cm: bind mount DOWNLOAD_CACHE to /data if /cache is less then 20MB

this is useful for all user which want to use cMTD or static
  partition size (like alpharev) to assign more space to /data
  reducing /cache size

Change-Id: Ib251c9bea1dea50b6c444df977aa605e58008c41

prebuilt/common/etc/init.d/06mountdl

@@ -0,0 +1,13 @@
+#!/system/bin/sh
+#
+# bind mount /data/local/download to /cache/download if cache
+# partition is too small
+#
+
+CACHESIZE=$(df -k /cache | tail -n1 | tr -s ' ' | cut -d ' ' -f2)
+if [ $CACHESIZE -lt 20000 ]
+then
+  mount -o bind /data/local/download /cache/download
+fi
+
+exit 0

products/common.mk

@@ -69,6 +69,8 @@ PRODUCT_COPY_FILES += \
     vendor/cyanogen/prebuilt/common/etc/init.d/01sysctl:system/etc/init.d/01sysctl \
     vendor/cyanogen/prebuilt/common/etc/init.d/03firstboot:system/etc/init.d/03firstboot \
     vendor/cyanogen/prebuilt/common/etc/init.d/04modules:system/etc/init.d/04modules \
+    vendor/cyanogen/prebuilt/common/etc/init.d/05mountsd:system/etc/init.d/05mountsd \
+    vendor/cyanogen/prebuilt/common/etc/init.d/06mountdl:system/etc/init.d/06mountdl \
     vendor/cyanogen/prebuilt/common/etc/init.d/20userinit:system/etc/init.d/20userinit \
     vendor/cyanogen/prebuilt/common/bin/handle_compcache:system/bin/handle_compcache \
     vendor/cyanogen/prebuilt/common/bin/compcache:system/bin/compcache \
@@ -80,7 +82,6 @@ PRODUCT_COPY_FILES += \
     vendor/cyanogen/prebuilt/common/xbin/openvpn-up.sh:system/xbin/openvpn-up.sh
 
 PRODUCT_COPY_FILES += \
-    vendor/cyanogen/prebuilt/common/etc/init.d/05mountsd:system/etc/init.d/05mountsd
 #    vendor/cyanogen/prebuilt/common/etc/init.d/10apps2sd:system/etc/init.d/10apps2sd
 
 PRODUCT_COPY_FILES +=  \