*/
#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 <stdarg.h>
#include <stdio.h>
#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
+#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 <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");
}
}
if (data[510] != 0x55 || data[511] != 0xaa) {
- errno = -EINVAL;
- return -1;
+ return -EINVAL;
}
for (i = 0; i < 4; i++) {
}
}
- 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
* modprobe nbd max_part=63
*/
nbd = open(device, O_RDWR);
- if (nbd != -1) {
+ if (nbd >= 0) {
close(nbd);
}
return NULL;
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",
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 (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++;
}
}
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' },
{ "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 }
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.
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;
errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
}
break;
+ case 'f':
+ fmt = optarg;
+ break;
case 't':
persistent = 1;
break;
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);
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");
}
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");
}
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");
}
}
}
- 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);
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));
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);
}
projects / qemu.git / blobdiff