Revert "MDEV-6928: Add trx pointer to struct mtr_t"

This reverts commit 3486135.

The commit comment ended in the words: "This is needed later."
Apparently the "later" never arrived.

storage/innobase/api/api0api.cc

@@ -398,7 +398,7 @@ ib_read_tuple(
 
 			data = btr_rec_copy_externally_stored_field(
 				copy, offsets, zip_size, i, &len,
-				tuple->heap, NULL);
+				tuple->heap);
 
 			ut_a(len != UNIV_SQL_NULL);
 		}

storage/innobase/btr/btr0cur.cc

@@ -3681,8 +3681,7 @@ btr_estimate_n_rows_in_range(
 	const dtuple_t*	tuple1,	/*!< in: range start, may also be empty tuple */
 	ulint		mode1,	/*!< in: search mode for range start */
 	const dtuple_t*	tuple2,	/*!< in: range end, may also be empty tuple */
-	ulint		mode2,	/*!< in: search mode for range end */
-	trx_t*		trx)	/*!< in: trx */
+	ulint		mode2)	/*!< in: search mode for range end */
 {
 	btr_path_t	path1[BTR_PATH_ARRAY_N_SLOTS];
 	btr_path_t	path2[BTR_PATH_ARRAY_N_SLOTS];
@@ -3700,7 +3699,7 @@ btr_estimate_n_rows_in_range(
 
 	table_n_rows = dict_table_get_n_rows(index->table);
 
-	mtr_start_trx(&mtr, trx);
+	mtr_start(&mtr);
 
 	cursor.path_arr = path1;
 
@@ -3718,7 +3717,7 @@ btr_estimate_n_rows_in_range(
 
 	mtr_commit(&mtr);
 
-	mtr_start_trx(&mtr, trx);
+	mtr_start(&mtr);
 
 	cursor.path_arr = path2;
 
@@ -5329,8 +5328,7 @@ btr_copy_blob_prefix(
 	ulint		len,	/*!< in: length of buf, in bytes */
 	ulint		space_id,/*!< in: space id of the BLOB pages */
 	ulint		page_no,/*!< in: page number of the first BLOB page */
-	ulint		offset,	/*!< in: offset on the first BLOB page */
-	trx_t*		trx)	/*!< in: transaction handle */
+	ulint		offset)	/*!< in: offset on the first BLOB page */
 {
 	ulint	copied_len	= 0;
 
@@ -5342,7 +5340,7 @@ btr_copy_blob_prefix(
 		ulint		part_len;
 		ulint		copy_len;
 
-		mtr_start_trx(&mtr, trx);
+		mtr_start(&mtr);
 
 		block = buf_page_get(space_id, 0, page_no, RW_S_LATCH, &mtr);
 		buf_block_dbg_add_level(block, SYNC_EXTERN_STORAGE);
@@ -5545,8 +5543,7 @@ btr_copy_externally_stored_field_prefix_low(
 				zero for uncompressed BLOBs */
 	ulint		space_id,/*!< in: space id of the first BLOB page */
 	ulint		page_no,/*!< in: page number of the first BLOB page */
-	ulint		offset,	/*!< in: offset on the first BLOB page */
-	trx_t*		trx)	/*!< in: transaction handle */
+	ulint		offset)	/*!< in: offset on the first BLOB page */
 {
 	if (UNIV_UNLIKELY(len == 0)) {
 		return(0);
@@ -5557,7 +5554,7 @@ btr_copy_externally_stored_field_prefix_low(
 					     space_id, page_no, offset));
 	} else {
 		return(btr_copy_blob_prefix(buf, len, space_id,
-					    page_no, offset, trx));
+					    page_no, offset));
 	}
 }
 
@@ -5578,8 +5575,7 @@ btr_copy_externally_stored_field_prefix(
 				field containing also the reference to
 				the external part; must be protected by
 				a lock or a page latch */
-	ulint		local_len,/*!< in: length of data, in bytes */
-	trx_t*		trx)	/*!< in: transaction handle */
+	ulint		local_len)/*!< in: length of data, in bytes */
 {
 	ulint	space_id;
 	ulint	page_no;
@@ -5618,7 +5614,7 @@ btr_copy_externally_stored_field_prefix(
 							     len - local_len,
 							     zip_size,
 							     space_id, page_no,
-							     offset, trx));
+							     offset));
 }
 
