diff options
Diffstat (limited to 'src/grp-system/systemd-shutdown/shutdown.c')
-rw-r--r-- | src/grp-system/systemd-shutdown/shutdown.c | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/src/grp-system/systemd-shutdown/shutdown.c b/src/grp-system/systemd-shutdown/shutdown.c new file mode 100644 index 0000000000..11e2143089 --- /dev/null +++ b/src/grp-system/systemd-shutdown/shutdown.c @@ -0,0 +1,446 @@ +/*** + 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 <errno.h> +#include <getopt.h> +#include <signal.h> +#include <stdbool.h> +#include <stdlib.h> +#include <sys/mman.h> +#include <sys/mount.h> +#include <sys/reboot.h> +#include <sys/stat.h> +#include <unistd.h> + +#include <linux/reboot.h> + +#include "core/killall.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/cgroup-util.h" +#include "systemd-basic/def.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/log.h" +#include "systemd-basic/missing.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/process-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/terminal-util.h" +#include "systemd-basic/util.h" +#include "systemd-basic/virt.h" +#include "systemd-shared/switch-root.h" +#include "systemd-shared/watchdog.h" + +#include "umount.h" + +#define FINALIZE_ATTEMPTS 50 + +static char* arg_verb; +static uint8_t arg_exit_code; + +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, + }; + + 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 }, + {} + }; + + 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("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 ARG_EXIT_CODE: + r = safe_atou8(optarg, &arg_exit_code); + if (r < 0) + log_error("Failed to parse exit code %s, ignoring", 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) { + log_error("Verb argument missing."); + return -EINVAL; + } + + 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); +} + +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; + static const char* const dirs[] = {SYSTEM_SHUTDOWN_PATH, NULL}; + + 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 command line 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 if (streq(arg_verb, "exit")) + cmd = 0; /* ignored, just checking that arg_verb is valid */ + else { + r = -EINVAL; + log_error("Unknown action '%s'.", arg_verb); + goto error; + } + + (void) cg_get_root_path(&cgroup); + in_container = detect_container() > 0; + + use_watchdog = !!getenv("WATCHDOG_USEC"); + + /* Lock us into memory */ + 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. */ + if (!in_container) + sync(); + + log_info("Sending SIGTERM to remaining processes..."); + broadcast_signal(SIGTERM, true, true); + + log_info("Sending SIGKILL to remaining processes..."); + broadcast_signal(SIGKILL, true, false); + + need_umount = !in_container; + 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_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); + 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); + 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) { + 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_directories(dirs, DEFAULT_TIMEOUT_USEC, arguments); + + if (!in_container && !in_initrd() && + access("/run/initramfs/shutdown", X_OK) == 0) { + 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 doit once more. */ + if (!in_container) + sync(); + + if (streq(arg_verb, "exit")) { + if (in_container) + exit(arg_exit_code); + else { + /* We cannot exit() on the host, fallback on another + * method. */ + cmd = RB_POWER_OFF; + } + } + + 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_errno(errno, "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, true); + } + + cmd = RB_AUTOBOOT; + /* Fall through */ + + case RB_AUTOBOOT: + + if (!in_container) { + _cleanup_free_ char *param = NULL; + + r = read_one_line_file("/run/systemd/reboot-param", ¶m); + if (r < 0) + log_warning_errno(r, "Failed to read reboot parameter file: %m"); + + if (!isempty(param)) { + log_info("Rebooting with argument '%s'.", param); + syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_RESTART2, param); + log_warning_errno(errno, "Failed to reboot with parameter, retrying without: %m"); + } + } + + 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); + } + + r = log_error_errno(errno, "Failed to invoke reboot(): %m"); + + error: + log_emergency_errno(r, "Critical error while doing system shutdown: %m"); + freeze(); +} |