HBASE-22480 Get block from BlockCache once and return this block to BlockCache twice make ref count error.

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFileReaderImpl.java

@@ -1308,7 +1308,12 @@ public class HFileReaderImpl implements HFile.Reader, Configurable {
             compressedBlock.release();
           }
         }
+        try {
           validateBlockType(cachedBlock, expectedBlockType);
+        } catch (IOException e) {
+          returnAndEvictBlock(cache, cacheKey, cachedBlock);
+          throw e;
+        }
 
         if (expectedDataBlockEncoding == null) {
           return cachedBlock;
@@ -1341,8 +1346,7 @@ public class HFileReaderImpl implements HFile.Reader, Configurable {
                 + " because of a data block encoding mismatch" + "; expected: "
                 + expectedDataBlockEncoding + ", actual: " + actualDataBlockEncoding + ", path=" + path);
             // This is an error scenario. so here we need to release the block.
-            cachedBlock.release();
+            returnAndEvictBlock(cache, cacheKey, cachedBlock);
-            cache.evictBlock(cacheKey);
           }
           return null;
         }
@@ -1352,6 +1356,11 @@ public class HFileReaderImpl implements HFile.Reader, Configurable {
     return null;
   }
 
+  private void returnAndEvictBlock(BlockCache cache, BlockCacheKey cacheKey, Cacheable block) {
+    block.release();
+    cache.evictBlock(cacheKey);
+  }
+
   /**
    * @param metaBlockName
    * @param cacheBlock Add block to cache, if found
@@ -1481,7 +1490,9 @@ public class HFileReaderImpl implements HFile.Reader, Configurable {
               // type in the cache key, and we expect it to match on a cache hit.
               if (cachedBlock.getDataBlockEncoding() != dataBlockEncoder.getDataBlockEncoding()) {
                 // Remember to release the block when in exceptional path.
-                cachedBlock.release();
+                cacheConf.getBlockCache().ifPresent(cache -> {
+                  returnAndEvictBlock(cache, cacheKey, cachedBlock);
+                });
                 throw new IOException("Cached block under key " + cacheKey + " "
                     + "has wrong encoding: " + cachedBlock.getDataBlockEncoding() + " (expected: "
                     + dataBlockEncoder.getDataBlockEncoding() + "), path=" + path);

hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestHFileReaderImpl.java

@@ -0,0 +1,155 @@
+/**
+ * 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.hbase.io.hfile;
+
+import static org.junit.Assert.assertEquals;
+import java.io.IOException;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.CellComparatorImpl;
+import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.io.hfile.bucket.BucketCache;
+import org.apache.hadoop.hbase.testclassification.IOTests;
+import org.apache.hadoop.hbase.testclassification.SmallTests;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+import org.apache.hbase.thirdparty.com.google.common.collect.Lists;
+
+/**
+ * Test
+ */
+@Category({ IOTests.class, SmallTests.class})
+public class TestHFileReaderImpl {
+
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+      HBaseClassTestRule.forClass(TestHFileReaderImpl.class);
+
+  private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
+
+  static KeyValue toKV(String row) {
+    return new KeyValue(Bytes.toBytes(row), Bytes.toBytes("family"), Bytes.toBytes("qualifier"),
+        Bytes.toBytes("value"));
+  }
+
+  static String toRowStr(Cell c) {
+    return Bytes.toString(c.getRowArray(), c.getRowOffset(), c.getRowLength());
+  }
+
+  Path makeNewFile() throws IOException {
+    Path ncTFile = new Path(TEST_UTIL.getDataTestDir(), "basic.hfile");
+    FSDataOutputStream fout = TEST_UTIL.getTestFileSystem().create(ncTFile);
+    int blocksize = toKV("a").getLength() * 3;
+    HFileContext context =
+        new HFileContextBuilder().withBlockSize(blocksize).withIncludesTags(true).build();
+    Configuration conf = TEST_UTIL.getConfiguration();
+    HFile.Writer writer =
+        HFile.getWriterFactoryNoCache(conf).withOutputStream(fout).withFileContext(context)
+            .withComparator(CellComparatorImpl.COMPARATOR).create();
+    // 4 bytes * 3 * 2 for each key/value +
+    // 3 for keys, 15 for values = 42 (woot)
+    writer.append(toKV("c"));
+    writer.append(toKV("e"));
+    writer.append(toKV("g"));
+    // block transition
+    writer.append(toKV("i"));
+    writer.append(toKV("k"));
+    writer.close();
+    fout.close();
+    return ncTFile;
+  }
+
+  @Test
+  public void testSeekBefore() throws Exception {
+    Path p = makeNewFile();
+    FileSystem fs = TEST_UTIL.getTestFileSystem();
+    Configuration conf = TEST_UTIL.getConfiguration();
+    int[] bucketSizes = { 512, 2048, 4096, 64 * 1024, 128 * 1024 };
+    BucketCache bucketcache =
+        new BucketCache("offheap", 128 * 1024 * 1024, 64 * 1024, bucketSizes, 5, 64 * 100, null);
+
+    HFile.Reader reader = HFile.createReader(fs, p, new CacheConfig(conf, bucketcache), true, conf);
+    reader.loadFileInfo();
+
+    // warm cache
+    HFileScanner scanner = reader.getScanner(true, true);
+    scanner.seekTo(toKV("i"));
+    assertEquals("i", toRowStr(scanner.getCell()));
+    scanner.close();
+
+    while (bucketcache.getBlockCount() <= 0) {
+      Thread.sleep(10);
+    }
+
+    // reopen again.
+    scanner = reader.getScanner(true, true);
+    scanner.seekTo(toKV("i"));
+    assertEquals("i", toRowStr(scanner.getCell()));
+    scanner.seekBefore(toKV("i"));
+    assertEquals("g", toRowStr(scanner.getCell()));
+    scanner.close();
+
+    for (CachedBlock cachedBlock : Lists.newArrayList(bucketcache)) {
+      BlockCacheKey cacheKey =
+          new BlockCacheKey(cachedBlock.getFilename(), cachedBlock.getOffset());
+      int refCount = bucketcache.getRpcRefCount(cacheKey);
+      assertEquals(0, refCount);
+    }
+
+    // case 2
+    scanner = reader.getScanner(true, true);
+    scanner.seekTo(toKV("i"));
+    assertEquals("i", toRowStr(scanner.getCell()));
+    scanner.seekBefore(toKV("c"));
+    scanner.close();
+    for (CachedBlock cachedBlock : Lists.newArrayList(bucketcache)) {
+      BlockCacheKey cacheKey =
+          new BlockCacheKey(cachedBlock.getFilename(), cachedBlock.getOffset());
+      int refCount = bucketcache.getRpcRefCount(cacheKey);
+      assertEquals(0, refCount);
+    }
+
+    reader.close();
+
+    // clear bucketcache
+    for (CachedBlock cachedBlock : Lists.newArrayList(bucketcache)) {
+      BlockCacheKey cacheKey =
+          new BlockCacheKey(cachedBlock.getFilename(), cachedBlock.getOffset());
+      bucketcache.evictBlock(cacheKey);
+    }
+    bucketcache.shutdown();
+
+    deleteTestDir(fs);
+  }
+
+  protected void deleteTestDir(FileSystem fs) throws IOException {
+    Path dataTestDir = TEST_UTIL.getDataTestDir();
+    if(fs.exists(dataTestDir)) {
+      fs.delete(dataTestDir, true);
+    }
+  }
+
+}