HDFS-8200. Refactor FSDirStatAndListingOp. Contributed by Haohui Mai.

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -162,6 +162,8 @@ Release 2.8.0 - UNRELEASED
     HDFS-5574. Remove buffer copy in BlockReader.skip.
     (Binglin Chang via aajisaka)
 
+    HDFS-8200. Refactor FSDirStatAndListingOp. (wheat9)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirStatAndListingOp.java

@@ -24,7 +24,6 @@ import org.apache.hadoop.fs.ContentSummary;
 import org.apache.hadoop.fs.DirectoryListingStartAfterNotFoundException;
 import org.apache.hadoop.fs.FileEncryptionInfo;
 import org.apache.hadoop.fs.InvalidPathException;
-import org.apache.hadoop.fs.UnresolvedLinkException;
 import org.apache.hadoop.fs.permission.FsAction;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.DFSUtil;
@@ -180,10 +179,14 @@ class FSDirStatAndListingOp {
           .BLOCK_STORAGE_POLICY_ID_UNSPECIFIED;
 
       if (!targetNode.isDirectory()) {
+        INodeAttributes nodeAttrs = getINodeAttributes(
+            fsd, src, HdfsFileStatus.EMPTY_NAME, targetNode,
+            snapshot);
         return new DirectoryListing(
-            new HdfsFileStatus[]{createFileStatus(fsd, src,
-                HdfsFileStatus.EMPTY_NAME, targetNode, needLocation,
-                parentStoragePolicy, snapshot, isRawPath, iip)}, 0);
+            new HdfsFileStatus[]{ createFileStatus(
+                fsd, HdfsFileStatus.EMPTY_NAME, targetNode, nodeAttrs,
+                needLocation, parentStoragePolicy, snapshot, isRawPath, iip)
+            }, 0);
       }
 
       final INodeDirectory dirInode = targetNode.asDirectory();
@@ -200,8 +203,11 @@ class FSDirStatAndListingOp {
         byte curPolicy = isSuperUser && !cur.isSymlink()?
             cur.getLocalStoragePolicyID():
             HdfsConstantsClient.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED;
-        listing[i] = createFileStatus(fsd, src, cur.getLocalNameBytes(), cur,
-            needLocation, getStoragePolicyID(curPolicy,
+        INodeAttributes nodeAttrs = getINodeAttributes(
+            fsd, src, cur.getLocalNameBytes(), cur,
+            snapshot);
+        listing[i] = createFileStatus(fsd, cur.getLocalNameBytes(),
+            cur, nodeAttrs, needLocation, getStoragePolicyID(curPolicy,
                 parentStoragePolicy), snapshot, isRawPath, iip);
         listingCnt++;
         if (needLocation) {
@@ -253,9 +259,15 @@ class FSDirStatAndListingOp {
     final HdfsFileStatus listing[] = new HdfsFileStatus[numOfListing];
     for (int i = 0; i < numOfListing; i++) {
       Snapshot.Root sRoot = snapshots.get(i + skipSize).getRoot();
-      listing[i] = createFileStatus(fsd, src, sRoot.getLocalNameBytes(), sRoot,
-          HdfsConstantsClient.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED, Snapshot.CURRENT_STATE_ID,
-          false, INodesInPath.fromINode(sRoot));
+      INodeAttributes nodeAttrs = getINodeAttributes(
+          fsd, src, sRoot.getLocalNameBytes(),
+          node, Snapshot.CURRENT_STATE_ID);
+      listing[i] = createFileStatus(
+          fsd, sRoot.getLocalNameBytes(),
+          sRoot, nodeAttrs,
+          HdfsConstantsClient.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED,
+          Snapshot.CURRENT_STATE_ID, false,
+          INodesInPath.fromINode(sRoot));
     }
     return new DirectoryListing(
         listing, snapshots.size() - skipSize - numOfListing);
@@ -276,11 +288,20 @@ class FSDirStatAndListingOp {
     fsd.readLock();
     try {
       final INode i = src.getLastINode();
-      byte policyId = includeStoragePolicy && i != null && !i.isSymlink() ?
-          i.getStoragePolicyID() : HdfsConstantsClient.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED;
-      return i == null ? null : createFileStatus(
-          fsd, path, HdfsFileStatus.EMPTY_NAME, i, policyId,
-          src.getPathSnapshotId(), isRawPath, src);
+      if (i == null) {
+        return null;
+      }
+
+      byte policyId = includeStoragePolicy && !i.isSymlink() ?
+          i.getStoragePolicyID() : HdfsConstantsClient
+          .BLOCK_STORAGE_POLICY_ID_UNSPECIFIED;
+      INodeAttributes nodeAttrs = getINodeAttributes(
+          fsd, path, HdfsFileStatus.EMPTY_NAME, i, src.getPathSnapshotId());
+      return createFileStatus(
+          fsd, HdfsFileStatus.EMPTY_NAME,
+          i, nodeAttrs, policyId,
+          src.getPathSnapshotId(),
+          isRawPath, src);
     } finally {
       fsd.readUnlock();
     }
@@ -309,23 +330,6 @@ class FSDirStatAndListingOp {
     }
   }
 
