Bug #55284 diagnostics: Introduce UNIV_BLOB_LIGHT_DEBUG, enabled by UNIV_DEBUG

btr_rec_get_field_ref_offs(), btr_rec_get_field_ref(): New functions.
Get the pointer to an externally stored field.

btr_cur_set_ownership_of_extern_field(): Assert that the BLOB has not
already been disowned.

btr_store_big_rec_extern_fields(): Rename to
btr_store_big_rec_extern_fields_func() and add the debug parameter
update_in_place. All pointers to externally stored columns in the
record must either be zero or they must be pointers to inherited
columns, owned by this record or an earlier record version. For any
BLOB that is stored, the BLOB pointer must previously have been
zero. When the function completes, all BLOB pointers must be nonzero
and owned by the record.

rb://549 approved by Jimmy Yang

storage/innodb_plugin/btr/btr0cur.c

@@ -186,7 +186,7 @@ static
 ulint
 btr_rec_get_externally_stored_len(
 /*==============================*/
-	rec_t*		rec,	/*!< in: record */
+	const rec_t*	rec,	/*!< in: record */
 	const ulint*	offsets);/*!< in: array returned by rec_get_offsets() */
 #endif /* !UNIV_HOTBACKUP */
 
@@ -3483,6 +3483,35 @@ btr_estimate_number_of_different_key_vals(
 
 /*================== EXTERNAL STORAGE OF BIG FIELDS ===================*/
 
+/***********************************************************//**
+Gets the offset of the pointer to the externally stored part of a field.
+@return	offset of the pointer to the externally stored part */
+static
+ulint
+btr_rec_get_field_ref_offs(
+/*=======================*/
+	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
+	ulint		n)	/*!< in: index of the external field */
+{
+	ulint	field_ref_offs;
+	ulint	local_len;
+
+	ut_a(rec_offs_nth_extern(offsets, n));
+	field_ref_offs = rec_get_nth_field_offs(offsets, n, &local_len);
+	ut_a(local_len != UNIV_SQL_NULL);
+	ut_a(local_len >= BTR_EXTERN_FIELD_REF_SIZE);
+
+	return(field_ref_offs + local_len - BTR_EXTERN_FIELD_REF_SIZE);
+}
+
+/** Gets a pointer to the externally stored part of a field.
+@param rec	record
+@param offsets	rec_get_offsets(rec)
+@param n	index of the externally stored field
+@return pointer to the externally stored part */
+#define btr_rec_get_field_ref(rec, offsets, n)			\
+	((rec) + btr_rec_get_field_ref_offs(offsets, n))
+
 /***********************************************************//**
 Gets the externally stored size of a record, in units of a database page.
 @return	externally stored part, in units of a database page */
@@ -3490,28 +3519,27 @@ static
 ulint
 btr_rec_get_externally_stored_len(
 /*==============================*/
-	rec_t*		rec,	/*!< in: record */
+	const rec_t*	rec,	/*!< in: record */
 	const ulint*	offsets)/*!< in: array returned by rec_get_offsets() */
 {
 	ulint	n_fields;
-	byte*	data;
-	ulint	local_len;
-	ulint	extern_len;
 	ulint	total_extern_len = 0;
 	ulint	i;
 
 	ut_ad(!rec_offs_comp(offsets) || !rec_get_node_ptr_flag(rec));
+
+	if (!rec_offs_any_extern(offsets)) {
+		return(0);
+	}
+
 	n_fields = rec_offs_n_fields(offsets);
 
 	for (i = 0; i < n_fields; i++) {
 		if (rec_offs_nth_extern(offsets, i)) {
 
-			data = rec_get_nth_field(rec, offsets, i, &local_len);
-
-			local_len -= BTR_EXTERN_FIELD_REF_SIZE;
-
-			extern_len = mach_read_from_4(data + local_len
-						      + BTR_EXTERN_LEN + 4);
+			ulint	extern_len = mach_read_from_4(
+				btr_rec_get_field_ref(rec, offsets, i)
+				+ BTR_EXTERN_LEN + 4);
 
