diff --git a/core/src/main/scala/org/apache/spark/TestUtils.scala b/core/src/main/scala/org/apache/spark/TestUtils.scala
index 8ca731038e528..c5e7a73c53fe9 100644
--- a/core/src/main/scala/org/apache/spark/TestUtils.scala
+++ b/core/src/main/scala/org/apache/spark/TestUtils.scala
@@ -23,8 +23,8 @@ import java.util.jar.{JarEntry, JarOutputStream}
 
 import scala.collection.JavaConversions._
 
+import com.google.common.io.{ByteStreams, Files}
 import javax.tools.{JavaFileObject, SimpleJavaFileObject, ToolProvider}
-import com.google.common.io.Files
 
 /**
  * Utilities for tests. Included in main codebase since it's used by multiple
@@ -63,12 +63,7 @@ private[spark] object TestUtils {
       jarStream.putNextEntry(jarEntry)
 
       val in = new FileInputStream(file)
-      val buffer = new Array[Byte](10240)
-      var nRead = 0
-      while (nRead <= 0) {
-        nRead = in.read(buffer, 0, buffer.length)
-        jarStream.write(buffer, 0, nRead)
-      }
+      ByteStreams.copy(in, jarStream)
       in.close()
     }
     jarStream.close()
diff --git a/core/src/main/scala/org/apache/spark/storage/DiskStore.scala b/core/src/main/scala/org/apache/spark/storage/DiskStore.scala
index 295c70670857b..247e2400158ea 100644
--- a/core/src/main/scala/org/apache/spark/storage/DiskStore.scala
+++ b/core/src/main/scala/org/apache/spark/storage/DiskStore.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.storage
 
-import java.io.{FileOutputStream, RandomAccessFile}
+import java.io.{IOException, FileOutputStream, RandomAccessFile}
 import java.nio.ByteBuffer
 import java.nio.channels.FileChannel.MapMode
 
@@ -111,7 +111,13 @@ private[spark] class DiskStore(blockManager: BlockManager, diskManager: DiskBloc
       // For small files, directly read rather than memory map
       if (segment.length < minMemoryMapBytes) {
         val buf = ByteBuffer.allocate(segment.length.toInt)
-        channel.read(buf, segment.offset)
+        channel.position(segment.offset)
+        while (buf.remaining() != 0) {
+          if (channel.read(buf) == -1) {
+            throw new IOException("Reached EOF before filling buffer\n" +
+              s"offset=${segment.offset}\nblockId=$blockId\nbuf.remaining=${buf.remaining}")
+          }
+        }
         buf.flip()
         Some(buf)
       } else {
diff --git a/core/src/main/scala/org/apache/spark/storage/TachyonStore.scala b/core/src/main/scala/org/apache/spark/storage/TachyonStore.scala
index 932b5616043b4..6dbad5ff0518e 100644
--- a/core/src/main/scala/org/apache/spark/storage/TachyonStore.scala
+++ b/core/src/main/scala/org/apache/spark/storage/TachyonStore.scala
@@ -20,6 +20,7 @@ package org.apache.spark.storage
 import java.io.IOException
 import java.nio.ByteBuffer
 
+import com.google.common.io.ByteStreams
 import tachyon.client.{ReadType, WriteType}
 
 import org.apache.spark.Logging
@@ -105,25 +106,17 @@ private[spark] class TachyonStore(
       return None
     }
     val is = file.getInStream(ReadType.CACHE)
-    var buffer: ByteBuffer = null
+    assert (is != null)
     try {
-      if (is != null) {
-        val size = file.length
-        val bs = new Array[Byte](size.asInstanceOf[Int])
-        val fetchSize = is.read(bs, 0, size.asInstanceOf[Int])
-        buffer = ByteBuffer.wrap(bs)
-        if (fetchSize != size) {
-          logWarning(s"Failed to fetch the block $blockId from Tachyon: Size $size " +
-            s"is not equal to fetched size $fetchSize")
-          return None
-        }
-      }
+      val size = file.length
+      val bs = new Array[Byte](size.asInstanceOf[Int])
+      ByteStreams.readFully(is, bs)
+      Some(ByteBuffer.wrap(bs))
     } catch {
       case ioe: IOException =>
         logWarning(s"Failed to fetch the block $blockId from Tachyon", ioe)
-        return None
+        None
     }
-    Some(buffer)
   }
 
   override def contains(blockId: BlockId): Boolean = {
diff --git a/core/src/main/scala/org/apache/spark/util/Utils.scala b/core/src/main/scala/org/apache/spark/util/Utils.scala
index aefbb24f01217..6d3bef007e6e4 100644
--- a/core/src/main/scala/org/apache/spark/util/Utils.scala
+++ b/core/src/main/scala/org/apache/spark/util/Utils.scala
@@ -33,7 +33,7 @@ import scala.reflect.ClassTag
 import scala.util.Try
 import scala.util.control.{ControlThrowable, NonFatal}
 
-import com.google.common.io.Files
+import com.google.common.io.{ByteStreams, Files}
 import com.google.common.util.concurrent.ThreadFactoryBuilder
 import org.apache.commons.lang3.SystemUtils
 import org.apache.hadoop.fs.{FileSystem, FileUtil, Path}
@@ -1005,8 +1005,8 @@ private[spark] object Utils extends Logging {
     val stream = new FileInputStream(file)
 
     try {
-      stream.skip(effectiveStart)
-      stream.read(buff)
+      ByteStreams.skipFully(stream, effectiveStart)
+      ByteStreams.readFully(stream, buff)
     } finally {
       stream.close()
     }
diff --git a/core/src/test/scala/org/apache/spark/FileServerSuite.scala b/core/src/test/scala/org/apache/spark/FileServerSuite.scala
index 7e18f45de7b5b..5997e014c5ca8 100644
--- a/core/src/test/scala/org/apache/spark/FileServerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/FileServerSuite.scala
@@ -20,6 +20,7 @@ package org.apache.spark
 import java.io._
 import java.util.jar.{JarEntry, JarOutputStream}
 
+import com.google.common.io.ByteStreams
 import com.google.common.io.Files
 import org.scalatest.FunSuite
 
@@ -60,12 +61,7 @@ class FileServerSuite extends FunSuite with LocalSparkContext {
     jar.putNextEntry(jarEntry)
 
     val in = new FileInputStream(textFile)
-    val buffer = new Array[Byte](10240)
-    var nRead = 0
-    while (nRead <= 0) {
-      nRead = in.read(buffer, 0, buffer.length)
-      jar.write(buffer, 0, nRead)
-    }
+    ByteStreams.copy(in, jar)
 
     in.close()
     jar.close()