src/remount-fs/remount-fs.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2010 Lennart Poettering
   4 ***/
   5
   6 #include <errno.h>
   7 #include <mntent.h>
   8 #include <string.h>
   9 #include <sys/prctl.h>
  10 #include <sys/stat.h>
  11 #include <sys/wait.h>
  12 #include <unistd.h>
  13
  14 #include "exit-status.h"
  15 #include "log.h"
  16 #include "mount-setup.h"
  17 #include "mount-util.h"
  18 #include "path-util.h"
  19 #include "process-util.h"
  20 #include "signal-util.h"
  21 #include "strv.h"
  22 #include "util.h"
  23
  24 /* Goes through /etc/fstab and remounts all API file systems, applying
  25  * options that are in /etc/fstab that systemd might not have
  26  * respected */
  27
  28 int main(int argc, char *argv[]) {
  29         _cleanup_hashmap_free_free_ Hashmap *pids = NULL;
  30         _cleanup_endmntent_ FILE *f = NULL;
  31         struct mntent* me;
  32         int r;
  33
  34         if (argc > 1) {
  35                 log_error("This program takes no argument.");
  36                 return EXIT_FAILURE;
  37         }
  38
  39         log_set_target(LOG_TARGET_AUTO);
  40         log_parse_environment();
  41         log_open();
  42
  43         umask(0022);
  44
  45         f = setmntent("/etc/fstab", "re");
  46         if (!f) {
  47                 if (errno == ENOENT) {
  48                         r = 0;
  49                         goto finish;
  50                 }
  51
  52                 r = log_error_errno(errno, "Failed to open /etc/fstab: %m");
  53                 goto finish;
  54         }
  55
  56         pids = hashmap_new(NULL);
  57         if (!pids) {
  58                 r = log_oom();
  59                 goto finish;
  60         }
  61
  62         while ((me = getmntent(f))) {
  63                 pid_t pid;
  64                 int k;
  65                 char *s;
  66
  67                 /* Remount the root fs, /usr and all API VFS */
  68                 if (!mount_point_is_api(me->mnt_dir) &&
  69                     !path_equal(me->mnt_dir, "/") &&
  70                     !path_equal(me->mnt_dir, "/usr"))
  71                         continue;
  72
  73                 log_debug("Remounting %s", me->mnt_dir);
  74
  75                 r = safe_fork("(remount)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid);
  76                 if (r < 0)
  77                         goto finish;
  78                 if (r == 0) {
  79                         /* Child */
  80
  81                         execv(MOUNT_PATH, STRV_MAKE(MOUNT_PATH, me->mnt_dir, "-o", "remount"));
  82
  83                         log_error_errno(errno, "Failed to execute " MOUNT_PATH ": %m");
  84                         _exit(EXIT_FAILURE);
  85                 }
  86
  87                 /* Parent */
  88
  89                 s = strdup(me->mnt_dir);
  90                 if (!s) {
  91                         r = log_oom();
  92                         goto finish;
  93                 }
  94
  95                 k = hashmap_put(pids, PID_TO_PTR(pid), s);
  96                 if (k < 0) {
  97                         free(s);
  98                         r = log_oom();
  99                         goto finish;
 100                 }
 101         }
 102
 103         r = 0;
 104         while (!hashmap_isempty(pids)) {
 105                 siginfo_t si = {};
 106                 char *s;
 107
 108                 if (waitid(P_ALL, 0, &si, WEXITED) < 0) {
 109
 110                         if (errno == EINTR)
 111                                 continue;
 112
 113                         r = log_error_errno(errno, "waitid() failed: %m");
 114                         goto finish;
 115                 }
 116
 117                 s = hashmap_remove(pids, PID_TO_PTR(si.si_pid));
 118                 if (s) {
 119                         if (!is_clean_exit(si.si_code, si.si_status, EXIT_CLEAN_COMMAND, NULL)) {
 120                                 if (si.si_code == CLD_EXITED)
 121                                         log_error(MOUNT_PATH " for %s exited with exit status %i.", s, si.si_status);
 122                                 else
 123                                         log_error(MOUNT_PATH " for %s terminated by signal %s.", s, signal_to_string(si.si_status));
 124
 125                                 r = -ENOEXEC;
 126                         }
 127
 128                         free(s);
 129                 }
 130         }
 131
 132 finish:
 133         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 134 }