/**
* 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.hdfs.server.namenode;
import org.apache.hadoop.HadoopIllegalArgumentException;
import org.apache.hadoop.fs.InvalidPathException;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsAction;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.hdfs.protocol.FSLimitException;
import org.apache.hadoop.hdfs.protocol.SnapshotDiffReport;
import org.apache.hadoop.hdfs.protocol.SnapshotException;
import org.apache.hadoop.hdfs.protocol.SnapshottableDirectoryStatus;
import org.apache.hadoop.hdfs.server.namenode.snapshot.DirectorySnapshottableFeature;
import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot;
import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotManager;
import org.apache.hadoop.util.ChunkedArrayList;
import java.io.IOException;
import java.util.List;
class FSDirSnapshotOp {
/** Verify if the snapshot name is legal. */
static void verifySnapshotName(FSDirectory fsd, String snapshotName,
String path)
throws FSLimitException.PathComponentTooLongException {
if (snapshotName.contains(Path.SEPARATOR)) {
throw new HadoopIllegalArgumentException(
"Snapshot name cannot contain \"" + Path.SEPARATOR + "\"");
}
final byte[] bytes = DFSUtil.string2Bytes(snapshotName);
fsd.verifyINodeName(bytes);
fsd.verifyMaxComponentLength(bytes, path);
}
/** Allow snapshot on a directory. */
static void allowSnapshot(FSDirectory fsd, SnapshotManager snapshotManager,
String path) throws IOException {
fsd.writeLock();
try {
snapshotManager.setSnapshottable(path, true);
} finally {
fsd.writeUnlock();
}
fsd.getEditLog().logAllowSnapshot(path);
}
static void disallowSnapshot(
FSDirectory fsd, SnapshotManager snapshotManager,
String path) throws IOException {
fsd.writeLock();
try {
snapshotManager.resetSnapshottable(path);
} finally {
fsd.writeUnlock();
}
fsd.getEditLog().logDisallowSnapshot(path);
}
/**
* Create a snapshot
* @param snapshotRoot The directory path where the snapshot is taken
* @param snapshotName The name of the snapshot
*/
static String createSnapshot(
FSDirectory fsd, SnapshotManager snapshotManager, String snapshotRoot,
String snapshotName, boolean logRetryCache)
throws IOException {
final INodesInPath iip = fsd.getINodesInPath4Write(snapshotRoot);
if (fsd.isPermissionEnabled()) {
FSPermissionChecker pc = fsd.getPermissionChecker();
fsd.checkOwner(pc, iip);
}
if (snapshotName == null || snapshotName.isEmpty()) {
snapshotName = Snapshot.generateDefaultSnapshotName();
} else if (!DFSUtil.isValidNameForComponent(snapshotName)) {
throw new InvalidPathException("Invalid snapshot name: " + snapshotName);
}
String snapshotPath = null;
verifySnapshotName(fsd, snapshotName, snapshotRoot);
fsd.writeLock();
try {
snapshotPath = snapshotManager.createSnapshot(iip, snapshotRoot,
snapshotName);
} finally {
fsd.writeUnlock();
}
fsd.getEditLog().logCreateSnapshot(snapshotRoot, snapshotName,
logRetryCache);
return snapshotPath;
}
static void renameSnapshot(FSDirectory fsd, SnapshotManager snapshotManager,
String path, String snapshotOldName, String snapshotNewName,
boolean logRetryCache) throws IOException {
final INodesInPath iip = fsd.getINodesInPath4Write(path);
if (fsd.isPermissionEnabled()) {
FSPermissionChecker pc = fsd.getPermissionChecker();
fsd.checkOwner(pc, iip);
}
verifySnapshotName(fsd, snapshotNewName, path);
fsd.writeLock();
try {
snapshotManager.renameSnapshot(iip, path, snapshotOldName,
snapshotNewName);
} finally {
fsd.writeUnlock();
}
fsd.getEditLog().logRenameSnapshot(path, snapshotOldName,
