BLOB instrumentation for Bug#12612184 Race condition in row_upd_clust_rec()

If UNIV_DEBUG or UNIV_BLOB_LIGHT_DEBUG is enabled, add
!rec_offs_any_null_extern() assertions, ensuring that records do not
contain null pointers to externally stored columns in inappropriate
places.

btr_cur_optimistic_update(): Assert !rec_offs_any_null_extern().
Incomplete records must never be updated or deleted. This assertion
will cover also the pessimistic route.

row_build(): Assert !rec_offs_any_null_extern(). Search tuples must
never be built from incomplete index entries.

row_rec_to_index_entry(): Assert !rec_offs_any_null_extern() unless
ROW_COPY_DATA is requested. ROW_COPY_DATA is used for
multi-versioning, and therefore it might be valid to copy the most
recent (uncommitted) version while it contains a null pointer to
off-page columns.

row_vers_build_for_consistent_read(),
row_vers_build_for_semi_consistent_read(): Assert !rec_offs_any_null_extern()
on all versions except the most recent one.

trx_undo_prev_version_build(): Assert !rec_offs_any_null_extern() on
the previous version.

rb:682 approved by Sunny Bains

storage/innobase/btr/btr0cur.c

@@ -73,6 +73,13 @@ this many index pages */
 	  + not_empty)							\
 	 / (BTR_KEY_VAL_ESTIMATE_N_PAGES + ext_size))
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+/* A BLOB field reference full of zero, for use in assertions and tests.
+Initially, BLOB field references are set to zero, in
+dtuple_convert_big_rec(). */
+const byte field_ref_zero[BTR_EXTERN_FIELD_REF_SIZE];
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 /***********************************************************************
 Marks all extern fields in a record as owned by the record. This function
 should be called if the delete mark of a record is removed: a not delete
@@ -1585,6 +1592,9 @@ btr_cur_optimistic_update(
 
 	heap = mem_heap_create(1024);
 	offsets = rec_get_offsets(rec, index, NULL, ULINT_UNDEFINED, &heap);
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	ut_a(!rec_offs_any_null_extern(rec, offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 
 #ifdef UNIV_DEBUG
 	if (btr_cur_print_record_ops && thr) {

storage/innobase/include/btr0types.h

@@ -18,4 +18,9 @@ typedef struct btr_pcur_struct		btr_pcur_t;
 typedef struct btr_cur_struct		btr_cur_t;
 typedef struct btr_search_struct	btr_search_t;
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+#define BTR_EXTERN_FIELD_REF_SIZE	20
+extern const byte field_ref_zero[BTR_EXTERN_FIELD_REF_SIZE];
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 #endif

storage/innobase/include/rem0rec.h

@@ -339,6 +339,19 @@ rec_offs_any_extern(
 /*================*/
 				/* out: TRUE if a field is stored externally */
 	const ulint*	offsets);/* in: array returned by rec_get_offsets() */
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+/********************************************************
+Determine if the offsets are for a record containing null BLOB pointers. */
+UNIV_INLINE
+const byte*
+rec_offs_any_null_extern(
+/*=====================*/
+					/* out: first field containing
+					a null BLOB pointer,
+					or NULL if none found */
+	rec_t*		rec,		/*!< in: record */
+	const ulint*	offsets);	/*!< in: rec_get_offsets(rec) */
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 /***************************************************************
 Sets the value of the ith field extern storage bit. */
 UNIV_INLINE

storage/innobase/include/rem0rec.ic

@@ -9,6 +9,7 @@ Created 5/30/1994 Heikki Tuuri
 #include "mach0data.h"
 #include "ut0byte.h"
 #include "dict0dict.h"
+#include "btr0types.h"
 
 /* Compact flag ORed to the extra size returned by rec_get_offsets() */
 #define REC_OFFS_COMPACT	((ulint) 1 << 31)
@@ -1020,6 +1021,42 @@ rec_offs_any_extern(
 	return(FALSE);
 }
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+/********************************************************
+Determine if the offsets are for a record containing null BLOB pointers. */
+UNIV_INLINE
+const byte*
+rec_offs_any_null_extern(
+/*=====================*/
+					/* out: first field containing
+					a null BLOB pointer,
+					or NULL if none found */
+	rec_t*		rec,		/*!< in: record */
+	const ulint*	offsets)	/*!< in: rec_get_offsets(rec) */
+{
+	ulint	i;
+	ut_ad(rec_offs_validate(rec, NULL, offsets));
+
+	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
+		if (rec_offs_nth_extern(offsets, i)) {
+			ulint		len;
+			const byte*	field
+				= rec_get_nth_field(rec, offsets, i, &len);
+
+			ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
+			if (!memcmp(field + len
+				    - BTR_EXTERN_FIELD_REF_SIZE,
+				    field_ref_zero,
+				    BTR_EXTERN_FIELD_REF_SIZE)) {
+				return(field);
+			}
+		}
+	}
+
+	return(NULL);
+}
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 /***************************************************************
 Sets the value of the ith field extern storage bit. */
 UNIV_INLINE

