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_AUTO);
  52         log_parse_environment();
  53         log_open();
  54
  55         umask(0022);
  56
  57         f = setmntent("/etc/fstab", "r");
  58         if (!f) {
  59                 log_error("Failed to open /etc/fstab: %m");
  60                 goto finish;
  61         }
  62
  63         pids = hashmap_new(trivial_hash_func, trivial_compare_func);
  64         if (!pids) {
  65                 log_error("Failed to allocate set");
  66                 goto finish;
  67         }
  68
  69         ret = EXIT_SUCCESS;
  70
  71         while ((me = getmntent(f))) {
  72                 pid_t pid;
  73                 int k;
  74                 char *s;
  75
  76                 if (!mount_point_is_api(me->mnt_dir))
  77                         continue;
  78
  79                 log_debug("Remounting %s", me->mnt_dir);
  80
  81                 pid = fork();
  82                 if (pid < 0) {
  83                         log_error("Failed to fork: %m");
  84                         ret = EXIT_FAILURE;
  85                         continue;
  86                 }
  87
  88                 if (pid == 0) {
  89                         const char *arguments[5];
  90                         /* Child */
  91
  92                         arguments[0] = "/bin/mount";
  93                         arguments[1] = me->mnt_dir;
  94                         arguments[2] = "-o";
  95                         arguments[3] = "remount";
  96                         arguments[4] = NULL;
  97
  98                         execv("/bin/mount", (char **) arguments);
  99
 100                         log_error("Failed to execute /bin/mount: %m");
 101                         _exit(EXIT_FAILURE);
 102                 }
 103
 104                 /* Parent */
 105
 106                 s = strdup(me->mnt_dir);
 107                 if (!s) {
 108                         log_error("Out of memory.");
 109                         ret = EXIT_FAILURE;
 110                         continue;
 111                 }
 112
 113
 114                 k = hashmap_put(pids, UINT_TO_PTR(pid), s);
 115                 if (k < 0) {
 116                         log_error("Failed to add PID to set: %s", strerror(-k));
 117                         ret = EXIT_FAILURE;
 118                         continue;
 119                 }
 120         }
 121
 122         while (!hashmap_isempty(pids)) {
 123                 siginfo_t si;
 124                 char *s;
 125
 126                 zero(si);
 127                 if (waitid(P_ALL, 0, &si, WEXITED) < 0) {
 128
 129                         if (errno == EINTR)
 130                                 continue;
 131
 132                         log_error("waitid() failed: %m");
 133                         ret = EXIT_FAILURE;
 134                         break;
 135                 }
 136
 137                 s = hashmap_remove(pids, UINT_TO_PTR(si.si_pid));
 138                 if (s) {
 139                         if (!is_clean_exit(si.si_code, si.si_status)) {
 140                                 if (si.si_code == CLD_EXITED)
 141                                         log_error("/bin/mount for %s exited with exit status %i.", s, si.si_status);
 142                                 else
 143                                         log_error("/bin/mount for %s terminated by signal %s.", s, signal_to_string(si.si_status));
 144
 145                                 ret = EXIT_FAILURE;
 146                         }
 147
 148                         free(s);
 149                 }
 150         }
 151
 152 finish:
 153
 154         if (pids)
 155                 hashmap_free_free(pids);
 156
 157         if (f)
 158                 endmntent(f);
 159
 160         return ret;
 161 }