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-rw-r--r--src/shutdown/shutdown.c663
1 files changed, 663 insertions, 0 deletions
diff --git a/src/shutdown/shutdown.c b/src/shutdown/shutdown.c
new file mode 100644
index 0000000..b709078
--- /dev/null
+++ b/src/shutdown/shutdown.c
@@ -0,0 +1,663 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/***
+ Copyright © 2010 ProFUSION embedded systems
+***/
+
+#include <errno.h>
+#include <getopt.h>
+#include <linux/reboot.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 "sd-daemon.h"
+#include "sd-messages.h"
+
+#include "alloc-util.h"
+#include "async.h"
+#include "binfmt-util.h"
+#include "cgroup-setup.h"
+#include "cgroup-util.h"
+#include "constants.h"
+#include "coredump-util.h"
+#include "detach-dm.h"
+#include "detach-loopback.h"
+#include "detach-md.h"
+#include "detach-swap.h"
+#include "errno-util.h"
+#include "exec-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "getopt-defs.h"
+#include "initrd-util.h"
+#include "killall.h"
+#include "log.h"
+#include "parse-util.h"
+#include "process-util.h"
+#include "reboot-util.h"
+#include "rlimit-util.h"
+#include "signal-util.h"
+#include "string-util.h"
+#include "switch-root.h"
+#include "sysctl-util.h"
+#include "terminal-util.h"
+#include "umount.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 {
+ COMMON_GETOPT_ARGS,
+ SHUTDOWN_GETOPT_ARGS,
+ };
+
+ static const struct option options[] = {
+ COMMON_GETOPT_OPTIONS,
+ SHUTDOWN_GETOPT_OPTIONS,
+ {}
+ };
+
+ int c, r;
+
+ assert(argc >= 1);
+ assert(argv);
+
+ /* Resetting to 0 forces the invocation of an internal initialization routine of getopt_long()
+ * that checks for GNU extensions in optstring ('-' or '+' at the beginning). */
+ optind = 0;
+
+ /* "-" 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_LOG_TIME:
+
+ if (optarg) {
+ r = log_show_time_from_string(optarg);
+ if (r < 0)
+ log_error_errno(r, "Failed to parse log time setting %s, ignoring: %m", optarg);
+ } else
+ log_show_time(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();
+ }
+
+ if (!arg_verb)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Verb argument missing.");
+
+ return 0;
+}
+
+static int switch_root_initramfs(void) {
+ /* Do not detach the old root, because /run/initramfs/shutdown needs to access it.
+ *
+ * Disable sync() during switch-root, we after all sync'ed here plenty, and a dumb sync (as opposed
+ * to the "smart" sync() we did here that looks at progress parameters) would defeat much of our
+ * efforts here. As the new root will be /run/initramfs/, it is not necessary to mount /run/
+ * recursively. */
+ return switch_root(
+ /* new_root= */ "/run/initramfs",
+ /* old_root_after= */ "/oldroot",
+ /* flags= */ SWITCH_ROOT_DONT_SYNC);
+}
+
+/* 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 int sync_making_progress(unsigned long long *prev_dirty) {
+ _cleanup_fclose_ FILE *f = NULL;
+ unsigned long long val = 0;
+ int ret;
+
+ 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;
+ }
+
+ ret = *prev_dirty > val;
+ *prev_dirty = val;
+ return ret;
+}
+
+static void sync_with_progress(void) {
+ unsigned long long dirty = ULLONG_MAX;
+ unsigned checks;
+ pid_t pid;
+ int r;
+
+ BLOCK_SIGNALS(SIGCHLD);
+
+ /* Due to the possibility of the sync operation hanging, we fork a child process and monitor
+ * the progress. If the timeout lapses, the assumption is that the 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) > 0)
+ 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);
+}
+
+static int read_current_sysctl_printk_log_level(void) {
