#include <libgen.h>
#include <pthread.h>
-#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
static NBDExport *exp;
static int verbose;
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 <anthony@codemonkey.ws>\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 <qemu-devel@nongnu.org>\n"
, name, NBD_DEFAULT_PORT, "DEVICE");
}
static void termsig_handler(int signum)
{
- sigterm_reported = true;
+ state = TERMINATE;
qemu_notify_event();
}
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)
socklen_t addr_len = sizeof(addr);
int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
- nbd_started = true;
+ if (state >= TERMINATE) {
+ close(fd);
+ return;
+ }
+
if (fd >= 0 && nbd_client_new(exp, fd, nbd_client_closed)) {
nb_fds++;
}
{ "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
{ "shared", 1, NULL, 'e' },
{ "persistent", 0, NULL, 't' },
{ "verbose", 0, NULL, 'v' },
int partition = -1;
int ret;
int fd;
- int persistent = 0;
+ bool seen_cache = false;
+#ifdef CONFIG_LINUX_AIO
+ bool seen_aio = false;
+#endif
pthread_t client_thread;
/* The client thread uses SIGTERM to interrupt the server. A signal
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 'b':
bindto = optarg;
break;
}
}
- 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);
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);
}
projects / qemu.git / blobdiff