#include <sys/wait.h>
#include <fcntl.h>
#include <sys/prctl.h>
+#include <sys/mount.h>
#include "manager.h"
#include "log.h"
#include "def.h"
#include "virt.h"
#include "watchdog.h"
+#include "path-util.h"
#include "mount-setup.h"
#include "loopback-setup.h"
sleep(10);
}
+static int do_switch_root(const char *switch_root) {
+ int r=0;
+ /* Don't try to unmount the old "/", there's no way to do it. */
+ const char *umounts[] = { "/dev", "/proc", "/sys", "/run", NULL };
+ int i;
+ int cfd = -1;
+ struct stat switch_root_stat, sb;
+
+ if (path_equal(switch_root, "/"))
+ return 0;
+
+ if (stat(switch_root, &switch_root_stat) != 0) {
+ r = -errno;
+ log_error("failed to stat directory %s", switch_root);
+ goto fail;
+ }
+
+ for (i = 0; umounts[i] != NULL; i++) {
+ char newmount[PATH_MAX];
+
+ snprintf(newmount, sizeof(newmount), "%s%s", switch_root, umounts[i]);
+
+ if ((stat(newmount, &sb) != 0) || (sb.st_dev != switch_root_stat.st_dev)) {
+ /* mount point seems to be mounted already or stat failed */
+ umount2(umounts[i], MNT_DETACH);
+ continue;
+ }
+
+ if (mount(umounts[i], newmount, NULL, MS_MOVE, NULL) < 0) {
+ log_error("failed to mount moving %s to %s",
+ umounts[i], newmount);
+ log_error("forcing unmount of %s", umounts[i]);
+ umount2(umounts[i], MNT_FORCE);
+ }
+ }
+
+ if (chdir(switch_root)) {
+ r = -errno;
+ log_error("failed to change directory to %s", switch_root);
+ goto fail;
+ }
+
+ cfd = open("/", O_RDONLY);
+
+ if (mount(switch_root, "/", NULL, MS_MOVE, NULL) < 0) {
+ r = -errno;
+ log_error("failed to mount moving %s to /", switch_root);
+ goto fail;
+ }
+
+ if (chroot(".")) {
+ r = -errno;
+ log_error("failed to change root");
+ goto fail;
+ }
+
+ if (cfd >= 0) {
+ rm_rf_children(cfd, false, false);
+ close(cfd);
+ cfd=-1;
+ }
+
+ return 0;
+
+fail:
+ if (cfd >= 0)
+ close(cfd);
+
+ log_error("Failed to switch root, ignoring: %s", strerror(-r));
+
+ return r;
+}
+
int main(int argc, char *argv[]) {
Manager *m = NULL;
int r, retval = EXIT_FAILURE;
int j;
bool loaded_policy = false;
bool arm_reboot_watchdog = false;
+ char *switch_root = NULL, *switch_root_init = NULL;
#ifdef HAVE_SYSV_COMPAT
if (getpid() != 1 && strstr(program_invocation_short_name, "init")) {
break;
case MANAGER_REEXECUTE:
+
if (prepare_reexecute(m, &serialization, &fds) < 0)
goto finish;
log_notice("Reexecuting.");
goto finish;
+ case MANAGER_SWITCH_ROOT:
+ /* Steal the switch root parameters */
+ switch_root = m->switch_root;
+ switch_root_init = m->switch_root_init;
+ m->switch_root = m->switch_root_init = NULL;
+
+ if (!switch_root_init)
+ if (prepare_reexecute(m, &serialization, &fds) < 0)
+ goto finish;
+
+ reexecute = true;
+ log_notice("Switching root.");
+ goto finish;
+
case MANAGER_REBOOT:
case MANAGER_POWEROFF:
case MANAGER_HALT:
free_join_controllers();
dbus_shutdown();
-
label_finish();
if (reexecute) {
- const char *args[15];
- unsigned i = 0;
- char sfd[16];
+ const char **args;
+ unsigned i, args_size;
- assert(serialization);
- assert(fds);
+ /* Close and disarm the watchdog, so that the new
+ * instance can reinitialize it, but doesn't get
+ * rebooted while we do that */
+ watchdog_close(true);
- args[i++] = SYSTEMD_BINARY_PATH;
+ if (switch_root)
+ do_switch_root(switch_root);
- args[i++] = "--log-level";
- args[i++] = log_level_to_string(log_get_max_level());
+ args_size = MAX(5, argc+1);
+ args = newa(const char*, args_size);
- args[i++] = "--log-target";
- args[i++] = log_target_to_string(log_get_target());
+ if (!switch_root_init) {
+ char sfd[16];
- if (arg_running_as == MANAGER_SYSTEM)
- args[i++] = "--system";
- else
- args[i++] = "--user";
+ /* First try to spawn ourselves with the right
+ * path, and with full serialization. We do
+ * this only if the user didn't specify an
+ * explicit init to spawn. */
- if (arg_dump_core)
- args[i++] = "--dump-core";
+ assert(serialization);
+ assert(fds);
- if (arg_crash_shell)
- args[i++] = "--crash-shell";
+ snprintf(sfd, sizeof(sfd), "%i", fileno(serialization));
+ char_array_0(sfd);
- if (arg_confirm_spawn)
- args[i++] = "--confirm-spawn";
+ i = 0;
+ args[i++] = SYSTEMD_BINARY_PATH;
+ args[i++] = arg_running_as == MANAGER_SYSTEM ? "--system" : "--user";
+ args[i++] = "--deserialize";
+ args[i++] = sfd;
+ args[i++] = NULL;
- if (arg_show_status)
- args[i++] = "--show-status=1";
- else
- args[i++] = "--show-status=0";
+ assert(i <= args_size);
+ execv(args[0], (char* const*) args);
+ }
-#ifdef HAVE_SYSV_COMPAT
- if (arg_sysv_console)
- args[i++] = "--sysv-console=1";
- else
- args[i++] = "--sysv-console=0";
-#endif
+ /* Try the fallback, if there is any, without any
+ * serialization. We pass the original argv[] and
+ * envp[]. (Well, modulo the ordering changes due to
+ * getopt() in argv[], and some cleanups in envp[],
+ * but let's hope that doesn't matter.) */
- snprintf(sfd, sizeof(sfd), "%i", fileno(serialization));
- char_array_0(sfd);
+ if (serialization) {
+ fclose(serialization);
+ serialization = NULL;
+ }
- args[i++] = "--deserialize";
- args[i++] = sfd;
+ if (fds) {
+ fdset_free(fds);
+ fds = NULL;
+ }
+ for (j = 1, i = 1; j < argc; j++)
+ args[i++] = argv[j];
args[i++] = NULL;
+ assert(i <= args_size);
- assert(i <= ELEMENTSOF(args));
-
- /* Close and disarm the watchdog, so that the new
- * instance can reinitialize it, but doesn't get
- * rebooted while we do that */
- watchdog_close(true);
+ if (switch_root_init) {
+ args[0] = switch_root_init;
+ execv(args[0], (char* const*) args);
+ log_warning("Failed to execute configured init, trying fallback: %m");
+ }
+ args[0] = "/sbin/init";
execv(args[0], (char* const*) args);
- log_error("Failed to reexecute: %m");
+ log_warning("Failed to execute /sbin/init, trying fallback: %m");
+
+ args[0] = "/bin/sh";
+ args[1] = NULL;
+ execv(args[0], (char* const*) args);
+ log_error("Failed to execute /bin/sh, giving up: %m");
}
if (serialization)