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Systemd/src/shutdown/shutdown.c

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/* 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 "sysctl-util.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 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 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) > 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);
}
int main(int argc, char *argv[]) {
bool need_umount, need_swapoff, need_loop_detach, need_dm_detach, in_container, use_watchdog = false, can_initrd;
_cleanup_free_ char *cgroup = NULL;
char *arguments[3], *watchdog_device;
int cmd, r, umount_log_level = LOG_INFO;
static const char* const dirs[] = {SYSTEM_SHUTDOWN_PATH, NULL};
/* 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;
/* 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);
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)
(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, 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;
(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)
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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