src/remount-api-vfs.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 General Public License as published by
  10   the Free Software Foundation; either version 2 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   General Public License for more details.
  17
  18   You should have received a copy of the GNU 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 "set.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         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_SYSLOG_OR_KMSG);
  52         log_parse_environment();
  53         log_open();
  54
  55         if (!(f = setmntent("/etc/fstab", "r"))) {
  56                 log_error("Failed to open /etc/fstab: %m");
  57                 goto finish;
  58         }
  59
  60         if (!(pids = hashmap_new(trivial_hash_func, trivial_compare_func))) {
  61                 log_error("Failed to allocate set");
  62                 goto finish;
  63         }
  64
  65         ret = EXIT_SUCCESS;
  66
  67         while ((me = getmntent(f))) {
  68                 pid_t pid;
  69                 int k;
  70                 char *s;
  71
  72                 if (!mount_point_is_api(me->mnt_dir))
  73                         continue;
  74
  75                 log_debug("Remounting %s", me->mnt_dir);
  76
  77                 if ((pid = fork()) < 0) {
  78                         log_error("Failed to fork: %m");
  79                         ret = 1;
  80                         continue;
  81                 }
  82
  83                 if (pid == 0) {
  84                         const char *arguments[5];
  85                         /* Child */
  86
  87                         arguments[0] = "/bin/mount";
  88                         arguments[1] = me->mnt_dir;
  89                         arguments[2] = "-o";
  90                         arguments[3] = "remount";
  91                         arguments[4] = NULL;
  92
  93                         execv("/bin/mount", (char **) arguments);
  94
  95                         log_error("Failed to execute /bin/mount: %m");
  96                         _exit(EXIT_FAILURE);
  97                 }
  98
  99                 /* Parent */
 100
 101                 s = strdup(me->mnt_dir);
 102
 103                 if ((k = hashmap_put(pids, UINT_TO_PTR(pid), s)) < 0) {
 104                         log_error("Failed to add PID to set: %s", strerror(-k));
 105                         ret = EXIT_FAILURE;
 106                         continue;
 107                 }
 108         }
 109
 110         while (!hashmap_isempty(pids)) {
 111                 siginfo_t si;
 112                 char *s;
 113
 114                 zero(si);
 115                 if (waitid(P_ALL, 0, &si, WEXITED) < 0) {
 116
 117                         if (errno == EINTR)
 118                                 continue;
 119
 120                         log_error("waitid() failed: %m");
 121                         ret = EXIT_FAILURE;
 122                         break;
 123                 }
 124
 125                 if ((s = hashmap_remove(pids, UINT_TO_PTR(si.si_pid)))) {
 126                         if (!is_clean_exit(si.si_code, si.si_status)) {
 127                                 if (si.si_code == CLD_EXITED)
 128                                         log_error("/bin/mount for %s exited with exit status %i.", s, si.si_status);
 129                                 else
 130                                         log_error("/bin/mount for %s terminated by signal %s.", s, signal_to_string(si.si_status));
 131
 132                                 ret = EXIT_FAILURE;
 133                         }
 134
 135                         free(s);
 136                 }
 137         }
 138
 139 finish:
 140
 141         if (pids)
 142                 hashmap_free_free(pids);
 143
 144         if (f)
 145                 endmntent(f);
 146
 147         return ret;
 148 }