storage/innobase/include/univ.i

@@ -88,6 +88,8 @@ memory is read outside the allocated blocks. */
 #if 0
 #define UNIV_DEBUG_VALGRIND			/* Enable extra
 						Valgrind instrumentation */
+#define UNIV_BLOB_LIGHT_DEBUG			/* Enable off-page column
+						debugging without UNIV_DEBUG */
 #define UNIV_DEBUG				/* Enable ut_ad() assertions */
 #define UNIV_LIST_DEBUG				/* debug UT_LIST_ macros */
 #define UNIV_MEM_DEBUG				/* detect memory leaks etc */

storage/innobase/row/row0row.c

@@ -210,6 +210,10 @@ row_build(
 		ut_ad(rec_offs_validate(rec, index, offsets));
 	}
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	ut_a(!rec_offs_any_null_extern(rec, offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 	if (type != ROW_COPY_POINTERS) {
 		/* Take a copy of rec to heap */
 		buf = mem_heap_alloc(heap, rec_offs_size(offsets));
@@ -302,6 +306,10 @@ row_rec_to_index_entry(
 		rec = rec_copy(buf, rec, offsets);
 		/* Avoid a debug assertion in rec_offs_validate(). */
 		rec_offs_make_valid(rec, index, offsets);
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	} else {
+		ut_a(!rec_offs_any_null_extern(rec, offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 	}
 
 	rec_len = rec_offs_n_fields(offsets);

storage/innobase/row/row0vers.c

@@ -473,6 +473,11 @@ row_vers_build_for_consistent_read(
 				/* The view already sees this version: we can
 				copy it to in_heap and return */
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+				ut_a(!rec_offs_any_null_extern(
+					     version, *offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 				buf = mem_heap_alloc(in_heap,
 						     rec_offs_size(*offsets));
 				*old_vers = rec_copy(buf, version, *offsets);
@@ -506,6 +511,10 @@ row_vers_build_for_consistent_read(
 		*offsets = rec_get_offsets(prev_version, index, *offsets,
 					   ULINT_UNDEFINED, offset_heap);
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+		ut_a(!rec_offs_any_null_extern(prev_version, *offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 		trx_id = row_get_rec_trx_id(prev_version, index, *offsets);
 
 		if (read_view_sees_trx_id(view, trx_id)) {
@@ -606,6 +615,10 @@ row_vers_build_for_semi_consistent_read(
 			/* We found a version that belongs to a
 			committed transaction: return it. */
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+			ut_a(!rec_offs_any_null_extern(version, *offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 			if (rec == version) {
 				*old_vers = rec;
 				err = DB_SUCCESS;
@@ -663,6 +676,9 @@ row_vers_build_for_semi_consistent_read(
 		version = prev_version;
 		*offsets = rec_get_offsets(version, index, *offsets,
 					   ULINT_UNDEFINED, offset_heap);
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+		ut_a(!rec_offs_any_null_extern(version, *offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 	}/* for (;;) */
 
 	if (heap) {

storage/innobase/trx/trx0rec.c

@@ -1397,6 +1397,10 @@ trx_undo_prev_version_build(
 		return(DB_ERROR);
 	}
 
+# if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	ut_a(!rec_offs_any_null_extern(rec, offsets));
+# endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 	if (row_upd_changes_field_size_or_external(index, offsets, update)) {
 		ulint*	ext_vect;
 		ulint	n_ext_vect;

storage/innodb_plugin/ChangeLog

@@ -1,3 +1,8 @@
+2011-06-09	The InnoDB Team
+	* btr/btr0cur.c, include/rem0rec.h, include/rem0rec.ic,
+	* row/row0row.c, row/row0vers.c, trx/trx0rec.c:
+	Instrumentation for Bug#12612184 Race condition in row_upd_clust_rec()
+
 2011-04-07	The InnoDB Team
 
 	* handler/ha_innodb.cc, handler/ha_innodb.h, handler/handler0alter.cc:

storage/innodb_plugin/btr/btr0cur.c

@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1994, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1994, 2011, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, Google Inc.
 
 Portions of this file contain modifications contributed and copyrighted by
@@ -1871,6 +1871,9 @@ btr_cur_optimistic_update(
 
 	heap = mem_heap_create(1024);
 	offsets = rec_get_offsets(rec, index, NULL, ULINT_UNDEFINED, &heap);
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	ut_a(!rec_offs_any_null_extern(rec, offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 
 #ifdef UNIV_DEBUG
 	if (btr_cur_print_record_ops && thr) {

storage/innodb_plugin/include/rem0rec.h

@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1994, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 1994, 2011, 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 the Free Software
@@ -480,6 +480,18 @@ ulint
 rec_offs_any_extern(
 /*================*/
 	const ulint*	offsets);/*!< in: array returned by rec_get_offsets() */
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+/******************************************************//**
+Determine if the offsets are for a record containing null BLOB pointers.
+@return	first field containing a null BLOB pointer, or NULL if none found */
+UNIV_INLINE
+const byte*
+rec_offs_any_null_extern(
+/*=====================*/
+	const rec_t*	rec,		/*!< in: record */
+	const ulint*	offsets)	/*!< in: rec_get_offsets(rec) */
+	__attribute__((nonnull, warn_unused_result));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 /******************************************************//**
 Returns nonzero if the extern bit is set in nth field of rec.
 @return	nonzero if externally stored */

storage/innodb_plugin/include/rem0rec.ic

@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1994, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 1994, 2011, 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 the Free Software
@@ -26,6 +26,7 @@ Created 5/30/1994 Heikki Tuuri
 #include "mach0data.h"
 #include "ut0byte.h"
 #include "dict0dict.h"
+#include "btr0types.h"
 
