Re: [PATCHv2] udev 124: add cache invalidation logic on kernel change or its bootargs/cmdline/atags

[Tom Rini <trini@kernel.crashing.org>]

On Wed, Apr 22, 2009 at 10:43:02PM -0400, Denys Dmytriyenko wrote:

> also add /etc/default/udev with the option to disable device caching
> 
> Signed-off-by: Denys Dmytriyenko <denis@denix.org>

Yay, thanks.

Acked-by: Tom Rini <trini@embeddedalley.com>

> ---
>  recipes/udev/udev-124/default |    4 ++++
>  recipes/udev/udev-124/init    |   29 +++++++++++++++++++++++++----
>  recipes/udev/udev_124.bb      |   10 +++++++++-
>  3 files changed, 38 insertions(+), 5 deletions(-)
>  create mode 100644 recipes/udev/udev-124/default
> 
> diff --git a/recipes/udev/udev-124/default b/recipes/udev/udev-124/default
> new file mode 100644
> index 0000000..5c4937a
> --- /dev/null
> +++ b/recipes/udev/udev-124/default
> @@ -0,0 +1,4 @@
> +# Default for /etc/init.d/udev
> +
> +# Comment this out to disable device cache
> +DEVCACHE="/etc/dev.tar"
> diff --git a/recipes/udev/udev-124/init b/recipes/udev/udev-124/init
> index 9e11f08..efe4470 100644
> --- a/recipes/udev/udev-124/init
> +++ b/recipes/udev/udev-124/init
> @@ -14,6 +14,7 @@ export TZ=/etc/localtime
>  [ -d /sys/class ] || exit 1
>  [ -r /proc/mounts ] || exit 1
>  [ -x /sbin/udevd ] || exit 1
> +[ -f /etc/default/udev ] && . /etc/default/udev
>  [ -f /etc/udev/udev.conf ] && . /etc/udev/udev.conf
>  
>  kill_udevd() {
> @@ -34,9 +35,18 @@ LANG=C awk "\$2 == \"/dev\" && \$4 == \"tmpfs\" { exit 1 }" /proc/mounts && {
>          mkdir -m 0755 /dev/shm
>  }
>  
> -if [ -e /etc/dev.tar ]; then
> -	(cd /; tar xf /etc/dev.tar)
> -	not_first_boot=1
> +if [ "$DEVCACHE" != "" ]; then
> +	# Invalidate udev cache if the kernel or its bootargs/cmdline have changed
> +	[ -x /bin/uname ] && /bin/uname -mrspv > /tmp/uname || touch /tmp/uname
> +	[ -r /proc/cmdline ] && cat /proc/cmdline > /tmp/cmdline || touch /tmp/cmdline
> +	[ -r /proc/atags ] && cat /proc/atags > /tmp/atags || touch /tmp/atags
> +	if [ -e $DEVCACHE ] && \
> +	   cmp -s /tmp/uname /etc/udev/saved.uname && \
> +	   cmp -s /tmp/cmdline /etc/udev/saved.cmdline && \
> +	   cmp -s /tmp/atags /etc/udev/saved.atags; then
> +		(cd /; tar xf $DEVCACHE)
> +		not_first_boot=1
> +	fi
>  fi
>  
>  # make_extra_nodes
> @@ -50,10 +60,21 @@ kill_udevd > "/dev/null" 2>&1
>  		if [ "$not_first_boot" != "" ];then
>  			/sbin/udevadm trigger --subsystem-nomatch=tty --subsystem-nomatch=mem --subsystem-nomatch=vc --subsystem-nomatch=vtconsole --subsystem-nomatch=misc --subsystem-nomatch=dcon --subsystem-nomatch=pci_bus  --subsystem-nomatch=graphics  --subsystem-nomatch=backlight --subsystem-nomatch=video4linux  --subsystem-nomatch=platform
>  			(/sbin/udevadm settle --timeout=3; /sbin/udevadm control env STARTUP=)&
> +			if [ "$DEVCACHE" != "" ]; then
> +				rm -f /tmp/uname
> +				rm -f /tmp/cmdline
> +				rm -f /tmp/atags
> +			fi
>  		else
>  			/sbin/udevadm trigger
>  			/sbin/udevadm settle
> -			(cd /; tar cf /etc/dev.tar dev)
> +			if [ "$DEVCACHE" != "" ]; then
> +				echo -n " and populating dev cache"
> +				(cd /; tar cf $DEVCACHE dev)
> +				mv /tmp/uname /etc/udev/saved.uname
> +				mv /tmp/cmdline /etc/udev/saved.cmdline
> +				mv /tmp/atags /etc/udev/saved.atags
> +			fi
>  		fi
>  
>  echo
> diff --git a/recipes/udev/udev_124.bb b/recipes/udev/udev_124.bb
> index 37dc3a7..e5d9d73 100644
> --- a/recipes/udev/udev_124.bb
> +++ b/recipes/udev/udev_124.bb
> @@ -2,7 +2,7 @@ DESCRIPTION = "udev is a daemon which dynamically creates and removes device nod
>  /dev/, handles hotplug events and loads drivers at boot time. It replaces \
>  the hotplug package and requires a kernel not older than 2.6.12."
>  RPROVIDES_${PN} = "hotplug"
> -PR = "r15"
> +PR = "r16"
>  
>  SRC_URI = "http://kernel.org/pub/linux/utils/kernel/hotplug/udev-${PV}.tar.gz \
>  	   file://noasmlinkage.patch;patch=1 \
> @@ -12,6 +12,7 @@ SRC_URI = "http://kernel.org/pub/linux/utils/kernel/hotplug/udev-${PV}.tar.gz \
>  	   file://libvolume-id-soname.patch;patch=1 \
>  	   file://mount.blacklist \
>  	   file://run.rules \
> +	   file://default \
>  	   "
>  
>  SRC_URI_append_h2200 = " file://50-hostap_cs.rules "
> @@ -33,6 +34,9 @@ do_install () {
>  	install -d ${D}${sysconfdir}/init.d
>  	install -m 0755 ${WORKDIR}/init ${D}${sysconfdir}/init.d/udev
>  
> +	install -d ${D}${sysconfdir}/default
> +	install -m 0755 ${WORKDIR}/default ${D}${sysconfdir}/default/udev
> +
>  	install -d ${D}${sysconfdir}/udev/rules.d/
>  
>  	install -m 0644 ${WORKDIR}/mount.blacklist     ${D}${sysconfdir}/udev/
> @@ -45,6 +49,10 @@ do_install () {
>  		install -m 0644 ${WORKDIR}/devfs-udev.rules ${D}${sysconfdir}/udev/rules.d/devfs-udev.rules
>  	fi
>  
> +	touch ${D}${sysconfdir}/udev/saved.uname
> +	touch ${D}${sysconfdir}/udev/saved.cmdline
> +	touch ${D}${sysconfdir}/udev/saved.atags
> +
>  	install -d ${D}${sysconfdir}/udev/scripts/
>  
>  	install -m 0755 ${WORKDIR}/mount.sh ${D}${sysconfdir}/udev/scripts/mount.sh
> -- 
> 1.6.0.6
> 
> 
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-- 
Tom Rini