MDEV-14756 - Remove trx_sys_t::rw_trx_list

Reduce divergence between trx_sys_t::rw_trx_hash and trx_sys_t::rw_trx_list
by not adding recovered COMMITTED transactions to trx_sys_t::rw_trx_list.

Such transactions are discarded immediately without creating trx object.

This also required to split rollback and cleanup phases of recovery. To
reflect these updates the following renames happened:
trx_rollback_or_clean_all_recovered() -> trx_rollback_all_recovered()
trx_rollback_or_clean_is_active -> trx_rollback_is_active
trx_rollback_or_clean_recovered() -> trx_rollback_recovered()
trx_cleanup_at_db_startup() -> trx_cleanup_recovered()

Also removed a hack from lock_trx_release_locks(). Instead let recovery
rollback thread to skip committed XA transactions.

storage/innobase/btr/btr0cur.cc

@@ -7782,7 +7782,7 @@ btr_free_externally_stored_field(
 					 MLOG_4BYTES, &mtr);
 			/* Zero out the BLOB length.  If the server
 			crashes during the execution of this function,
-			trx_rollback_or_clean_all_recovered() could
+			trx_rollback_all_recovered() could
 			dereference the half-deleted BLOB, fetching a
 			wrong prefix for the BLOB. */
 			mlog_write_ulint(field_ref + BTR_EXTERN_LEN + 4,

storage/innobase/include/trx0roll.h

@@ -33,7 +33,7 @@ Created 3/26/1996 Heikki Tuuri
 #include "mtr0mtr.h"
 #include "trx0sys.h"
 
-extern bool		trx_rollback_or_clean_is_active;
+extern bool		trx_rollback_is_active;
 extern const trx_t*	trx_roll_crash_recv_trx;
 
 /*******************************************************************//**
@@ -71,12 +71,11 @@ trx_roll_must_shutdown();
 Rollback or clean up any incomplete transactions which were
 encountered in crash recovery.  If the transaction already was
 committed, then we clean up a possible insert undo log. If the
-transaction was not yet committed, then we roll it back. */
+transaction was not yet committed, then we roll it back.
+@param all true=roll back all recovered active transactions;
+false=roll back any incomplete dictionary transaction */
 void
-trx_rollback_or_clean_recovered(
-/*============================*/
-	ibool	all);	/*!< in: FALSE=roll back dictionary transactions;
-			TRUE=roll back all non-PREPARED transactions */
+trx_rollback_recovered(bool all);
 /*******************************************************************//**
 Rollback or clean up any incomplete transactions which were
 encountered in crash recovery.  If the transaction already was
@@ -86,11 +85,7 @@ Note: this is done in a background thread.
 @return a dummy parameter */
 extern "C"
 os_thread_ret_t
-DECLARE_THREAD(trx_rollback_or_clean_all_recovered)(
-/*================================================*/
-	void*	arg MY_ATTRIBUTE((unused)));
-			/*!< in: a dummy parameter required by
-			os_thread_create */
+DECLARE_THREAD(trx_rollback_all_recovered)(void*);
 /*********************************************************************//**
 Creates a rollback command node struct.
 @return own: rollback node struct */

storage/innobase/include/trx0trx.h

@@ -246,14 +246,6 @@ trx_commit_low(
 	trx_t*	trx,	/*!< in/out: transaction */
 	mtr_t*	mtr);	/*!< in/out: mini-transaction (will be committed),
 			or NULL if trx made no modifications */
-/****************************************************************//**
-Cleans up a transaction at database startup. The cleanup is needed if
-the transaction already got to the middle of a commit when the database
-crashed, and we cannot roll it back. */
-void
-trx_cleanup_at_db_startup(
-/*======================*/
-	trx_t*	trx);	/*!< in: transaction */
 /**********************************************************************//**
 Does the transaction commit for MySQL.
 @return DB_SUCCESS or error number */

storage/innobase/lock/lock0lock.cc

@@ -7630,8 +7630,6 @@ lock_trx_release_locks(
 		lock_mutex_enter();
 	}
 
-	trx_mutex_enter(trx);
-
 	/* The following assignment makes the transaction committed in memory
 	and makes its changes to data visible to other transactions.
 	NOTE that there is a small discrepancy from the strict formal
@@ -7647,7 +7645,9 @@ lock_trx_release_locks(
 	committed. */
 
 	/*--------------------------------------*/
+	trx_mutex_enter(trx);
 	trx->state = TRX_STATE_COMMITTED_IN_MEMORY;
+	trx_mutex_exit(trx);
 	/*--------------------------------------*/
 
 	if (trx->is_referenced()) {
@@ -7658,41 +7658,18 @@ lock_trx_release_locks(
 
 		while (trx->is_referenced()) {
 
-			trx_mutex_exit(trx);
-
 			DEBUG_SYNC_C("waiting_trx_is_not_referenced");
 
