MDEV-17794 Do not assign persistent ID for temporary tables

InnoDB in MySQL 5.7 introduced two new parameters to the function
dict_hdr_get_new_id(), to allow redo logging to be disabled when
assigning identifiers to temporary tables or during the
backup-unfriendly TRUNCATE TABLE that was replaced in MariaDB
by MDEV-13564.

Now that MariaDB 10.4.0 removed the crash recovery code for the
backup-unfriendly TRUNCATE, we can revert dict_hdr_get_new_id()
to be used only for persistent data structures.

dict_table_assign_new_id(): Remove. This was a simple 2-line function
that was called from few places.

dict_table_open_on_id_low(): Declare in the only file where it
is called.

dict_sys_t::temp_id_hash: A separate lookup table for temporary tables.
Table names will be in the common dict_sys_t::table_hash.

dict_sys_t::get_temporary_table_id(): Assign a temporary table ID.

dict_sys_t::get_table(): Look up a persistent table.

dict_sys_t::get_temporary_table(): Look up a temporary table.

dict_sys_t::temp_table_id: The sequence of temporary table identifiers.
Starts from DICT_HDR_FIRST_ID, so that we can continue to simply compare
dict_table_t::id to a few constants for the persistent hard-coded
data dictionary tables.

undo_node_t::state: Distinguish temporary and persistent tables.

lock_check_dict_lock(), lock_get_table_id(): Assert that there cannot
be locks on temporary tables.

row_rec_to_index_entry_impl(): Assert that there cannot be metadata
records on temporary tables.

row_undo_ins_parse_undo_rec(): Distinguish temporary and persistent tables.
Move some assertions from the only caller. Return whether the table was
found.

row_undo_ins(): Add some assertions.

row_undo_mod_clust(), row_undo_mod(): Do not assign node->state.
Let row_undo() do that.

row_undo_mod_parse_undo_rec(): Distinguish temporary and persistent tables.
Move some assertions from the only caller. Return whether the table was
found.

row_undo_try_truncate(): Renamed and simplified from trx_roll_try_truncate().

row_undo_rec_get(): Replaces trx_roll_pop_top_rec_of_trx() and
trx_roll_pop_top_rec(). Fetch an undo log record, and assign undo->state
accordingly.

trx_undo_truncate_end(): Acquire the rseg->mutex only for the minimum
required duration, and release it between mini-transactions.

1 files changed, 27 insertions, 26 deletions

diff --git a/storage/innobase/trx/trx0undo.cc b/storage/innobase/trx/trx0undo.cc
index 61ba65ebc19..e084b0b67bf 100644
--- a/storage/innobase/trx/trx0undo.cc
+++ b/storage/innobase/trx/trx0undo.cc
@@ -888,54 +888,55 @@ trx_undo_free_last_page(trx_undo_t* undo, mtr_t* mtr)
 @param[in,out]	undo	undo log
 @param[in]	limit	all undo logs after this limit will be discarded
 @param[in]	is_temp	whether this is temporary undo log */
-void
-trx_undo_truncate_end(trx_undo_t* undo, undo_no_t limit, bool is_temp)
+void trx_undo_truncate_end(trx_undo_t& undo, undo_no_t limit, bool is_temp)
 {
-	ut_ad(mutex_own(&undo->rseg->mutex));
-	ut_ad(is_temp == !undo->rseg->is_persistent());
+	mtr_t mtr;
+	ut_ad(is_temp == !undo.rseg->is_persistent());
 
 	for (;;) {
-		mtr_t		mtr;
 		mtr.start();
 		if (is_temp) {
 			mtr.set_log_mode(MTR_LOG_NO_REDO);
 		}
 
 		trx_undo_rec_t* trunc_here = NULL;
+		mutex_enter(&undo.rseg->mutex);
 		page_t*		undo_page = trx_undo_page_get(
-			page_id_t(undo->rseg->space->id, undo->last_page_no),
+			page_id_t(undo.rseg->space->id, undo.last_page_no),
 			&mtr);
 		trx_undo_rec_t* rec = trx_undo_page_get_last_rec(
-			undo_page, undo->hdr_page_no, undo->hdr_offset);
+			undo_page, undo.hdr_page_no, undo.hdr_offset);
 		while (rec) {
-			if (trx_undo_rec_get_undo_no(rec) >= limit) {
-				/* Truncate at least this record off, maybe
-				more */
-				trunc_here = rec;
-			} else {
-				goto function_exit;
+			if (trx_undo_rec_get_undo_no(rec) < limit) {
+				goto func_exit;
 			}
+			/* Truncate at least this record off, maybe more */
+			trunc_here = rec;
 
 			rec = trx_undo_page_get_prev_rec(rec,
-							 undo->hdr_page_no,
-							 undo->hdr_offset);
+							 undo.hdr_page_no,
+							 undo.hdr_offset);
 		}
 
-		if (undo->last_page_no == undo->hdr_page_no) {
-function_exit:
-			if (trunc_here) {
-				mlog_write_ulint(undo_page + TRX_UNDO_PAGE_HDR
-						 + TRX_UNDO_PAGE_FREE,
-						 ulint(trunc_here - undo_page),
-						 MLOG_2BYTES, &mtr);
-			}
-
+		if (undo.last_page_no != undo.hdr_page_no) {
+			trx_undo_free_last_page(&undo, &mtr);
+			mutex_exit(&undo.rseg->mutex);
 			mtr.commit();
-			return;
+			continue;
+		}
+
+func_exit:
+		mutex_exit(&undo.rseg->mutex);
+
+		if (trunc_here) {
+			mlog_write_ulint(undo_page + TRX_UNDO_PAGE_HDR
+					 + TRX_UNDO_PAGE_FREE,
+					 ulint(trunc_here - undo_page),
+					 MLOG_2BYTES, &mtr);
 		}
 
-		trx_undo_free_last_page(undo, &mtr);
 		mtr.commit();
+		return;
 	}
 }