HBASE-22185 RAMQueueEntry#writeToCache should freeBlock if any exception encountered instead of the IOException catch block

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

@@ -1531,42 +1531,49 @@ public void access(long accessCounter) {
       this.accessCounter = accessCounter;
     }
 
-    public BucketEntry writeToCache(final IOEngine ioEngine,
-        final BucketAllocator bucketAllocator,
-        final LongAdder realCacheSize) throws CacheFullException, IOException,
-        BucketAllocatorException {
+    private BucketEntry getBucketEntry(IOEngine ioEngine, long offset, int len) {
+      if (ioEngine.usesSharedMemory()) {
+        if (UnsafeAvailChecker.isAvailable()) {
+          return new UnsafeSharedMemoryBucketEntry(offset, len, accessCounter, inMemory);
+        } else {
+          return new SharedMemoryBucketEntry(offset, len, accessCounter, inMemory);
+        }
+      } else {
+        return new BucketEntry(offset, len, accessCounter, inMemory);
+      }
+    }
+
+    public BucketEntry writeToCache(final IOEngine ioEngine, final BucketAllocator bucketAllocator,
+        final LongAdder realCacheSize) throws IOException {
       int len = data.getSerializedLength();
       // This cacheable thing can't be serialized
-      if (len == 0) return null;
+      if (len == 0) {
+        return null;
+      }
       long offset = bucketAllocator.allocateBlock(len);
-      BucketEntry bucketEntry = ioEngine.usesSharedMemory()
-          ? UnsafeAvailChecker.isAvailable()
-              ? new UnsafeSharedMemoryBucketEntry(offset, len, accessCounter, inMemory)
-              : new SharedMemoryBucketEntry(offset, len, accessCounter, inMemory)
-          : new BucketEntry(offset, len, accessCounter, inMemory);
-      bucketEntry.setDeserialiserReference(data.getDeserializer());
+      boolean succ = false;
+      BucketEntry bucketEntry;
       try {
+        bucketEntry = getBucketEntry(ioEngine, offset, len);
+        bucketEntry.setDeserialiserReference(data.getDeserializer());
         if (data instanceof HFileBlock) {
           // If an instance of HFileBlock, save on some allocations.
-          HFileBlock block = (HFileBlock)data;
+          HFileBlock block = (HFileBlock) data;
           ByteBuff sliceBuf = block.getBufferReadOnly();
           ByteBuffer metadata = block.getMetaData();
-          if (LOG.isTraceEnabled()) {
-            LOG.trace("Write offset=" + offset + ", len=" + len);
-          }
           ioEngine.write(sliceBuf, offset);
           ioEngine.write(metadata, offset + len - metadata.limit());
         } else {
           ByteBuffer bb = ByteBuffer.allocate(len);
           data.serialize(bb, true);
           ioEngine.write(bb, offset);
         }
-      } catch (IOException ioe) {
-        // free it in bucket allocator
-        bucketAllocator.freeBlock(offset);
-        throw ioe;
+        succ = true;
+      } finally {
+        if (!succ) {
+          bucketAllocator.freeBlock(offset);
+        }
       }
-
       realCacheSize.add(len);
       return bucketEntry;
     }

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

@@ -50,15 +50,19 @@
 import org.apache.hadoop.hbase.io.hfile.HFileContextBuilder;
 import org.apache.hadoop.hbase.io.hfile.bucket.BucketAllocator.BucketSizeInfo;
 import org.apache.hadoop.hbase.io.hfile.bucket.BucketAllocator.IndexStatistics;
+import org.apache.hadoop.hbase.io.hfile.bucket.BucketCache.RAMQueueEntry;
+import org.apache.hadoop.hbase.nio.ByteBuff;
 import org.apache.hadoop.hbase.testclassification.IOTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.junit.After;
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
+import org.mockito.Mockito;
 
 import org.apache.hbase.thirdparty.com.google.common.collect.ImmutableMap;
 
@@ -460,4 +464,39 @@ public void testCacheBlockNextBlockMetadataMissing() throws Exception {
     CacheTestUtils.getBlockAndAssertEquals(cache, key, blockWithNextBlockMetadata, actualBuffer,
       block1Buffer);
   }
+
+  @Test
+  public void testFreeBlockWhenIOEngineWriteFailure() throws IOException {
+    // initialize an block.
+    int size = 100, offset = 20;
+    int length = HConstants.HFILEBLOCK_HEADER_SIZE + size;
+    ByteBuffer buf = ByteBuffer.allocate(length);
+    HFileContext meta = new HFileContextBuilder().build();
+    HFileBlock block = new HFileBlock(BlockType.DATA, size, size, -1, buf, HFileBlock.FILL_HEADER,
+        offset, 52, -1, meta);
+
+    // initialize an mocked ioengine.
+    IOEngine ioEngine = Mockito.mock(IOEngine.class);
+    Mockito.when(ioEngine.usesSharedMemory()).thenReturn(false);
+    // Mockito.doNothing().when(ioEngine).write(Mockito.any(ByteBuffer.class), Mockito.anyLong());
+    Mockito.doThrow(RuntimeException.class).when(ioEngine).write(Mockito.any(ByteBuffer.class),
+      Mockito.anyLong());
+    Mockito.doThrow(RuntimeException.class).when(ioEngine).write(Mockito.any(ByteBuff.class),
+      Mockito.anyLong());
+
+    // create an bucket allocator.
+    long availableSpace = 1024 * 1024 * 1024L;
+    BucketAllocator allocator = new BucketAllocator(availableSpace, null);
+
+    BlockCacheKey key = new BlockCacheKey("dummy", 1L);
+    RAMQueueEntry re = new RAMQueueEntry(key, block, 1, true);
+
+    Assert.assertEquals(0, allocator.getUsedSize());
+    try {
+      re.writeToCache(ioEngine, allocator, null);
+      Assert.fail();
+    } catch (Exception e) {
+    }
+    Assert.assertEquals(0, allocator.getUsedSize());
+  }
 }