int main(int argc, char *argv[])
{
assert(sizeof(localbuf) >= getpagesize());
close(STDIN_FILENO);
setlocale(LC_ALL, "C");
if (!configure(argc, argv)) return EXIT_FAILURE;
if (unlikely(!read_proc_swaps()) ||
unlikely(!activate_old_swaps()) ||
unlikely(!check_memory_status()))
return EXIT_FAILURE;
if (erase) return retire_all() ? EXIT_SUCCESS : EXIT_FAILURE;
install_sigs();
if (unlikely(!startpidfile())) return EXIT_FAILURE;
/* Do a first iteration here so we can report any startup errors, and if we're
* going to run as a daemon, we can do so in a steady state.
*/
handle_requirements();
/* If we're going to fork(), this is the last chance to read /proc/swaps in a
* nonempty state before we do so. Make one last attempt to check its format.
*/
if (!proc_swaps_parsed())
{
if (!read_proc_swaps()) return EXIT_FAILURE;
#ifndef NO_CONFIG
if (!quiet && !proc_swaps_parsed())
fputs("[/proc/swaps is empty, so cannot check its format]\n", stderr);
#endif
}
if (godaemon)
{
#ifndef NO_CONFIG
if (verbose) logm(LOG_DEBUG, "daemonizing...");
#endif
const pid_t pid = daemonize();
if (unlikely(pid < 0))
{
rmpidfile();
return EXIT_FAILURE;
}
if (pid > 0)
{
/* New process, so new pid. Parent process rewrites pidfile. We do this
* from the parent, not the child process so that we're sure that the
* pidfile is in a stable state when the parent exits.
*/
lseek(pidfd, 0, SEEK_SET);
#ifndef NO_CONFIG
if (verbose) logm(LOG_DEBUG, "got process id %d", pid);
#endif
return writepid(pid) ? EXIT_SUCCESS : EXIT_FAILURE;
}
}
finishpidfile();
if (godaemon)
{
close(STDERR_FILENO);
close(STDOUT_FILENO);
// From here on std output is pointless in daemon mode. Use syslog instead.
log_start(argv[0]);
}
// Central loop
for (++runclock; !stop; ++runclock)
{
if (unlikely(print_status)) print_status = false, dump_stats();
else if (unlikely(adjust_swap)) adjust_swap = false, request_diet();
else handle_requirements();
sleep(1);
}
int result = EXIT_SUCCESS;
#ifndef NO_CONFIG
/* If we're worried about attackers getting unguarded access to the disk, we
* need to retire and erase all swap files to keep them secret.
*/
if (paranoid && !retire_all()) result = EXIT_FAILURE;
#endif
rmpidfile();
log_close();
return result;
}
static void mtnfs_destroy(void *buff)
{
MTNFS *mtnfs = MTNFS_CONTEXT;
rmpidfile(mtnfs->pid);
mtnlogger(mtnfs->mtn, 0, "%s finished\n", MODULE_NAME);
}
