Split MOUNT_FLAG_VISIBLE into MOUNT_FLAG_VISIBLE_FOR_{READ, WRITE}

Currently, VolumeInfo.isVisibleForUser(), VolumeInfo.isVisibleForRead(),
and VolumeInfo.isVisibleForWrite() are all equivalent; all of them just
mean that the volume has MOUNT_FLAG_VISIBLE.

This CL splits MOUNT_FLAG_VISIBLE into MOUNT_FLAG_VISIBLE_FOR_READ and
MOUNT_FLAG_VISIBLE_FOR_WRITE. They correspond to isVisibleForRead() and
isVisibleForWrite(), respectively, whereas isVisibleForUser() is now
defined as isVisibleForRead() || isVisibleForWrite().

Accordingly, all usages of MOUNT_FLAG_VISIBLE are replaced with
MOUNT_FLAG_VISIBLE_FOR_WRITE, and all usages of isVisibleForRead() are
replaced with isVisibleForUser().

Bug: 206019156
Test: m
Change-Id: I576430680620363f4fbe49787035bd52445b3554
Merged-In: I576430680620363f4fbe49787035bd52445b3554

3 files changed, 39 insertions, 23 deletions

diff --git a/core/java/android/os/storage/VolumeInfo.java b/core/java/android/os/storage/VolumeInfo.java
index f57d1574d399..39a2e1353237 100644
--- a/core/java/android/os/storage/VolumeInfo.java
+++ b/core/java/android/os/storage/VolumeInfo.java
@@ -56,11 +56,12 @@ import java.util.UUID;
  * <ul>
  * <li>{@link #MOUNT_FLAG_PRIMARY} means the volume provides primary external
  * storage, historically found at {@code /sdcard}.
- * <li>{@link #MOUNT_FLAG_VISIBLE} means the volume is visible to third-party
- * apps for direct filesystem access. The system should send out relevant
- * storage broadcasts and index any media on visible volumes. Visible volumes
- * are considered a more stable part of the device, which is why we take the
- * time to index them. In particular, transient volumes like USB OTG devices
+ * <li>{@link #MOUNT_FLAG_VISIBLE_FOR_READ} and
+ * {@link #MOUNT_FLAG_VISIBLE_FOR_WRITE} mean the volume is visible to
+ * third-party apps for direct filesystem access. The system should send out
+ * relevant storage broadcasts and index any media on visible volumes. Visible
+ * volumes are considered a more stable part of the device, which is why we take
+ * the time to index them. In particular, transient volumes like USB OTG devices
  * <em>should not</em> be marked as visible; their contents should be surfaced
  * to apps through the Storage Access Framework.
  * </ul>
@@ -100,7 +101,8 @@ public class VolumeInfo implements Parcelable {
     public static final int STATE_BAD_REMOVAL = IVold.VOLUME_STATE_BAD_REMOVAL;
 
     public static final int MOUNT_FLAG_PRIMARY = IVold.MOUNT_FLAG_PRIMARY;
-    public static final int MOUNT_FLAG_VISIBLE = IVold.MOUNT_FLAG_VISIBLE;
+    public static final int MOUNT_FLAG_VISIBLE_FOR_READ = IVold.MOUNT_FLAG_VISIBLE_FOR_READ;
+    public static final int MOUNT_FLAG_VISIBLE_FOR_WRITE = IVold.MOUNT_FLAG_VISIBLE_FOR_WRITE;
 
     private static SparseArray<String> sStateToEnvironment = new SparseArray<>();
     private static ArrayMap<String, String> sEnvironmentToBroadcast = new ArrayMap<>();
@@ -312,17 +314,31 @@ public class VolumeInfo implements Parcelable {
         return isPrimary() && (getType() == TYPE_PUBLIC);
     }
 
+    private boolean isVisibleForRead() {
+        return (mountFlags & MOUNT_FLAG_VISIBLE_FOR_READ) != 0;
+    }
+
+    private boolean isVisibleForWrite() {
+        return (mountFlags & MOUNT_FLAG_VISIBLE_FOR_WRITE) != 0;
+    }
+
     @UnsupportedAppUsage
     public boolean isVisible() {
-        return (mountFlags & MOUNT_FLAG_VISIBLE) != 0;
+        return isVisibleForRead() || isVisibleForWrite();
     }
 
-    public boolean isVisibleForUser(int userId) {
-        if ((type == TYPE_PUBLIC || type == TYPE_STUB || type == TYPE_EMULATED)
-                && mountUserId == userId) {
-            return isVisible();
+    private boolean isVolumeSupportedForUser(int userId) {
+        if (mountUserId != userId) {
+            return false;
         }
-        return false;
+        return type == TYPE_PUBLIC || type == TYPE_STUB || type == TYPE_EMULATED;
+    }
+
+    /**
+     * Returns {@code true} if this volume is visible for {@code userId}, {@code false} otherwise.
+     */
+    public boolean isVisibleForUser(int userId) {
+        return isVolumeSupportedForUser(userId) && isVisible();
     }
 
