MDEV-13542 fixup: Improve page reorganize

btr_page_reorganize_low(): Restore mtr->set_log_mode() before returning.

innobase_instant_try(): Do not invoke rec_get_offsets() if
btr_cur_pessimistic_update() failed. The cursor position may be
invalid.

storage/innobase/btr/btr0btr.cc

@@ -1246,8 +1246,6 @@ btr_write_autoinc(dict_index_t* index, ib_uint64_t autoinc, bool reset)
 static dberr_t btr_page_reorganize_low(page_cur_t *cursor, dict_index_t *index,
                                        mtr_t *mtr)
 {
-  const mtr_log_t log_mode= mtr->set_log_mode(MTR_LOG_NO_REDO);
-
   buf_block_t *const block= cursor->block;
 
   ut_ad(mtr->memo_contains_flagged(block, MTR_MEMO_PAGE_X_FIX));
@@ -1271,6 +1269,8 @@ static dberr_t btr_page_reorganize_low(page_cur_t *cursor, dict_index_t *index,
   memcpy_aligned<UNIV_PAGE_SIZE_MIN>(old->page.frame, block->page.frame,
                                      srv_page_size);
 
+  const mtr_log_t log_mode= mtr->set_log_mode(MTR_LOG_NO_REDO);
+
   page_create(block, mtr, index->table->not_redundant());
   if (index->is_spatial())
     block->page.frame[FIL_PAGE_TYPE + 1]= byte(FIL_PAGE_RTREE);
@@ -1281,10 +1281,13 @@ static dberr_t btr_page_reorganize_low(page_cur_t *cursor, dict_index_t *index,
   /* Copy the records from the temporary space to the recreated page;
   do not copy the lock bits yet */
 
-  if (dberr_t err=
-      page_copy_rec_list_end_no_locks(block, old,
-                                      page_get_infimum_rec(old->page.frame),
-                                      index, mtr))
+  dberr_t err=
+    page_copy_rec_list_end_no_locks(block, old,
+                                    page_get_infimum_rec(old->page.frame),
+                                    index, mtr);
+  mtr->set_log_mode(log_mode);
+
+  if (UNIV_UNLIKELY(err != DB_SUCCESS))
     return err;
 
   /* Copy the PAGE_MAX_TRX_ID or PAGE_ROOT_AUTO_INC. */
@@ -1329,8 +1332,6 @@ static dberr_t btr_page_reorganize_low(page_cur_t *cursor, dict_index_t *index,
   else if (!(cursor->rec= page_rec_get_nth(block->page.frame, pos)))
     return DB_CORRUPTION;
 
-  mtr->set_log_mode(log_mode);
-
   if (block->page.id().page_no() != index->page ||
       fil_page_get_type(old->page.frame) != FIL_PAGE_TYPE_INSTANT)
     ut_ad(!memcmp(old->page.frame, block->page.frame, PAGE_HEADER));

storage/innobase/handler/handler0alter.cc

@@ -6119,10 +6119,13 @@ static bool innobase_instant_try(
 			&offsets, &offsets_heap, ctx->heap,
 			&big_rec, update, UPD_NODE_NO_ORD_CHANGE,
 			thr, trx->id, &mtr);
+		if (err == DB_SUCCESS) {
+			offsets = rec_get_offsets(
+				btr_pcur_get_rec(&pcur), index, offsets,
+				index->n_core_fields, ULINT_UNDEFINED,
+				&offsets_heap);
+		}
 
-		offsets = rec_get_offsets(
-			btr_pcur_get_rec(&pcur), index, offsets,
-			index->n_core_fields, ULINT_UNDEFINED, &offsets_heap);
 		if (big_rec) {
 			if (err == DB_SUCCESS) {
 				err = btr_store_big_rec_extern_fields(