rootdir / sdcard : Stop creating /data/media/obb.

This directory is no longer used. OBB content is
placed in /data/media/$user/Android.

Test: make
Test: manually verify the path doesn't exist.
Bug: 129167772

Change-Id: I8549826586b9a68c8cfa3fe2e51295363f9b4e11
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 1b7367c..2601997 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -586,7 +586,6 @@
     symlink /data/data /data/user/0
 
     mkdir /data/media 0770 media_rw media_rw
-    mkdir /data/media/obb 0770 media_rw media_rw
 
     mkdir /data/cache 0770 system cache
     mkdir /data/cache/recovery 0770 system cache
diff --git a/sdcard/sdcard.cpp b/sdcard/sdcard.cpp
index 2b35819..0acea72 100644
--- a/sdcard/sdcard.cpp
+++ b/sdcard/sdcard.cpp
@@ -214,7 +214,14 @@
 
     if (multi_user) {
         std::string obb_path = source_path + "/obb";
-        fs_prepare_dir(obb_path.c_str(), 0775, uid, gid);
+        // Only attempt to prepare the /obb dir if it already exists. We want
+        // the legacy obb path "/data/media/obb" to be fixed up so that we can
+        // migrate it to its new location, but we don't want the directory to be
+        // created if it doesn't already exist.
+        struct stat sb;
+        if (TEMP_FAILURE_RETRY(lstat(obb_path.c_str(), &sb)) == 0) {
+            fs_prepare_dir(obb_path.c_str(), 0775, uid, gid);
+        }
     }
 
     exit(0);