 /*******************************************************************//**
@@ -5637,8 +5633,7 @@ btr_copy_externally_stored_field(
 	ulint		zip_size,/*!< in: nonzero=compressed BLOB page size,
 				zero for uncompressed BLOBs */
 	ulint		local_len,/*!< in: length of data */
-	mem_heap_t*	heap,	/*!< in: mem heap */
-	trx_t*		trx)	/*!< in: transaction handle */
+	mem_heap_t*	heap)	/*!< in: mem heap */
 {
 	ulint	space_id;
 	ulint	page_no;
@@ -5669,8 +5664,7 @@ btr_copy_externally_stored_field(
 							      extern_len,
 							      zip_size,
 							      space_id,
-							      page_no, offset,
-							      trx);
+							      page_no, offset);
 
 	return(buf);
 }
@@ -5689,8 +5683,7 @@ btr_rec_copy_externally_stored_field(
 				zero for uncompressed BLOBs */
 	ulint		no,	/*!< in: field number */
 	ulint*		len,	/*!< out: length of the field */
-	mem_heap_t*	heap,	/*!< in: mem heap */
-	trx_t*		trx)	/*!< in: transaction handle */
+	mem_heap_t*	heap)	/*!< in: mem heap */
 {
 	ulint		local_len;
 	const byte*	data;
@@ -5721,7 +5714,6 @@ btr_rec_copy_externally_stored_field(
 	}
 
 	return(btr_copy_externally_stored_field(len, data,
-						zip_size, local_len, heap,
-						trx));
+						zip_size, local_len, heap));
 }
 #endif /* !UNIV_HOTBACKUP */

storage/innobase/btr/btr0pcur.cc

@@ -486,7 +486,7 @@ btr_pcur_move_backward_from_page(
 
 	mtr_commit(mtr);
 
-	mtr_start_trx(mtr, mtr->trx);
+	mtr_start(mtr);
 
 	btr_pcur_restore_position(latch_mode2, cursor, mtr);
 

storage/innobase/fts/fts0fts.cc

@@ -3361,8 +3361,7 @@ fts_fetch_doc_from_rec(
 					dict_table_zip_size(table),
 					clust_pos, &doc->text.f_len,
 					static_cast<mem_heap_t*>(
-						doc->self_heap->arg),
-					NULL);
+						doc->self_heap->arg));
 		} else {
 			doc->text.f_str = (byte*) rec_get_nth_field(
 				clust_rec, offsets, clust_pos,
@@ -7599,8 +7598,7 @@ fts_init_recover_doc(
 				&doc.text.f_len,
 				static_cast<byte*>(dfield_get_data(dfield)),
 				zip_size, len,
-				static_cast<mem_heap_t*>(doc.self_heap->arg),
-				NULL);
+				static_cast<mem_heap_t*>(doc.self_heap->arg));
 		} else {
 			doc.text.f_str = static_cast<byte*>(
 				dfield_get_data(dfield));

storage/innobase/fts/fts0que.cc

@@ -1917,8 +1917,7 @@ fts_query_fetch_document(
 		if (dfield_is_ext(dfield)) {
 			data = btr_copy_externally_stored_field(
 				&cur_len, data, phrase->zip_size,
-				dfield_get_len(dfield), phrase->heap,
-				NULL);
+				dfield_get_len(dfield), phrase->heap);
 		} else {
 			cur_len = dfield_get_len(dfield);
 		}

storage/innobase/handler/ha_innodb.cc

@@ -11163,7 +11163,7 @@ ha_innobase::records_in_range(
 
 		n_rows = btr_estimate_n_rows_in_range(index, range_start,
 						      mode1, range_end,
-						      mode2, prebuilt->trx);
+						      mode2);
 	} else {
 
 		n_rows = HA_POS_ERROR;

storage/innobase/include/btr0cur.h

@@ -566,8 +566,7 @@ btr_estimate_n_rows_in_range(
 	const dtuple_t*	tuple1,	/*!< in: range start, may also be empty tuple */
 	ulint		mode1,	/*!< in: search mode for range start */
 	const dtuple_t*	tuple2,	/*!< in: range end, may also be empty tuple */
-	ulint		mode2,	/*!< in: search mode for range end */
-	trx_t*		trx);	/*!< in: trx */
+	ulint		mode2);	/*!< in: search mode for range end */
 /*******************************************************************//**
 Estimates the number of different key values in a given index, for
 each n-column prefix of the index where 1 <= n <= dict_index_get_n_unique(index).
@@ -703,8 +702,7 @@ btr_copy_externally_stored_field_prefix(
 				field containing also the reference to
 				the external part; must be protected by
 				a lock or a page latch */
-	ulint		local_len,/*!< in: length of data, in bytes */
-	trx_t*		trx);	/*!< in: transaction handle */
+	ulint		local_len);/*!< in: length of data, in bytes */
 /*******************************************************************//**
 Copies an externally stored field of a record to mem heap.  The
 clustered index record must be protected by a lock or a page latch.
@@ -721,8 +719,7 @@ btr_copy_externally_stored_field(
 	ulint		zip_size,/*!< in: nonzero=compressed BLOB page size,
 				zero for uncompressed BLOBs */
 	ulint		local_len,/*!< in: length of data */
-	mem_heap_t*	heap,	/*!< in: mem heap */
-	trx_t*		trx);	/*!< in: transaction handle */
+	mem_heap_t*	heap);	/*!< in: mem heap */
 /*******************************************************************//**
 Copies an externally stored field of a record to mem heap.
 @return	the field copied to heap, or NULL if the field is incomplete */
@@ -737,8 +734,7 @@ btr_rec_copy_externally_stored_field(
 				zero for uncompressed BLOBs */
 	ulint		no,	/*!< in: field number */
 	ulint*		len,	/*!< out: length of the field */
-	mem_heap_t*	heap,	/*!< in: mem heap */
-	trx_t*		trx);	/*!< in: transaction handle */
+	mem_heap_t*	heap);	/*!< in: mem heap */
 /*******************************************************************//**
 Flags the data tuple fields that are marked as extern storage in the
 update vector.  We use this function to remember which fields we must

storage/innobase/include/mtr0mtr.h

@@ -36,7 +36,6 @@ Created 11/26/1995 Heikki Tuuri
 #include "ut0byte.h"
 #include "mtr0types.h"
 #include "page0types.h"
-#include "trx0types.h"
 