 /* Compact flag ORed to the extra size returned by rec_get_offsets() */
 #define REC_OFFS_COMPACT	((ulint) 1 << 31)
@@ -1087,6 +1088,44 @@ rec_offs_any_extern(
 	return(UNIV_UNLIKELY(*rec_offs_base(offsets) & REC_OFFS_EXTERNAL));
 }
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+/******************************************************//**
+Determine if the offsets are for a record containing null BLOB pointers.
+@return	first field containing a null BLOB pointer, or NULL if none found */
+UNIV_INLINE
+const byte*
+rec_offs_any_null_extern(
+/*=====================*/
+	const rec_t*	rec,		/*!< in: record */
+	const ulint*	offsets)	/*!< in: rec_get_offsets(rec) */
+{
+	ulint	i;
+	ut_ad(rec_offs_validate(rec, NULL, offsets));
+
+	if (!rec_offs_any_extern(offsets)) {
+		return(NULL);
+	}
+
+	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
+		if (rec_offs_nth_extern(offsets, i)) {
+			ulint		len;
+			const byte*	field
+				= rec_get_nth_field(rec, offsets, i, &len);
+
+			ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
+			if (!memcmp(field + len
+				    - BTR_EXTERN_FIELD_REF_SIZE,
+				    field_ref_zero,
+				    BTR_EXTERN_FIELD_REF_SIZE)) {
+				return(field);
+			}
+		}
+	}
+
+	return(NULL);
+}
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 /******************************************************//**
 Returns nonzero if the extern bit is set in nth field of rec.
 @return	nonzero if externally stored */

storage/innodb_plugin/row/row0row.c

@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1996, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1996, 2011, 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 the Free Software
@@ -231,6 +231,10 @@ row_build(
 		ut_ad(rec_offs_validate(rec, index, offsets));
 	}
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	ut_a(!rec_offs_any_null_extern(rec, offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 	if (type != ROW_COPY_POINTERS) {
 		/* Take a copy of rec to heap */
 		buf = mem_heap_alloc(heap, rec_offs_size(offsets));
@@ -415,6 +419,10 @@ row_rec_to_index_entry(
 		rec = rec_copy(buf, rec, offsets);
 		/* Avoid a debug assertion in rec_offs_validate(). */
 		rec_offs_make_valid(rec, index, offsets);
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	} else {
+		ut_a(!rec_offs_any_null_extern(rec, offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 	}
 
 	entry = row_rec_to_index_entry_low(rec, index, offsets, n_ext, heap);

storage/innodb_plugin/row/row0vers.c

@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1997, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 1997, 2011, 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 the Free Software
@@ -550,6 +550,11 @@ row_vers_build_for_consistent_read(
 				/* The view already sees this version: we can
 				copy it to in_heap and return */
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+				ut_a(!rec_offs_any_null_extern(
+					     version, *offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 				buf = mem_heap_alloc(in_heap,
 						     rec_offs_size(*offsets));
 				*old_vers = rec_copy(buf, version, *offsets);
@@ -583,6 +588,10 @@ row_vers_build_for_consistent_read(
 		*offsets = rec_get_offsets(prev_version, index, *offsets,
 					   ULINT_UNDEFINED, offset_heap);
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+		ut_a(!rec_offs_any_null_extern(prev_version, *offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 		trx_id = row_get_rec_trx_id(prev_version, index, *offsets);
 
 		if (read_view_sees_trx_id(view, trx_id)) {
@@ -682,6 +691,10 @@ row_vers_build_for_semi_consistent_read(
 			/* We found a version that belongs to a
 			committed transaction: return it. */
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+			ut_a(!rec_offs_any_null_extern(version, *offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 			if (rec == version) {
 				*old_vers = rec;
 				err = DB_SUCCESS;
@@ -739,6 +752,9 @@ row_vers_build_for_semi_consistent_read(
 		version = prev_version;
 		*offsets = rec_get_offsets(version, index, *offsets,
 					   ULINT_UNDEFINED, offset_heap);
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+		ut_a(!rec_offs_any_null_extern(version, *offsets));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 	}/* for (;;) */
 
 	if (heap) {

storage/innodb_plugin/trx/trx0rec.c

@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1996, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1996, 2011, 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 the Free Software
@@ -1577,6 +1577,10 @@ trx_undo_prev_version_build(
 		return(DB_ERROR);
 	}
 
+# if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	ut_a(!rec_offs_any_null_extern(rec, offsets));
+# endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+
 	if (row_upd_changes_field_size_or_external(index, offsets, update)) {
 		ulint	n_ext;