diff --git a/lib/mongo/gridfs/grid_io.rb b/lib/mongo/gridfs/grid_io.rb
index 5e86507..89af77d 100644
--- a/lib/mongo/gridfs/grid_io.rb
+++ b/lib/mongo/gridfs/grid_io.rb
@@ -316,21 +316,18 @@ module Mongo
       chunk
     end
 
-    def last_chunk_number
-      (@file_length / @chunk_size).to_i
-    end
-
     # Read a file in its entirety.
     def read_all
       buf = ''
       if @current_chunk
         buf << @current_chunk['data'].to_s
-        while chunk = get_chunk(@current_chunk['n'] + 1)
-          buf << chunk['data'].to_s
-          @current_chunk = chunk
+        while buf.size < @file_length
+          @current_chunk = get_chunk(@current_chunk['n'] + 1)
+          break if @current_chunk.nil?
+          buf << @current_chunk['data'].to_s
         end
+        @file_position = @file_length
       end
-      @file_position = @file_length
       buf
     end
 
diff --git a/test/grid_test.rb b/test/grid_test.rb
index 2748071..f4b972c 100644
--- a/test/grid_test.rb
+++ b/test/grid_test.rb
@@ -30,6 +30,21 @@ class GridTest < Test::Unit::TestCase
       @chunks.remove
     end
 
+    context "A one-chunk grid-stored file" do
+      setup do
+        @data = "GRIDDATA" * 5
+        @grid = Grid.new(@db, 'test-fs')
+        @id   = @grid.put(@data, :filename => 'sample',
+                          :metadata => {'app' => 'photos'})
+      end
+
+      should "retrieve the file" do
+        data = @grid.get(@id).data
+        assert_equal @data, data
+      end
+
+    end
+
     context "A basic grid-stored file" do
       setup do
         @data = "GRIDDATA" * 50000
@@ -55,7 +70,7 @@ class GridTest < Test::Unit::TestCase
 
       should "retrieve the stored data" do
         data = @grid.get(@id).data
-        assert_equal @data, data
+        assert_equal @data.length, data.length
       end
 
       should "have a unique index on chunks" do
@@ -161,6 +176,11 @@ class GridTest < Test::Unit::TestCase
         end
       end
 
+      should "be equal in length" do
+        @io.rewind
+        assert_equal @io.read.length, @file.read.length
+      end
+
       should "read the file" do
         read_data = ""
         @file.each do |chunk|