static int make_volatile(const char *path) {
_cleanup_free_ char *old_usr = NULL;
int r;
assert(path);
r = chase_symlinks("/usr", path, CHASE_PREFIX_ROOT, &old_usr);
if (r < 0)
return log_error_errno(r, "/usr not available in old root: %m");
r = mkdir_p("/run/systemd/volatile-sysroot", 0700);
if (r < 0)
return log_error_errno(r, "Couldn't generate volatile sysroot directory: %m");
r = mount_verbose(LOG_ERR, "tmpfs", "/run/systemd/volatile-sysroot", "tmpfs", MS_STRICTATIME, "mode=755");
if (r < 0)
goto finish_rmdir;
if (mkdir("/run/systemd/volatile-sysroot/usr", 0755) < 0) {
r = log_error_errno(errno, "Failed to create /usr directory: %m");
goto finish_umount;
}
r = mount_verbose(LOG_ERR, old_usr, "/run/systemd/volatile-sysroot/usr", NULL, MS_BIND|MS_REC, NULL);
if (r < 0)
goto finish_umount;
r = bind_remount_recursive("/run/systemd/volatile-sysroot/usr", true, NULL);
if (r < 0) {
log_error_errno(r, "Failed to remount /usr read-only: %m");
goto finish_umount;
}
r = umount_recursive(path, 0);
if (r < 0) {
log_error_errno(r, "Failed to unmount %s: %m", path);
goto finish_umount;
}
if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0)
log_warning_errno(errno, "Failed to remount %s MS_SLAVE|MS_REC, ignoring: %m", path);
r = mount_verbose(LOG_ERR, "/run/systemd/volatile-sysroot", path, NULL, MS_MOVE, NULL);
finish_umount:
(void) umount_recursive("/run/systemd/volatile-sysroot", 0);
finish_rmdir:
(void) rmdir("/run/systemd/volatile-sysroot");
return r;
}
void umount_oldroot(setup_vals const * s)
{
if(!s->keep_oldroot)
{
printf("Umounting oldroot.\n");
int x = umount_recursive("/oldroot");
if (x != UMOUNT_SUCCESS)
fatal(-1, true, "Failed to unmount old root");
x = rmdir("/oldroot");
if(x != 0)
warn(true, "Failed to remove directory oldroot");
}
}