 			/** Doing an implicit to explicit conversion
 			should not be expensive. */
 			ut_delay(ut_rnd_interval(0, srv_spin_wait_delay));
-
-			trx_mutex_enter(trx);
 		}
 
-		trx_mutex_exit(trx);
-
 		lock_mutex_enter();
-
-		trx_mutex_enter(trx);
 	}
 
 	ut_ad(!trx->is_referenced());
 
-	/* If the background thread trx_rollback_or_clean_recovered()
-	is still active then there is a chance that the rollback
-	thread may see this trx as COMMITTED_IN_MEMORY and goes ahead
-	to clean it up calling trx_cleanup_at_db_startup(). This can
-	happen in the case we are committing a trx here that is left
-	in PREPARED state during the crash. Note that commit of the
-	rollback of a PREPARED trx happens in the recovery thread
-	while the rollback of other transactions happen in the
-	background thread. To avoid this race we unconditionally unset
-	the is_recovered flag. */
-
-	trx->is_recovered = false;
-
-	trx_mutex_exit(trx);
-
 	if (release_lock) {
 
 		lock_release(trx);

storage/innobase/log/log0log.cc

@@ -1949,7 +1949,7 @@ logs_empty_and_mark_files_at_shutdown(void)
 		goto wait_suspend_loop;
 	} else if (btr_defragment_thread_active) {
 		thread_name = "btr_defragment_thread";
-	} else if (srv_fast_shutdown != 2 && trx_rollback_or_clean_is_active) {
+	} else if (srv_fast_shutdown != 2 && trx_rollback_is_active) {
 		thread_name = "rollback of recovered transactions";
 	} else {
 		thread_name = NULL;

storage/innobase/log/log0recv.cc

@@ -3426,8 +3426,8 @@ recv_recovery_rollback_active(void)
 		/* Rollback the uncommitted transactions which have no user
 		session */
 
-		trx_rollback_or_clean_is_active = true;
-		os_thread_create(trx_rollback_or_clean_all_recovered, 0, 0);
+		trx_rollback_is_active = true;
+		os_thread_create(trx_rollback_all_recovered, 0, 0);
 	}
 }
 

storage/innobase/row/row0ext.cc

@@ -70,7 +70,7 @@ row_ext_cache_fill(
 		} else {
 			/* Fetch at most ext->max_len of the column.
 			The column should be non-empty.  However,
-			trx_rollback_or_clean_all_recovered() may try to
+			trx_rollback_all_recovered() may try to
 			access a half-deleted BLOB if the server previously
 			crashed during the execution of
 			btr_free_externally_stored_field(). */

storage/innobase/srv/srv0start.cc

@@ -1649,7 +1649,7 @@ innobase_start_or_create_for_mysql()
 			    + 1 /* dict_stats_thread */
 			    + 1 /* fts_optimize_thread */
 			    + 1 /* recv_writer_thread */
-			    + 1 /* trx_rollback_or_clean_all_recovered */
+			    + 1 /* trx_rollback_all_recovered */
 			    + 128 /* added as margin, for use of
 				  InnoDB Memcached etc. */
 			    + max_connections
@@ -2471,7 +2471,7 @@ innobase_start_or_create_for_mysql()
 		The data dictionary latch should guarantee that there is at
 		most one data dictionary transaction active at a time. */
 		if (srv_force_recovery < SRV_FORCE_NO_TRX_UNDO) {
-			trx_rollback_or_clean_recovered(FALSE);
+			trx_rollback_recovered(false);
 		}
 
 		/* Fix-up truncate of tables in the system tablespace

storage/innobase/trx/trx0purge.cc

@@ -300,7 +300,7 @@ trx_purge_add_undo_to_history(const trx_t* trx, trx_undo_t*& undo, mtr_t* mtr)
 	continue to execute user transactions. */
 	ut_ad(srv_undo_sources
 	      || ((srv_startup_is_before_trx_rollback_phase
-		   || trx_rollback_or_clean_is_active)
+		   || trx_rollback_is_active)
 		  && purge_sys->state == PURGE_STATE_INIT)
 	      || (srv_force_recovery >= SRV_FORCE_NO_BACKGROUND
 		  && purge_sys->state == PURGE_STATE_DISABLED)

storage/innobase/trx/trx0roll.cc

@@ -54,8 +54,8 @@ Created 3/26/1996 Heikki Tuuri
 rollback */
 static const ulint TRX_ROLL_TRUNC_THRESHOLD = 1;
 
-/** true if trx_rollback_or_clean_all_recovered() thread is active */
-bool			trx_rollback_or_clean_is_active;
+/** true if trx_rollback_all_recovered() thread is active */
+bool			trx_rollback_is_active;
 
