Subject: init.d: add support for read-only rootfs

Upstream-Status: Inappropriate [oe specific]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 init.d |   40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/init.d b/init.d
index 0111ed4..24677c8 100644
--- a/init.d
+++ b/init.d
@@ -6,8 +6,48 @@ PATH=/sbin:/bin:/usr/sbin:/usr/bin
 # Don't modify this line, change or create /etc/default/bind9.
 OPTIONS=""
 
+test -f /etc/default/rcS && . /etc/default/rcS
 test -f /etc/default/bind9 && . /etc/default/bind9
 
+# This function is here because it's possible that /var and / are on different partitions.
+is_on_read_only_partition () {
+    DIRECTORY=$1
+    dir=`readlink -f $DIRECTORY`
+    while true; do
+	if [ ! -d "$dir" ]; then
+	    echo "ERROR: $dir is not a directory"
+	    exit 1
+	else
+	    for flag in `awk -v dir=$dir '{ if ($2 == dir) { print "FOUND"; split($4,FLAGS,",") } }; \
+		END { for (f in FLAGS) print FLAGS[f] }' < /proc/mounts`; do
+		[ "$flag" = "FOUND" ] && partition="read-write"
+		[ "$flag" = "ro" ] && { partition="read-only"; break; }
+	    done
+	    if [ "$dir" = "/" -o -n "$partition" ]; then
+		break
+	    else
+		dir=`dirname $dir`
+	    fi
+	fi
+    done
+    [ "$partition" = "read-only" ] && echo "yes" || echo "no"
+}
+
+bind_mount () {
+    olddir=$1
+    newdir=$2
+    mkdir -p $olddir
+    cp -a $newdir/* $olddir
+    mount --bind $olddir $newdir
+}
+
+# Deal with read-only rootfs
+if [ "$ROOTFS_READ_ONLY" = "yes" ]; then
+    [ "$VERBOSE" != "no" ] && echo "WARN: start bind service in read-only rootfs"
+    [ `is_on_read_only_partition /etc/bind` = "yes" ] && bind_mount /var/volatile/bind/etc /etc/bind
+    [ `is_on_read_only_partition /var/named` = "yes" ] && bind_mount /var/volatile/bind/named /var/named
+fi
+
 test -x /usr/sbin/rndc || exit 0
 
 case "$1" in
-- 
1.7.9.5