src/remount-fs/remount-fs.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <unistd.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <sys/stat.h>
  26 #include <sys/wait.h>
  27 #include <mntent.h>
  28
  29 #include "log.h"
  30 #include "util.h"
  31 #include "path-util.h"
  32 #include "signal-util.h"
  33 #include "mount-setup.h"
  34 #include "exit-status.h"
  35
  36 /* Goes through /etc/fstab and remounts all API file systems, applying
  37  * options that are in /etc/fstab that systemd might not have
  38  * respected */
  39
  40 int main(int argc, char *argv[]) {
  41         int ret = EXIT_FAILURE;
  42         _cleanup_endmntent_ FILE *f = NULL;
  43         struct mntent* me;
  44         Hashmap *pids = NULL;
  45
  46         if (argc > 1) {
  47                 log_error("This program takes no argument.");
  48                 return EXIT_FAILURE;
  49         }
  50
  51         log_set_target(LOG_TARGET_AUTO);
  52         log_parse_environment();
  53         log_open();
  54
  55         umask(0022);
  56
  57         f = setmntent("/etc/fstab", "r");
  58         if (!f) {
  59                 if (errno == ENOENT)
  60                         return EXIT_SUCCESS;
  61
  62                 log_error_errno(errno, "Failed to open /etc/fstab: %m");
  63                 return EXIT_FAILURE;
  64         }
  65
  66         pids = hashmap_new(NULL);
  67         if (!pids) {
  68                 log_error("Failed to allocate set");
  69                 goto finish;
  70         }
  71
  72         ret = EXIT_SUCCESS;
  73
  74         while ((me = getmntent(f))) {
  75                 pid_t pid;
  76                 int k;
  77                 char *s;
  78
  79                 /* Remount the root fs, /usr and all API VFS */
  80                 if (!mount_point_is_api(me->mnt_dir) &&
  81                     !path_equal(me->mnt_dir, "/") &&
  82                     !path_equal(me->mnt_dir, "/usr"))
  83                         continue;
  84
  85                 log_debug("Remounting %s", me->mnt_dir);
  86
  87                 pid = fork();
  88                 if (pid < 0) {
  89                         log_error_errno(errno, "Failed to fork: %m");
  90                         ret = EXIT_FAILURE;
  91                         continue;
  92                 }
  93
  94                 if (pid == 0) {
  95                         const char *arguments[5];
  96                         /* Child */
  97
  98                         arguments[0] = MOUNT_PATH;
  99                         arguments[1] = me->mnt_dir;
 100                         arguments[2] = "-o";
 101                         arguments[3] = "remount";
 102                         arguments[4] = NULL;
 103
 104                         execv(MOUNT_PATH, (char **) arguments);
 105
 106                         log_error_errno(errno, "Failed to execute " MOUNT_PATH ": %m");
 107                         _exit(EXIT_FAILURE);
 108                 }
 109
 110                 /* Parent */
 111
 112                 s = strdup(me->mnt_dir);
 113                 if (!s) {
 114                         log_oom();
 115                         ret = EXIT_FAILURE;
 116                         continue;
 117                 }
 118
 119
 120                 k = hashmap_put(pids, UINT_TO_PTR(pid), s);
 121                 if (k < 0) {
 122                         log_error_errno(k, "Failed to add PID to set: %m");
 123                         ret = EXIT_FAILURE;
 124                         continue;
 125                 }
 126         }
 127
 128         while (!hashmap_isempty(pids)) {
 129                 siginfo_t si = {};
 130                 char *s;
 131
 132                 if (waitid(P_ALL, 0, &si, WEXITED) < 0) {
 133
 134                         if (errno == EINTR)
 135                                 continue;
 136
 137                         log_error_errno(errno, "waitid() failed: %m");
 138                         ret = EXIT_FAILURE;
 139                         break;
 140                 }
 141
 142                 s = hashmap_remove(pids, UINT_TO_PTR(si.si_pid));
 143                 if (s) {
 144                         if (!is_clean_exit(si.si_code, si.si_status, NULL)) {
 145                                 if (si.si_code == CLD_EXITED)
 146                                         log_error(MOUNT_PATH " for %s exited with exit status %i.", s, si.si_status);
 147                                 else
 148                                         log_error(MOUNT_PATH " for %s terminated by signal %s.", s, signal_to_string(si.si_status));
 149
 150                                 ret = EXIT_FAILURE;
 151                         }
 152
 153                         free(s);
 154                 }
 155         }
 156
 157 finish:
 158
 159         if (pids)
 160                 hashmap_free_free(pids);
 161
 162         return ret;
 163 }