Merge "Populate APK files using hard links (2/n)" (94dae5c0) · Commits · e / os / android_frameworks_base

core/java/android/content/pm/IPackageInstallerSession.aidl

+1 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,7 @@ interface IPackageInstallerSession {
		ParcelFileDescriptor openRead(String name);

		void write(String name, long offsetBytes, long lengthBytes, in ParcelFileDescriptor fd);
		void stageViaHardLink(String target);

		void addChecksums(String name, in Checksum[] checksums);

+25 −0

Original line number	Diff line number	Diff line
		@@ -1048,6 +1048,31 @@ public class PackageInstaller {
		}
		}

		/**
		* Populate an APK file by creating a hard link to avoid the need to copy.
		* <p>
		* Note this API is used by RollbackManager only and can only be called from system_server.
		* {@code target} will be relabeled if link is created successfully. RollbackManager has
		* to delete {@code target} when the session is committed successfully to avoid SELinux
		* label conflicts.
		* <p>
		* Note No more bytes should be written to the file once the link is created successfully.
		*
		* @param target the path of the link target
		*
		* @hide
		*/
		public void stageViaHardLink(String target) throws IOException {
		try {
		mSession.stageViaHardLink(target);
		} catch (RuntimeException e) {
		ExceptionUtils.maybeUnwrapIOException(e);
		throw e;
		} catch (RemoteException e) {
		throw e.rethrowFromSystemServer();
		}
		}

		/**
		* Ensure that any outstanding data for given stream has been committed
		* to disk. This is only valid for streams returned from

+26 −0

Original line number	Diff line number	Diff line
		@@ -104,6 +104,7 @@ import android.os.ParcelableException;
		import android.os.Process;
		import android.os.RemoteException;
		import android.os.RevocableFileDescriptor;
		import android.os.SELinux;
		import android.os.SystemProperties;
		import android.os.UserHandle;
		import android.os.incremental.IStorageHealthListener;
		@@ -1088,6 +1089,31 @@ public class PackageInstallerSession extends IPackageInstallerSession.Stub {
		}
		}

		@Override
		public void stageViaHardLink(String path) {
		final int callingUid = Binder.getCallingUid();
		if (callingUid != Process.SYSTEM_UID) {
		throw new SecurityException("link() can only be run by the system");
		}

		try {
		final File target = new File(path);
		final File source = new File(stageDir, target.getName());
		try {
		Os.link(path, source.getAbsolutePath());
		// Grant READ access for APK to be read successfully
		Os.chmod(source.getAbsolutePath(), 0644);
		} catch (ErrnoException e) {
		e.rethrowAsIOException();
		}
		if (!SELinux.restorecon(source)) {
		throw new IOException("Can't relabel file: " + source);
		}
		} catch (IOException e) {
		throw ExceptionUtils.wrap(e);
		}
		}

		private ParcelFileDescriptor openTargetInternal(String path, int flags, int mode)
		throws IOException, ErrnoException {
		// TODO: this should delegate to DCS so the system process avoids

+12 −3

Original line number	Diff line number	Diff line
		@@ -581,9 +581,18 @@ class Rollback {
		ParcelFileDescriptor.MODE_READ_ONLY)) {
		final long token = Binder.clearCallingIdentity();
		try {
		boolean fallbackToCopy = false;
		try {
		// Populate apk/apex files using hard links to avoid copy
		session.stageViaHardLink(packageCodePath.getAbsolutePath());
		} catch (Exception ignore) {
		fallbackToCopy = true;
		}
		if (fallbackToCopy) {
		session.write(packageCodePath.getName(), 0,
		packageCodePath.length(),
		fd);
		}
		} finally {
		Binder.restoreCallingIdentity(token);
		}