backuptool_ab: Make copy_file preserve file/directory attrs

Change-Id: I52c7b124ff8364464643c51b3f17dba4e4e49435

prebuilt/common/bin/backuptool_ab.functions

@@ -9,40 +9,28 @@ export V=16.0
 export backuptool_ab=true
 
 copy_file() {
-  # toybox's cp doesn't do directories correctly for whatever reason
-  mkdir -p `dirname $2`
+  old=`umask`
+  umask 0322
+  mkdir -m755 -p `dirname $2`
+  umask "$old"
 
-  cp -dp "$1" "$2"
-  # symlinks don't have a context
-  if [ ! -L "$1" ]; then
-    # it is assumed that every label starts with 'u:object_r' and has no white-spaces
-    local context=`ls -Z "$1" | grep -o 'u:object_r:[^ ]*' | head -1`
-    chcon "$context" "$2"
-  fi
+  cp -dp --preserve=a "$1" "$2"
 }
 
 backup_file() {
   if [ -e "$1" -o -L "$1" ]; then
-    local FILE=`basename "$1"`
-    local DIR=`dirname "$1"`
     # dont backup any apps that have odex files, they are useless
-    if ( echo "$FILE" | grep -q "\.apk$" ) && [ -e `echo "$1" | sed -e 's/\.apk$/\.odex/'` ]; then
+    if ( echo "$1" | grep -q "\.apk$" ) && [ -e `echo "$1" | sed -e 's/\.apk$/\.odex/'` ]; then
       echo "Skipping odexed apk $1";
     else
-      mkdir -p "$C/$DIR"
-      copy_file "$1" "$C/$DIR/$FILE"
+      copy_file "$1" "$C/$1"
     fi
   fi
 }
 
 restore_file() {
-  local FILE=`basename "$1"`
-  local DIR=`dirname "$1"`
-  if [ -e "$C/$DIR/$FILE" -o -L "$C/$DIR/$FILE" ]; then
-    if [ ! -d "/postinstall/$DIR" ]; then
-      mkdir -p "/postinstall/$DIR";
-    fi
-    copy_file "$C/$DIR/$FILE" "/postinstall/$1";
+  if [ -e "$C/$1" -o -L "$C/$1" ]; then
+    copy_file "$C/$1" "/postinstall/$1";
     if [ -n "$2" ]; then
       echo "Deleting obsolete file $2"
       rm "$2";