diff --git a/core/java/android/app/ResourcesManager.java b/core/java/android/app/ResourcesManager.java
index 25a8b66..31d254dc 100644
--- a/core/java/android/app/ResourcesManager.java
+++ b/core/java/android/app/ResourcesManager.java
@@ -29,7 +29,6 @@
 import android.content.res.ResourcesKey;
 import android.hardware.display.DisplayManagerGlobal;
 import android.os.IBinder;
-import android.os.LocaleList;
 import android.os.Trace;
 import android.util.ArrayMap;
 import android.util.DisplayMetrics;
@@ -38,13 +37,12 @@
 import android.util.Slog;
 import android.view.Display;
 import android.view.DisplayAdjustments;
+
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.ArrayUtils;
 
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashSet;
 import java.util.Objects;
 import java.util.WeakHashMap;
 import java.util.function.Predicate;
@@ -120,6 +118,30 @@
         }
     }
 
+    /**
+     * Invalidate and destroy any resources that reference content under the
+     * given filesystem path. Typically used when unmounting a storage device to
+     * try as hard as possible to release any open FDs.
+     */
+    public void invalidatePath(String path) {
+        synchronized (this) {
+            int count = 0;
+            for (int i = 0; i < mResourceImpls.size();) {
+                final ResourcesKey key = mResourceImpls.keyAt(i);
+                if (key.isPathReferenced(path)) {
+                    final ResourcesImpl res = mResourceImpls.removeAt(i).get();
+                    if (res != null) {
+                        res.flushLayoutCache();
+                    }
+                    count++;
+                } else {
+                    i++;
+                }
+            }
+            Log.i(TAG, "Invalidated " + count + " asset managers that referenced " + path);
+        }
+    }
+
     public Configuration getConfiguration() {
         synchronized (this) {
             return mResConfiguration;
diff --git a/core/java/android/content/res/ResourcesKey.java b/core/java/android/content/res/ResourcesKey.java
index e894492..64b6bf1 100644
--- a/core/java/android/content/res/ResourcesKey.java
+++ b/core/java/android/content/res/ResourcesKey.java
@@ -77,6 +77,26 @@
         return !Configuration.EMPTY.equals(mOverrideConfiguration);
     }
 
+    public boolean isPathReferenced(String path) {
+        if (mResDir != null && mResDir.startsWith(path)) {
+            return true;
+        } else {
+            return anyStartsWith(mSplitResDirs, path) || anyStartsWith(mOverlayDirs, path)
+                    || anyStartsWith(mLibDirs, path);
+        }
+    }
+
+    private static boolean anyStartsWith(String[] list, String prefix) {
+        if (list != null) {
+            for (String s : list) {
+                if (s != null && s.startsWith(prefix)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
     @Override
     public int hashCode() {
         return mHash;
diff --git a/services/core/java/com/android/server/AttributeCache.java b/services/core/java/com/android/server/AttributeCache.java
index 427dbc0..57f18c0 100644
--- a/services/core/java/com/android/server/AttributeCache.java
+++ b/services/core/java/com/android/server/AttributeCache.java
@@ -24,10 +24,12 @@
 import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.os.UserHandle;
+import android.util.ArrayMap;
 import android.util.SparseArray;
 
-import java.util.HashMap;
-import java.util.WeakHashMap;
+import com.android.internal.annotations.GuardedBy;
+
+import java.lang.ref.WeakReference;
 
