summaryrefslogtreecommitdiff
path: root/src/core/shutdown.c
blob: 0b7cbd8d3410e52ee13e7dca9877610a477b00a4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  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 <sys/mman.h>
#include <sys/types.h>
#include <sys/reboot.h>
#include <linux/reboot.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/syscall.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

#include "missing.h"
#include "log.h"
#include "umount.h"
#include "util.h"
#include "mkdir.h"
#include "virt.h"
#include "watchdog.h"
#include "killall.h"

#define FINALIZE_ATTEMPTS 50

static int prepare_new_root(void) {
        static const char dirs[] =
                "/run/initramfs/oldroot\0"
                "/run/initramfs/proc\0"
                "/run/initramfs/sys\0"
                "/run/initramfs/dev\0"
                "/run/initramfs/run\0";

        const char *dir;

        if (mount("/run/initramfs", "/run/initramfs", NULL, MS_BIND, NULL) < 0) {
                log_error("Failed to mount bind /run/initramfs on /run/initramfs: %m");
                return -errno;
        }

        if (mount(NULL, "/run/initramfs", NULL, MS_PRIVATE, NULL) < 0) {
                log_error("Failed to make /run/initramfs private mount: %m");
                return -errno;
        }

        NULSTR_FOREACH(dir, dirs)
                if (mkdir_p_label(dir, 0755) < 0 && errno != EEXIST) {
                        log_error("Failed to mkdir %s: %m", dir);
                        return -errno;
                }

        if (mount("/sys", "/run/initramfs/sys", NULL, MS_BIND, NULL) < 0) {
                log_error("Failed to mount bind /sys on /run/initramfs/sys: %m");
                return -errno;
        }

        if (mount("/proc", "/run/initramfs/proc", NULL, MS_BIND, NULL) < 0) {
                log_error("Failed to mount bind /proc on /run/initramfs/proc: %m");
                return -errno;
        }

        if (mount("/dev", "/run/initramfs/dev", NULL, MS_BIND, NULL) < 0) {
                log_error("Failed to mount bind /dev on /run/initramfs/dev: %m");
                return -errno;
        }

        if (mount("/run", "/run/initramfs/run", NULL, MS_BIND, NULL) < 0) {
                log_error("Failed to mount bind /run on /run/initramfs/run: %m");
                return -errno;
        }

        return 0;
}

static int pivot_to_new_root(void) {

        if (chdir("/run/initramfs") < 0) {
                log_error("Failed to change directory to /run/initramfs: %m");
                return -errno;
        }

        /*
          In case some evil process made "/" MS_SHARED
          It works for pivot_root, but the ref count for the root device
          is not decreasing :-/
        */
        if (mount(NULL, "/", NULL, MS_REC|MS_PRIVATE, NULL) < 0) {
                log_error("Failed to make \"/\" private mount %m");
                return -errno;
        }

        if (pivot_root(".", "oldroot") < 0) {
                log_error("pivot failed: %m");
                /* only chroot if pivot root succeeded */
                return -errno;
        }

        chroot(".");

        setsid();
        make_console_stdio();

        log_info("Successfully changed into root pivot.");

        return 0;
}

int main(int argc, char *argv[]) {
        int cmd, r;
        unsigned retries;
        bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;
        bool in_container, use_watchdog = false;
        char *arguments[3];

        log_parse_environment();
        log_set_target(LOG_TARGET_CONSOLE); /* syslog will die if not gone yet */
        log_open();

        umask(0022);

        if (getpid() != 1) {
                log_error("Not executed by init (pid 1).");
                r = -EPERM;
                goto error;
        }

        if (argc != 2) {
                log_error("Invalid number of arguments.");
                r = -EINVAL;
                goto error;
        }

        in_container = detect_container(NULL) > 0;

        if (streq(argv[1], "reboot"))
                cmd = RB_AUTOBOOT;
        else if (streq(argv[1], "poweroff"))
                cmd = RB_POWER_OFF;
        else if (streq(argv[1], "halt"))
                cmd = RB_HALT_SYSTEM;
        else if (streq(argv[1], "kexec"))
                cmd = LINUX_REBOOT_CMD_KEXEC;
        else {
                log_error("Unknown action '%s'.", argv[1]);
                r = -EINVAL;
                goto error;
        }

        use_watchdog = !!getenv("WATCHDOG_USEC");

