X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/d6aa671f1853cc5589c180861c720ff04af13738..837c36e7871a74dda78d2ca89d9027b19553a871:/qemu-nbd.c
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 59bd2f14f3..5a0300eb07 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -13,12 +13,11 @@
* 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
-#include <qemu-common.h>
-#include "block_int.h"
+#include "qemu-common.h"
+#include "block.h"
#include "nbd.h"
#include <stdarg.h>
@@ -31,12 +30,19 @@
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <signal.h>
+#include <libgen.h>
+#include <pthread.h>
#define SOCKET_PATH "/var/lock/qemu-nbd-%s"
-#define NBD_BUFFER_SIZE (1024*1024)
-
+static NBDExport *exp;
static int verbose;
+static char *srcpath;
+static char *sockpath;
+static bool sigterm_reported;
+static bool nbd_started;
+static int shared = 1;
+static int nb_fds;
static void usage(const char *name)
{
@@ -44,7 +50,7 @@ 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"
@@ -62,7 +68,7 @@ static void usage(const char *name)
" -V, --version output version information and exit\n"
"\n"
"Report bugs to <anthony@codemonkey.ws>\n"
- , name, "DEVICE");
+ , name, NBD_DEFAULT_PORT, "DEVICE");
}
static void version(const char *name)
@@ -112,13 +118,15 @@ 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;
- return -1;
+ return -EINVAL;
}
for (i = 0; i < 4; i++) {
@@ -132,8 +140,10 @@ 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]);
@@ -154,24 +164,110 @@ static int find_partition(BlockDriverState *bs, int partition,
}
}
- errno = -ENOENT;
- return -1;
+ return -ENOENT;
}
-static void show_parts(const char *device)
+static void termsig_handler(int signum)
{
- if (fork() == 0) {
- int nbd;
+ sigterm_reported = true;
+ qemu_notify_event();
+}
- /* 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);
+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;
+ off_t size;
+ size_t blocksize;
+ uint32_t nbdflags;
+ int fd, sock;
+ int ret;
+ pthread_t show_parts_thread;
+
+ sock = unix_socket_outgoing(sockpath);
+ if (sock < 0) {
+ goto out;
+ }
+
+ ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
+ &size, &blocksize);
+ 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 < 0) {
+ 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);
+ }
+
+ ret = nbd_client(fd);
+ if (ret) {
+ goto out;
+ }
+ close(fd);
+ kill(getpid(), SIGTERM);
+ return (void *) EXIT_SUCCESS;
+
+out:
+ kill(getpid(), SIGTERM);
+ return (void *) EXIT_FAILURE;
+}
+
+static int nbd_can_accept(void *opaque)
+{
+ return nb_fds < shared;
+}
+
+static void nbd_client_closed(NBDClient *client)
+{
+ nb_fds--;
+ qemu_notify_event();
+}
+
+static void nbd_accept(void *opaque)
+{
+ int server_fd = (uintptr_t) opaque;
+ struct sockaddr_in addr;
+ socklen_t addr_len = sizeof(addr);
+
+ int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
+ nbd_started = true;
+ if (fd >= 0 && nbd_client_new(exp, fd, nbd_client_closed)) {
+ nb_fds++;
}
}
@@ -179,52 +275,49 @@ int main(int argc, char **argv)
{
BlockDriverState *bs;
off_t dev_offset = 0;
- off_t offset = 0;
- bool readonly = false;
+ uint32_t nbdflags = 0;
bool disconnect = false;
const char *bindto = "0.0.0.0";
- int port = 1024;
- struct sockaddr_in addr;
- socklen_t addr_len = sizeof(addr);
- off_t fd_size;
char *device = NULL;
- char *socket = NULL;
- char sockpath[128];
+ int port = NBD_DEFAULT_PORT;
+ off_t fd_size;
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' },
- { "socket", 1, 0, 'k' },
- { "offset", 1, 0, 'o' },
- { "read-only", 0, 0, 'r' },
- { "partition", 1, 0, 'P' },
- { "connect", 1, 0, 'c' },
- { "disconnect", 0, 0, 'd' },
- { "snapshot", 0, 0, 's' },
- { "nocache", 0, 0, 'n' },
- { "shared", 1, 0, 'e' },
- { "persistent", 0, 0, 't' },
- { "verbose", 0, 0, 'v' },
- { NULL, 0, 0, 0 }
+ { "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;
- int flags = 0;
+ 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;
+ pthread_t client_thread;
+
+ /* The client thread uses SIGTERM to interrupt the server. A signal
+ * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
+ */
+ struct sigaction sa_sigterm;
+ memset(&sa_sigterm, 0, sizeof(sa_sigterm));
+ sa_sigterm.sa_handler = termsig_handler;
+ sigaction(SIGTERM, &sa_sigterm, NULL);
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
@@ -232,7 +325,7 @@ int main(int argc, char **argv)
flags |= BDRV_O_SNAPSHOT;
break;
case 'n':
- flags |= BDRV_O_NOCACHE;
+ flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB;
break;
case 'b':
bindto = optarg;
@@ -240,36 +333,37 @@ 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;
+ nbdflags |= NBD_FLAG_READ_ONLY;
+ 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(EINVAL, "socket path must be absolute\n");
+ sockpath = optarg;
+ if (sockpath[0] != '/')
+ errx(EXIT_FAILURE, "socket path must be absolute\n");
break;
case 'd':
disconnect = true;
@@ -280,10 +374,10 @@ int main(int argc, char **argv)
case 'e':
shared = strtol(optarg, &end, 0);
if (*end) {
- errx(EINVAL, "Invalid shared device number '%s'", optarg);
+ errx(EXIT_FAILURE, "Invalid shared device number '%s'", optarg);
}
if (shared < 1) {
- errx(EINVAL, "Shared device number must be greater than 0\n");
+ errx(EXIT_FAILURE, "Shared device number must be greater than 0\n");
}
break;
case 't':
@@ -301,22 +395,22 @@ 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)
- errx(errno, "Cannot open %s", argv[optind]);
-
+ if (fd < 0) {
+ err(EXIT_FAILURE, "Cannot open %s", argv[optind]);
+ }
nbd_disconnect(fd);
close(fd);
@@ -326,153 +420,132 @@ int main(int argc, char **argv)
return 0;
}
- bdrv_init();
-
- bs = bdrv_new("hda");
- if (bs == NULL)
- return 1;
-
- if (bdrv_open(bs, argv[optind], flags) == -1)
- return 1;
-
- 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);
-
- if (device) {
+ if (device && !verbose) {
+ int stderr_fd[2];
pid_t pid;
- int sock;
-
- if (!verbose)
- daemon(0, 0); /* detach client and server */
+ int ret;
- if (socket == NULL) {
- sprintf(sockpath, SOCKET_PATH, basename(device));
- socket = sockpath;
+ if (qemu_pipe(stderr_fd) < 0) {
+ err(EXIT_FAILURE, "Error setting up communication pipe");
}
+ /* Now daemonize, but keep a communication channel open to
+ * print errors and exit with the proper status code.
