src/remount-fs/remount-fs.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <mntent.h>
   5 #include <string.h>
   6 #include <sys/prctl.h>
   7 #include <sys/stat.h>
   8 #include <sys/wait.h>
   9 #include <unistd.h>
  10
  11 #include "exit-status.h"
  12 #include "log.h"
  13 #include "mount-setup.h"
  14 #include "mount-util.h"
  15 #include "path-util.h"
  16 #include "process-util.h"
  17 #include "signal-util.h"
  18 #include "strv.h"
  19 #include "util.h"
  20
  21 /* Goes through /etc/fstab and remounts all API file systems, applying
  22  * options that are in /etc/fstab that systemd might not have
  23  * respected */
  24
  25 int main(int argc, char *argv[]) {
  26         _cleanup_hashmap_free_free_ Hashmap *pids = NULL;
  27         _cleanup_endmntent_ FILE *f = NULL;
  28         struct mntent* me;
  29         int r;
  30
  31         if (argc > 1) {
  32                 log_error("This program takes no argument.");
  33                 return EXIT_FAILURE;
  34         }
  35
  36         log_set_target(LOG_TARGET_AUTO);
  37         log_parse_environment();
  38         log_open();
  39
  40         umask(0022);
  41
  42         f = setmntent("/etc/fstab", "re");
  43         if (!f) {
  44                 if (errno == ENOENT) {
  45                         r = 0;
  46                         goto finish;
  47                 }
  48
  49                 r = log_error_errno(errno, "Failed to open /etc/fstab: %m");
  50                 goto finish;
  51         }
  52
  53         pids = hashmap_new(NULL);
  54         if (!pids) {
  55                 r = log_oom();
  56                 goto finish;
  57         }
  58
  59         while ((me = getmntent(f))) {
  60                 pid_t pid;
  61                 int k;
  62                 char *s;
  63
  64                 /* Remount the root fs, /usr and all API VFS */
  65                 if (!mount_point_is_api(me->mnt_dir) &&
  66                     !path_equal(me->mnt_dir, "/") &&
  67                     !path_equal(me->mnt_dir, "/usr"))
  68                         continue;
  69
  70                 log_debug("Remounting %s", me->mnt_dir);
  71
  72                 r = safe_fork("(remount)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid);
  73                 if (r < 0)
  74                         goto finish;
  75                 if (r == 0) {
  76                         /* Child */
  77
  78                         execv(MOUNT_PATH, STRV_MAKE(MOUNT_PATH, me->mnt_dir, "-o", "remount"));
  79
  80                         log_error_errno(errno, "Failed to execute " MOUNT_PATH ": %m");
  81                         _exit(EXIT_FAILURE);
  82                 }
  83
  84                 /* Parent */
  85
  86                 s = strdup(me->mnt_dir);
  87                 if (!s) {
  88                         r = log_oom();
  89                         goto finish;
  90                 }
  91
  92                 k = hashmap_put(pids, PID_TO_PTR(pid), s);
  93                 if (k < 0) {
  94                         free(s);
  95                         r = log_oom();
  96                         goto finish;
  97                 }
  98         }
  99
 100         r = 0;
 101         while (!hashmap_isempty(pids)) {
 102                 siginfo_t si = {};
 103                 char *s;
 104
 105                 if (waitid(P_ALL, 0, &si, WEXITED) < 0) {
 106
 107                         if (errno == EINTR)
 108                                 continue;
 109
 110                         r = log_error_errno(errno, "waitid() failed: %m");
 111                         goto finish;
 112                 }
 113
 114                 s = hashmap_remove(pids, PID_TO_PTR(si.si_pid));
 115                 if (s) {
 116                         if (!is_clean_exit(si.si_code, si.si_status, EXIT_CLEAN_COMMAND, NULL)) {
 117                                 if (si.si_code == CLD_EXITED)
 118                                         log_error(MOUNT_PATH " for %s exited with exit status %i.", s, si.si_status);
 119                                 else
 120                                         log_error(MOUNT_PATH " for %s terminated by signal %s.", s, signal_to_string(si.si_status));
 121
 122                                 r = -ENOEXEC;
 123                         }
 124
 125                         free(s);
 126                 }
 127         }
 128
 129 finish:
 130         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 131 }