Set incremental apk directories

Set up incremental storages such that it works with the new app code
path layout.

Ensures that package names do not show up in /proc/mounts

$ cat /proc/self/mountinfo
2806 90 0:79 / /data/incremental/data_incremental_tmp_1042476774/mount rw,nosuid,nodev,noatime shared:34 - incremental-fs incfs.img rw,read_timeout_ms=10000,readahead=0,rlog_pages=2,rlog_wakeup_cnt=10
6946 90 0:79 /st2 /data/app/~~WE4d9B-MZg0iZckOxIhPGQ== rw,nosuid,nodev,noatime shared:34 - incremental-fs incfs.img rw,read_timeout_ms=10000,readahead=0,rlog_pages=2,rlog_wakeup_cnt=10
7014 2806 0:79 /st2 /data/incremental/data_incremental_tmp_1042476774/mount/st2 rw,nosuid,nodev,noatime shared:34 - incremental-fs incfs.img rw,read_timeout_ms=10000,readahead=0,rlog_pages=2,rlog_wakeup_cnt=10
7013 6946 0:79 /st2 /data/app/~~WE4d9B-MZg0iZckOxIhPGQ== rw,nosuid,nodev,noatime shared:34 - incremental-fs incfs.img rw,read_timeout_ms=10000,readahead=0,rlog_pages=2,rlog_wakeup_cnt=10

BUG: b/147371381 b/148237378
Test: manual
Change-Id: I149903ae63ee27da5957e41c16f21f3435f9e636

2 files changed, 40 insertions, 106 deletions

diff --git a/core/java/android/os/incremental/IncrementalManager.java b/core/java/android/os/incremental/IncrementalManager.java
index 8990bdf06a6f..35fa37a491de 100644
--- a/core/java/android/os/incremental/IncrementalManager.java
+++ b/core/java/android/os/incremental/IncrementalManager.java
@@ -23,8 +23,6 @@ import android.annotation.SystemService;
 import android.content.Context;
 import android.content.pm.DataLoaderParams;
 import android.os.RemoteException;
-import android.system.ErrnoException;
-import android.system.Os;
 import android.util.SparseArray;
 
 import com.android.internal.annotations.GuardedBy;
@@ -193,116 +191,54 @@ public final class IncrementalManager {
     }
 