     /**
@@ -335,12 +351,12 @@ public class VolumeInfo implements Parcelable {
     }
 
     public boolean isVisibleForRead(int userId) {
-        return isVisibleForUser(userId);
+        return isVolumeSupportedForUser(userId) && isVisibleForRead();
     }
 
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
     public boolean isVisibleForWrite(int userId) {
-        return isVisibleForUser(userId);
+        return isVolumeSupportedForUser(userId) && isVisibleForWrite();
     }
 
     @UnsupportedAppUsage
diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
index 801b490406cc..a3eb0eccad9d 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
@@ -251,7 +251,7 @@ public class ExternalStorageProvider extends FileSystemProvider {
             if (volume.getType() == VolumeInfo.TYPE_PUBLIC) {
                 root.flags |= Root.FLAG_HAS_SETTINGS;
             }
-            if (volume.isVisibleForRead(userId)) {
+            if (volume.isVisibleForUser(userId)) {
                 root.visiblePath = volume.getPathForUser(userId);
             } else {
                 root.visiblePath = null;
diff --git a/services/core/java/com/android/server/StorageManagerService.java b/services/core/java/com/android/server/StorageManagerService.java
index 59bbb0d90076..0e6e7dfdd4a6 100644
--- a/services/core/java/com/android/server/StorageManagerService.java
+++ b/services/core/java/com/android/server/StorageManagerService.java
@@ -1230,7 +1230,7 @@ class StorageManagerService extends IStorageManager.Stub
             }
             for (int i = 0; i < mVolumes.size(); i++) {
                 final VolumeInfo vol = mVolumes.valueAt(i);
-                if (vol.isVisibleForRead(userId) && vol.isMountedReadable()) {
+                if (vol.isVisibleForUser(userId) && vol.isMountedReadable()) {
                     final StorageVolume userVol = vol.buildStorageVolume(mContext, userId, false);
                     mHandler.obtainMessage(H_VOLUME_BROADCAST, userVol).sendToTarget();
 
@@ -1558,13 +1558,13 @@ class StorageManagerService extends IStorageManager.Stub
                     && VolumeInfo.ID_PRIVATE_INTERNAL.equals(privateVol.id)) {
                 Slog.v(TAG, "Found primary storage at " + vol);
                 vol.mountFlags |= VolumeInfo.MOUNT_FLAG_PRIMARY;
-                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE;
+                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE_FOR_WRITE;
                 mHandler.obtainMessage(H_VOLUME_MOUNT, vol).sendToTarget();
 
             } else if (Objects.equals(privateVol.fsUuid, mPrimaryStorageUuid)) {
                 Slog.v(TAG, "Found primary storage at " + vol);
                 vol.mountFlags |= VolumeInfo.MOUNT_FLAG_PRIMARY;
-                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE;
+                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE_FOR_WRITE;
                 mHandler.obtainMessage(H_VOLUME_MOUNT, vol).sendToTarget();
             }
 
@@ -1574,13 +1574,13 @@ class StorageManagerService extends IStorageManager.Stub
                     && vol.disk.isDefaultPrimary()) {
                 Slog.v(TAG, "Found primary storage at " + vol);
                 vol.mountFlags |= VolumeInfo.MOUNT_FLAG_PRIMARY;
-                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE;
+                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE_FOR_WRITE;
             }
 
             // Adoptable public disks are visible to apps, since they meet
             // public API requirement of being in a stable location.
             if (vol.disk.isAdoptable()) {
-                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE;
+                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE_FOR_WRITE;
             }
 
             vol.mountUserId = mCurrentUserId;
@@ -1591,7 +1591,7 @@ class StorageManagerService extends IStorageManager.Stub
 
         } else if (vol.type == VolumeInfo.TYPE_STUB) {
             if (vol.disk.isStubVisible()) {
-                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE;
+                vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE_FOR_WRITE;
             }
             vol.mountUserId = mCurrentUserId;
             mHandler.obtainMessage(H_VOLUME_MOUNT, vol).sendToTarget();
@@ -1738,7 +1738,7 @@ class StorageManagerService extends IStorageManager.Stub
                 // started after this point will trigger additional
                 // user-specific broadcasts.
                 for (int userId : mSystemUnlockedUsers) {
-                    if (vol.isVisibleForRead(userId)) {
+                    if (vol.isVisibleForUser(userId)) {
                         final StorageVolume userVol = vol.buildStorageVolume(mContext, userId,
                                 false);
                         mHandler.obtainMessage(H_VOLUME_BROADCAST, userVol).sendToTarget();
@@ -3766,7 +3766,7 @@ class StorageManagerService extends IStorageManager.Stub
                 if (forWrite) {
                     match = vol.isVisibleForWrite(userId);
                 } else {
-                    match = vol.isVisibleForRead(userId)
+                    match = vol.isVisibleForUser(userId)
                             || (includeInvisible && vol.getPath() != null);
                 }
                 if (!match) continue;