944f3d05b5
The patch introduces support for system reboot functionality and process teardown, allowing for a clean shutdown and unmounting of the root filesystem. This is necessary for ensuring a proper system shutdown process, especially when dealing with resource cleanup and ensuring that all processes have exited before system shutdown. Changes: - Added `lwp_teardown()` function to handle process cleanup and system teardown. - Introduced `lwp_pid_wait_for_empty()` to wait for process ID table emptiness before proceeding with shutdown. - Updated `dfs_mnt_unref()` to trigger callbacks when unmounting a filesystem. - Added new reboot types (`RB_AUTOBOOT`, `RB_POWER_OFF`) and implemented their corresponding actions, including cleanup of processes and unmounting root filesystem. - Extended `sys_reboot()` to handle reboot and power off types with appropriate callbacks for process and filesystem teardown. - Introduced callback mechanism for root filesystem unmount notifications. Signed-off-by: Shell <smokewood@qq.com>