     /**
-     * Renames an Incremental path to a new path. If source path is a file, make a link from the old
-     * Incremental file to the new one. If source path is a dir, unbind old dir from Incremental
-     * Storage and bind the new one.
-     * <ol>
-     *     <li> For renaming a dir, dest dir will be created if not exists, and does not need to
-     *          be on the same Incremental storage as the source. </li>
-     *     <li> For renaming a file, dest file must be on the same Incremental storage as source.
-     *     </li>
-     * </ol>
+     * Set up an app's code path. The expected outcome of this method is:
+     * 1) The actual apk directory under /data/incremental is bind-mounted to the parent directory
+     * of {@code afterCodeFile}.
+     * 2) All the files under {@code beforeCodeFile} will show up under {@code afterCodeFile}.
      *
-     * @param sourcePath Absolute path to the source. Should be the same type as the destPath (file
-     *                   or dir). Expected to already exist and is an Incremental path.
-     * @param destPath   Absolute path to the destination.
-     * @throws IllegalArgumentException when 1) source does not exist, or 2) source and dest type
-     *                                  mismatch (one is file and the other is dir), or 3) source
-     *                                  path is not on Incremental File System,
-     * @throws IOException              when 1) cannot find the root path of the Incremental storage
-     *                                  of source, or 2) cannot retrieve the Incremental storage
-     *                                  instance of the source, or 3) renaming a file, but dest is
-     *                                  not on the same Incremental Storage, or 4) renaming a dir,
-     *                                  dest dir does not exist but fails to be created.
-     *                                  <p>
-     *                                  TODO(b/136132412): add unit tests
+     * @param beforeCodeFile Path that is currently bind-mounted and have APKs under it.
+     *                       Should no longer have any APKs after this method is called.
+     *                       Example: /data/app/vmdl*tmp
+     * @param afterCodeFile Path that should will have APKs after this method is called. Its parent
+     *                      directory should be bind-mounted to a directory under /data/incremental.
+     *                      Example: /data/app/~~[randomStringA]/[packageName]-[randomStringB]
+     * @throws IllegalArgumentException
+     * @throws IOException
+     * TODO(b/147371381): add unit tests
      */
-    public void rename(@NonNull String sourcePath, @NonNull String destPath) throws IOException {
-        final File source = new File(sourcePath);
-        final File dest = new File(destPath);
-        if (!source.exists()) {
-            throw new IllegalArgumentException("Path not exist: " + sourcePath);
+    public void renameCodePath(File beforeCodeFile, File afterCodeFile)
+            throws IllegalArgumentException, IOException {
+        final String beforeCodePath = beforeCodeFile.getAbsolutePath();
+        final String afterCodePathParent = afterCodeFile.getParentFile().getAbsolutePath();
+        if (!isIncrementalPath(beforeCodePath)) {
+            throw new IllegalArgumentException("Not an Incremental path: " + beforeCodePath);
         }
-        if (dest.exists()) {
-            throw new IllegalArgumentException("Target path already exists: " + destPath);
+        final String afterCodePathName = afterCodeFile.getName();
+        final Path apkStoragePath = Paths.get(beforeCodePath);
+        if (apkStoragePath == null || apkStoragePath.toAbsolutePath() == null) {
+            throw new IOException("Invalid source storage path for: " + beforeCodePath);
         }
-        if (source.isDirectory() && dest.exists() && dest.isFile()) {
-            throw new IllegalArgumentException(
-                    "Trying to rename a dir but destination is a file: " + destPath);
-        }
-        if (source.isFile() && dest.exists() && dest.isDirectory()) {
-            throw new IllegalArgumentException(
-                    "Trying to rename a file but destination is a dir: " + destPath);
-        }
-        if (!isIncrementalPath(sourcePath)) {
-            throw new IllegalArgumentException("Not an Incremental path: " + sourcePath);
-        }
-
-        Path storagePath = Paths.get(sourcePath);
-        if (source.isFile()) {
-            storagePath = getStoragePathForFile(source);
-        }
-        if (storagePath == null || storagePath.toAbsolutePath() == null) {
-            throw new IOException("Invalid source storage path for: " + sourcePath);
-        }
-        final IncrementalStorage storage = openStorage(storagePath.toAbsolutePath().toString());
-        if (storage == null) {
+        final IncrementalStorage apkStorage =
+                openStorage(apkStoragePath.toAbsolutePath().toString());
+        if (apkStorage == null) {
             throw new IOException("Failed to retrieve storage from Incremental Service.");
         }
-
-        if (source.isFile()) {
-            renameFile(storage, storagePath, source, dest);
-        } else {
-            renameDir(storage, storagePath, source, dest);
-        }
-    }
-
-    private void renameFile(IncrementalStorage storage, Path storagePath,
-            File source, File dest) throws IOException {
-        Path sourcePath = source.toPath();
-        Path destPath = dest.toPath();
-        if (!sourcePath.startsWith(storagePath)) {
-            throw new IOException("Path: " + source.getAbsolutePath() + " is not on storage at: "
-                    + storagePath.toString());
-        }
-        if (!destPath.startsWith(storagePath)) {
-            throw new IOException("Path: " + dest.getAbsolutePath() + " is not on storage at: "
-                    + storagePath.toString());
+        final IncrementalStorage linkedApkStorage = createStorage(afterCodePathParent, apkStorage,
+                IncrementalManager.CREATE_MODE_CREATE
+                        | IncrementalManager.CREATE_MODE_PERMANENT_BIND);
+        if (linkedApkStorage == null) {
+            throw new IOException("Failed to create linked storage at dir: " + afterCodePathParent);
         }
-        final Path sourceRelativePath = storagePath.relativize(sourcePath);
-        final Path destRelativePath = storagePath.relativize(destPath);
-        storage.moveFile(sourceRelativePath.toString(), destRelativePath.toString());
-
-    }
-
-    private void renameDir(IncrementalStorage storage, Path storagePath,
-            File source, File dest) throws IOException {
-        Path destPath = dest.toPath();
-        boolean usedMkdir = false;
-        try {
-            Os.mkdir(dest.getAbsolutePath(), 0755);
-            usedMkdir = true;
-        } catch (ErrnoException e) {
-            // Traditional mkdir fails but maybe we can create it on Incremental File System if
-            // the dest path is on the same Incremental storage as the source.
-            if (destPath.startsWith(storagePath)) {
-                storage.makeDirectories(storagePath.relativize(destPath).toString());
-            } else {
-                throw new IOException("Failed to create directory: " + dest.getAbsolutePath(), e);
-            }
-        }
-        try {
-            storage.moveDir(source.getAbsolutePath(), dest.getAbsolutePath());
-        } catch (Exception ex) {
-            if (usedMkdir) {
-                try {
-                    Os.remove(dest.getAbsolutePath());
-                } catch (ErrnoException ignored) {
-                }
+        linkedApkStorage.makeDirectory(afterCodePathName);
+        File[] files = beforeCodeFile.listFiles();
+        for (int i = 0; i < files.length; i++) {
+            if (files[i].isFile()) {
+                String fileName = files[i].getName();
+                apkStorage.makeLink(
+                        fileName, linkedApkStorage, afterCodePathName + "/" + fileName);
             }
-            throw new IOException(
-                    "Failed to move " + source.getAbsolutePath() + " to " + dest.getAbsolutePath());
         }
+        apkStorage.unBind(beforeCodePath);
     }
 
     /**
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index c14b42dd69c8..541ac0cf871c 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -14983,9 +14983,7 @@ public class PackageManagerService extends IPackageManager.Stub
             try {
                 makeDirRecursive(afterCodeFile.getParentFile(), 0775);
                 if (onIncremental) {
-                    // TODO(b/147371381): fix incremental installation
-                    mIncrementalManager.rename(beforeCodeFile.getAbsolutePath(),
-                            afterCodeFile.getAbsolutePath());
+                    mIncrementalManager.renameCodePath(beforeCodeFile, afterCodeFile);
                 } else {
                     Os.rename(beforeCodeFile.getAbsolutePath(), afterCodeFile.getAbsolutePath());
                 }