errx(EXIT_FAILURE, "-n and --cache can only be specified once"); + } + seen_cache = true; + if (bdrv_parse_cache_flags(optarg, &flags) == -1) { + errx(EXIT_FAILURE, "Invalid cache mode `%s'", optarg); + } + break; +#ifdef CONFIG_LINUX_AIO + case QEMU_NBD_OPT_AIO: + if (seen_aio) { + errx(EXIT_FAILURE, "--aio can only be specified once"); + } + seen_aio = true; + if (!strcmp(optarg, "native")) { + flags |= BDRV_O_NATIVE_AIO; + } else if (!strcmp(optarg, "threads")) { + /* this is the default */ + } else { + errx(EXIT_FAILURE, "invalid aio mode `%s'", optarg); + } + break; +#endif + case QEMU_NBD_OPT_DISCARD: + if (seen_discard) { + errx(EXIT_FAILURE, "--discard can only be specified once"); + } + seen_discard = true; + if (bdrv_parse_discard_flags(optarg, &flags) == -1) { + errx(EXIT_FAILURE, "Invalid discard mode `%s'", optarg); + } break; case 'b': bindto = optarg; @@ -376,6 +459,9 @@ int main(int argc, char **argv) errx(EXIT_FAILURE, "Shared device number must be greater than 0\n"); } break; + case 'f': + fmt = optarg; + break; case 't': persistent = 1; break; @@ -404,9 +490,9 @@ int main(int argc, char **argv) if (disconnect) { fd = open(argv[optind], O_RDWR); - if (fd == -1) + if (fd < 0) { err(EXIT_FAILURE, "Cannot open %s", argv[optind]); - + } nbd_disconnect(fd); close(fd); @@ -421,7 +507,7 @@ int main(int argc, char **argv) pid_t pid; int ret; - if (qemu_pipe(stderr_fd) == -1) { + if (qemu_pipe(stderr_fd) < 0) { err(EXIT_FAILURE, "Error setting up communication pipe"); } @@ -431,11 +517,11 @@ int main(int argc, char **argv) pid = fork(); if (pid == 0) { close(stderr_fd[0]); - ret = qemu_daemon(0, 0); + ret = qemu_daemon(1, 0); /* Temporarily redirect stderr to the parent's pipe... */ dup2(stderr_fd[1], STDERR_FILENO); - if (ret == -1) { + if (ret < 0) { err(EXIT_FAILURE, "Failed to daemonize"); } @@ -453,11 +539,11 @@ int main(int argc, char **argv) while ((ret = read(stderr_fd[0], buf, 1024)) > 0) { errors = true; ret = qemu_write_full(STDERR_FILENO, buf, ret); - if (ret == -1) { + if (ret < 0) { exit(EXIT_FAILURE); } } - if (ret == -1) { + if (ret < 0) { err(EXIT_FAILURE, "Cannot read from daemon"); } @@ -468,39 +554,44 @@ int main(int argc, char **argv) } } - if (device) { - /* Open before spawning new threads. In the future, we may - * drop privileges after opening. - */ - fd = open(device, O_RDWR); - if (fd == -1) { - err(EXIT_FAILURE, "Failed to open %s", device); - } - - if (sockpath == NULL) { - sockpath = g_malloc(128); - snprintf(sockpath, 128, SOCKET_PATH, basename(device)); - } + if (device != NULL && sockpath == NULL) { + sockpath = g_malloc(128); + snprintf(sockpath, 128, SOCKET_PATH, basename(device)); } + qemu_init_main_loop(); bdrv_init(); atexit(bdrv_close_all); + if (fmt) { + drv = bdrv_find_format(fmt); + if (!drv) { + errx(EXIT_FAILURE, "Unknown file format '%s'", fmt); + } + } else { + drv = NULL; + } + bs = bdrv_new("hda"); srcpath = argv[optind]; - if ((ret = bdrv_open(bs, srcpath, flags, NULL)) < 0) { + ret = bdrv_open(bs, srcpath, NULL, flags, drv, &local_err); + if (ret < 0) { errno = -ret; - err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]); + err(EXIT_FAILURE, "Failed to bdrv_open '%s': %s", argv[optind], + error_get_pretty(local_err)); } - fd_size = bs->total_sectors * 512; + fd_size = bdrv_getlength(bs); - if (partition != -1 && - find_partition(bs, partition, &dev_offset, &fd_size)) { - err(EXIT_FAILURE, "Could not find partition %d", partition); + if (partition != -1) { + ret = find_partition(bs, partition, &dev_offset, &fd_size); + if (ret < 0) { + errno = -ret; + err(EXIT_FAILURE, "Could not find partition %d", partition); + } } - exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags); + exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed); if (sockpath) { fd = unix_socket_incoming(sockpath); @@ -508,14 +599,14 @@ int main(int argc, char **argv) fd = tcp_socket_incoming(bindto, port); } - if (fd == -1) { + if (fd < 0) { return 1; } if (device) { int ret; - ret = pthread_create(&client_thread, NULL, nbd_client_thread, &fd); + ret = pthread_create(&client_thread, NULL, nbd_client_thread, device); if (ret != 0) { errx(EXIT_FAILURE, "Failed to create client thread: %s", strerror(ret)); @@ -525,15 +616,27 @@ int main(int argc, char **argv) memset(&client_thread, 0, sizeof(client_thread)); } - qemu_init_main_loop(); qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL, (void *)(uintptr_t)fd); + /* now when the initialization is (almost) complete, chdir("/") + * to free any busy filesystems */ + if (chdir("/") < 0) { + err(EXIT_FAILURE, "Could not chdir to root directory"); + } + + state = RUNNING; do { main_loop_wait(false); - } while (!sigterm_reported && (persistent || !nbd_started || nb_fds > 0)); + if (state == TERMINATE) { + state = TERMINATING; + nbd_export_close(exp); + nbd_export_put(exp); + exp = NULL; + } + } while (state != TERMINATED); - nbd_export_close(exp); + bdrv_close(bs); if (sockpath) { unlink(sockpath); }