Merge "Maintain compatibility by deleting target directory before renaming... (9481bbbf) · Commits · e / os / android_frameworks_base

core/java/android/util/AtomicFile.java

+20 −11

Original line number	Original line	Diff line number	Diff line
	@@ -116,10 +116,7 @@ public class AtomicFile {
	mStartTime = startTime;		mStartTime = startTime;

	if (mLegacyBackupName.exists()) {		if (mLegacyBackupName.exists()) {
	if (!mLegacyBackupName.renameTo(mBaseName)) {		rename(mLegacyBackupName, mBaseName);
	Log.e(LOG_TAG, "Failed to rename legacy backup file " + mLegacyBackupName
	+ " to base file " + mBaseName);
	}
	}		}

	try {		try {
	@@ -157,9 +154,7 @@ public class AtomicFile {
	} catch (IOException e) {		} catch (IOException e) {
	Log.e(LOG_TAG, "Failed to close file output stream", e);		Log.e(LOG_TAG, "Failed to close file output stream", e);
	}		}
	if (!mNewName.renameTo(mBaseName)) {		rename(mNewName, mBaseName);
	Log.e(LOG_TAG, "Failed to rename new file " + mNewName + " to base file " + mBaseName);
	}
	if (mCommitTag != null) {		if (mCommitTag != null) {
	com.android.internal.logging.EventLogTags.writeCommitSysConfigFile(		com.android.internal.logging.EventLogTags.writeCommitSysConfigFile(
	mCommitTag, SystemClock.uptimeMillis() - mStartTime);		mCommitTag, SystemClock.uptimeMillis() - mStartTime);
	@@ -221,10 +216,7 @@ public class AtomicFile {
	*/		*/
	public FileInputStream openRead() throws FileNotFoundException {		public FileInputStream openRead() throws FileNotFoundException {
	if (mLegacyBackupName.exists()) {		if (mLegacyBackupName.exists()) {
	if (!mLegacyBackupName.renameTo(mBaseName)) {		rename(mLegacyBackupName, mBaseName);
	Log.e(LOG_TAG, "Failed to rename legacy backup file " + mLegacyBackupName
	+ " to base file " + mBaseName);
	}
	}		}

	// It was okay to call openRead() between startWrite() and finishWrite() for the first time		// It was okay to call openRead() between startWrite() and finishWrite() for the first time
	@@ -311,4 +303,21 @@ public class AtomicFile {
	IoUtils.closeQuietly(out);		IoUtils.closeQuietly(out);
	}		}
	}		}

			private static void rename(File source, File target) {
			// We used to delete the target file before rename, but that isn't atomic, and the rename()
			// syscall should atomically replace the target file. However in the case where the target
			// file is a directory, a simple rename() won't work. We need to delete the file in this
			// case because there are callers who erroneously called mBaseName.mkdirs() (instead of
			// mBaseName.getParentFile().mkdirs()) before creating the AtomicFile, and it worked
			// regardless, so this deletion became some kind of API.
			if (target.isDirectory()) {
			if (!target.delete()) {
			Log.e(LOG_TAG, "Failed to delete file which is a directory " + target);
			}
			}
			if (!source.renameTo(target)) {
			Log.e(LOG_TAG, "Failed to rename " + source + " to " + target);
			}
			}
	}		}