On 02.03.2016 13:06, Pratyush Anand wrote: > 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. > > It is reasonable to always add kernel watchdog module if dracut watchdog > module has been added. When an user does not want to add kernel module, > then he/she 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 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 > # lsinitrd -f tmp/active-watchdogs initramfs-test.img > iTCO_wdt > > -- When watchdog is inactive then watchdog modules were not added > # cat /sys/class/watchdog/watchdog0/state > inactive > # dracut initramfs-test.img -a watchdog > # lsinitrd initramfs-test.img | grep iTCO > # lsinitrd -f tmp/active-watchdogs initramfs-test.img > > Signed-off-by: Pratyush Anand <panand@xxxxxxxxxx> > Cc: Dave Young <dyoung@xxxxxxxxxx> > Cc: Don Zickus <dzickus@xxxxxxxxxx> > Cc: Harald Hoyer <harald@xxxxxxxxxx> > --- > modules.d/04watchdog/module-setup.sh | 33 +++++++++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > > diff --git a/modules.d/04watchdog/module-setup.sh b/modules.d/04watchdog/module-setup.sh > index 7ec757aec032..6232afb0d9ca 100755 > --- a/modules.d/04watchdog/module-setup.sh > +++ b/modules.d/04watchdog/module-setup.sh > @@ -32,3 +32,36 @@ install() { > inst_multiple -o wdctl > } > > +installkernel() { > + cd /sys/class/watchdog > + for dir in */; do > + cd $dir > + active=`[ -f state ] && cat state` > + if [ "$active" = "active" ]; then > + # applications like kdump need to know that, which > + # watchdog modules have been added into initramfs > + echo `cat identity` >> "$initdir/tmp/active-watchdogs" > + # device/modalias will return driver of this device > + wdtdrv=`cat 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 $wdtdrv | tr "\n" "," | sed 's/.$//'` > + instmods $wdtdrv > + # however in some cases, we also need to check that if > + # there is a specific driver for the parent bus/device. > + # In such cases we also need to enable driver for parent > + # bus/device. > + wdtppath="device/.."; > + while [ -f "$wdtppath/modalias" ] > + do > + wdtpdrv=`cat $wdtppath/modalias` > + wdtpdrv=`modprobe -R $wdtpdrv | tr "\n" "," | sed 's/.$//'` > + instmods $wdtpdrv > + wdtppath="$wdtppath/.." > + done > + fi > + cd .. > + done > +} > This part should only matter/execute in the "hostonly" case. Please use $() instead of backticks. $() can be nested. $(cat file) can be expressed as $(< file) you have to catch the case: a) there is no /sys/class/watchdog b) there is no subdir in /sys/class/watchdog cd $dir and cd .. is not ideal you might want to use subshells with () or use pushd/popd something like this: installkernel() { [[ $hostonly ]] || return for dir in /sys/class/watchdog/*; do [[ -d "$dir" ]] || continue [[ -f "$dir/state" ]] || continue active=$(< "$dir/state") [[ "$active" == "active" ]] || continue ( cd $dir echo $(< identity) >> "$initdir/tmp/active-watchdogs" […] # no need for "cd .." ) } Also I don't know, if the ".." method works for the wdtppath with the symlinks. You might want: wdtppath=$(readlink -f device/..) instead of: wdtppath="device/.." why do you use tr "\n" "," | sed 's/.$//' to construct the instmods string? -- To unsubscribe from this list: send the line "unsubscribe initramfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