snapshotNewName, logRetryCache);
}
static SnapshottableDirectoryStatus[] getSnapshottableDirListing(
FSDirectory fsd, SnapshotManager snapshotManager) throws IOException {
FSPermissionChecker pc = fsd.getPermissionChecker();
fsd.readLock();
try {
final String user = pc.isSuperUser()? null : pc.getUser();
return snapshotManager.getSnapshottableDirListing(user);
} finally {
fsd.readUnlock();
}
}
static SnapshotDiffReport getSnapshotDiffReport(FSDirectory fsd,
SnapshotManager snapshotManager, String path,
String fromSnapshot, String toSnapshot) throws IOException {
SnapshotDiffReport diffs;
final FSPermissionChecker pc = fsd.getPermissionChecker();
fsd.readLock();
try {
if (fsd.isPermissionEnabled()) {
checkSubtreeReadPermission(fsd, pc, path, fromSnapshot);
checkSubtreeReadPermission(fsd, pc, path, toSnapshot);
}
INodesInPath iip = fsd.getINodesInPath(path, true);
diffs = snapshotManager.diff(iip, path, fromSnapshot, toSnapshot);
} finally {
fsd.readUnlock();
}
return diffs;
}
/**
* Delete a snapshot of a snapshottable directory
* @param snapshotRoot The snapshottable directory
* @param snapshotName The name of the to-be-deleted snapshot
* @throws IOException
*/
static INode.BlocksMapUpdateInfo deleteSnapshot(
FSDirectory fsd, SnapshotManager snapshotManager, String snapshotRoot,
String snapshotName, boolean logRetryCache)
throws IOException {
final INodesInPath iip = fsd.getINodesInPath4Write(snapshotRoot);
if (fsd.isPermissionEnabled()) {
FSPermissionChecker pc = fsd.getPermissionChecker();
fsd.checkOwner(pc, iip);
}
INode.BlocksMapUpdateInfo collectedBlocks = new INode.BlocksMapUpdateInfo();
ChunkedArrayList<INode> removedINodes = new ChunkedArrayList<>();
INode.ReclaimContext context = new INode.ReclaimContext(
fsd.getBlockStoragePolicySuite(), collectedBlocks, removedINodes, null);
fsd.writeLock();
try {
snapshotManager.deleteSnapshot(iip, snapshotName, context);
fsd.updateCount(iip, context.quotaDelta(), false);
fsd.removeFromInodeMap(removedINodes);
} finally {
fsd.writeUnlock();
}
removedINodes.clear();
fsd.getEditLog().logDeleteSnapshot(snapshotRoot, snapshotName,
logRetryCache);
return collectedBlocks;
}
private static void checkSubtreeReadPermission(
FSDirectory fsd, final FSPermissionChecker pc, String snapshottablePath,
String snapshot) throws IOException {
final String fromPath = snapshot == null ?
snapshottablePath : Snapshot.getSnapshotPath(snapshottablePath,
snapshot);
INodesInPath iip = fsd.getINodesInPath(fromPath, true);
fsd.checkPermission(pc, iip, false, null, null, FsAction.READ,
FsAction.READ);
}
/**
* Check if the given INode (or one of its descendants) is snapshottable and
* already has snapshots.
*
* @param target The given INode
* @param snapshottableDirs The list of directories that are snapshottable
* but do not have snapshots yet
*/
static void checkSnapshot(
INode target, List<INodeDirectory> snapshottableDirs)
throws SnapshotException {
if (target.isDirectory()) {
INodeDirectory targetDir = target.asDirectory();
DirectorySnapshottableFeature sf = targetDir
.getDirectorySnapshottableFeature();
if (sf != null) {
if (sf.getNumSnapshots() > 0) {
String fullPath = targetDir.getFullPathName();
throw new SnapshotException("The directory " + fullPath
+ " cannot be deleted since " + fullPath
+ " is snapshottable and already has snapshots");
} else {
if (snapshottableDirs != null) {
snapshottableDirs.add(targetDir);
}
}
}
for (INode child : targetDir.getChildrenList(Snapshot.CURRENT_STATE_ID)) {
checkSnapshot(child, snapshottableDirs);
}
}
}
}