 			total_extern_len += ut_calc_align(extern_len,
 							  UNIV_PAGE_SIZE);
@@ -3541,7 +3569,7 @@ btr_cur_set_ownership_of_extern_field(
 	ulint	byte_val;
 
 	data = rec_get_nth_field(rec, offsets, i, &local_len);
-
+	ut_ad(rec_offs_nth_extern(offsets, i));
 	ut_a(local_len >= BTR_EXTERN_FIELD_REF_SIZE);
 
 	local_len -= BTR_EXTERN_FIELD_REF_SIZE;
@@ -3551,6 +3579,9 @@ btr_cur_set_ownership_of_extern_field(
 	if (val) {
 		byte_val = byte_val & (~BTR_EXTERN_OWNER_FLAG);
 	} else {
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+		ut_a(!(byte_val & BTR_EXTERN_OWNER_FLAG));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 		byte_val = byte_val | BTR_EXTERN_OWNER_FLAG;
 	}
 
@@ -3788,8 +3819,8 @@ file segment of the index tree.
 @return	DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
 UNIV_INTERN
 ulint
-btr_store_big_rec_extern_fields(
-/*============================*/
+btr_store_big_rec_extern_fields_func(
+/*=================================*/
 	dict_index_t*	index,		/*!< in: index of rec; the index tree
 					MUST be X-latched */
 	buf_block_t*	rec_block,	/*!< in/out: block containing rec */
@@ -3798,11 +3829,17 @@ btr_store_big_rec_extern_fields(
 					the "external storage" flags in offsets
 					will not correspond to rec when
 					this function returns */
-	big_rec_t*	big_rec_vec,	/*!< in: vector containing fields
+#ifdef UNIV_DEBUG
+	mtr_t*		local_mtr,	/*!< in: mtr containing the
+					latch to rec and to the tree */
+#endif /* UNIV_DEBUG */
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	ibool		update_in_place,/*! in: TRUE if the record is updated
+					in place (not delete+insert) */
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+	const big_rec_t*big_rec_vec)	/*!< in: vector containing fields
 					to be stored externally */
-	mtr_t*		local_mtr __attribute__((unused))) /*!< in: mtr
-					containing the latch to rec and to the
-					tree */
+
 {
 	ulint	rec_page_no;
 	byte*	field_ref;
@@ -3820,6 +3857,7 @@ btr_store_big_rec_extern_fields(
 	z_stream c_stream;
 
 	ut_ad(rec_offs_validate(rec, index, offsets));
+	ut_ad(rec_offs_any_extern(offsets));
 	ut_ad(mtr_memo_contains(local_mtr, dict_index_get_lock(index),
 				MTR_MEMO_X_LOCK));
 	ut_ad(mtr_memo_contains(local_mtr, rec_block, MTR_MEMO_PAGE_X_FIX));
@@ -3851,21 +3889,37 @@ btr_store_big_rec_extern_fields(
 		ut_a(err == Z_OK);
 	}
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	/* All pointers to externally stored columns in the record
+	must either be zero or they must be pointers to inherited
+	columns, owned by this record or an earlier record version. */
+	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
+		if (!rec_offs_nth_extern(offsets, i)) {
+			continue;
+		}
+		field_ref = btr_rec_get_field_ref(rec, offsets, i);
+
+		ut_a(!(field_ref[BTR_EXTERN_LEN] & BTR_EXTERN_OWNER_FLAG));
+		/* Either this must be an update in place,
+		or the BLOB must be inherited, or the BLOB pointer
+		must be zero (will be written in this function). */
+		ut_a(update_in_place
+		     || (field_ref[BTR_EXTERN_LEN] & BTR_EXTERN_INHERITED_FLAG)
+		     || !memcmp(field_ref, field_ref_zero,
+				BTR_EXTERN_FIELD_REF_SIZE));
+	}
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 	/* We have to create a file segment to the tablespace
 	for each field and put the pointer to the field in rec */
 