 /* Logging modes for a mini-transaction */
 #define MTR_LOG_ALL		21	/* default mode: log all operations
@@ -202,26 +201,14 @@ functions).  The page number parameter was originally written as 0. @{ */
 /* included here because it needs MLOG_LSN defined */
 #include "log0log.h"
 
-/***************************************************************//**
-Starts a mini-transaction. */
-UNIV_INLINE
-void
-mtr_start_trx(
-/*======*/
-	mtr_t*	mtr,	/*!< out: mini-transaction */
-	trx_t*	trx)	/*!< in: transaction */
-	MY_ATTRIBUTE((nonnull (1)));
 /***************************************************************//**
 Starts a mini-transaction. */
 UNIV_INLINE
 void
 mtr_start(
 /*======*/
 	mtr_t*	mtr)	/*!< out: mini-transaction */
-{
-	mtr_start_trx(mtr, NULL);
-}
-	MY_ATTRIBUTE((nonnull))
+	MY_ATTRIBUTE((nonnull));
 /***************************************************************//**
 Commits a mini-transaction. */
 UNIV_INTERN
@@ -417,7 +404,6 @@ struct mtr_t{
 #ifdef UNIV_DEBUG
 	ulint		magic_n;
 #endif /* UNIV_DEBUG */
-	trx_t*		trx;	/*!< transaction */
 };
 
 #ifdef UNIV_DEBUG

storage/innobase/include/mtr0mtr.ic

@@ -43,10 +43,9 @@ mtr_block_dirtied(
 Starts a mini-transaction. */
 UNIV_INLINE
 void
-mtr_start_trx(
+mtr_start(
 /*======*/
-	mtr_t*	mtr,	/*!< out: mini-transaction */
-	trx_t*	trx)	/*!< in: transaction */
+	mtr_t*	mtr)	/*!< out: mini-transaction */
 {
 	UNIV_MEM_INVALID(mtr, sizeof *mtr);
 
@@ -59,7 +58,6 @@ mtr_start_trx(
 	mtr->made_dirty = FALSE;
 	mtr->n_log_recs = 0;
 	mtr->n_freed_pages = 0;
-	mtr->trx = trx;
 
 	ut_d(mtr->state = MTR_ACTIVE);
 	ut_d(mtr->magic_n = MTR_MAGIC_N);

storage/innobase/include/trx0undo.h

@@ -246,13 +246,22 @@ Truncates an undo log from the end. This function is used during a rollback
 to free space from an undo log. */
 UNIV_INTERN
 void
-trx_undo_truncate_end(
+trx_undo_truncate_end_func(
 /*=======================*/
-	trx_t*		trx,	/*!< in: transaction whose undo log it is */
+#ifdef UNIV_DEBUG
+	const trx_t*	trx,	/*!< in: transaction whose undo log it is */
+#endif /* UNIV_DEBUG */
 	trx_undo_t*	undo,	/*!< in/out: undo log */
 	undo_no_t	limit)	/*!< in: all undo records with undo number
 				>= this value should be truncated */
 	MY_ATTRIBUTE((nonnull));
+#ifdef UNIV_DEBUG
+# define trx_undo_truncate_end(trx,undo,limit)		\
+	trx_undo_truncate_end_func(trx,undo,limit)
+#else /* UNIV_DEBUG */
+# define trx_undo_truncate_end(trx,undo,limit)		\
+	trx_undo_truncate_end_func(undo,limit)
+#endif /* UNIV_DEBUG */
 
 /***********************************************************************//**
 Truncates an undo log from the start. This function is used during a purge

storage/innobase/row/row0ext.cc

@@ -78,8 +78,7 @@ row_ext_cache_fill(
 			crashed during the execution of
 			btr_free_externally_stored_field(). */
 			ext->len[i] = btr_copy_externally_stored_field_prefix(
-				buf, ext->max_len, zip_size, field, f_len,
-				NULL);
+				buf, ext->max_len, zip_size, field, f_len);
 		}
 	}
 }

storage/innobase/row/row0ftsort.cc

@@ -675,8 +675,7 @@ fts_parallel_tokenization(
 				doc.text.f_str =
 					btr_copy_externally_stored_field(
 						&doc.text.f_len, data,
-						zip_size, data_len, blob_heap,
-						NULL);
+						zip_size, data_len, blob_heap);
 			} else {
 				doc.text.f_str = data;
 				doc.text.f_len = data_len;