/*-*- 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/types.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 "missing.h" #include "log.h" #include "umount.h" #include "util.h" #include "mkdir.h" #include "virt.h" #include "watchdog.h" #include "killall.h" #define FINALIZE_ATTEMPTS 50 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[]) { int cmd, r; unsigned retries; bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true; bool in_container, use_watchdog = false; char *arguments[3]; log_parse_environment(); log_set_target(LOG_TARGET_CONSOLE); /* syslog will die if not gone yet */ log_open(); umask(0022); if (getpid() != 1) { log_error("Not executed by init (pid 1)."); r = -EPERM; goto error; } if (argc != 2) { log_error("Invalid number of arguments."); r = -EINVAL; goto error; } in_container = detect_container(NULL) > 0; if (streq(argv[1], "reboot")) cmd = RB_AUTOBOOT; else if (streq(argv[1], "poweroff")) cmd = RB_POWER_OFF; else if (streq(argv[1], "halt")) cmd = RB_HALT_SYSTEM; else if (streq(argv[1], "kexec")) cmd = LINUX_REBOOT_CMD_KEXEC; else { log_error("Unknown action '%s'.", argv[1]); r = -EINVAL; goto error; } 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); log_info("Sending SIGKILL to remaining processes..."); broadcast_signal(SIGKILL, true); if (in_container) { need_swapoff = false; need_dm_detach = false; need_loop_detach = false; } /* Unmount all mountpoints, swaps, and loopback devices */ for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) { bool changed = false; if (use_watchdog) watchdog_ping(); 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 */ break; } /* If in this iteration we didn't manage to * unmount/deactivate anything, we simply give up */ if (!changed) { log_error("Cannot finalize remaining file systems and devices, giving up."); break; } log_debug("Couldn't finalize remaining file systems and devices after %u retries, trying again.", retries+1); } if (retries >= FINALIZE_ATTEMPTS) log_error("Too many iterations, giving up."); arguments[0] = NULL; arguments[1] = argv[1]; arguments[2] = NULL; execute_directory(SYSTEM_SHUTDOWN_PATH, NULL, arguments); if (!in_container && !in_initrd() && access("/run/initramfs/shutdown", X_OK) == 0) { if (prepare_new_root() >= 0 && pivot_to_new_root() >= 0) { execv("/shutdown", argv); log_error("Failed to execute shutdown binary: %m"); } } /* 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(); if (cmd == LINUX_REBOOT_CMD_KEXEC) { if (!in_container) { /* We cheat and exec kexec to avoid doing all its work */ pid_t pid = fork(); if (pid < 0) log_error("Could not fork: %m. Falling back to normal reboot."); else if (pid > 0) { wait_for_terminate_and_warn("kexec", pid); log_warning("kexec failed. Falling back to normal reboot."); } else { /* Child */ const char *args[3] = { "/sbin/kexec", "-e", NULL }; execv(args[0], (char * const *) args); return EXIT_FAILURE; } } cmd = RB_AUTOBOOT; } 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_error("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(); return EXIT_FAILURE; }