/* SPDX-License-Identifier: LGPL-2.1+ */ /*** Copyright © 2010 ProFUSION embedded systems ***/ #include #include #include #include #include #include #include #include #include #include #include #include "alloc-util.h" #include "async.h" #include "cgroup-util.h" #include "def.h" #include "exec-util.h" #include "fd-util.h" #include "fileio.h" #include "killall.h" #include "log.h" #include "missing.h" #include "parse-util.h" #include "process-util.h" #include "reboot-util.h" #include "signal-util.h" #include "string-util.h" #include "switch-root.h" #include "terminal-util.h" #include "umount.h" #include "util.h" #include "virt.h" #include "watchdog.h" #define SYNC_PROGRESS_ATTEMPTS 3 #define SYNC_TIMEOUT_USEC (10*USEC_PER_SEC) static char* arg_verb; static uint8_t arg_exit_code; static usec_t arg_timeout = DEFAULT_TIMEOUT_USEC; static int parse_argv(int argc, char *argv[]) { enum { ARG_LOG_LEVEL = 0x100, ARG_LOG_TARGET, ARG_LOG_COLOR, ARG_LOG_LOCATION, ARG_EXIT_CODE, ARG_TIMEOUT, }; 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 }, { "exit-code", required_argument, NULL, ARG_EXIT_CODE }, { "timeout", required_argument, NULL, ARG_TIMEOUT }, {} }; int c, r; assert(argc >= 1); assert(argv); /* "-" prevents getopt from permuting argv[] and moving the verb away * from argv[1]. Our interface to initrd promises it'll be there. */ 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_errno(r, "Failed to parse log level %s, ignoring: %m", optarg); break; case ARG_LOG_TARGET: r = log_set_target_from_string(optarg); if (r < 0) log_error_errno(r, "Failed to parse log target %s, ignoring: %m", optarg); break; case ARG_LOG_COLOR: if (optarg) { r = log_show_color_from_string(optarg); if (r < 0) log_error_errno(r, "Failed to parse log color setting %s, ignoring: %m", 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_errno(r, "Failed to parse log location setting %s, ignoring: %m", optarg); } else log_show_location(true); break; case ARG_EXIT_CODE: r = safe_atou8(optarg, &arg_exit_code); if (r < 0) log_error_errno(r, "Failed to parse exit code %s, ignoring: %m", optarg); break; case ARG_TIMEOUT: r = parse_sec(optarg, &arg_timeout); if (r < 0) log_error_errno(r, "Failed to parse shutdown timeout %s, ignoring: %m", optarg); break; case '\001': if (!arg_verb) arg_verb = optarg; else log_error("Excess arguments, ignoring"); break; case '?': return -EINVAL; default: assert_not_reached("Unhandled option code."); } if (!arg_verb) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Verb argument missing."); return 0; } static int switch_root_initramfs(void) { if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0) return log_error_errno(errno, "Failed to mount bind /run/initramfs on /run/initramfs: %m"); if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0) return log_error_errno(errno, "Failed to make /run/initramfs private mount: %m"); /* switch_root with MS_BIND, because there might still be processes lurking around, which have open file descriptors. * /run/initramfs/shutdown will take care of these. * Also do not detach the old root, because /run/initramfs/shutdown needs to access it. */ return switch_root("/run/initramfs", "/oldroot", false, MS_BIND); } /* Read the following fields from /proc/meminfo: * * NFS_Unstable * Writeback * Dirty * * Return true if the sum of these fields is greater than the previous * value input. For all other issues, report the failure and indicate that * the sync is not making progress. */ static bool sync_making_progress(unsigned long long *prev_dirty) { _cleanup_fclose_ FILE *f = NULL; unsigned long long val = 0; bool r = false; f = fopen("/proc/meminfo", "re"); if (!f) return log_warning_errno(errno, "Failed to open /proc/meminfo: %m"); for (;;) { _cleanup_free_ char *line = NULL; unsigned long long ull = 0; int q; q = read_line(f, LONG_LINE_MAX, &line); if (q < 0) return