Commit b50fa7c8 authored May 05, 2011 by Kay Sievers Committed by Greg Kroah-Hartman May 06, 2011

reboot: disable usermodehelper to prevent fs access



In case CONFIG_UEVENT_HELPER_PATH is not set to "", which it
should be on every system, the kernel forks processes during
shutdown, which try to access the rootfs, even when the
binary does not exist. It causes exceptions and long delays in
the disk driver, which gets read requests at the time it tries
to shut down the disk.

This patch disables all kernel-forked processes during reboot to
allow a clean poweroff.

Cc: Tejun Heo <htejun@gmail.com>
Tested-By: Anton Guda <atu@dmeti.dp.ua>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent aabb6e15

kernel/sys.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -314,6 +314,7 @@ void kernel_restart_prepare(char *cmd)
		{
		blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
		system_state = SYSTEM_RESTART;
		usermodehelper_disable();
		device_shutdown();
		sysdev_shutdown();
		syscore_shutdown();
		@@ -344,6 +345,7 @@ static void kernel_shutdown_prepare(enum system_states state)
		blocking_notifier_call_chain(&reboot_notifier_list,
		(state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
		system_state = state;
		usermodehelper_disable();
		device_shutdown();
		}
		/**

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