From 0be17528e527c3e5081fc7e03ec51bb17d9b08cc Mon Sep 17 00:00:00 2001 From: Pratyush Anand Date: Wed, 16 Mar 2016 09:09:10 +0530 Subject: [PATCH] watchdog: install module for active watchdog 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=6551881c86c791237a3bebf11eb3bd70b60ea782 http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=906d7a5cfeda508e7361f021605579a00cd82815 http://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 Cc: Dave Young Cc: Don Zickus Cc: Harald Hoyer --- modules.d/04watchdog/module-setup.sh | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/modules.d/04watchdog/module-setup.sh b/modules.d/04watchdog/module-setup.sh index 7e32210e..4680936f 100755 --- a/modules.d/04watchdog/module-setup.sh +++ b/modules.d/04watchdog/module-setup.sh @@ -31,3 +31,31 @@ install() { inst_multiple -o wdctl } +installkernel() { + [[ -d /sys/class/watchdog/ ]] || return + for dir in /sys/class/watchdog/*; do + [[ -d "$dir" ]] || continue + [[ -f "$dir/state" ]] || continue + active=$(< "$dir/state") + ! [[ $hostonly ]] || [[ "$active" = "active" ]] || continue + # device/modalias will return driver of this device + wdtdrv=$(< "$dir/device/modalias") + # There can be more than one module represented by same + # modalias. Currently load all of them. + # TODO: Need to find a way to avoid any unwanted module + # represented by modalias + wdtdrv=$(modprobe -R $wdtdrv) + instmods $wdtdrv + # however in some cases, we also need to check that if there is + # a specific driver for the parent bus/device. In such cases + # we also need to enable driver for parent bus/device. + wdtppath=$(readlink -f "$dir/device/..") + while [ -f "$wdtppath/modalias" ] + do + wdtpdrv=$(< "$wdtppath/modalias") + wdtpdrv=$(modprobe -R $wdtpdrv) + instmods $wdtpdrv + wdtppath=$(readlink -f "$wdtppath/..") + done + done +}