 	for (i = 0; i < big_rec_vec->n_fields; i++) {
-		ut_ad(rec_offs_nth_extern(offsets,
-					  big_rec_vec->fields[i].field_no));
-		{
-			ulint	local_len;
-			field_ref = rec_get_nth_field(
-				rec, offsets, big_rec_vec->fields[i].field_no,
-				&local_len);
-			ut_a(local_len >= BTR_EXTERN_FIELD_REF_SIZE);
-			local_len -= BTR_EXTERN_FIELD_REF_SIZE;
-			field_ref += local_len;
-		}
+		field_ref = btr_rec_get_field_ref(
+			rec, offsets, big_rec_vec->fields[i].field_no);
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+		/* A zero BLOB pointer should have been initially inserted. */
+		ut_a(!memcmp(field_ref, field_ref_zero,
+			     BTR_EXTERN_FIELD_REF_SIZE));
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 		extern_len = big_rec_vec->fields[i].len;
 		UNIV_MEM_ASSERT_RW(big_rec_vec->fields[i].data,
 				   extern_len);
@@ -4147,6 +4201,23 @@ btr_store_big_rec_extern_fields(
 		mem_heap_free(heap);
 	}
 
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	/* All pointers to externally stored columns in the record
+	must be valid. */
+	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
+		if (!rec_offs_nth_extern(offsets, i)) {
+			continue;
+		}
+
+		field_ref = btr_rec_get_field_ref(rec, offsets, i);
+
+		/* The pointer must not be zero. */
+		ut_a(0 != memcmp(field_ref, field_ref_zero,
+				 BTR_EXTERN_FIELD_REF_SIZE));
+		/* The column must not be disowned by this record. */
+		ut_a(!(field_ref[BTR_EXTERN_LEN] & BTR_EXTERN_OWNER_FLAG));
+	}
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 	return(DB_SUCCESS);
 }
 
@@ -4228,23 +4299,13 @@ btr_free_externally_stored_field(
 	ulint		page_no;
 	ulint		next_page_no;
 	mtr_t		mtr;
-#ifdef UNIV_DEBUG
+
 	ut_ad(mtr_memo_contains(local_mtr, dict_index_get_lock(index),
 				MTR_MEMO_X_LOCK));
 	ut_ad(mtr_memo_contains_page(local_mtr, field_ref,
 				     MTR_MEMO_PAGE_X_FIX));
 	ut_ad(!rec || rec_offs_validate(rec, index, offsets));
-
-	if (rec) {
-		ulint	local_len;
-		const byte*	f = rec_get_nth_field(rec, offsets,
-						      i, &local_len);
-		ut_a(local_len >= BTR_EXTERN_FIELD_REF_SIZE);
-		local_len -= BTR_EXTERN_FIELD_REF_SIZE;
-		f += local_len;
-		ut_ad(f == field_ref);
-	}
-#endif /* UNIV_DEBUG */
+	ut_ad(!rec || field_ref == btr_rec_get_field_ref(rec, offsets, i));
 
 	if (UNIV_UNLIKELY(!memcmp(field_ref, field_ref_zero,
 				  BTR_EXTERN_FIELD_REF_SIZE))) {
@@ -4409,13 +4470,8 @@ btr_rec_free_externally_stored_fields(
 
 	for (i = 0; i < n_fields; i++) {
 		if (rec_offs_nth_extern(offsets, i)) {
-			ulint	len;
-			byte*	data
-				= rec_get_nth_field(rec, offsets, i, &len);
-			ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
-
 			btr_free_externally_stored_field(
-				index, data + len - BTR_EXTERN_FIELD_REF_SIZE,
+				index, btr_rec_get_field_ref(rec, offsets, i),
 				rec, offsets, page_zip, i, rb_ctx, mtr);
 		}
 	}

