src/core/shutdown.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 ProFUSION embedded systems
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <getopt.h>
  22 #include <linux/reboot.h>
  23 #include <signal.h>
  24 #include <stdbool.h>
  25 #include <stdlib.h>
  26 #include <sys/mman.h>
  27 #include <sys/mount.h>
  28 #include <sys/reboot.h>
  29 #include <sys/stat.h>
  30 #include <unistd.h>
  31
  32 #include "alloc-util.h"
  33 #include "cgroup-util.h"
  34 #include "def.h"
  35 #include "fileio.h"
  36 #include "killall.h"
  37 #include "log.h"
  38 #include "missing.h"
  39 #include "parse-util.h"
  40 #include "process-util.h"
  41 #include "string-util.h"
  42 #include "switch-root.h"
  43 #include "terminal-util.h"
  44 #include "umount.h"
  45 #include "util.h"
  46 #include "virt.h"
  47 #include "watchdog.h"
  48
  49 #define FINALIZE_ATTEMPTS 50
  50
  51 static char* arg_verb;
  52 static uint8_t arg_exit_code;
  53
  54 static int parse_argv(int argc, char *argv[]) {
  55         enum {
  56                 ARG_LOG_LEVEL = 0x100,
  57                 ARG_LOG_TARGET,
  58                 ARG_LOG_COLOR,
  59                 ARG_LOG_LOCATION,
  60                 ARG_EXIT_CODE,
  61         };
  62
  63         static const struct option options[] = {
  64                 { "log-level",     required_argument, NULL, ARG_LOG_LEVEL    },
  65                 { "log-target",    required_argument, NULL, ARG_LOG_TARGET   },
  66                 { "log-color",     optional_argument, NULL, ARG_LOG_COLOR    },
  67                 { "log-location",  optional_argument, NULL, ARG_LOG_LOCATION },
  68                 { "exit-code",     required_argument, NULL, ARG_EXIT_CODE    },
  69                 {}
  70         };
  71
  72         int c, r;
  73
  74         assert(argc >= 1);
  75         assert(argv);
  76
  77         /* "-" prevents getopt from permuting argv[] and moving the verb away
  78          * from argv[1]. Our interface to initrd promises it'll be there. */
  79         while ((c = getopt_long(argc, argv, "-", options, NULL)) >= 0)
  80                 switch (c) {
  81
  82                 case ARG_LOG_LEVEL:
  83                         r = log_set_max_level_from_string(optarg);
  84                         if (r < 0)
  85                                 log_error("Failed to parse log level %s, ignoring.", optarg);
  86
  87                         break;
  88
  89                 case ARG_LOG_TARGET:
  90                         r = log_set_target_from_string(optarg);
  91                         if (r < 0)
  92                                 log_error("Failed to parse log target %s, ignoring", optarg);
  93
  94                         break;
  95
  96                 case ARG_LOG_COLOR:
  97
  98                         if (optarg) {
  99                                 r = log_show_color_from_string(optarg);
 100                                 if (r < 0)
 101                                         log_error("Failed to parse log color setting %s, ignoring", optarg);
 102                         } else
 103                                 log_show_color(true);
 104
 105                         break;
 106
 107                 case ARG_LOG_LOCATION:
 108                         if (optarg) {
 109                                 r = log_show_location_from_string(optarg);
 110                                 if (r < 0)
 111                                         log_error("Failed to parse log location setting %s, ignoring", optarg);
 112                         } else
 113                                 log_show_location(true);
 114
 115                         break;
 116
 117                 case ARG_EXIT_CODE:
 118                         r = safe_atou8(optarg, &arg_exit_code);
 119                         if (r < 0)
 120                                 log_error("Failed to parse exit code %s, ignoring", optarg);
 121
 122                         break;
 123
 124                 case '\001':
 125                         if (!arg_verb)
 126                                 arg_verb = optarg;
 127                         else
 128                                 log_error("Excess arguments, ignoring");
 129                         break;
 130
 131                 case '?':
 132                         return -EINVAL;
 133
 134                 default:
 135                         assert_not_reached("Unhandled option code.");
 136                 }
 137
 138         if (!arg_verb) {
 139                 log_error("Verb argument missing.");
 140                 return -EINVAL;
 141         }
 142
 143         return 0;
 144 }
 145
 146 static int switch_root_initramfs(void) {
 147         if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0)
 148                 return log_error_errno(errno, "Failed to mount bind /run/initramfs on /run/initramfs: %m");
 149
 150         if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0)
 151                 return log_error_errno(errno, "Failed to make /run/initramfs private mount: %m");
 152
 153         /* switch_root with MS_BIND, because there might still be processes lurking around, which have open file descriptors.
 154          * /run/initramfs/shutdown will take care of these.
 155          * Also do not detach the old root, because /run/initramfs/shutdown needs to access it.
