From e4cb0d351450dba10cd6a0a6d999cc4423f1c2a9 Mon Sep 17 00:00:00 2001 From: Uma Maheswara Rao G Date: Wed, 16 Sep 2020 22:43:00 -0700 Subject: [PATCH] HDFS-15578: Fix the rename issues with fallback fs enabled (#2305). Contributed by Uma Maheswara Rao G. Co-authored-by: Uma Maheswara Rao G --- .../apache/hadoop/fs/viewfs/InodeTree.java | 24 +++-- .../hadoop/fs/viewfs/ViewFileSystem.java | 52 +++++++-- .../org/apache/hadoop/fs/viewfs/ViewFs.java | 59 ++++++++-- .../fs/viewfs/TestViewfsFileStatus.java | 4 +- .../hadoop/fs/viewfs/ViewFsBaseTest.java | 4 +- .../fs/viewfs/TestViewFsLinkFallback.java | 101 ++++++++++++++++++ ...ewDistributedFileSystemWithMountLinks.java | 95 +++++++++++++++- 7 files changed, 307 insertions(+), 32 deletions(-) diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/InodeTree.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/InodeTree.java index fceb73a56a..2a38693d09 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/InodeTree.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/InodeTree.java @@ -706,19 +706,27 @@ static class ResolveResult { final T targetFileSystem; final String resolvedPath; final Path remainingPath; // to resolve in the target FileSystem + private final boolean isLastInternalDirLink; ResolveResult(final ResultKind k, final T targetFs, final String resolveP, - final Path remainingP) { + final Path remainingP, boolean isLastIntenalDirLink) { kind = k; targetFileSystem = targetFs; resolvedPath = resolveP; remainingPath = remainingP; + this.isLastInternalDirLink = isLastIntenalDirLink; } // Internal dir path resolution completed within the mount table boolean isInternalDir() { return (kind == ResultKind.INTERNAL_DIR); } + + // Indicates whether the internal dir path resolution completed at the link + // or resolved due to fallback. + boolean isLastInternalDirLink() { + return this.isLastInternalDirLink; + } } /** @@ -737,7 +745,7 @@ ResolveResult resolve(final String p, final boolean resolveLastComponent) getRootDir().getInternalDirFs() : getRootLink().getTargetFileSystem(); resolveResult = new ResolveResult(ResultKind.INTERNAL_DIR, - targetFs, root.fullPath, SlashPath); + targetFs, root.fullPath, SlashPath, false); return resolveResult; } @@ -755,7 +763,8 @@ ResolveResult resolve(final String p, final boolean resolveLastComponent) } remainingPath = new Path(remainingPathStr.toString()); resolveResult = new ResolveResult(ResultKind.EXTERNAL_DIR, - getRootLink().getTargetFileSystem(), root.fullPath, remainingPath); + getRootLink().getTargetFileSystem(), root.fullPath, remainingPath, + true); return resolveResult; } Preconditions.checkState(root.isInternalDir()); @@ -775,7 +784,7 @@ ResolveResult resolve(final String p, final boolean resolveLastComponent) if (hasFallbackLink()) { resolveResult = new ResolveResult(ResultKind.EXTERNAL_DIR, getRootFallbackLink().getTargetFileSystem(), root.fullPath, - new Path(p)); + new Path(p), false); return resolveResult; } else { StringBuilder failedAt = new StringBuilder(path[0]); @@ -801,7 +810,8 @@ ResolveResult resolve(final String p, final boolean resolveLastComponent) remainingPath = new Path(remainingPathStr.toString()); } resolveResult = new ResolveResult(ResultKind.EXTERNAL_DIR, - link.getTargetFileSystem(), nextInode.fullPath, remainingPath); + link.getTargetFileSystem(), nextInode.fullPath, remainingPath, + true); return resolveResult; } else if (nextInode.isInternalDir()) { curInode = (INodeDir) nextInode; @@ -824,7 +834,7 @@ ResolveResult resolve(final String p, final boolean resolveLastComponent) remainingPath = new Path(remainingPathStr.toString()); } resolveResult = new ResolveResult(ResultKind.INTERNAL_DIR, - curInode.getInternalDirFs(), curInode.fullPath, remainingPath); + curInode.getInternalDirFs(), curInode.fullPath, remainingPath, false); return resolveResult; } @@ -874,7 +884,7 @@ protected ResolveResult buildResolveResultForRegexMountPoint( T targetFs = getTargetFileSystem( new URI(targetOfResolvedPathStr)); return new ResolveResult(resultKind, targetFs, resolvedPathStr, - remainingPath); + remainingPath, true); } catch (IOException ex) { LOGGER.error(String.format( "Got Exception while build resolve result." diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java index b90699675c..0b4e68b1e5 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java @@ -670,18 +670,52 @@ public FSDataInputStream open(final Path f, final int bufferSize) @Override public boolean rename(final Path src, final Path dst) throws IOException { // passing resolveLastComponet as false to catch renaming a mount point to - // itself. We need to catch this as an internal operation and fail. - InodeTree.ResolveResult resSrc = - fsState.resolve(getUriPath(src), false); - + // itself. We need to catch this as an internal operation and fail if no + // fallback. + InodeTree.ResolveResult resSrc = + fsState.resolve(getUriPath(src), false); + if (resSrc.isInternalDir()) { - throw readOnlyMountTable("rename", src); + if (fsState.getRootFallbackLink() == null) { + // If fallback is null, we can't rename from src. + throw readOnlyMountTable("rename", src); + } + InodeTree.ResolveResult resSrcWithLastComp = + fsState.resolve(getUriPath(src), true); + if (resSrcWithLastComp.isInternalDir() || resSrcWithLastComp + .isLastInternalDirLink()) { + throw readOnlyMountTable("rename", src); + } else { + // This is fallback and let's set the src fs with this fallback + resSrc = resSrcWithLastComp; + } } - - InodeTree.ResolveResult resDst = - fsState.resolve(getUriPath(dst), false); + + InodeTree.ResolveResult resDst = + fsState.resolve(getUriPath(dst), false); + if (resDst.isInternalDir()) { - throw readOnlyMountTable("rename", dst); + if (fsState.getRootFallbackLink() == null) { + // If fallback is null, we can't rename to dst. + throw readOnlyMountTable("rename", dst); + } + // if the fallback exist, we may have chance to rename to fallback path + // where dst parent is matching to internalDir. + InodeTree.ResolveResult resDstWithLastComp = + fsState.resolve(getUriPath(dst), true); + if (resDstWithLastComp.isInternalDir()) { + // We need to get fallback here. If matching fallback path not exist, it + // will fail later. This is a very special case: Even though we are on + // internal directory, we should allow to rename, so that src files will + // moved under matching fallback dir. + resDst = new InodeTree.ResolveResult( + InodeTree.ResultKind.INTERNAL_DIR, + fsState.getRootFallbackLink().getTargetFileSystem(), "/", + new Path(resDstWithLastComp.resolvedPath), false); + } else { + // The link resolved to some target fs or fallback fs. + resDst = resDstWithLastComp; + } } URI srcUri = resSrc.targetFileSystem.getUri(); diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java index a6ce33a043..e74c409478 100644 --- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java +++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java @@ -548,23 +548,60 @@ public boolean truncate(final Path f, final long newLength) public void renameInternal(final Path src, final Path dst, final boolean overwrite) throws IOException, UnresolvedLinkException { // passing resolveLastComponet as false to catch renaming a mount point - // itself we need to catch this as an internal operation and fail. - InodeTree.ResolveResult resSrc = - fsState.resolve(getUriPath(src), false); - + // itself we need to catch this as an internal operation and fail if no + // fallback. + InodeTree.ResolveResult resSrc = + fsState.resolve(getUriPath(src), false); + if (resSrc.isInternalDir()) { - throw new AccessControlException( - "Cannot Rename within internal dirs of mount table: src=" + src - + " is readOnly"); + if (fsState.getRootFallbackLink() == null) { + // If fallback is null, we can't rename from src. + throw new AccessControlException( + "Cannot Rename within internal dirs of mount table: src=" + src + + " is readOnly"); + } + InodeTree.ResolveResult resSrcWithLastComp = + fsState.resolve(getUriPath(src), true); + if (resSrcWithLastComp.isInternalDir() || resSrcWithLastComp + .isLastInternalDirLink()) { + throw new AccessControlException( + "Cannot Rename within internal dirs of mount table: src=" + src + + " is readOnly"); + } else { + // This is fallback and let's set the src fs with this fallback + resSrc = resSrcWithLastComp; + } } InodeTree.ResolveResult resDst = - fsState.resolve(getUriPath(dst), false); + fsState.resolve(getUriPath(dst), false); + if (resDst.isInternalDir()) { - throw new AccessControlException( - "Cannot Rename within internal dirs of mount table: dest=" + dst - + " is readOnly"); + if (fsState.getRootFallbackLink() == null) { + // If fallback is null, we can't rename to dst. + throw new AccessControlException( + "Cannot Rename within internal dirs of mount table: dest=" + dst + + " is readOnly"); + } + // if the fallback exist, we may have chance to rename to fallback path + // where dst parent is matching to internalDir. + InodeTree.ResolveResult resDstWithLastComp = + fsState.resolve(getUriPath(dst), true); + if (resDstWithLastComp.isInternalDir()) { + // We need to get fallback here. If matching fallback path not exist, it + // will fail later. This is a very special case: Even though we are on + // internal directory, we should allow to rename, so that src files will + // moved under matching fallback dir. + resDst = new InodeTree.ResolveResult( + InodeTree.ResultKind.INTERNAL_DIR, + fsState.getRootFallbackLink().getTargetFileSystem(), "/", + new Path(resDstWithLastComp.resolvedPath), false); + } else { + // The link resolved to some target fs or fallback fs. + resDst = resDstWithLastComp; + } } + //Alternate 1: renames within same file system URI srcUri = resSrc.targetFileSystem.getUri(); URI dstUri = resDst.targetFileSystem.getUri(); diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewfsFileStatus.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewfsFileStatus.java index 75557456ed..8ac447eb02 100644 --- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewfsFileStatus.java +++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestViewfsFileStatus.java @@ -165,8 +165,8 @@ public void testGetFileChecksum() throws IOException { final Path path = new Path("/tmp/someFile"); FileSystem mockFS = Mockito.mock(FileSystem.class); InodeTree.ResolveResult res = - new InodeTree.ResolveResult(null, mockFS , null, - new Path("someFile")); + new InodeTree.ResolveResult(null, mockFS, null, + new Path("someFile"), true); @SuppressWarnings("unchecked") InodeTree fsState = Mockito.mock(InodeTree.class); Mockito.when(fsState.resolve(path.toString(), true)).thenReturn(res); diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java index 21b0c159e2..73f6265eee 100644 --- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java +++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java @@ -547,8 +547,8 @@ public void testGetFileChecksum() throws AccessControlException, UnresolvedLinkException, IOException, URISyntaxException { AbstractFileSystem mockAFS = mock(AbstractFileSystem.class); InodeTree.ResolveResult res = - new InodeTree.ResolveResult(null, mockAFS , null, - new Path("someFile")); + new InodeTree.ResolveResult(null, mockAFS, null, + new Path("someFile"), true); @SuppressWarnings("unchecked") InodeTree fsState = mock(InodeTree.class); when(fsState.resolve(anyString(), anyBoolean())).thenReturn(res); diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsLinkFallback.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsLinkFallback.java index dc2eb0e350..09e02be640 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsLinkFallback.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsLinkFallback.java @@ -23,6 +23,7 @@ import static org.junit.Assert.assertNotNull; import static org.junit.Assert.assertTrue; +import java.io.FileNotFoundException; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; @@ -41,8 +42,10 @@ import org.apache.hadoop.fs.RemoteIterator; import org.apache.hadoop.fs.permission.FsPermission; import org.apache.hadoop.hdfs.DFSConfigKeys; +import org.apache.hadoop.hdfs.DistributedFileSystem; import org.apache.hadoop.hdfs.MiniDFSCluster; import org.apache.hadoop.hdfs.MiniDFSNNTopology; +import org.apache.hadoop.test.LambdaTestUtils; import org.junit.AfterClass; import org.junit.Assert; import org.junit.Before; @@ -472,4 +475,102 @@ public void testListFiles() throws Exception { assertEquals(fileInFallBackRoot.getName(), iterator.next().getPath().getName()); } + + @Test + public void testRenameOnInternalDirWithFallback() throws Exception { + Configuration conf = new Configuration(); + Path fallbackTarget = new Path(targetTestRoot, "fallbackDir"); + fsTarget.mkdirs(fallbackTarget); + ConfigUtil.addLink(conf, "/user1", + new Path(targetTestRoot.toString() + "/user1").toUri()); + ConfigUtil.addLink(conf, "/NewHDFSUser/next", + new Path(targetTestRoot.toString() + "/newUser1").toUri()); + ConfigUtil.addLinkFallback(conf, fallbackTarget.toUri()); + + //Make sure target fs has parent dir structures + try (DistributedFileSystem dfs = new DistributedFileSystem()) { + dfs.initialize(fsDefault.getUri(), conf); + dfs.mkdirs(new Path(targetTestRoot.toString() + "/user1")); + dfs.mkdirs(new Path(fallbackTarget.toString() + "/newUser1")); + } + + final AbstractFileSystem fs = + AbstractFileSystem.get(viewFsDefaultClusterUri, conf); + + Path src = new Path("/newFileOnRoot"); + Path dst = new Path("/newFileOnRoot1"); + fs.create(src, EnumSet.of(CREATE), + Options.CreateOpts.perms(FsPermission.getDefault())).close(); + verifyRename(fs, src, dst); + + src = new Path("/newFileOnRoot1"); + dst = new Path("/newUser1/newFileOnRoot"); + fs.mkdir(dst.getParent(), FsPermission.getDefault(), true); + verifyRename(fs, src, dst); + + src = new Path("/newUser1/newFileOnRoot"); + dst = new Path("/newUser1/newFileOnRoot1"); + verifyRename(fs, src, dst); + + src = new Path("/newUser1/newFileOnRoot1"); + dst = new Path("/newFileOnRoot"); + verifyRename(fs, src, dst); + + src = new Path("/user1/newFileOnRoot1"); + dst = new Path("/user1/newFileOnRoot"); + fs.create(src, EnumSet.of(CREATE), + Options.CreateOpts.perms(FsPermission.getDefault())).close(); + verifyRename(fs, src, dst); + } + + @Test + public void testRenameWhenDstOnInternalDirWithFallback() throws Exception { + Configuration conf = new Configuration(); + Path fallbackTarget = new Path(targetTestRoot, "fallbackDir"); + fsTarget.mkdirs(fallbackTarget); + ConfigUtil.addLink(conf, "/InternalDirDoesNotExistInFallback/test", + new Path(targetTestRoot.toString() + "/user1").toUri()); + ConfigUtil.addLink(conf, "/NewHDFSUser/next/next1", + new Path(targetTestRoot.toString() + "/newUser1").toUri()); + ConfigUtil.addLinkFallback(conf, fallbackTarget.toUri()); + + try (DistributedFileSystem dfs = new DistributedFileSystem()) { + dfs.initialize(fsDefault.getUri(), conf); + dfs.mkdirs(new Path(targetTestRoot.toString() + "/newUser1")); + dfs.mkdirs( + new Path(fallbackTarget.toString() + "/NewHDFSUser/next/next1")); + } + + final AbstractFileSystem fs = + AbstractFileSystem.get(viewFsDefaultClusterUri, conf); + final Path src = new Path("/newFileOnRoot"); + final Path dst = new Path("/NewHDFSUser/next"); + fs.mkdir(src, FsPermission.getDefault(), true); + // src and dst types are must be either same dir or files + LambdaTestUtils.intercept(IOException.class, + () -> fs.rename(src, dst, Options.Rename.OVERWRITE)); + + final Path src1 = new Path("/newFileOnRoot1"); + final Path dst1 = new Path("/NewHDFSUser/next/file"); + fs.create(src1, EnumSet.of(CREATE), + Options.CreateOpts.perms(FsPermission.getDefault())).close(); + verifyRename(fs, src1, dst1); + + final Path src2 = new Path("/newFileOnRoot2"); + final Path dst2 = new Path("/InternalDirDoesNotExistInFallback/file"); + fs.create(src2, EnumSet.of(CREATE), + Options.CreateOpts.perms(FsPermission.getDefault())).close(); + // If fallback does not have same structure as internal, rename will fail. + LambdaTestUtils.intercept(FileNotFoundException.class, + () -> fs.rename(src2, dst2, Options.Rename.OVERWRITE)); + } + + private void verifyRename(AbstractFileSystem fs, Path src, Path dst) + throws Exception { + fs.rename(src, dst, Options.Rename.OVERWRITE); + LambdaTestUtils + .intercept(FileNotFoundException.class, () -> fs.getFileStatus(src)); + Assert.assertNotNull(fs.getFileStatus(dst)); + } + } diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestViewDistributedFileSystemWithMountLinks.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestViewDistributedFileSystemWithMountLinks.java index 23b5793eee..1e66252d51 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestViewDistributedFileSystemWithMountLinks.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestViewDistributedFileSystemWithMountLinks.java @@ -20,9 +20,12 @@ import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.CommonConfigurationKeys; import org.apache.hadoop.fs.CommonConfigurationKeysPublic; +import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.fs.viewfs.ConfigUtil; import org.apache.hadoop.fs.viewfs.TestViewFileSystemOverloadSchemeWithHdfsScheme; +import org.apache.hadoop.fs.viewfs.ViewFsTestSetup; +import org.junit.Assert; import org.junit.Test; import java.io.IOException; @@ -48,7 +51,7 @@ public void setUp() throws IOException { URI defaultFSURI = URI.create(conf.get(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY)); ConfigUtil.addLinkFallback(conf, defaultFSURI.getAuthority(), - new Path(defaultFSURI.toString()).toUri()); + new Path(defaultFSURI.toString() + "/").toUri()); setConf(conf); } @@ -61,4 +64,94 @@ public void testCreateOnRoot() throws Exception { public void testMountLinkWithNonExistentLink() throws Exception { testMountLinkWithNonExistentLink(false); } + + @Test + public void testRenameOnInternalDirWithFallback() throws Exception { + Configuration conf = getConf(); + URI defaultFSURI = + URI.create(conf.get(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY)); + final Path hdfsTargetPath1 = new Path(defaultFSURI + "/HDFSUser"); + final Path hdfsTargetPath2 = new Path(defaultFSURI + "/NewHDFSUser/next"); + ViewFsTestSetup.addMountLinksToConf(defaultFSURI.getAuthority(), + new String[] {"/HDFSUser", "/NewHDFSUser/next"}, + new String[] {hdfsTargetPath1.toUri().toString(), + hdfsTargetPath2.toUri().toString()}, conf); + //Making sure parent dir structure as mount points available in fallback. + try (DistributedFileSystem dfs = new DistributedFileSystem()) { + dfs.initialize(defaultFSURI, conf); + dfs.mkdirs(hdfsTargetPath1); + dfs.mkdirs(hdfsTargetPath2); + } + + try (FileSystem fs = FileSystem.get(conf)) { + Path src = new Path("/newFileOnRoot"); + Path dst = new Path("/newFileOnRoot1"); + fs.create(src).close(); + verifyRename(fs, src, dst); + + src = new Path("/newFileOnRoot1"); + dst = new Path("/NewHDFSUser/newFileOnRoot"); + fs.mkdirs(dst.getParent()); + verifyRename(fs, src, dst); + + src = new Path("/NewHDFSUser/newFileOnRoot"); + dst = new Path("/NewHDFSUser/newFileOnRoot1"); + verifyRename(fs, src, dst); + + src = new Path("/NewHDFSUser/newFileOnRoot1"); + dst = new Path("/newFileOnRoot"); + verifyRename(fs, src, dst); + + src = new Path("/HDFSUser/newFileOnRoot1"); + dst = new Path("/HDFSUser/newFileOnRoot"); + fs.create(src).close(); + verifyRename(fs, src, dst); + } + } + + @Test + public void testRenameWhenDstOnInternalDirWithFallback() throws Exception { + Configuration conf = getConf(); + URI defaultFSURI = + URI.create(conf.get(CommonConfigurationKeys.FS_DEFAULT_NAME_KEY)); + final Path hdfsTargetPath1 = new Path(defaultFSURI + "/HDFSUser"); + final Path hdfsTargetPath2 = + new Path(defaultFSURI + "/dstNewHDFSUser" + "/next"); + ViewFsTestSetup.addMountLinksToConf(defaultFSURI.getAuthority(), + new String[] {"/InternalDirDoesNotExistInFallback/test", + "/NewHDFSUser/next/next1"}, + new String[] {hdfsTargetPath1.toUri().toString(), + hdfsTargetPath2.toUri().toString()}, conf); + try (DistributedFileSystem dfs = new DistributedFileSystem()) { + dfs.initialize(defaultFSURI, conf); + dfs.mkdirs(hdfsTargetPath1); + dfs.mkdirs(hdfsTargetPath2); + dfs.mkdirs(new Path("/NewHDFSUser/next/next1")); + } + + try (FileSystem fs = FileSystem.get(conf)) { + Path src = new Path("/newFileOnRoot"); + Path dst = new Path("/NewHDFSUser/next"); + fs.create(src).close(); + verifyRename(fs, src, dst); + + src = new Path("/newFileOnRoot"); + dst = new Path("/NewHDFSUser/next/file"); + fs.create(src).close(); + verifyRename(fs, src, dst); + + src = new Path("/newFileOnRoot"); + dst = new Path("/InternalDirDoesNotExistInFallback/file"); + fs.create(src).close(); + // If fallback does not have same structure as internal, rename will fail. + Assert.assertFalse(fs.rename(src, dst)); + } + } + + private void verifyRename(FileSystem fs, Path src, Path dst) + throws IOException { + fs.rename(src, dst); + Assert.assertFalse(fs.exists(src)); + Assert.assertTrue(fs.exists(dst)); + } }