In some cases, user only want to include the watchdog module, not the
wdctl or any other userspace helper. For example, systemd have a
RebootWatchdogSec option that use watchdog to prevent reboot hangs. And
it can help prevent machines hangs when reboot directly within the
initramfs stage. So split the module installation to a standlone module.
Also when watchdog-module get included, install driver for all loaded
watchdog instaed of only install driver for active watchdog. Both
watchdog and watchdog-module return 255 in check(), so it's enabled only
when manually included, the watchdog may get configured/activated later.
Signed-off-by: Kairui Song <kasong@redhat.com>
- use local variables with _
- use associative array for the kernel modules
- install emergency hook even in the systemd case
- follow device path until /sys is reached
- set kernel version for modprobe checking
It is expected that a watchdog module will disable an active watchdog when
its probe is called ie, when it is loaded. So an early load of the module
will help to disable it earlier.
This can be helpful in some corner cases where kdump and watchdog daemon
both are active.
Testing:
-- When watchdog kernel modules were added
# dracut --no-hostonly initramfs-test.img -a watchdog
# lsinitrd initramfs-test.img -f etc/cmdline.d/00-watchdog.conf
rd.driver.pre=iTCO_wdt,lpc_ich,
Signed-off-by: Pratyush Anand <panand@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Harald Hoyer <harald@redhat.com>
Recently following patches have been added in upstream Linux kernel, which
(1) fixes parent of watchdog_device so that
/sys/class/watchdog/watchdogn/device is populated. (2) adds some sysfs
device attributes so that different watchdog status can be read.
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6551881c86c791237a3bebf11eb3bd70b60ea782http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=906d7a5cfeda508e7361f021605579a00cd82815http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=33b711269ade3f6bc9d9d15e4343e6fa922d999b
With the above support, now we can find out whether a watchdog is active or
not. We can also find out the driver/module responsible for that watchdog
device.
Proposed patch uses above support and then adds module of active watchdog
in initramfs generated by dracut for hostonly mode. Kernel module for
inactive watchdog will be added as well for none hostonly mode.
When an user does not want to add kernel module, then one should exclude
complete dracut watchdog module with --omit.
Testing:
-- When watchdog is active watchdog modules were added
# cat /sys/class/watchdog/watchdog0/identity
iTCO_wdt
# cat /sys/class/watchdog/watchdog0/state
active
# dracut --hostonly initramfs-test.img -a watchdog
# lsinitrd initramfs-test.img | grep iTCO
-rw-r--r-- 1 root root 9100 Feb 24 09:19 usr/lib/modules/.../kernel/drivers/watchdog/iTCO_vendor_support.ko
-rw-r--r-- 1 root root 19252 Feb 24 09:19 usr/lib/modules/.../kernel/drivers/watchdog/iTCO_wdt.ko
-- When watchdog is inactive then watchdog modules were not added
# cat /sys/class/watchdog/watchdog0/state
inactive
# dracut --hostonly initramfs-test.img -a watchdog
# lsinitrd initramfs-test.img | grep iTCO
-- When watchdog is inactive, but no hostonly mode, watchdog modules were added
# cat /sys/class/watchdog/watchdog0/state
inactive
# dracut --no-hostonly initramfs-test.img -a watchdog
# lsinitrd initramfs-test.img | grep iTCO
-rw-r--r-- 1 root root 9100 Feb 24 09:19 usr/lib/modules/.../kernel/drivers/watchdog/iTCO_vendor_support.ko
-rw-r--r-- 1 root root 19252 Feb 24 09:19 usr/lib/modules/.../kernel/drivers/watchdog/iTCO_wdt.ko
Signed-off-by: Pratyush Anand <panand@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Harald Hoyer <harald@redhat.com>
When systemd is present, let it manage watchdog feed.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Harald Hoyer <harald@redhat.com>
Harald Hoyer