 156          */
 157         return switch_root("/run/initramfs", "/oldroot", false, MS_BIND);
 158 }
 159
 160
 161 int main(int argc, char *argv[]) {
 162         bool need_umount, need_swapoff, need_loop_detach, need_dm_detach;
 163         bool in_container, use_watchdog = false;
 164         _cleanup_free_ char *cgroup = NULL;
 165         char *arguments[3];
 166         unsigned retries;
 167         int cmd, r;
 168         static const char* const dirs[] = {SYSTEM_SHUTDOWN_PATH, NULL};
 169
 170         log_parse_environment();
 171         r = parse_argv(argc, argv);
 172         if (r < 0)
 173                 goto error;
 174
 175         /* journald will die if not gone yet. The log target defaults
 176          * to console, but may have been changed by command line options. */
 177
 178         log_close_console(); /* force reopen of /dev/console */
 179         log_open();
 180
 181         umask(0022);
 182
 183         if (getpid() != 1) {
 184                 log_error("Not executed by init (PID 1).");
 185                 r = -EPERM;
 186                 goto error;
 187         }
 188
 189         if (streq(arg_verb, "reboot"))
 190                 cmd = RB_AUTOBOOT;
 191         else if (streq(arg_verb, "poweroff"))
 192                 cmd = RB_POWER_OFF;
 193         else if (streq(arg_verb, "halt"))
 194                 cmd = RB_HALT_SYSTEM;
 195         else if (streq(arg_verb, "kexec"))
 196                 cmd = LINUX_REBOOT_CMD_KEXEC;
 197         else if (streq(arg_verb, "exit"))
 198                 cmd = 0; /* ignored, just checking that arg_verb is valid */
 199         else {
 200                 r = -EINVAL;
 201                 log_error("Unknown action '%s'.", arg_verb);
 202                 goto error;
 203         }
 204
 205         cg_get_root_path(&cgroup);
 206
 207         use_watchdog = !!getenv("WATCHDOG_USEC");
 208
 209         /* lock us into memory */
 210         mlockall(MCL_CURRENT|MCL_FUTURE);
 211
 212         log_info("Sending SIGTERM to remaining processes...");
 213         broadcast_signal(SIGTERM, true, true);
 214
 215         log_info("Sending SIGKILL to remaining processes...");
 216         broadcast_signal(SIGKILL, true, false);
 217
 218         in_container = detect_container() > 0;
 219
 220         need_umount = !in_container;
 221         need_swapoff = !in_container;
 222         need_loop_detach = !in_container;
 223         need_dm_detach = !in_container;
 224
 225         /* Unmount all mountpoints, swaps, and loopback devices */
 226         for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) {
 227                 bool changed = false;
 228
 229                 if (use_watchdog)
 230                         watchdog_ping();
 231
 232                 /* Let's trim the cgroup tree on each iteration so
 233                    that we leave an empty cgroup tree around, so that
 234                    container managers get a nice notify event when we
 235                    are down */
 236                 if (cgroup)
 237                         cg_trim(SYSTEMD_CGROUP_CONTROLLER, cgroup, false);
 238
 239                 if (need_umount) {
 240                         log_info("Unmounting file systems.");
 241                         r = umount_all(&changed);
 242                         if (r == 0) {
 243                                 need_umount = false;
 244                                 log_info("All filesystems unmounted.");
 245                         } else if (r > 0)
 246                                 log_info("Not all file systems unmounted, %d left.", r);
 247                         else
 248                                 log_error_errno(r, "Failed to unmount file systems: %m");
 249                 }
 250
 251                 if (need_swapoff) {
 252                         log_info("Deactivating swaps.");
 253                         r = swapoff_all(&changed);
 254                         if (r == 0) {
 255                                 need_swapoff = false;
 256                                 log_info("All swaps deactivated.");
 257                         } else if (r > 0)
 258                                 log_info("Not all swaps deactivated, %d left.", r);
 259                         else
 260                                 log_error_errno(r, "Failed to deactivate swaps: %m");
 261                 }
 262
 263                 if (need_loop_detach) {
 264                         log_info("Detaching loop devices.");
 265                         r = loopback_detach_all(&changed);
 266                         if (r == 0) {
 267                                 need_loop_detach = false;
 268                                 log_info("All loop devices detached.");
 269                         } else if (r > 0)
 270                                 log_info("Not all loop devices detached, %d left.", r);
 271                         else
 272                                 log_error_errno(r, "Failed to detach loop devices: %m");
 273                 }
 274
 275                 if (need_dm_detach) {
 276                         log_info("Detaching DM devices.");
 277                         r = dm_detach_all(&changed);
 278                         if (r == 0) {
 279                                 need_dm_detach = false;
 280                                 log_info("All DM devices detached.");
 281                         } else if (r > 0)
 282                                 log_info("Not all DM devices detached, %d left.", r);
 283                         else
 284                                 log_error_errno(r, "Failed to detach DM devices: %m");
 285                 }
 286
 287                 if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach) {
 288                         if (retries > 0)
 289                                 log_info("All filesystems, swaps, loop devices, DM devices detached.");
 290                         /* Yay, done */
 291                         goto initrd_jump;