        /* lock us into memory */
        mlockall(MCL_CURRENT|MCL_FUTURE);

        log_info("Sending SIGTERM to remaining processes...");
        broadcast_signal(SIGTERM, true);

        log_info("Sending SIGKILL to remaining processes...");
        broadcast_signal(SIGKILL, true);

        if (in_container) {
                need_swapoff = false;
                need_dm_detach = false;
                need_loop_detach = false;
        }

        /* Unmount all mountpoints, swaps, and loopback devices */
        for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) {
                bool changed = false;

                if (use_watchdog)
                        watchdog_ping();

                if (need_umount) {
                        log_info("Unmounting file systems.");
                        r = umount_all(&changed);
                        if (r == 0)
                                need_umount = false;
                        else if (r > 0)
                                log_info("Not all file systems unmounted, %d left.", r);
                        else
                                log_error("Failed to unmount file systems: %s", strerror(-r));
                }

                if (need_swapoff) {
                        log_info("Disabling swaps.");
                        r = swapoff_all(&changed);
                        if (r == 0)
                                need_swapoff = false;
                        else if (r > 0)
                                log_info("Not all swaps are turned off, %d left.", r);
                        else
                                log_error("Failed to turn off swaps: %s", strerror(-r));
                }

                if (need_loop_detach) {
                        log_info("Detaching loop devices.");
                        r = loopback_detach_all(&changed);
                        if (r == 0)
                                need_loop_detach = false;
                        else if (r > 0)
                                log_info("Not all loop devices detached, %d left.", r);
                        else
                                log_error("Failed to detach loop devices: %s", strerror(-r));
                }

                if (need_dm_detach) {
                        log_info("Detaching DM devices.");
                        r = dm_detach_all(&changed);
                        if (r == 0)
                                need_dm_detach = false;
                        else if (r > 0)
                                log_warning("Not all DM devices detached, %d left.", r);
                        else
                                log_error("Failed to detach DM devices: %s", strerror(-r));
                }

                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 */
                        break;
                }

                /* If in this iteration we didn't manage to
                 * unmount/deactivate anything, we simply give up */
                if (!changed) {
                        log_error("Cannot finalize remaining file systems and devices, giving up.");
                        break;
                }

                log_debug("Couldn't finalize remaining file systems and devices after %u retries, trying again.", retries+1);
        }

        if (retries >= FINALIZE_ATTEMPTS)
                log_error("Too many iterations, giving up.");

        arguments[0] = NULL;
        arguments[1] = argv[1];
        arguments[2] = NULL;
        execute_directory(SYSTEM_SHUTDOWN_PATH, NULL, arguments);

        /* If we are in a container, just exit, this will kill our
         * container for good. */
        if (in_container) {
                log_error("Exiting container.");
                exit(0);
        }

        if (access("/run/initramfs/shutdown", X_OK) == 0) {

                if (prepare_new_root() >= 0 &&
                    pivot_to_new_root() >= 0) {
                        execv("/shutdown", argv);
                        log_error("Failed to execute shutdown binary: %m");
                }
        }

        sync();

        if (cmd == LINUX_REBOOT_CMD_KEXEC) {
                /* We cheat and exec kexec to avoid doing all its work */
                pid_t pid = fork();

                if (pid < 0)
                        log_error("Could not fork: %m. Falling back to normal reboot.");
                else if (pid > 0) {
                        wait_for_terminate_and_warn("kexec", pid);
                        log_warning("kexec failed. Falling back to normal reboot.");
                } else {
                        /* Child */
                        const char *args[3] = { "/sbin/kexec", "-e", NULL };
                        execv(args[0], (char * const *) args);
                        return EXIT_FAILURE;
                }

                cmd = RB_AUTOBOOT;
        }

        reboot(cmd);
        log_error("Failed to invoke reboot(): %m");
        r = -errno;

  error:
        log_error("Critical error while doing system shutdown: %s", strerror(-r));

        freeze();
        return EXIT_FAILURE;
}