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 <fcntl.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <sys/stat.h>
  27 #include <sys/wait.h>
  28 #include <mntent.h>
  29
  30 #include "log.h"
  31 #include "util.h"
  32 #include "path-util.h"
  33 #include "set.h"
  34 #include "mount-setup.h"
  35 #include "exit-status.h"
  36
  37 /* Goes through /etc/fstab and remounts all API file systems, applying
  38  * options that are in /etc/fstab that systemd might not have
  39  * respected */
  40
  41 int main(int argc, char *argv[]) {
  42         int ret = EXIT_FAILURE;
  43         _cleanup_endmntent_ FILE *f = NULL;
  44         struct mntent* me;
  45         Hashmap *pids = NULL;
  46
  47         if (argc > 1) {
  48                 log_error("This program takes no argument.");
  49                 return EXIT_FAILURE;
  50         }
  51
  52         log_set_target(LOG_TARGET_AUTO);
  53         log_parse_environment();
  54         log_open();
  55
  56         umask(0022);
  57
  58         f = setmntent("/etc/fstab", "r");
  59         if (!f) {
  60                 if (errno == ENOENT)
  61                         return EXIT_SUCCESS;
  62
  63                 log_error_errno(errno, "Failed to open /etc/fstab: %m");
  64                 return EXIT_FAILURE;
  65         }
  66
  67         pids = hashmap_new(NULL);
  68         if (!pids) {
  69                 log_error("Failed to allocate set");
  70                 goto finish;
  71         }
  72
  73         ret = EXIT_SUCCESS;
  74
  75         while ((me = getmntent(f))) {
  76                 pid_t pid;
  77                 int k;
  78                 char *s;
  79
  80                 /* Remount the root fs, /usr and all API VFS */
  81                 if (!mount_point_is_api(me->mnt_dir) &&
  82                     !path_equal(me->mnt_dir, "/") &&
  83                     !path_equal(me->mnt_dir, "/usr"))
  84                         continue;
  85
  86                 log_debug("Remounting %s", me->mnt_dir);
  87
  88                 pid = fork();
  89                 if (pid < 0) {
  90                         log_error_errno(errno, "Failed to fork: %m");
  91                         ret = EXIT_FAILURE;
  92                         continue;
  93                 }
  94
  95                 if (pid == 0) {
  96                         const char *arguments[5];
  97                         /* Child */
  98
  99                         arguments[0] = "/bin/mount";
 100                         arguments[1] = me->mnt_dir;
 101                         arguments[2] = "-o";
 102                         arguments[3] = "remount";
 103                         arguments[4] = NULL;
 104
 105                         execv("/bin/mount", (char **) arguments);
 106
 107                         log_error_errno(errno, "Failed to execute /bin/mount: %m");
 108                         _exit(EXIT_FAILURE);
 109                 }
 110
 111                 /* Parent */
 112
 113                 s = strdup(me->mnt_dir);
 114                 if (!s) {
 115                         log_oom();
 116                         ret = EXIT_FAILURE;
 117                         continue;
 118                 }
 119
 120
 121                 k = hashmap_put(pids, UINT_TO_PTR(pid), s);
 122                 if (k < 0) {
 123                         log_error_errno(k, "Failed to add PID to set: %m");
 124                         ret = EXIT_FAILURE;
 125                         continue;
 126                 }
 127         }
 128
 129         while (!hashmap_isempty(pids)) {
 130                 siginfo_t si = {};
 131                 char *s;
 132
 133                 if (waitid(P_ALL, 0, &si, WEXITED) < 0) {
 134
 135                         if (errno == EINTR)
 136                                 continue;
 137
 138                         log_error_errno(errno, "waitid() failed: %m");
 139                         ret = EXIT_FAILURE;
 140                         break;
 141                 }
 142
 143                 s = hashmap_remove(pids, UINT_TO_PTR(si.si_pid));
 144                 if (s) {
 145                         if (!is_clean_exit(si.si_code, si.si_status, NULL)) {
 146                                 if (si.si_code == CLD_EXITED)
 147                                         log_error("/bin/mount for %s exited with exit status %i.", s, si.si_status);
 148                                 else
 149                                         log_error("/bin/mount for %s terminated by signal %s.", s, signal_to_string(si.si_status));
 150
 151                                 ret = EXIT_FAILURE;
 152                         }
 153
 154                         free(s);
 155                 }
 156         }
 157
 158 finish:
 159
 160         if (pids)
 161                 hashmap_free_free(pids);
 162
 163         return ret;
 164 }