[OE-core] [PATCH 1/1] populate-volatile.sh: detect the change of configuration files

[Chen Qi]

In case the configuration files are modified by user, the cached script,
/etc/volatile.cache should not be executed. Instead, the configuration
files should be parsed again and generate the new cache. Otherwise, the
user modifications take no effect which would obviously confuse users.

Signed-off-by: Chen Qi <Qi.Chen at windriver.com>
---
 .../initscripts/initscripts-1.0/populate-volatile.sh  | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/meta/recipes-core/initscripts/initscripts-1.0/populate-volatile.sh b/meta/recipes-core/initscripts/initscripts-1.0/populate-volatile.sh
index 904037e..eaf0f1c 100755
--- a/meta/recipes-core/initscripts/initscripts-1.0/populate-volatile.sh
+++ b/meta/recipes-core/initscripts/initscripts-1.0/populate-volatile.sh
@@ -204,9 +204,25 @@ do
 done
 exec 9>&-
 
-if test -e ${ROOT_DIR}/etc/volatile.cache -a "$VOLATILE_ENABLE_CACHE" = "yes" -a "x$1" != "xupdate" -a "x$clearcache" = "x0"
+# Check whether configuration files have changed, if so, the cache needs to be removed
+# and generated again
+CACHE_MATCH="no"
+CACHE_DATA="${ROOT_DIR}/etc/.volatile.cache.data"
+CACHE_TMP="${ROOT_DIR}/etc/.volatile.cache.tmp"
+VOLATILE_CONFFILES="${ROOT_DIR}/etc/default/volatiles/*"
+if [ "$VOLATILE_ENABLE_CACHE" = "yes" ]; then
+	stat -c '%s %Y %n' $VOLATILE_CONFFILES | awk -F/ '{print $1 " " $NF;}' > $CACHE_TMP
+	if [ -e $CACHE_DATA ]; then
+		if cmp $CACHE_DATA $CACHE_TMP > /dev/null; then
+			CACHE_MATCH="yes"
+		fi
+	fi
+fi
+
+if test -e ${ROOT_DIR}/etc/volatile.cache -a "$VOLATILE_ENABLE_CACHE" = "yes" -a "x$1" != "xupdate" -a "x$clearcache" = "x0" -a "$CACHE_MATCH" = "yes"
 then
 	sh ${ROOT_DIR}/etc/volatile.cache
+	[ -e $CACHE_TMP ] && rm $CACHE_TMP
 else
 	rm -f ${ROOT_DIR}/etc/volatile.cache ${ROOT_DIR}/etc/volatile.cache.build
 	for file in `ls -1 "${CFGDIR}" | sort`; do
@@ -214,6 +230,7 @@ else
 	done
 
 	[ -e ${ROOT_DIR}/etc/volatile.cache.build ] && sync && mv ${ROOT_DIR}/etc/volatile.cache.build ${ROOT_DIR}/etc/volatile.cache
+	[ -e $CACHE_TMP ] && mv $CACHE_TMP $CACHE_DATA
 fi
 
 if [ -z "${ROOT_DIR}" ] && [ -f /etc/ld.so.cache ] && [ ! -f /var/run/ld.so.cache ]
-- 
1.9.1