-  /**
-   * Currently we only support "ls /xxx/.snapshot" which will return all the
-   * snapshots of a directory. The FSCommand Ls will first call getFileInfo to
-   * make sure the file/directory exists (before the real getListing call).
-   * Since we do not have a real INode for ".snapshot", we return an empty
-   * non-null HdfsFileStatus here.
-   */
-  private static HdfsFileStatus getFileInfo4DotSnapshot(
-      FSDirectory fsd, String src)
-      throws UnresolvedLinkException {
-    if (fsd.getINode4DotSnapshot(src) != null) {
-      return new HdfsFileStatus(0, true, 0, 0, 0, 0, null, null, null, null,
-          HdfsFileStatus.EMPTY_NAME, -1L, 0, null,
-          HdfsConstantsClient.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED);
-    }
-    return null;
-  }
 
   /**
    * create an hdfs file status from an inode
@@ -339,52 +343,63 @@ class FSDirStatAndListingOp {
    * @return a file status
    * @throws java.io.IOException if any error occurs
    */
-  static HdfsFileStatus createFileStatus(
-      FSDirectory fsd, String fullPath, byte[] path, INode node,
+  private static HdfsFileStatus createFileStatus(
+      FSDirectory fsd, byte[] path, INode node, INodeAttributes nodeAttrs,
       boolean needLocation, byte storagePolicy, int snapshot, boolean isRawPath,
       INodesInPath iip)
       throws IOException {
     if (needLocation) {
-      return createLocatedFileStatus(fsd, fullPath, path, node, storagePolicy,
-          snapshot, isRawPath, iip);
+      return createLocatedFileStatus(fsd, path, node, nodeAttrs, storagePolicy,
+                                     snapshot, isRawPath, iip);
     } else {
-      return createFileStatus(fsd, fullPath, path, node, storagePolicy, snapshot,
-          isRawPath, iip);
+      return createFileStatus(fsd, path, node, nodeAttrs, storagePolicy,
+                              snapshot, isRawPath, iip);
     }
   }
 
   /**
    * Create FileStatus by file INode
    */
-  static HdfsFileStatus createFileStatus(
+  static HdfsFileStatus createFileStatusForEditLog(
       FSDirectory fsd, String fullPath, byte[] path, INode node,
       byte storagePolicy, int snapshot, boolean isRawPath,
       INodesInPath iip) throws IOException {
-     long size = 0;     // length is zero for directories
-     short replication = 0;
-     long blocksize = 0;
-     final boolean isEncrypted;
-
-     final FileEncryptionInfo feInfo = isRawPath ? null :
-         fsd.getFileEncryptionInfo(node, snapshot, iip);
-
-     if (node.isFile()) {
-       final INodeFile fileNode = node.asFile();
-       size = fileNode.computeFileSize(snapshot);
-       replication = fileNode.getFileReplication(snapshot);
-       blocksize = fileNode.getPreferredBlockSize();
-       isEncrypted = (feInfo != null) ||
-           (isRawPath && fsd.isInAnEZ(INodesInPath.fromINode(node)));
-     } else {
-       isEncrypted = fsd.isInAnEZ(INodesInPath.fromINode(node));
-     }
-
-     int childrenNum = node.isDirectory() ?
-         node.asDirectory().getChildrenNum(snapshot) : 0;
-
-     INodeAttributes nodeAttrs =
-         fsd.getAttributes(fullPath, path, node, snapshot);
-     return new HdfsFileStatus(
+    INodeAttributes nodeAttrs = getINodeAttributes(
+        fsd, fullPath, path, node, snapshot);
+    return createFileStatus(fsd, path, node, nodeAttrs,
+                            storagePolicy, snapshot, isRawPath, iip);
+  }
+
+  /**
+   * Create FileStatus by file INode
+   */
+  static HdfsFileStatus createFileStatus(
+      FSDirectory fsd, byte[] path, INode node,
+      INodeAttributes nodeAttrs, byte storagePolicy, int snapshot,
+      boolean isRawPath, INodesInPath iip) throws IOException {
+    long size = 0;     // length is zero for directories
+    short replication = 0;
+    long blocksize = 0;
+    final boolean isEncrypted;
+
+    final FileEncryptionInfo feInfo = isRawPath ? null :
+        fsd.getFileEncryptionInfo(node, snapshot, iip);
+
+    if (node.isFile()) {
+      final INodeFile fileNode = node.asFile();
+      size = fileNode.computeFileSize(snapshot);
+      replication = fileNode.getFileReplication(snapshot);
+      blocksize = fileNode.getPreferredBlockSize();
+      isEncrypted = (feInfo != null) ||
+          (isRawPath && fsd.isInAnEZ(INodesInPath.fromINode(node)));
+    } else {
+      isEncrypted = fsd.isInAnEZ(INodesInPath.fromINode(node));
+    }
+
+    int childrenNum = node.isDirectory() ?
+        node.asDirectory().getChildrenNum(snapshot) : 0;
+
+    return new HdfsFileStatus(
         size,
         node.isDirectory(),
         replication,
@@ -402,13 +417,18 @@ class FSDirStatAndListingOp {
         storagePolicy);
   }
 