storage/innodb_plugin/include/btr0cur.h

@@ -512,8 +512,8 @@ file segment of the index tree.
 @return	DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
 UNIV_INTERN
 ulint
-btr_store_big_rec_extern_fields(
-/*============================*/
+btr_store_big_rec_extern_fields_func(
+/*=================================*/
 	dict_index_t*	index,		/*!< in: index of rec; the index tree
 					MUST be X-latched */
 	buf_block_t*	rec_block,	/*!< in/out: block containing rec */
@@ -522,10 +522,42 @@ btr_store_big_rec_extern_fields(
 					the "external storage" flags in offsets
 					will not correspond to rec when
 					this function returns */
-	big_rec_t*	big_rec_vec,	/*!< in: vector containing fields
+#ifdef UNIV_DEBUG
+	mtr_t*		local_mtr,	/*!< in: mtr containing the
+					latch to rec and to the tree */
+#endif /* UNIV_DEBUG */
+#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
+	ibool		update_in_place,/*! in: TRUE if the record is updated
+					in place (not delete+insert) */
+#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
+	const big_rec_t*big_rec_vec)	/*!< in: vector containing fields
 					to be stored externally */
-	mtr_t*		local_mtr);	/*!< in: mtr containing the latch to
-					rec and to the tree */
+	__attribute__((nonnull));
+
+/** Stores the fields in big_rec_vec to the tablespace and puts pointers to
+them in rec.  The extern flags in rec will have to be set beforehand.
+The fields are stored on pages allocated from leaf node
+file segment of the index tree.
+@param index	in: clustered index; MUST be X-latched by mtr
+@param b	in/out: block containing rec; MUST be X-latched by mtr
+@param rec	in/out: clustered index record
+@param offsets	in: rec_get_offsets(rec, index);
+		the "external storage" flags in offsets will not be adjusted
+@param mtr	in: mini-transaction that holds x-latch on index and b
+@param upd	in: TRUE if the record is updated in place (not delete+insert)
+@param big	in: vector containing fields to be stored externally
+@return	DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
+#ifdef UNIV_DEBUG
+# define btr_store_big_rec_extern_fields(index,b,rec,offsets,mtr,upd,big) \
+	btr_store_big_rec_extern_fields_func(index,b,rec,offsets,mtr,upd,big)
+#elif defined UNIV_BLOB_LIGHT_DEBUG
+# define btr_store_big_rec_extern_fields(index,b,rec,offsets,mtr,upd,big) \
+	btr_store_big_rec_extern_fields_func(index,b,rec,offsets,upd,big)
+#else
+# define btr_store_big_rec_extern_fields(index,b,rec,offsets,mtr,upd,big) \
+	btr_store_big_rec_extern_fields_func(index,b,rec,offsets,big)
+#endif
+
 /*******************************************************************//**
 Frees the space in an externally stored field to the file space
 management if the field in data is owned the externally stored field,

storage/innodb_plugin/include/univ.i

@@ -177,6 +177,8 @@ command. Not tested on Windows. */
 						debugging without UNIV_DEBUG */
 #define UNIV_BUF_DEBUG				/* Enable buffer pool
 						debugging without UNIV_DEBUG */
+#define UNIV_BLOB_LIGHT_DEBUG			/* Enable off-page column
+						debugging without UNIV_DEBUG */
 #define UNIV_DEBUG				/* Enable ut_ad() assertions
 						and disable UNIV_INLINE */
 #define UNIV_DEBUG_LOCK_VALIDATE		/* Enable

storage/innodb_plugin/row/row0ins.c

@@ -2130,7 +2130,7 @@ row_ins_index_entry_low(
 
 		err = btr_store_big_rec_extern_fields(
 			index, btr_cur_get_block(&cursor),
-			rec, offsets, big_rec, &mtr);
+			rec, offsets, &mtr, FALSE, big_rec);
 
 		if (modify) {
 			dtuple_big_rec_free(big_rec);

storage/innodb_plugin/row/row0upd.c

@@ -1952,7 +1952,7 @@ row_upd_clust_rec(
 			index, btr_cur_get_block(btr_cur), rec,
 			rec_get_offsets(rec, index, offsets_,
 					ULINT_UNDEFINED, &heap),
-			big_rec, mtr);
+			mtr, TRUE, big_rec);
 		mtr_commit(mtr);
 	}