Add a limit on how much data an app can acquire a lease on.

+ Allow this limit to be modified using DeviceConfig properties.
+ Support DeviceConfig.getProperties() in TestableDeviceConfig.

Bug: 144155182
Test: atest --test-mapping apex/blobstore
Test: atest services/tests/mockingservicestests/src/com/android/server/testables/TestableDeviceConfigTest.java
Test: atest services/tests/mockingservicestests/src/com/android/server/am/CachedAppOptimizerTest.java
Change-Id: I28e67a27771be04ed1d37f367abd392505adc5c4

3 files changed, 169 insertions, 15 deletions

diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java b/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
index 4a85a69b82d3..909e8984454a 100644
--- a/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
@@ -239,7 +239,7 @@ class BlobMetadata {
         return hasOtherLeasees(null, uid);
     }
 
-    private boolean isALeasee(@Nullable String packageName, int uid) {
+    boolean isALeasee(@Nullable String packageName, int uid) {
         synchronized (mMetadataLock) {
             // Check if the package is a leasee of the data blob.
             for (int i = 0, size = mLeasees.size(); i < size; ++i) {
diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java b/apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java
index bcc1610435d9..0910e3392bb9 100644
--- a/apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java
@@ -15,12 +15,23 @@
  */
 package com.android.server.blob;
 
+import static android.provider.DeviceConfig.NAMESPACE_BLOBSTORE;
+import static android.text.format.Formatter.FLAG_IEC_UNITS;
+import static android.text.format.Formatter.formatFileSize;
+import static android.util.TimeUtils.formatDuration;
+
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.content.Context;
 import android.os.Environment;
+import android.provider.DeviceConfig;
+import android.provider.DeviceConfig.Properties;
+import android.util.DataUnit;
 import android.util.Log;
 import android.util.Slog;
 
+import com.android.internal.util.IndentingPrintWriter;
+
 import java.io.File;
 import java.util.concurrent.TimeUnit;
 
@@ -54,6 +65,76 @@ class BlobStoreConfig {
      */
     public static final long SESSION_EXPIRY_TIMEOUT_MILLIS = TimeUnit.DAYS.toMillis(7);
 
