diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
index 11e4d34de2..4e1f0e1d62 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -193,8 +193,7 @@ module ActiveRecord
         rescue Exception => database_transaction_rollback
           if transaction_open && !outside_transaction?
             transaction_open = false
-            txn = decrement_open_transactions
-            txn.aborted!
+            decrement_open_transactions
             if open_transactions == 0
               rollback_db_transaction
               rollback_transaction_records(true)
@@ -209,10 +208,9 @@ module ActiveRecord
         @transaction_joinable = last_transaction_joinable
 
         if outside_transaction?
-          @current_transaction = nil
+          @open_transactions = 0
         elsif transaction_open
-          txn = decrement_open_transactions
-          txn.committed!
+          decrement_open_transactions
           begin
             if open_transactions == 0
               commit_db_transaction
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 27700e4fd2..b3f9187429 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -69,7 +69,6 @@ module ActiveRecord
         @last_use            = false
         @logger              = logger
         @open_transactions   = 0
-        @current_transaction = nil
         @pool                = pool
         @query_cache         = Hash.new { |h,sql| h[sql] = {} }
         @query_cache_enabled = false
@@ -237,30 +236,14 @@ module ActiveRecord
         @connection
       end
 
-      def open_transactions
-        count = 0
-        txn   = current_transaction
-
-        while txn
-          count += 1
-          txn = txn.next
-        end
-
-        count
-      end
-
-      attr_reader :current_transaction
+      attr_reader :open_transactions
 
       def increment_open_transactions
-        @current_transaction = Transaction.new(current_transaction)
+        @open_transactions += 1
       end
 
       def decrement_open_transactions
-        return unless current_transaction
-
-        txn = current_transaction
-        @current_transaction = txn.next
-        txn
+        @open_transactions -= 1
       end
 
       def transaction_joinable=(joinable)
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index cf64985ddb..43ffca0227 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -387,7 +387,6 @@ module ActiveRecord
       @marked_for_destruction  = false
       @new_record              = true
       @mass_assignment_options = nil
-      @txn                     = nil
       @_start_transaction_state = {}
     end
   end
diff --git a/activerecord/lib/active_record/transactions.rb b/activerecord/lib/active_record/transactions.rb
index e008b32170..09318879d5 100644
--- a/activerecord/lib/active_record/transactions.rb
+++ b/activerecord/lib/active_record/transactions.rb
@@ -1,32 +1,6 @@
 require 'thread'
 
 module ActiveRecord
-  class Transaction
-    attr_reader :next
-
-    def initialize(txn = nil)
-      @next      = txn
-      @committed = false
-      @aborted   = false
-    end
-
-    def committed!
-      @committed = true
-    end
-
-    def aborted!
-      @aborted = true
-    end
-
-    def committed?
-      @committed
-    end
-
-    def aborted?
-      @aborted
-    end
-  end
-
   # See ActiveRecord::Transactions::ClassMethods for documentation.
   module Transactions
     extend ActiveSupport::Concern
@@ -333,11 +307,11 @@ module ActiveRecord
     def with_transaction_returning_status
       status = nil
       self.class.transaction do
-        @txn = self.class.connection.current_transaction
         add_to_transaction
         begin
           status = yield
         rescue ActiveRecord::Rollback
+          @_start_transaction_state[:level] = (@_start_transaction_state[:level] || 0) - 1
           status = nil
         end
 
@@ -353,17 +327,20 @@ module ActiveRecord
       @_start_transaction_state[:id] = id if has_attribute?(self.class.primary_key)
       @_start_transaction_state[:new_record] = @new_record
       @_start_transaction_state[:destroyed] = @destroyed
+      @_start_transaction_state[:level] = (@_start_transaction_state[:level] || 0) + 1
     end
 
     # Clear the new record state and id of a record.
     def clear_transaction_record_state #:nodoc:
-      @_start_transaction_state.clear if @txn.committed?
+      @_start_transaction_state[:level] = (@_start_transaction_state[:level] || 0) - 1
+      @_start_transaction_state.clear if @_start_transaction_state[:level] < 1
     end
 
     # Restore the new record state and id of a record that was previously saved by a call to save_record_state.
     def restore_transaction_record_state(force = false) #:nodoc:
       unless @_start_transaction_state.empty?
-        if @txn.aborted? || force
+        @_start_transaction_state[:level] = (@_start_transaction_state[:level] || 0) - 1
+        if @_start_transaction_state[:level] < 1 || force
           restore_state = @_start_transaction_state
           was_frozen = @attributes.frozen?
           @attributes = @attributes.dup if was_frozen