 /**
  * TODO: This should be better integrated into the system so it doesn't need
@@ -35,17 +37,18 @@
  */
 public final class AttributeCache {
     private static AttributeCache sInstance = null;
-    
+
     private final Context mContext;
-    private final WeakHashMap<String, Package> mPackages =
-            new WeakHashMap<String, Package>();
+
+    @GuardedBy("this")
+    private final ArrayMap<String, WeakReference<Package>> mPackages = new ArrayMap<>();
+    @GuardedBy("this")
     private final Configuration mConfiguration = new Configuration();
-    
+
     public final static class Package {
         public final Context context;
-        private final SparseArray<HashMap<int[], Entry>> mMap
-                = new SparseArray<HashMap<int[], Entry>>();
-        
+        private final SparseArray<ArrayMap<int[], Entry>> mMap = new SparseArray<>();
+
         public Package(Context c) {
             context = c;
         }
@@ -59,6 +62,12 @@
             context = c;
             array = ta;
         }
+
+        void recycle() {
+            if (array != null) {
+                array.recycle();
+            }
+        }
     }
     
     public static void init(Context context) {
@@ -74,13 +83,27 @@
     public AttributeCache(Context context) {
         mContext = context;
     }
-    
+
     public void removePackage(String packageName) {
         synchronized (this) {
-            mPackages.remove(packageName);
+            final WeakReference<Package> ref = mPackages.remove(packageName);
+            final Package pkg = (ref != null) ? ref.get() : null;
+            if (pkg != null) {
+                if (pkg.mMap != null) {
+                    for (int i = 0; i < pkg.mMap.size(); i++) {
+                        final ArrayMap<int[], Entry> map = pkg.mMap.valueAt(i);
+                        for (int j = 0; j < map.size(); j++) {
+                            map.valueAt(j).recycle();
+                        }
+                    }
+                }
+
+                final Resources res = pkg.context.getResources();
+                res.flushLayoutCache();
+            }
         }
     }
-    
+
     public void updateConfiguration(Configuration config) {
         synchronized (this) {
             int changes = mConfiguration.updateFrom(config);
@@ -97,8 +120,9 @@
     
     public Entry get(String packageName, int resId, int[] styleable, int userId) {
         synchronized (this) {
-            Package pkg = mPackages.get(packageName);
-            HashMap<int[], Entry> map = null;
+            WeakReference<Package> ref = mPackages.get(packageName);
+            Package pkg = (ref != null) ? ref.get() : null;
+            ArrayMap<int[], Entry> map = null;
             Entry ent = null;
             if (pkg != null) {
                 map = pkg.mMap.get(resId);
@@ -120,11 +144,11 @@
                     return null;
                 }
                 pkg = new Package(context);
-                mPackages.put(packageName, pkg);
+                mPackages.put(packageName, new WeakReference<>(pkg));
             }
             
             if (map == null) {
-                map = new HashMap<int[], Entry>();
+                map = new ArrayMap<>();
                 pkg.mMap.put(resId, map);
             }
             
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index a2bdde4..3450aff 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -105,6 +105,7 @@
 import android.app.ActivityManager;
 import android.app.ActivityManagerNative;
 import android.app.IActivityManager;
+import android.app.ResourcesManager;
 import android.app.admin.DevicePolicyManagerInternal;
 import android.app.admin.IDevicePolicyManager;
 import android.app.admin.SecurityLog;
@@ -238,6 +239,7 @@
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.internal.util.Preconditions;
 import com.android.internal.util.XmlUtils;
+import com.android.server.AttributeCache;
 import com.android.server.EventLogTags;
 import com.android.server.FgThread;
 import com.android.server.IntentResolver;
@@ -19135,6 +19137,11 @@
                         Slog.w(TAG, "Failed to unload " + ps.codePath);
                     }
                 }
+
+                // Try very hard to release any references to this package
+                // so we don't risk the system server being killed due to
+                // open FDs
+                AttributeCache.instance().removePackage(ps.name);
             }
 
             mSettings.writeLPr();
@@ -19143,6 +19150,15 @@
 
         if (DEBUG_INSTALL) Slog.d(TAG, "Unloaded packages " + unloaded);
         sendResourcesChangedBroadcast(false, false, unloaded, null);
+
+        // Try very hard to release any references to this path so we don't risk
+        // the system server being killed due to open FDs
+        ResourcesManager.getInstance().invalidatePath(vol.getPath().getAbsolutePath());
+
+        for (int i = 0; i < 3; i++) {
+            System.gc();
+            System.runFinalization();
+        }
     }
 
     /**