+    public static class DeviceConfigProperties {
+        /**
+         * Denotes how low the limit for the amount of data, that an app will be allowed to acquire
+         * a lease on, can be.
+         */
+        public static final String KEY_TOTAL_BYTES_PER_APP_LIMIT_FLOOR =
+                "total_bytes_per_app_limit_floor";
+        public static final long DEFAULT_TOTAL_BYTES_PER_APP_LIMIT_FLOOR =
+                DataUnit.MEBIBYTES.toBytes(300); // 300 MiB
+        public static long TOTAL_BYTES_PER_APP_LIMIT_FLOOR =
+                DEFAULT_TOTAL_BYTES_PER_APP_LIMIT_FLOOR;
+
+        /**
+         * Denotes the maximum amount of data an app can acquire a lease on, in terms of fraction
+         * of total disk space.
+         */
+        public static final String KEY_TOTAL_BYTES_PER_APP_LIMIT_FRACTION =
+                "total_bytes_per_app_limit_fraction";
+        public static final float DEFAULT_TOTAL_BYTES_PER_APP_LIMIT_FRACTION = 0.01f;
+        public static float TOTAL_BYTES_PER_APP_LIMIT_FRACTION =
+                DEFAULT_TOTAL_BYTES_PER_APP_LIMIT_FRACTION;
+
+        static void refresh(Properties properties) {
+            if (!NAMESPACE_BLOBSTORE.equals(properties.getNamespace())) {
+                return;
+            }
+            properties.getKeyset().forEach(key -> {
+                switch (key) {
+                    case KEY_TOTAL_BYTES_PER_APP_LIMIT_FLOOR:
+                        TOTAL_BYTES_PER_APP_LIMIT_FLOOR = properties.getLong(key,
+                                DEFAULT_TOTAL_BYTES_PER_APP_LIMIT_FLOOR);
+                        break;
+                    case KEY_TOTAL_BYTES_PER_APP_LIMIT_FRACTION:
+                        TOTAL_BYTES_PER_APP_LIMIT_FRACTION = properties.getFloat(key,
+                                DEFAULT_TOTAL_BYTES_PER_APP_LIMIT_FRACTION);
+                        break;
+                    default:
+                        Slog.wtf(TAG, "Unknown key in device config properties: " + key);
+                }
+            });
+        }
+
+        static void dump(IndentingPrintWriter fout, Context context) {
+            final String dumpFormat = "%s: [cur: %s, def: %s]";
+            fout.println(String.format(dumpFormat, KEY_TOTAL_BYTES_PER_APP_LIMIT_FLOOR,
+                    formatFileSize(context, TOTAL_BYTES_PER_APP_LIMIT_FLOOR, FLAG_IEC_UNITS),
+                    formatFileSize(context, DEFAULT_TOTAL_BYTES_PER_APP_LIMIT_FLOOR,
+                            FLAG_IEC_UNITS)));
+            fout.println(String.format(dumpFormat, KEY_TOTAL_BYTES_PER_APP_LIMIT_FRACTION,
+                    TOTAL_BYTES_PER_APP_LIMIT_FRACTION,
+                    DEFAULT_TOTAL_BYTES_PER_APP_LIMIT_FRACTION));
+        }
+    }
+
+    public static void initialize(Context context) {
+        DeviceConfig.addOnPropertiesChangedListener(NAMESPACE_BLOBSTORE,
+                context.getMainExecutor(),
+                properties -> DeviceConfigProperties.refresh(properties));
+        DeviceConfigProperties.refresh(DeviceConfig.getProperties(NAMESPACE_BLOBSTORE));
+    }
+
+    /**
+     * Returns the maximum amount of data that an app can acquire a lease on.
+     */
+    public static long getAppDataBytesLimit() {
+        final long totalBytesLimit = (long) (Environment.getDataSystemDirectory().getTotalSpace()
+                * DeviceConfigProperties.TOTAL_BYTES_PER_APP_LIMIT_FRACTION);
+        return Math.max(DeviceConfigProperties.TOTAL_BYTES_PER_APP_LIMIT_FLOOR, totalBytesLimit);
+    }
+
     @Nullable
     public static File prepareBlobFile(long sessionId) {
         final File blobsDir = prepareBlobsDir();
@@ -122,4 +203,21 @@ class BlobStoreConfig {
     public static File getBlobStoreRootDir() {
         return new File(Environment.getDataSystemDirectory(), ROOT_DIR_NAME);
     }
+
+    public static void dump(IndentingPrintWriter fout, Context context) {
+        fout.println("XML current version: " + XML_VERSION_CURRENT);
+
+        fout.println("Idle job ID: " + IDLE_JOB_ID);
+        fout.println("Idle job period: " + formatDuration(IDLE_JOB_PERIOD_MILLIS));
+
+        fout.println("Session expiry timeout: " + formatDuration(SESSION_EXPIRY_TIMEOUT_MILLIS));
+
+        fout.println("Total bytes per app limit: " + formatFileSize(context,
+                getAppDataBytesLimit(), FLAG_IEC_UNITS));
+
+        fout.println("Device config properties:");
+        fout.increaseIndent();
+        DeviceConfigProperties.dump(fout, context);
+        fout.decreaseIndent();
+    }
 }
diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java b/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
index 91df1df0c5b5..d3c8ddc72553 100644
--- a/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
@@ -184,7 +184,9 @@ public class BlobStoreManagerService extends SystemService {
 
     @Override
     public void onBootPhase(int phase) {
-        if (phase == PHASE_THIRD_PARTY_APPS_CAN_START) {
+        if (phase == PHASE_ACTIVITY_MANAGER_READY) {
+            BlobStoreConfig.initialize(mContext);
+        } else if (phase == PHASE_THIRD_PARTY_APPS_CAN_START) {
             synchronized (mBlobsLock) {
                 final SparseArray<SparseArray<String>> allPackages = getAllPackages();
                 readBlobSessionsLocked(allPackages);
@@ -377,6 +379,11 @@ public class BlobStoreManagerService extends SystemService {
                 throw new IllegalArgumentException(
                         "Lease expiry cannot be later than blobs expiry time");
             }
+            if (getTotalUsageBytesLocked(callingUid, callingPackage)
+                    + blobMetadata.getSize() > BlobStoreConfig.getAppDataBytesLimit()) {
+                throw new IllegalStateException("Total amount of data with an active lease"
+                        + " is exceeding the max limit");
+            }
             blobMetadata.addLeasee(callingPackage, callingUid,
                     descriptionResId, description, leaseExpiryTimeMillis);
             if (LOGV) {
@@ -387,6 +394,18 @@ public class BlobStoreManagerService extends SystemService {
         }
     }
 
+    @VisibleForTesting
+    @GuardedBy("mBlobsLock")
+    long getTotalUsageBytesLocked(int callingUid, String callingPackage) {
+        final AtomicLong totalBytes = new AtomicLong(0);
+        forEachBlobInUser((blobMetadata) -> {
+            if (blobMetadata.isALeasee(callingPackage, callingUid)) {
+                totalBytes.getAndAdd(blobMetadata.getSize());
+            }
+        }, UserHandle.getUserId(callingUid));
+        return totalBytes.get();
+    }
+
     private void releaseLeaseInternal(BlobHandle blobHandle, int callingUid,
             String callingPackage) {
         synchronized (mBlobsLock) {
@@ -1218,8 +1237,10 @@ public class BlobStoreManagerService extends SystemService {
             }
 