log_warning_errno(q, "Failed to parse /proc/meminfo: %m"); if (q == 0) break; if (!first_word(line, "NFS_Unstable:") && !first_word(line, "Writeback:") && !first_word(line, "Dirty:")) continue; errno = 0; if (sscanf(line, "%*s %llu %*s", &ull) != 1) { if (errno != 0) log_warning_errno(errno, "Failed to parse /proc/meminfo: %m"); else log_warning("Failed to parse /proc/meminfo"); return false; } val += ull; } r = *prev_dirty > val; *prev_dirty = val; return r; } static void sync_with_progress(void) { unsigned long long dirty = ULONG_LONG_MAX; unsigned checks; pid_t pid; int r; BLOCK_SIGNALS(SIGCHLD); /* Due to the possiblity of the sync operation hanging, we fork a child process and monitor the progress. If * the timeout lapses, the assumption is that that particular sync stalled. */ r = asynchronous_sync(&pid); if (r < 0) { log_error_errno(r, "Failed to fork sync(): %m"); return; } log_info("Syncing filesystems and block devices."); /* Start monitoring the sync operation. If more than * SYNC_PROGRESS_ATTEMPTS lapse without progress being made, * we assume that the sync is stalled */ for (checks = 0; checks < SYNC_PROGRESS_ATTEMPTS; checks++) { r = wait_for_terminate_with_timeout(pid, SYNC_TIMEOUT_USEC); if (r == 0) /* Sync finished without error. * (The sync itself does not return an error code) */ return; else if (r == -ETIMEDOUT) { /* Reset the check counter if the "Dirty" value is * decreasing */ if (sync_making_progress(&dirty)) checks = 0; } else { log_error_errno(r, "Failed to sync filesystems and block devices: %m"); return; } } /* Only reached in the event of a timeout. We should issue a kill * to the stray process. */ log_error("Syncing filesystems and block devices - timed out, issuing SIGKILL to PID "PID_FMT".", pid); (void) kill(pid, SIGKILL); } int main(int argc, char *argv[]) { bool need_umount, need_swapoff, need_loop_detach, need_dm_detach; bool in_container, use_watchdog = false, can_initrd; _cleanup_free_ char *cgroup = NULL; char *arguments[3]; int cmd, r, umount_log_level = LOG_INFO; static const char* const dirs[] = {SYSTEM_SHUTDOWN_PATH, NULL}; char *watchdog_device; /* The log target defaults to console, but the original systemd process will pass its log target in through a * command line argument, which will override this default. Also, ensure we'll never log to the journal or * syslog, as these logging daemons are either already dead or will die very soon. */ log_set_target(LOG_TARGET_CONSOLE); log_set_prohibit_ipc(true); log_parse_environment(); r = parse_argv(argc, argv); if (r < 0) goto error; log_open(); umask(0022); if (getpid_cached() != 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 if (streq(arg_verb, "exit")) cmd = 0; /* ignored, just checking that arg_verb is valid */ else { log_error("Unknown action '%s'.", arg_verb); r = -EINVAL; goto error; } (void) cg_get_root_path(&cgroup); in_container = detect_container() > 0; use_watchdog = getenv("WATCHDOG_USEC"); watchdog_device = getenv("WATCHDOG_DEVICE"); if (watchdog_device) { r = watchdog_set_device(watchdog_device); if (r < 0) log_warning_errno(r, "Failed to set watchdog device to %s, ignoring: %m", watchdog_device); } /* Lock us into memory */ (void) mlockall(MCL_CURRENT|MCL_FUTURE); /* Synchronize everything that is not written to disk yet at this point already. This is a good idea so that * slow IO is processed here already and the final process killing spree is not impacted by processes * desperately trying to sync IO to disk within their timeout. Do not remove this sync, data corruption will * result. */ if (!in_container) sync_with_progress(); disable_coredumps(); log_info("Sending SIGTERM to remaining processes..."); broadcast_signal(SIGTERM, true, true, arg_timeout); log_info("Sending SIGKILL to remaining processes..."); broadcast_signal(SIGKILL, true, false, arg_timeout); need_umount = !in_container; need_swapoff = !in_container; need_loop_detach = !in_container; need_dm_detach = !in_container; can_initrd = !in_container && !in_initrd() && access("/run/initramfs/shutdown", X_OK) == 0; /* Unmount all mountpoints, swaps, and loopback devices */ for (;;) { 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, umount_log_level); 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_errno(r, "Failed to unmount file systems: %m"); } 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_errno(r, "Failed to deactivate swaps: %m"); } if (need_loop_detach) { log_info("Detaching loop devices."); r = loopback_detach_all(&changed, umount_log_level); 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_errno(r, "Failed to detach loop devices: %m"); } if (need_dm_detach) { log_info("Detaching DM devices."); r = dm_detach_all(&changed, umount_log_level); 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_errno(r, "Failed to detach DM devices: %m"); } if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach) { log_info("All filesystems, swaps, loop devices and DM devices detached."); /* Yay, done */ break; } if (!changed && umount_log_level == LOG_INFO && !can_initrd) { /* There are things we cannot get rid of. Loop one more time * with LOG_ERR to inform the user. Note that we don't need * to do this if there is a initrd to switch to, because that * one is likely to get rid of the remounting mounts. If not, * it will log about them. */ umount_log_level = LOG_ERR; continue; } /* 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," : ""); break; } log_debug("Couldn't finalize remaining %s%s%s%s trying again.", need_umount ? " file systems," : "", need_swapoff ? " swap devices," : "", need_loop_detach ? " loop devices," : "", need_dm_detach ? " DM devices," : ""); } /* We're done with the watchdog. */ watchdog_free_device(); arguments[0] = NULL; arguments[1] = arg_verb; arguments[2] = NULL; execute_directories(dirs, DEFAULT_TIMEOUT_USEC, NULL, NULL, arguments, NULL); if (can_initrd) { r = switch_root_initramfs(); if (r >= 0) { argv[0] = (char*) "/shutdown"; setsid(); make_console_stdio(); log_info("Successfully changed into root pivot.\n" "Returning to initrd..."); execv("/shutdown", argv); log_error_errno(errno, "Failed to execute shutdown binary: %m"); } else log_error_errno(r, "Failed to switch root to \"/run/initramfs\": %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 automatically flush ATA disks and suchlike on reboot(), but the file systems need to be * sync'ed explicitly in advance. So let's do this here, but not needlessly slow down containers. Note that we * sync'ed things already once above, but we did some more work since then which might have caused IO, hence * let's do it once more. Do not remove this sync, data corruption will result. */ if (!in_container) sync_with_progress(); if (streq(arg_verb, "exit")) { if (in_container) return arg_exit_code; cmd = RB_POWER_OFF; /* We cannot exit() on the host, fallback on another method. */ } switch (cmd) { case LINUX_REBOOT_CMD_KEXEC: if (!in_container) { /* We cheat and exec kexec to avoid doing all its work */ log_info("Rebooting with kexec."); r = safe_fork("(sd-kexec)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_WAIT, NULL); if (r == 0) { const char * const args[] = { KEXEC, "-e", NULL }; /* Child */ execv(args[0], (char * const *) args); _exit(EXIT_FAILURE); } /* If we are still running, then the kexec can't have worked, let's fall through */ } cmd = RB_AUTOBOOT; _fallthrough_; case RB_AUTOBOOT: (void) reboot_with_parameter(REBOOT_LOG); 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"); } (void) 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."); return EXIT_SUCCESS; } r = log_error_errno(errno, "Failed to invoke reboot(): %m"); error: log_emergency_errno(r, "Critical error while doing system shutdown: %m"); freeze(); }