ARG_SHOW_STATUS,
ARG_SYSV_CONSOLE,
ARG_DESERIALIZE,
+ ARG_SWITCHEDROOT,
ARG_INTROSPECT,
ARG_DEFAULT_STD_OUTPUT,
ARG_DEFAULT_STD_ERROR
{ "sysv-console", optional_argument, NULL, ARG_SYSV_CONSOLE },
#endif
{ "deserialize", required_argument, NULL, ARG_DESERIALIZE },
+ { "switchedroot", no_argument, NULL, ARG_SWITCHEDROOT },
{ "introspect", optional_argument, NULL, ARG_INTROSPECT },
{ "default-standard-output", required_argument, NULL, ARG_DEFAULT_STD_OUTPUT, },
{ "default-standard-error", required_argument, NULL, ARG_DEFAULT_STD_ERROR, },
break;
}
+ case ARG_SWITCHEDROOT:
+ /* Nothing special yet */
+ break;
+
case ARG_INTROSPECT: {
const char * const * i = NULL;
}
static int do_switch_root(const char *switch_root) {
- int r;
+ 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;
+ bool remove_old_root;
if (path_equal(switch_root, "/"))
return 0;
- if (chdir(switch_root) < 0) {
+ if (stat(switch_root, &switch_root_stat) != 0) {
r = -errno;
+ log_error("failed to stat directory %s", switch_root);
goto fail;
}
+ remove_old_root = in_initrd();
+
+ 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;
+ }
+
+ if (remove_old_root)
+ cfd = open("/", O_RDONLY);
+
if (mount(switch_root, "/", NULL, MS_MOVE, NULL) < 0) {
r = -errno;
- chdir("/");
+ log_error("failed to mount moving %s to /", switch_root);
goto fail;
}
- if (chroot(".") < 0)
- log_warning("Failed to change root, ignoring: %s", strerror(-r));
+ if (chroot(".")) {
+ r = -errno;
+ log_error("failed to change root");
+ goto fail;
+ }
- /* FIXME: remove old root */
+ 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;
break;
}
+ /* If we have switched root, do all the special things */
+ for (j = 1; j < argc; j++)
+ if (streq(argv[j], "--switchedroot")) {
+ is_reexec = false;
+ break;
+ }
+
/* If we get started via the /sbin/init symlink then we are
called 'init'. After a subsequent reexecution we are then
called 'systemd'. That is confusing, hence let's call us
if (reexecute) {
const char **args;
- unsigned i;
+ unsigned i, args_size;
/* Close and disarm the watchdog, so that the new
* instance can reinitialize it, but doesn't get
if (switch_root)
do_switch_root(switch_root);
- args = newa(const char*, MAX(5, argc+1));
+ args_size = MAX(6, argc+1);
+ args = newa(const char*, args_size);
if (!switch_root_init) {
char sfd[16];
i = 0;
args[i++] = SYSTEMD_BINARY_PATH;
+ if (switch_root)
+ args[i++] = "--switchedroot";
args[i++] = arg_running_as == MANAGER_SYSTEM ? "--system" : "--user";
args[i++] = "--deserialize";
args[i++] = sfd;
args[i++] = NULL;
- assert(i <= ELEMENTSOF(args));
+ assert(i <= args_size);
execv(args[0], (char* const*) args);
}
* getopt() in argv[], and some cleanups in envp[],
* but let's hope that doesn't matter.) */
- if (serialization)
+ if (serialization) {
fclose(serialization);
+ serialization = NULL;
+ }
- if (fds)
+ if (fds) {
fdset_free(fds);
+ fds = NULL;
+ }
- i = 0;
- args[i++] = switch_root_init ? switch_root_init : "/sbin/init";
- for (j = 1; j < argc; j++)
+ for (j = 1, i = 1; j < argc; j++)
args[i++] = argv[j];
args[i++] = NULL;
+ assert(i <= args_size);
+
+ 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");
+ }
- assert(i <= ELEMENTSOF(args));
+ 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)