             synchronized (mBlobsLock) {
-                fout.println("mCurrentMaxSessionId: " + mCurrentMaxSessionId);
-                fout.println();
+                if (dumpArgs.shouldDumpAllSections()) {
+                    fout.println("mCurrentMaxSessionId: " + mCurrentMaxSessionId);
+                    fout.println();
+                }
 
                 if (dumpArgs.shouldDumpSessions()) {
                     dumpSessionsLocked(fout, dumpArgs);
@@ -1230,6 +1251,14 @@ public class BlobStoreManagerService extends SystemService {
                     fout.println();
                 }
             }
+
+            if (dumpArgs.shouldDumpConfig()) {
+                fout.println("BlobStore config:");
+                fout.increaseIndent();
+                BlobStoreConfig.dump(fout, mContext);
+                fout.decreaseIndent();
+                fout.println();
+            }
         }
 
         @Override
@@ -1242,14 +1271,16 @@ public class BlobStoreManagerService extends SystemService {
     }
 
     static final class DumpArgs {
+        private static final int FLAG_DUMP_SESSIONS = 1 << 0;
+        private static final int FLAG_DUMP_BLOBS = 1 << 1;
+        private static final int FLAG_DUMP_CONFIG = 1 << 2;
+
+        private int mSelectedSectionFlags;
         private boolean mDumpFull;
         private final ArrayList<String> mDumpPackages = new ArrayList<>();
         private final ArrayList<Integer> mDumpUids = new ArrayList<>();
         private final ArrayList<Integer> mDumpUserIds = new ArrayList<>();
         private final ArrayList<Long> mDumpBlobIds = new ArrayList<>();
-        private boolean mDumpOnlySelectedSections;
-        private boolean mDumpSessions;
-        private boolean mDumpBlobs;
         private boolean mDumpHelp;
 
         public boolean shouldDumpSession(String packageName, int uid, long blobId) {
@@ -1268,18 +1299,41 @@ public class BlobStoreManagerService extends SystemService {
             return true;
         }
 
+        public boolean shouldDumpAllSections() {
+            return mSelectedSectionFlags == 0;
+        }
+
+        public void allowDumpSessions() {
+            mSelectedSectionFlags |= FLAG_DUMP_SESSIONS;
+        }
+
         public boolean shouldDumpSessions() {
-            if (!mDumpOnlySelectedSections) {
+            if (shouldDumpAllSections()) {
                 return true;
             }
-            return mDumpSessions;
+            return (mSelectedSectionFlags & FLAG_DUMP_SESSIONS) != 0;
+        }
+
+        public void allowDumpBlobs() {
+            mSelectedSectionFlags |= FLAG_DUMP_BLOBS;
         }
 
         public boolean shouldDumpBlobs() {
-            if (!mDumpOnlySelectedSections) {
+            if (shouldDumpAllSections()) {
+                return true;
+            }
+            return (mSelectedSectionFlags & FLAG_DUMP_BLOBS) != 0;
+        }
+
+        public void allowDumpConfig() {
+            mSelectedSectionFlags |= FLAG_DUMP_CONFIG;
+        }
+
+        public boolean shouldDumpConfig() {
+            if (shouldDumpAllSections()) {
                 return true;
             }
-            return mDumpBlobs;
+            return (mSelectedSectionFlags & FLAG_DUMP_CONFIG) != 0;
         }
 
         public boolean shouldDumpBlob(long blobId) {
@@ -1316,11 +1370,11 @@ public class BlobStoreManagerService extends SystemService {
                         dumpArgs.mDumpFull = true;
                     }
                 } else if ("--sessions".equals(opt)) {
-                    dumpArgs.mDumpOnlySelectedSections = true;
-                    dumpArgs.mDumpSessions = true;
+                    dumpArgs.allowDumpSessions();
                 } else if ("--blobs".equals(opt)) {
-                    dumpArgs.mDumpOnlySelectedSections = true;
-                    dumpArgs.mDumpBlobs = true;
+                    dumpArgs.allowDumpBlobs();
+                } else if ("--config".equals(opt)) {
+                    dumpArgs.allowDumpConfig();
                 } else if ("--package".equals(opt) || "-p".equals(opt)) {
                     dumpArgs.mDumpPackages.add(getStringArgRequired(args, ++i, "packageName"));
                 } else if ("--uid".equals(opt) || "-u".equals(opt)) {
@@ -1379,6 +1433,8 @@ public class BlobStoreManagerService extends SystemService {
             printWithIndent(pw, "Dump only the sessions info");
             pw.println("--blobs");
             printWithIndent(pw, "Dump only the committed blobs info");
+            pw.println("--config");
+            printWithIndent(pw, "Dump only the config values");
             pw.println("--package | -p [package-name]");
             printWithIndent(pw, "Dump blobs info associated with the given package");
             pw.println("--uid | -u [uid]");