 292                 }
 293
 294                 /* If in this iteration we didn't manage to
 295                  * unmount/deactivate anything, we simply give up */
 296                 if (!changed) {
 297                         log_info("Cannot finalize remaining%s%s%s%s continuing.",
 298                                  need_umount ? " file systems," : "",
 299                                  need_swapoff ? " swap devices," : "",
 300                                  need_loop_detach ? " loop devices," : "",
 301                                  need_dm_detach ? " DM devices," : "");
 302                         goto initrd_jump;
 303                 }
 304
 305                 log_debug("After %u retries, couldn't finalize remaining %s%s%s%s trying again.",
 306                           retries + 1,
 307                           need_umount ? " file systems," : "",
 308                           need_swapoff ? " swap devices," : "",
 309                           need_loop_detach ? " loop devices," : "",
 310                           need_dm_detach ? " DM devices," : "");
 311         }
 312
 313         log_error("Too many iterations, giving up.");
 314
 315  initrd_jump:
 316
 317         arguments[0] = NULL;
 318         arguments[1] = arg_verb;
 319         arguments[2] = NULL;
 320         execute_directories(dirs, DEFAULT_TIMEOUT_USEC, arguments);
 321
 322         if (!in_container && !in_initrd() &&
 323             access("/run/initramfs/shutdown", X_OK) == 0) {
 324                 r = switch_root_initramfs();
 325                 if (r >= 0) {
 326                         argv[0] = (char*) "/shutdown";
 327
 328                         setsid();
 329                         make_console_stdio();
 330
 331                         log_info("Successfully changed into root pivot.\n"
 332                                  "Returning to initrd...");
 333
 334                         execv("/shutdown", argv);
 335                         log_error_errno(errno, "Failed to execute shutdown binary: %m");
 336                 } else
 337                         log_error_errno(r, "Failed to switch root to \"/run/initramfs\": %m");
 338
 339         }
 340
 341         if (need_umount || need_swapoff || need_loop_detach || need_dm_detach)
 342                 log_error("Failed to finalize %s%s%s%s ignoring",
 343                           need_umount ? " file systems," : "",
 344                           need_swapoff ? " swap devices," : "",
 345                           need_loop_detach ? " loop devices," : "",
 346                           need_dm_detach ? " DM devices," : "");
 347
 348         /* The kernel will automaticall flush ATA disks and suchlike
 349          * on reboot(), but the file systems need to be synce'd
 350          * explicitly in advance. So let's do this here, but not
 351          * needlessly slow down containers. */
 352         if (!in_container)
 353                 sync();
 354
 355         if (streq(arg_verb, "exit")) {
 356                 if (in_container)
 357                         exit(arg_exit_code);
 358                 else {
 359                         /* We cannot exit() on the host, fallback on another
 360                          * method. */
 361                         cmd = RB_POWER_OFF;
 362                 }
 363         }
 364
 365         switch (cmd) {
 366
 367         case LINUX_REBOOT_CMD_KEXEC:
 368
 369                 if (!in_container) {
 370                         /* We cheat and exec kexec to avoid doing all its work */
 371                         pid_t pid;
 372
 373                         log_info("Rebooting with kexec.");
 374
 375                         pid = fork();
 376                         if (pid < 0)
 377                                 log_error_errno(errno, "Failed to fork: %m");
 378                         else if (pid == 0) {
 379
 380                                 const char * const args[] = {
 381                                         KEXEC, "-e", NULL
 382                                 };
 383
 384                                 /* Child */
 385
 386                                 execv(args[0], (char * const *) args);
 387                                 _exit(EXIT_FAILURE);
 388                         } else
 389                                 wait_for_terminate_and_warn("kexec", pid, true);
 390                 }
 391
 392                 cmd = RB_AUTOBOOT;
 393                 /* Fall through */
 394
 395         case RB_AUTOBOOT:
 396
 397                 if (!in_container) {
 398                         _cleanup_free_ char *param = NULL;
 399
 400                         if (read_one_line_file(REBOOT_PARAM_FILE, &param) >= 0) {
 401                                 log_info("Rebooting with argument '%s'.", param);
 402                                 syscall(SYS_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_RESTART2, param);
 403                         }
 404                 }
 405
 406                 log_info("Rebooting.");
 407                 break;
 408
 409         case RB_POWER_OFF:
 410                 log_info("Powering off.");
 411                 break;
 412
 413         case RB_HALT_SYSTEM:
 414                 log_info("Halting system.");
 415                 break;
 416
 417         default:
 418                 assert_not_reached("Unknown magic");
 419         }
 420
 421         reboot(cmd);
 422         if (errno == EPERM && in_container) {
 423                 /* If we are in a container, and we lacked
 424                  * CAP_SYS_BOOT just exit, this will kill our
 425                  * container for good. */
 426                 log_info("Exiting container.");
 427                 exit(0);
 428         }
 429
 430         r = log_error_errno(errno, "Failed to invoke reboot(): %m");
 431
 432   error:
 433         log_emergency_errno(r, "Critical error while doing system shutdown: %m");
 434         freeze();
 435 }