+ _cleanup_free_ char *sysctl_printk_vals = NULL, *sysctl_printk_curr = NULL;
+ int current_lvl;
+ const char *p;
+ int r;
+
+ r = sysctl_read("kernel/printk", &sysctl_printk_vals);
+ if (r < 0)
+ return log_debug_errno(r, "Cannot read sysctl kernel.printk: %m");
+
+ p = sysctl_printk_vals;
+ r = extract_first_word(&p, &sysctl_printk_curr, NULL, 0);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to split out kernel printk priority: %m");
+ if (r == 0)
+ return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Short read while reading kernel.printk sysctl");
+
+ r = safe_atoi(sysctl_printk_curr, &current_lvl);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to parse kernel.printk sysctl: %s", sysctl_printk_vals);
+
+ return current_lvl;
+}
+
+static void bump_sysctl_printk_log_level(int min_level) {
+ int current_lvl, r;
+
+ /* Set the logging level to be able to see messages with log level smaller or equal to min_level */
+
+ current_lvl = read_current_sysctl_printk_log_level();
+ if (current_lvl < 0 || current_lvl >= min_level + 1)
+ return;
+
+ r = sysctl_writef("kernel/printk", "%i", min_level + 1);
+ if (r < 0)
+ log_debug_errno(r, "Failed to bump kernel.printk to %i: %m", min_level + 1);
+}
+
+static void init_watchdog(void) {
+ const char *s;
+ int r;
+
+ s = getenv("WATCHDOG_DEVICE");
+ if (s) {
+ r = watchdog_set_device(s);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set watchdog device to %s, ignoring: %m", s);
+ }
+
+ s = getenv("WATCHDOG_USEC");
+ if (s) {
+ usec_t usec;
+
+ r = safe_atou64(s, &usec);
+ if (r < 0)
+ log_warning_errno(r, "Failed to parse watchdog timeout '%s', ignoring: %m", s);
+ else
+ (void) watchdog_setup(usec);
+ }
+}
+
+int main(int argc, char *argv[]) {
+ static const char* const dirs[] = {
+ SYSTEM_SHUTDOWN_PATH,
+ NULL
+ };
+ _cleanup_free_ char *cgroup = NULL;
+ char *arguments[3];
+ int cmd, r;
+
+ /* Close random fds we might have get passed, just for paranoia, before we open any new fds, for
+ * example for logging. After all this tool's purpose is about detaching any pinned resources, and
+ * open file descriptors are the primary way to pin resources. Note that we don't really expect any
+ * fds to be passed here. */
+ (void) close_all_fds(NULL, 0);
+
+ /* 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();
+
+ if (getpid_cached() == 1)
+ log_set_always_reopen_console(true);
+
+ r = parse_argv(argc, argv);
+ if (r < 0)
+ goto error;
+
+ log_open();
+
+ umask(0022);
+
+ if (getpid_cached() != 1) {
+ r = log_error_errno(SYNTHETIC_ERRNO(EPERM), "Not executed by init (PID 1).");
+ 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 = log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown action '%s'.", arg_verb);
+ goto error;
+ }
+
+ /* This is primarily useful when running systemd in a VM, as it provides the user running the VM with
+ * a mechanism to pick up systemd's exit status in the VM. Note that we execute this as early as
+ * possible since otherwise we might shut down the VM before the AF_VSOCK buffers have been flushed.
+ * While this doesn't guarantee the message will arrive, in practice we do enough work after this
+ * that the message should always arrive on the host */
+ (void) sd_notifyf(0, "EXIT_STATUS=%i", arg_exit_code);
+
+ (void) cg_get_root_path(&cgroup);
+ bool in_container = detect_container() > 0;
+
+ /* If the logging messages are going to KMSG, and if we are not running from a container, then try to
+ * update the sysctl kernel.printk current value in order to see "info" messages; This current log
+ * level is not updated if already big enough.