+ */
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)
- goto out;
- sleep(1); /* wait children */
- }
- } while (sock == -1);
-
- fd = open(device, O_RDWR);
- if (fd == -1) {
- ret = 1;
- goto out;
+ if (pid == 0) {
+ close(stderr_fd[0]);
+ ret = qemu_daemon(1, 0);
+
+ /* Temporarily redirect stderr to the parent's pipe... */
+ dup2(stderr_fd[1], STDERR_FILENO);
+ if (ret < 0) {
+ err(EXIT_FAILURE, "Failed to daemonize");
}
- ret = nbd_receive_negotiate(sock, &size, &blocksize);
- if (ret == -1) {
- ret = 1;
- goto out;
+ /* ... 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);
+ }
}
-
- ret = nbd_init(fd, sock, size, blocksize);
- if (ret == -1) {
- ret = 1;
- goto out;
+ if (ret < 0) {
+ err(EXIT_FAILURE, "Cannot read from daemon");
}
- printf("NBD device %s is now connected to file %s\n",
- device, argv[optind]);
+ /* Usually the daemon should not print any message.
+ * Exit with zero status in that case.
+ */
+ exit(errors);
+ }
+ }
+
+ if (device != NULL && sockpath == NULL) {
+ sockpath = g_malloc(128);
+ snprintf(sockpath, 128, SOCKET_PATH, basename(device));
+ }
- /* update partition table */
+ bdrv_init();
+ atexit(bdrv_close_all);
- show_parts(device);
+ bs = bdrv_new("hda");
+ srcpath = argv[optind];
+ if ((ret = bdrv_open(bs, srcpath, flags, NULL)) < 0) {
+ errno = -ret;
+ err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]);
+ }
- nbd_client(fd, sock);
- close(fd);
- out:
- kill(pid, SIGTERM);
- unlink(socket);
+ fd_size = bdrv_getlength(bs);
- return ret;
+ 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);
}
- /* children */
}
- sharing_fds = qemu_malloc((shared + 1) * sizeof(int));
- if (sharing_fds == NULL)
- errx(ENOMEM, "Cannot allocate sharing fds");
+ exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags);
- if (socket) {
- sharing_fds[0] = unix_socket_incoming(socket);
+ if (sockpath) {
+ fd = unix_socket_incoming(sockpath);
} else {
- sharing_fds[0] = tcp_socket_incoming(bindto, port);
+ fd = tcp_socket_incoming(bindto, port);
}
- if (sharing_fds[0] == -1)
+ if (fd < 0) {
return 1;
- max_fd = sharing_fds[0];
- nb_fds++;
+ }
- data = qemu_memalign(512, NBD_BUFFER_SIZE);
- if (data == NULL)
- errx(ENOMEM, "Cannot allocate data buffer");
+ if (device) {
+ int ret;
- do {
+ ret = pthread_create(&client_thread, NULL, nbd_client_thread, device);
+ if (ret != 0) {
+ errx(EXIT_FAILURE, "Failed to create client thread: %s",
+ strerror(ret));
+ }
+ } else {
+ /* Shut up GCC warnings. */
+ memset(&client_thread, 0, sizeof(client_thread));
+ }
- FD_ZERO(&fds);
- for (i = 0; i < nb_fds; i++)
- FD_SET(sharing_fds[i], &fds);
+ qemu_init_main_loop();
+ qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
+ (void *)(uintptr_t)fd);
- ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
- if (ret == -1)
- break;
+ /* 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");
+ }
- 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_free(data);
+ do {
+ main_loop_wait(false);
+ } while (!sigterm_reported && (persistent || !nbd_started || nb_fds > 0));
- close(sharing_fds[0]);
- bdrv_close(bs);
- qemu_free(sharing_fds);
- if (socket)
- unlink(socket);
+ nbd_export_close(exp);
+ if (sockpath) {
+ unlink(sockpath);
+ }
- return 0;
+ if (device) {
+ void *ret;
+ pthread_join(client_thread, &ret);
+ exit(ret != NULL);
+ } else {
+ exit(EXIT_SUCCESS);
+ }
}