MDEV-21024: Clean up IMPORT TABLESPACE

page_rec_write_field(): Remove.

dict_create_index_tree_step(): If the SYS_INDEXES.PAGE does not change,
do not update it in the data dictionary. Typically, all index page numbers
would be unchanged before and after IMPORT TABLESPACE, except if some
secondary indexes were created after loading some data.

btr_root_fseg_adjust_on_import(): Remove the redundant mtr_t* parameter.
Redo logging is disabled during the page adjustments that IMPORT TABLESPACE
is performing.

storage/innobase/btr/btr0btr.cc

@@ -321,26 +321,24 @@ btr_root_fseg_adjust_on_import(
 	fseg_header_t*	seg_header,	/*!< in/out: segment header */
 	page_zip_des_t*	page_zip,	/*!< in/out: compressed page,
 					or NULL */
-	ulint		space,		/*!< in: tablespace identifier */
-	mtr_t*		mtr)		/*!< in/out: mini-transaction */
+	ulint		space)		/*!< in: tablespace identifier */
 {
 	ulint	offset = mach_read_from_2(seg_header + FSEG_HDR_OFFSET);
 
 	if (offset < FIL_PAGE_DATA
-	    || offset > UNIV_PAGE_SIZE - FIL_PAGE_DATA_END) {
+	    || offset > srv_page_size - FIL_PAGE_DATA_END) {
+		return false;
+	}
 
-		return(FALSE);
+	seg_header += FSEG_HDR_SPACE;
 
-	} else if (page_zip) {
-		mach_write_to_4(seg_header + FSEG_HDR_SPACE, space);
-		page_zip_write_header(page_zip, seg_header + FSEG_HDR_SPACE,
-				      4, mtr);
-	} else {
-		mlog_write_ulint(seg_header + FSEG_HDR_SPACE,
-				 space, MLOG_4BYTES, mtr);
+	mach_write_to_4(seg_header, space);
+	if (UNIV_LIKELY_NULL(page_zip)) {
+		memcpy(page_zip->data + page_offset(seg_header), seg_header,
+		       4);
 	}
 
-	return(TRUE);
+	return true;
 }
 
 /**************************************************************//**
@@ -400,10 +398,10 @@ btr_root_adjust_on_import(
 	if (err == DB_SUCCESS
 	    && (!btr_root_fseg_adjust_on_import(
 			FIL_PAGE_DATA + PAGE_BTR_SEG_LEAF
-			+ page, page_zip, space_id, &mtr)
+			+ page, page_zip, space_id)
 		|| !btr_root_fseg_adjust_on_import(
 			FIL_PAGE_DATA + PAGE_BTR_SEG_TOP
-			+ page, page_zip, space_id, &mtr))) {
+			+ page, page_zip, space_id))) {
 
 		err = DB_CORRUPTION;
 	}

storage/innobase/dict/dict0crea.cc

@@ -894,11 +894,14 @@ dict_create_index_tree_step(
 				err = DB_OUT_OF_FILE_SPACE; );
 	}
 
-	page_rec_write_field(
-		btr_pcur_get_rec(&pcur), DICT_FLD__SYS_INDEXES__PAGE_NO,
-		node->page_no, &mtr);
-
-	btr_pcur_close(&pcur);
+	ulint   len;
+	byte*   data = rec_get_nth_field_old(btr_pcur_get_rec(&pcur),
+					     DICT_FLD__SYS_INDEXES__PAGE_NO,
+					     &len);
+	ut_ad(len == 4);
+	if (mach_read_from_4(data) != node->page_no) {
+		mlog_write_ulint(data, node->page_no, MLOG_4BYTES, &mtr);
+	}
 
 	mtr_commit(&mtr);
 

storage/innobase/include/page0page.h

@@ -832,17 +832,6 @@ page_rec_find_owner_rec(
 /*====================*/
 	rec_t*	rec);	/*!< in: the physical record */
 
-/***********************************************************************//**
-Write a 32-bit field in a data dictionary record. */
-UNIV_INLINE
-void
-page_rec_write_field(
-/*=================*/
-	rec_t*	rec,	/*!< in/out: record to update */
-	ulint	i,	/*!< in: index of the field to update */
-	ulint	val,	/*!< in: value to write */
-	mtr_t*	mtr)	/*!< in/out: mini-transaction */
-	MY_ATTRIBUTE((nonnull));
 /************************************************************//**
 Returns the maximum combined size of records which can be inserted on top
 of record heap.

storage/innobase/include/page0page.ic

@@ -919,27 +919,6 @@ page_get_free_space_of_empty(
 		       - 2 * PAGE_DIR_SLOT_SIZE));
 }
 
-/***********************************************************************//**
-Write a 32-bit field in a data dictionary record. */
-UNIV_INLINE
-void
-page_rec_write_field(
-/*=================*/
-	rec_t*	rec,	/*!< in/out: record to update */
-	ulint	i,	/*!< in: index of the field to update */
-	ulint	val,	/*!< in: value to write */
-	mtr_t*	mtr)	/*!< in/out: mini-transaction */
-{
-	byte*	data;
-	ulint	len;
-
-	data = rec_get_nth_field_old(rec, i, &len);
-
-	ut_ad(len == 4);
-
-	mlog_write_ulint(data, val, MLOG_4BYTES, mtr);
-}
-
 /************************************************************//**
 Each user record on a page, and also the deleted user records in the heap
 takes its size plus the fraction of the dir cell size /

storage/innobase/row/row0trunc.cc

@@ -1034,12 +1034,12 @@ CreateIndex::operator()(mtr_t* mtr, btr_pcur_t* pcur) const
 			root_page_no = FIL_NULL;);
 
 	if (root_page_no != FIL_NULL) {
-
-		rec_t*	rec = btr_pcur_get_rec(pcur);
-
-		page_rec_write_field(
-			rec, DICT_FLD__SYS_INDEXES__PAGE_NO,
-			root_page_no, mtr);
+		ulint   len;
+		byte*   data = rec_get_nth_field_old(
+			btr_pcur_get_rec(pcur),
+			DICT_FLD__SYS_INDEXES__PAGE_NO, &len);
+		ut_ad(len == 4);
+		mlog_write_ulint(data, root_page_no, MLOG_4BYTES, mtr);
 
 		/* We will need to commit and restart the
 		mini-transaction in order to avoid deadlocks.