/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 ProFUSION embedded systems systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <sys/mman.h> #include <sys/types.h> #include <sys/reboot.h> #include <linux/reboot.h> #include <sys/wait.h> #include <sys/stat.h> #include <sys/mount.h> #include <sys/syscall.h> #include <fcntl.h> #include <dirent.h> #include <errno.h> #include <unistd.h> #include <signal.h> #include <stdbool.h> #include <stdlib.h> #include <string.h> #include <getopt.h> #include "missing.h" #include "log.h" #include "fileio.h" #include "umount.h" #include "util.h" #include "mkdir.h" #include "virt.h" #include "watchdog.h" #include "killall.h" #include "cgroup-util.h" #include "def.h" #define FINALIZE_ATTEMPTS 50 static char* arg_verb; static int parse_argv(int argc, char *argv[]) { enum { ARG_LOG_LEVEL = 0x100, ARG_LOG_TARGET, ARG_LOG_COLOR, ARG_LOG_LOCATION, }; static const struct option options[] = { { "log-level", required_argument, NULL, ARG_LOG_LEVEL }, { "log-target", required_argument, NULL, ARG_LOG_TARGET }, { "log-color", optional_argument, NULL, ARG_LOG_COLOR }, { "log-location", optional_argument, NULL, ARG_LOG_LOCATION }, {} }; int c, r; assert(argc >= 1); assert(argv); while ((c = getopt_long(argc, argv, "", options, NULL)) >= 0) switch (c) { case ARG_LOG_LEVEL: r = log_set_max_level_from_string(optarg); if (r < 0) log_error("Failed to parse log level %s, ignoring.", optarg); break; case ARG_LOG_TARGET: r = log_set_target_from_string(optarg); if (r < 0) log_error("Failed to parse log target %s, ignoring", optarg); break; case ARG_LOG_COLOR: if (optarg) { r = log_show_color_from_string(optarg); if (r < 0) log_error("Failed to parse log color setting %s, ignoring", optarg); } else log_show_color(true); break; case ARG_LOG_LOCATION: if (optarg) { r = log_show_location_from_string(optarg); if (r < 0) log_error("Failed to parse log location setting %s, ignoring", optarg); } else log_show_location(true); break; case '?': return -EINVAL; default: assert_not_reached("Unhandled option code."); } if (optind >= argc) { log_error("Verb argument missing."); return -EINVAL; } arg_verb = argv[optind]; if (optind + 1 < argc) log_error("Excess arguments, ignoring"); return 0; } static int prepare_new_root(void) { static const char dirs[] = "/run/initramfs/oldroot\0" "/run/initramfs/proc\0" "/run/initramfs/sys\0" "/run/initramfs/dev\0" "/run/initramfs/run\0"; const char *dir; if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0) { log_error("Failed to mount bind /run/initramfs on /run/initramfs: %m"); return -errno; } if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0) { log_error("Failed to make /run/initramfs private mount: %m"); return -errno; } NULSTR_FOREACH(dir, dirs) if (mkdir_p_label(dir, 0755) < 0 && errno != EEXIST) { log_error("Failed to mkdir %s: %m", dir); return -errno; } if (mount("/sys", "/run/initramfs/sys", NULL, MS_BIND, NULL) < 0) { log_error("Failed to mount bind /sys on /run/initramfs/sys: %m"); return -errno; } if (mount("/proc", "/run/initramfs/proc", NULL, MS_BIND, NULL) < 0) { log_error("Failed to mount bind /proc on /run/initramfs/proc: %m"); return -errno; } if (mount("/dev", "/run/initramfs/dev", NULL, MS_BIND, NULL) < 0) { log_error("Failed to mount bind /dev on /run/initramfs/dev: %m"); return -errno; } if (mount("/run", "/run/initramfs/run", NULL, MS_BIND, NULL) < 0) { log_error("Failed to mount bind /run on /run/initramfs/run: %m"); return -errno; } return 0; } static int pivot_to_new_root(void) { if (chdir("/run/initramfs") < 0) { log_error("Failed to change directory to /run/initramfs: %m"); return -errno; } /* Work-around for a kernel bug: for some reason the kernel * refuses switching root if any file systems are mounted * MS_SHARED. Hence remount them MS_PRIVATE here as a * work-around. * * https://bugzilla.redhat.com/show_bug.cgi?id=847418 */ if (mount(NULL, "/", NULL, MS_REC|MS_PRIVATE, NULL) < 0) log_warning("Failed to make \"/\" private mount: %m"); if (pivot_root(".", "oldroot") < 0) { log_error("pivot failed: %m"); /* only chroot if pivot root succeeded */ return -errno; } chroot("."); setsid(); make_console_stdio(); log_info("Successfully changed into root pivot."); return 0; } int main(int argc, char *argv[]) { bool need_umount, need_swapoff, need_loop_detach, need_dm_detach; bool in_container, use_watchdog = false; _cleanup_free_ char *cgroup = NULL; char *arguments[3]; unsigned retries; int cmd, r; log_parse_environment(); r = parse_argv(argc, argv); if (r < 0) goto error; /* journald will die if not gone yet. The log target defaults * to console, but may have been changed by commandline options. */ log_close_console(); /* force reopen of /dev/console */ log_open(); umask(0022); if (getpid() != 1) { log_error("Not executed by init (PID 1)."); r = -EPERM; goto error; } if (streq(arg_verb, "reboot")) cmd = RB_AUTOBOOT; else if (streq(arg_verb, "poweroff")) cmd = RB_POWER_OFF; else if (streq(arg_verb, "halt")) cmd = RB_HALT_SYSTEM; else if (streq(arg_verb, "kexec")) cmd = LINUX_REBOOT_CMD_KEXEC; else { r = -EINVAL; log_error("Unknown action '%s'.", arg_verb); goto