@@ -31,6 +31,7 @@
#include <arpa/inet.h>
#include <signal.h>
#include <libgen.h>
+#include <pthread.h>
#define SOCKET_PATH "/var/lock/qemu-nbd-%s"
@@ -38,6 +39,9 @@
static int sigterm_wfd;
static int verbose;
+static char *device;
+static char *srcpath;
+static char *sockpath;
static void usage(const char *name)
{
@@ -172,21 +176,70 @@ static void termsig_handler(int signum)
}
}
-static void show_parts(const char *device)
+static void *show_parts(void *arg)
{
- if (fork() == 0) {
- int nbd;
+ 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);
+ }
+ return NULL;
+}
- /* 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 *nbd_client_thread(void *arg)
+{
+ int fd = *(int *)arg;
+ off_t size;
+ size_t blocksize;
+ uint32_t nbdflags;
+ int sock;
+ int ret;
+ pthread_t show_parts_thread;
+
+ do {
+ sock = unix_socket_outgoing(sockpath);
+ if (sock == -1) {
+ if (errno != ENOENT && errno != ECONNREFUSED) {
+ goto out;
+ }
+ sleep(1); /* wait parent */
+ }
+ } while (sock == -1);
+
+ ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
+ &size, &blocksize);
+ if (ret == -1) {
+ goto out;
+ }
+
+ ret = nbd_init(fd, sock, nbdflags, size, blocksize);
+ if (ret == -1) {
+ goto out;
+ }
+
+ /* update partition table */
+ pthread_create(&show_parts_thread, NULL, show_parts, NULL);
+
+ fprintf(stderr, "NBD device %s is now connected to %s\n",
+ device, srcpath);
+
+ 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;
}
int main(int argc, char **argv)
@@ -201,8 +254,6 @@ int main(int argc, char **argv)
struct sockaddr_in addr;
socklen_t addr_len = sizeof(addr);
off_t fd_size;
- char *device = NULL;
- char *sockpath = NULL;
const char *sopt = "hVb:o:p:rsnP:c:dvk:e:t";
struct option lopt[] = {
{ "help", 0, NULL, 'h' },
@@ -238,8 +289,11 @@ int main(int argc, char **argv)
int nb_fds = 0;
int max_fd;
int persistent = 0;
+ pthread_t client_thread;
- /* Set up a SIGTERM handler so that we exit with a nice status code. */
+ /* 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;
int sigterm_fd[2];
if (qemu_pipe(sigterm_fd) == -1) {
@@ -356,9 +410,10 @@ int main(int argc, char **argv)
bs = bdrv_new("hda");
- if ((ret = bdrv_open(bs, argv[optind], flags, NULL)) < 0) {
+ srcpath = argv[optind];
+ if ((ret = bdrv_open(bs, srcpath, flags, NULL)) < 0) {
errno = -ret;
- err(EXIT_FAILURE, "Failed to bdrv_open '%s'", argv[optind]);
+ err(EXIT_FAILURE, "Failed to bdrv_open '%s'", srcpath);
}
fd_size = bs->total_sectors * 512;
@@ -368,12 +423,14 @@ int main(int argc, char **argv)
err(EXIT_FAILURE, "Could not find partition %d", partition);
if (device) {
- pid_t pid;
- int sock;
+ int ret;
- /* want to fail before daemonizing */
- if (access(device, R_OK|W_OK) == -1) {
- err(EXIT_FAILURE, "Could not access '%s'", 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 (!verbose) {
@@ -388,64 +445,14 @@ int main(int argc, char **argv)
snprintf(sockpath, 128, SOCKET_PATH, basename(device));
}
- 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(sockpath);
- 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, nbdflags, 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);
-
- return ret;
+ ret = pthread_create(&client_thread, NULL, nbd_client_thread, &fd);
+ if (ret != 0) {
+ errx(EXIT_FAILURE, "Failed to create client thread: %s",
+ strerror(ret));
}
- /* children */
+ } else {
+ /* Shut up GCC warnings. */
+ memset(&client_thread, 0, sizeof(client_thread));
}
sharing_fds = g_malloc((shared + 1) * sizeof(int));
@@ -517,5 +524,11 @@ int main(int argc, char **argv)
unlink(sockpath);
}
- return 0;
+ if (device) {
+ void *ret;
+ pthread_join(client_thread, &ret);
+ exit(ret != NULL);
+ } else {
+ exit(EXIT_SUCCESS);
+ }
}