Debug patch for Bug#17665497 DATANODE CRASH IN DBTUPDISKALLOC.CPP DBTUP (LINE: 848) 0X00000000

Add some checks and failure points in debug and test mode to see if we got some test cases that exercise a suspect code path.

Author: zmur

storage/ndb/src/kernel/blocks/dbtup/DbtupDiskAlloc.cpp

@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
+ Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
 
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
@@ -1959,6 +1959,24 @@ Dbtup::disk_restart_alloc_extent(EmulatedJamBuffer* jamBuf,
 ndbassert(old.p->m_free_matrix_pos == RNIL);
 Uint32 pos= alloc.calc_extent_pos(old.p);
 Local_extent_info_list new_list(c_extent_pool, alloc.m_free_extents[pos]);
+#if defined VM_TRACE || defined ERROR_INSERT
+ ndbrequire(!"Bug17665497: debugging suspect code path.");
+ /**
+ * old is already in list with head alloc.m_extent_list.
+ * Before adding it to new_list it should be removed from
+ * previous list. Otherwise that list will become corrupt
+ * and Dbtup::disk_page_get_allocated() will eventually
+ * calculate wrong free value. Possibly it could also end
+ * up with derefering a released Extent_info.
+ *
+ * Something like below should be added, but since list is
+ * single linked remove is harder, might need to make list
+ * double linked.
+ *
+ * Local_fragment_extent_list list1(c_extent_pool, alloc.m_extent_list);
+ * list1.remove(old);
+ */
+#endif
  new_list.addFirst(old);
 old.p->m_free_matrix_pos= pos;
  }
@@ -2023,6 +2041,9 @@ Dbtup::disk_page_get_allocated(const Tablerec* tabPtrP,
  Ptr<Extent_info> extentPtr;
  for (list.first(extentPtr); !extentPtr.isNull(); list.next(extentPtr))
  {
+#if defined VM_TRACE || defined ERROR_INSERT
+ ndbrequire(extentPtr.p->m_free_matrix_pos == RNIL);
+#endif
  cnt++;
  free += extentPtr.p->m_free_space;
  }