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-rw-r--r--src/core/shutdown.c545
1 files changed, 545 insertions, 0 deletions
diff --git a/src/core/shutdown.c b/src/core/shutdown.c
new file mode 100644
index 0000000..cb47ee8
--- /dev/null
+++ b/src/core/shutdown.c
@@ -0,0 +1,545 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+/***
+ Copyright © 2010 ProFUSION embedded systems
+***/
+
+#include <errno.h>
+#include <getopt.h>
+#include <linux/reboot.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 "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 "rlimit-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);
+
+ (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)
+ 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();
+}
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