| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.hadoop.util; |
| |
| import java.io.File; |
| import java.io.IOException; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.fs.FileStatus; |
| import org.apache.hadoop.fs.LocalFileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.fs.permission.FsAction; |
| import org.apache.hadoop.fs.permission.FsPermission; |
| |
| /** |
| * Class that provides utility functions for checking disk problem |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| public class DiskChecker { |
| |
| public static class DiskErrorException extends IOException { |
| public DiskErrorException(String msg) { |
| super(msg); |
| } |
| } |
| |
| public static class DiskOutOfSpaceException extends IOException { |
| public DiskOutOfSpaceException(String msg) { |
| super(msg); |
| } |
| } |
| |
| /** |
| * The semantics of mkdirsWithExistsCheck method is different from the mkdirs |
| * method provided in the Sun's java.io.File class in the following way: |
| * While creating the non-existent parent directories, this method checks for |
| * the existence of those directories if the mkdir fails at any point (since |
| * that directory might have just been created by some other process). |
| * If both mkdir() and the exists() check fails for any seemingly |
| * non-existent directory, then we signal an error; Sun's mkdir would signal |
| * an error (return false) if a directory it is attempting to create already |
| * exists or the mkdir fails. |
| * @param dir |
| * @return true on success, false on failure |
| */ |
| public static boolean mkdirsWithExistsCheck(File dir) { |
| if (dir.mkdir() || dir.exists()) { |
| return true; |
| } |
| File canonDir = null; |
| try { |
| canonDir = dir.getCanonicalFile(); |
| } catch (IOException e) { |
| return false; |
| } |
| String parent = canonDir.getParent(); |
| return (parent != null) && |
| (mkdirsWithExistsCheck(new File(parent)) && |
| (canonDir.mkdir() || canonDir.exists())); |
| } |
| |
| /** |
| * Create the directory if it doesn't exist and |
| * @param dir |
| * @throws DiskErrorException |
| */ |
| public static void checkDir(File dir) throws DiskErrorException { |
| if (!mkdirsWithExistsCheck(dir)) |
| throw new DiskErrorException("can not create directory: " |
| + dir.toString()); |
| |
| if (!dir.isDirectory()) |
| throw new DiskErrorException("not a directory: " |
| + dir.toString()); |
| |
| if (!dir.canRead()) |
| throw new DiskErrorException("directory is not readable: " |
| + dir.toString()); |
| |
| if (!dir.canWrite()) |
| throw new DiskErrorException("directory is not writable: " |
| + dir.toString()); |
| } |
| |
| /** |
| * Create the directory or check permissions if it already exists. |
| * |
| * The semantics of mkdirsWithExistsAndPermissionCheck method is different |
| * from the mkdirs method provided in the Sun's java.io.File class in the |
| * following way: |
| * While creating the non-existent parent directories, this method checks for |
| * the existence of those directories if the mkdir fails at any point (since |
| * that directory might have just been created by some other process). |
| * If both mkdir() and the exists() check fails for any seemingly |
| * non-existent directory, then we signal an error; Sun's mkdir would signal |
| * an error (return false) if a directory it is attempting to create already |
| * exists or the mkdir fails. |
| * |
| * @param localFS local filesystem |
| * @param dir directory to be created or checked |
| * @param expected expected permission |
| * @throws IOException |
| */ |
| public static void mkdirsWithExistsAndPermissionCheck( |
| LocalFileSystem localFS, Path dir, FsPermission expected) |
| throws IOException { |
| File directory = localFS.pathToFile(dir); |
| boolean created = false; |
| |
| if (!directory.exists()) |
| created = mkdirsWithExistsCheck(directory); |
| |
| if (created || !localFS.getFileStatus(dir).getPermission().equals(expected)) |
| localFS.setPermission(dir, expected); |
| } |
| |
| /** |
| * Create the local directory if necessary, check permissions and also ensure |
| * it can be read from and written into. |
| * |
| * @param localFS local filesystem |
| * @param dir directory |
| * @param expected permission |
| * @throws DiskErrorException |
| * @throws IOException |
| */ |
| public static void checkDir(LocalFileSystem localFS, Path dir, |
| FsPermission expected) |
| throws DiskErrorException, IOException { |
| mkdirsWithExistsAndPermissionCheck(localFS, dir, expected); |
| |
| FileStatus stat = localFS.getFileStatus(dir); |
| FsPermission actual = stat.getPermission(); |
| |
| if (!stat.isDirectory()) |
| throw new DiskErrorException("not a directory: "+ dir.toString()); |
| |
| FsAction user = actual.getUserAction(); |
| if (!user.implies(FsAction.READ)) |
| throw new DiskErrorException("directory is not readable: " |
| + dir.toString()); |
| |
| if (!user.implies(FsAction.WRITE)) |
| throw new DiskErrorException("directory is not writable: " |
| + dir.toString()); |
| |
| if (!user.implies(FsAction.EXECUTE)) |
| throw new DiskErrorException("directory is not listable: " |
| + dir.toString()); |
| } |
| } |