+ */
+ if (!in_container &&
+ IN_SET(log_get_target(),
+ LOG_TARGET_AUTO,
+ LOG_TARGET_JOURNAL_OR_KMSG,
+ LOG_TARGET_SYSLOG_OR_KMSG,
+ LOG_TARGET_KMSG))
+ bump_sysctl_printk_log_level(LOG_WARNING);
+
+ init_watchdog();
+
+ /* Lock us into memory */
+ (void) mlockall(MCL_CURRENT|MCL_FUTURE);
+
+ /* We need to make mounts private so that we can MS_MOVE in unmount_all(). Kernel does not allow
+ * MS_MOVE when parent mountpoints have shared propagation. */
+ if (mount(NULL, "/", NULL, MS_REC|MS_PRIVATE, NULL) < 0)
+ log_warning_errno(errno, "Failed to make mounts private, ignoring: %m");
+
+ /* 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();
+ disable_binfmt();
+
+ 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);
+
+ bool need_umount = !in_container, need_swapoff = !in_container, need_loop_detach = !in_container,
+ need_dm_detach = !in_container, need_md_detach = !in_container, can_initrd, last_try = false;
+ can_initrd = !in_container && !in_initrd() && access("/run/initramfs/shutdown", X_OK) == 0;
+
+ /* Unmount all mountpoints, swaps, and loopback devices */
+ for (;;) {
+ bool changed = false;
+
+ (void) 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)
+ (void) cg_trim(SYSTEMD_CGROUP_CONTROLLER, cgroup, false);
+
+ if (need_umount) {
+ log_info("Unmounting file systems.");
+ r = umount_all(&changed, last_try);
+ 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, "Unable 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, "Unable to deactivate swaps: %m");
+ }
+
+ if (need_loop_detach) {
+ log_info("Detaching loop devices.");
+ r = loopback_detach_all(&changed, last_try);
+ 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, "Unable to detach loop devices: %m");
+ }
+
+ if (need_md_detach) {
+ log_info("Stopping MD devices.");
+ r = md_detach_all(&changed, last_try);
+ if (r == 0) {
+ need_md_detach = false;
+ log_info("All MD devices stopped.");
+ } else if (r > 0)
+ log_info("Not all MD devices stopped, %d left.", r);
+ else
+ log_error_errno(r, "Unable to stop MD devices: %m");
+ }
+
+ if (need_dm_detach) {
+ log_info("Detaching DM devices.");
+ r = dm_detach_all(&changed, last_try);
+ 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, "Unable to detach DM devices: %m");
+ }
+
+ if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach
+ && !need_md_detach) {
+ log_info("All filesystems, swaps, loop devices, MD devices and DM devices detached.");
+ /* Yay, done */
+ break;
+ }
+
+ if (!changed && !last_try && !can_initrd) {
+ /* There are things we cannot get rid of. Loop one more time in which we will log
+ * with higher priority to inform the user. Note that we don't need to do this if
+ * there is an initrd to switch to, because that one is likely to get rid of the
+ * remaining mounts. If not, it will log about them. */
+ last_try = true;
+ 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%s continuing.",
+ need_umount ? " file systems," : "",
+ need_swapoff ? " swap devices," : "",
+ need_loop_detach ? " loop devices," : "",
+ need_dm_detach ? " DM devices," : "",
+ need_md_detach ? " MD devices," : "");
+ break;
+ }
+
+ log_debug("Couldn't finalize remaining %s%s%s%s%s trying again.",
+ need_umount ? " file systems," : "",
+ need_swapoff ? " swap devices," : "",
+ need_loop_detach ? " loop devices," : "",
+ need_dm_detach ? " DM devices," : "",
+ need_md_detach ? " MD devices," : "");
+ }
+
+ /* We're done with the watchdog. Note that the watchdog is explicitly not stopped here. It remains
+ * active to guard against any issues during the rest of the shutdown sequence. */
+ watchdog_free_device();
+
+ arguments[0] = NULL; /* Filled in by execute_directories(), when needed */
+ arguments[1] = arg_verb;
+ arguments[2] = NULL;
+ (void) execute_directories(dirs, DEFAULT_TIMEOUT_USEC, NULL, NULL, arguments, NULL, EXEC_DIR_PARALLEL | EXEC_DIR_IGNORE_ERRORS);
+
+ (void) rlimit_nofile_safe();
+
+ if (can_initrd) {
+ r = switch_root_initramfs();
+ if (r >= 0) {
+ argv[0] = (char*) "/shutdown";
+
+ (void) setsid();
+ (void) 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 || need_md_detach)
+ log_error("Unable to finalize remaining%s%s%s%s%s ignoring.",
+ need_umount ? " file systems," : "",
+ need_swapoff ? " swap devices," : "",
+ need_loop_detach ? " loop devices," : "",
+ need_dm_detach ? " DM devices," : "",
+ need_md_detach ? " MD 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) {
+ log_info("Exiting 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);
+ log_debug_errno(errno, "Failed to execute '" KEXEC "' binary, proceeding with reboot(RB_KEXEC): %m");
+
+ /* execv failed (kexec binary missing?), so try simply reboot(RB_KEXEC) */
+ (void) reboot(cmd);
+ _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();
+ }
+
+ (void) reboot(cmd);
+ if (ERRNO_IS_PRIVILEGE(errno) && 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_struct_errno(LOG_EMERG, r,
+ LOG_MESSAGE("Critical error while doing system shutdown: %m"),
+ "MESSAGE_ID=" SD_MESSAGE_SHUTDOWN_ERROR_STR);
+ freeze();
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 16:56:19 +0000