udev: improve udev-cache robustness

 * allow udev-cache to be disabled at runtime (using
   /etc/default/udev-cache);

 * make cache invalidated if kernel, bootparams or device list
   changes;

(From OE-Core rev: 22b72b23653736436f10d394de36201c32630d5d)

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 11 insertions, 3 deletions

diff --git a/meta/recipes-core/udev/udev/udev-cache b/meta/recipes-core/udev/udev/udev-cache
index 77bbda6f1b..9c24e76514 100644
--- a/meta/recipes-core/udev/udev/udev-cache
+++ b/meta/recipes-core/udev/udev/udev-cache
@@ -9,12 +9,20 @@
 # Short-Description: cache /dev to speedup the udev next boot
 ### END INIT INFO
 
-[ -d /sys/class ] || exit 1
+export TZ=/etc/localtime
+
 [ -r /proc/mounts ] || exit 1
 [ -x /sbin/udevd ] || exit 1
+[ -d /sys/class ] || exit 1
+
+[ -f /etc/default/udev-cache ] && . /etc/default/udev-cache
 
-if [ ! -e /etc/dev.tar ]; then
-        (cd /; tar cf /etc/dev.tar dev)
+if [ "$DEVCACHE" != "" ]; then
+        echo "Populating dev cache"
+        (cd /; tar cf "$DEVCACHE" dev)
+        mv /dev/shm/udev.cache /etc/udev/cache.data
+else
+        rm -f /dev/shm/udev.cache
 fi
 
 exit 0