+  private static INodeAttributes getINodeAttributes(
+      FSDirectory fsd, String fullPath, byte[] path, INode node, int snapshot) {
+    return fsd.getAttributes(fullPath, path, node, snapshot);
+  }
+
   /**
    * Create FileStatus with location info by file INode
    */
   private static HdfsLocatedFileStatus createLocatedFileStatus(
-      FSDirectory fsd, String fullPath, byte[] path, INode node,
-      byte storagePolicy, int snapshot, boolean isRawPath,
-      INodesInPath iip) throws IOException {
+      FSDirectory fsd, byte[] path, INode node, INodeAttributes nodeAttrs,
+      byte storagePolicy, int snapshot,
+      boolean isRawPath, INodesInPath iip) throws IOException {
     assert fsd.hasReadLock();
     long size = 0; // length is zero for directories
     short replication = 0;
@@ -442,8 +462,6 @@ class FSDirStatAndListingOp {
     int childrenNum = node.isDirectory() ?
         node.asDirectory().getChildrenNum(snapshot) : 0;
 
-    INodeAttributes nodeAttrs =
-        fsd.getAttributes(fullPath, path, node, snapshot);
     HdfsLocatedFileStatus status =
         new HdfsLocatedFileStatus(size, node.isDirectory(), replication,
           blocksize, node.getModificationTime(snapshot),
@@ -468,7 +486,6 @@ class FSDirStatAndListingOp {
    * return an FsPermissionExtension.
    *
    * @param node INode to check
-   * @param snapshot int snapshot ID
    * @param isEncrypted boolean true if the file/dir is encrypted
    * @return FsPermission from inode, with ACL bit on if the inode has an ACL
    * and encrypted bit on if it represents an encrypted file/dir.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java

@@ -379,7 +379,7 @@ public class FSEditLogLoader {
 
         // add the op into retry cache if necessary
         if (toAddRetryCache) {
-          HdfsFileStatus stat = FSDirStatAndListingOp.createFileStatus(
+          HdfsFileStatus stat = FSDirStatAndListingOp.createFileStatusForEditLog(
               fsNamesys.dir, path, HdfsFileStatus.EMPTY_NAME, newFile,
               HdfsConstantsClient.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED, Snapshot.CURRENT_STATE_ID,
               false, iip);
@@ -398,7 +398,7 @@ public class FSEditLogLoader {
               false);
           // add the op into retry cache if necessary
           if (toAddRetryCache) {
-            HdfsFileStatus stat = FSDirStatAndListingOp.createFileStatus(
+            HdfsFileStatus stat = FSDirStatAndListingOp.createFileStatusForEditLog(
                 fsNamesys.dir, path,
                 HdfsFileStatus.EMPTY_NAME, newFile,
                 HdfsConstantsClient.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED,
@@ -472,7 +472,7 @@ public class FSEditLogLoader {
             false, false);
         // add the op into retry cache if necessary
         if (toAddRetryCache) {
-          HdfsFileStatus stat = FSDirStatAndListingOp.createFileStatus(
+          HdfsFileStatus stat = FSDirStatAndListingOp.createFileStatusForEditLog(
               fsNamesys.dir, path, HdfsFileStatus.EMPTY_NAME, file,
               HdfsConstantsClient.BLOCK_STORAGE_POLICY_ID_UNSPECIFIED,
               Snapshot.CURRENT_STATE_ID, false, iip);