error; } cg_get_root_path(&cgroup); use_watchdog = !!getenv("WATCHDOG_USEC"); /* lock us into memory */ mlockall(MCL_CURRENT|MCL_FUTURE); log_info("Sending SIGTERM to remaining processes..."); broadcast_signal(SIGTERM, true, true); log_info("Sending SIGKILL to remaining processes..."); broadcast_signal(SIGKILL, true, false); in_container = detect_container(NULL) > 0; need_umount = true; need_swapoff = !in_container; need_loop_detach = !in_container; need_dm_detach = !in_container; /* Unmount all mountpoints, swaps, and loopback devices */ for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) { bool changed = false; if (use_watchdog) watchdog_ping(); /* Let's trim the cgroup tree on each iteration so that we leave an empty cgroup tree around, so that container managers get a nice notify event when we are down */ if (cgroup) cg_trim(SYSTEMD_CGROUP_CONTROLLER, cgroup, false); if (need_umount) { log_info("Unmounting file systems."); r = umount_all(&changed); if (r == 0) { need_umount = false; log_info("All filesystems unmounted."); } else if (r > 0) log_info("Not all file systems unmounted, %d left.", r); else log_error("Failed to unmount file systems: %s", strerror(-r)); } if (need_swapoff) { log_info("Deactivating swaps."); r = swapoff_all(&changed); if (r == 0) { need_swapoff = false; log_info("All swaps deactivated."); } else if (r > 0) log_info("Not all swaps deactivated, %d left.", r); else log_error("Failed to deactivate swaps: %s", strerror(-r)); } if (need_loop_detach) { log_info("Detaching loop devices."); r = loopback_detach_all(&changed); if (r == 0) { need_loop_detach = false; log_info("All loop devices detached."); } else if (r > 0) log_info("Not all loop devices detached, %d left.", r); else log_error("Failed to detach loop devices: %s", strerror(-r)); } if (need_dm_detach) { log_info("Detaching DM devices."); r = dm_detach_all(&changed); if (r == 0) { need_dm_detach = false; log_info("All DM devices detached."); } else if (r > 0) log_info("Not all DM devices detached, %d left.", r); else log_error("Failed to detach DM devices: %s", strerror(-r)); } if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach) { if (retries > 0) log_info("All filesystems, swaps, loop devices, DM devices detached."); /* Yay, done */ goto initrd_jump; } /* If in this iteration we didn't manage to * unmount/deactivate anything, we simply give up */ if (!changed) { log_info("Cannot finalize remaining%s%s%s%s continuing.", need_umount ? " file systems," : "", need_swapoff ? " swap devices," : "", need_loop_detach ? " loop devices," : "", need_dm_detach ? " DM devices," : ""); goto initrd_jump; } log_debug("After %u retries, couldn't finalize remaining %s%s%s%s trying again.", retries + 1, need_umount ? " file systems," : "", need_swapoff ? " swap devices," : "", need_loop_detach ? " loop devices," : "", need_dm_detach ? " DM devices," : ""); } log_error("Too many iterations, giving up."); initrd_jump: arguments[0] = NULL; arguments[1] = arg_verb; arguments[2] = NULL; execute_directory(SYSTEM_SHUTDOWN_PATH, NULL, DEFAULT_TIMEOUT_USEC, arguments); if (!in_container && !in_initrd() && access("/run/initramfs/shutdown", X_OK) == 0) { if (prepare_new_root() >= 0 && pivot_to_new_root() >= 0) { arguments[0] = (char*) "/shutdown"; log_info("Returning to initrd..."); execv("/shutdown", arguments); log_error("Failed to execute shutdown binary: %m"); } } if (need_umount || need_swapoff || need_loop_detach || need_dm_detach) log_error("Failed to finalize %s%s%s%s ignoring", need_umount ? " file systems," : "", need_swapoff ? " swap devices," : "", need_loop_detach ? " loop devices," : "", need_dm_detach ? " DM devices," : ""); /* The kernel will automaticall flush ATA disks and suchlike * on reboot(), but the file systems need to be synce'd * explicitly in advance. So let's do this here, but not * needlessly slow down containers. */ if (!in_container) sync(); switch (cmd) { case LINUX_REBOOT_CMD_KEXEC: if (!in_container) { /* We cheat and exec kexec to avoid doing all its work */ pid_t pid; log_info("Rebooting with kexec."); pid = fork(); if (pid < 0) log_error("Failed to fork: %m"); else if (pid == 0) { const char * const args[] = { KEXEC, "-e", NULL }; /* Child */ execv(args[0], (char * const *) args); _exit(EXIT_FAILURE); } else wait_for_terminate_and_warn("kexec", pid); } cmd = RB_AUTOBOOT; /* Fall through */ case RB_AUTOBOOT: if (!in_container) { _cleanup_free_ char *param = NULL; if (read_one_line_file(REBOOT_PARAM_FILE, ¶m) >= 0) { log_info("Rebooting with argument '%s'.", param); syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_RESTART2, param); } } log_info("Rebooting."); break; case RB_POWER_OFF: log_info("Powering off."); break; case RB_HALT_SYSTEM: log_info("Halting system."); break; default: assert_not_reached("Unknown magic"); } reboot(cmd); if (errno == EPERM && in_container) { /* If we are in a container, and we lacked * CAP_SYS_BOOT just exit, this will kill our * container for good. */ log_info("Exiting container."); exit(0); } log_error("Failed to invoke reboot(): %m"); r = -errno; error: log_error("Critical error while doing system shutdown: %s", strerror(-r)); freeze(); }