 /** In crash recovery, the current trx to be rolled back; NULL otherwise */
 const trx_t*		trx_roll_crash_recv_trx;
@@ -734,7 +734,7 @@ ibool
 trx_rollback_resurrected(
 /*=====================*/
 	trx_t*	trx,	/*!< in: transaction to rollback or clean */
-	ibool*	all)	/*!< in/out: FALSE=roll back dictionary transactions;
+	bool*	all)	/*!< in/out: FALSE=roll back dictionary transactions;
 			TRUE=roll back all non-PREPARED transactions */
 {
 	ut_ad(trx_sys_mutex_own());
@@ -752,14 +752,6 @@ trx_rollback_resurrected(
 	}
 
 	switch (trx->state) {
-	case TRX_STATE_COMMITTED_IN_MEMORY:
-		trx_mutex_exit(trx);
-		trx_sys_mutex_exit();
-		ib::info() << "Cleaning up trx with id " << ib::hex(trx->id);
-
-		trx_cleanup_at_db_startup(trx);
-		trx_free_resurrected(trx);
-		return(TRUE);
 	case TRX_STATE_ACTIVE:
 		if (!srv_is_being_started
 		    && !srv_undo_sources && srv_fast_shutdown) {
@@ -767,7 +759,7 @@ trx_rollback_resurrected(
 			trx->state = TRX_STATE_PREPARED;
 			trx_sys->n_prepared_trx++;
 			trx_sys->n_prepared_recovered_trx++;
-			*all = FALSE;
+			*all = false;
 			goto func_exit;
 		}
 		trx_mutex_exit(trx);
@@ -788,6 +780,8 @@ trx_rollback_resurrected(
 			return(TRUE);
 		}
 		return(FALSE);
+	case TRX_STATE_COMMITTED_IN_MEMORY:
+		ut_ad(trx->xid);
 	case TRX_STATE_PREPARED:
 		goto func_exit;
 	case TRX_STATE_NOT_STARTED:
@@ -848,12 +842,11 @@ trx_roll_must_shutdown()
 Rollback or clean up any incomplete transactions which were
 encountered in crash recovery.  If the transaction already was
 committed, then we clean up a possible insert undo log. If the
-transaction was not yet committed, then we roll it back. */
+transaction was not yet committed, then we roll it back.
+@param all true=roll back all recovered active transactions;
+false=roll back any incomplete dictionary transaction */
 void
-trx_rollback_or_clean_recovered(
-/*============================*/
-	ibool	all)	/*!< in: FALSE=roll back dictionary transactions;
-			TRUE=roll back all non-PREPARED transactions */
+trx_rollback_recovered(bool all)
 {
 	trx_t*	trx;
 
@@ -917,11 +910,7 @@ Note: this is done in a background thread.
 @return a dummy parameter */
 extern "C"
 os_thread_ret_t
-DECLARE_THREAD(trx_rollback_or_clean_all_recovered)(
-/*================================================*/
-	void*	arg MY_ATTRIBUTE((unused)))
-			/*!< in: a dummy parameter required by
-			os_thread_create */
+DECLARE_THREAD(trx_rollback_all_recovered)(void*)
 {
 	my_thread_init();
 	ut_ad(!srv_read_only_mode);
@@ -930,9 +919,9 @@ DECLARE_THREAD(trx_rollback_or_clean_all_recovered)(
 	pfs_register_thread(trx_rollback_clean_thread_key);
 #endif /* UNIV_PFS_THREAD */
 
-	trx_rollback_or_clean_recovered(TRUE);
+	trx_rollback_recovered(true);
 
-	trx_rollback_or_clean_is_active = false;
+	trx_rollback_is_active = false;
 
 	my_thread_end();
 	/* We count the number of threads in os_thread_exit(). A created

storage/innobase/trx/trx0trx.cc

@@ -815,167 +815,6 @@ trx_resurrect_table_locks(
 	}
 }
 
-/****************************************************************//**
-Resurrect the transactions that were doing inserts the time of the
-crash, they need to be undone.
-@return trx_t instance */
-static
-trx_t*
-trx_resurrect_insert(
-/*=================*/
-	trx_undo_t*	undo,		/*!< in: entry to UNDO */
-	trx_rseg_t*	rseg)		/*!< in: rollback segment */
-{
-	trx_t*		trx;
-
-	trx = trx_allocate_for_background();
-
-	ut_d(trx->start_file = __FILE__);
-	ut_d(trx->start_line = __LINE__);
-
-	trx->rsegs.m_redo.rseg = rseg;
-	/* For transactions with active data will not have rseg size = 1
-	or will not qualify for purge limit criteria. So it is safe to increment
-	this trx_ref_count w/o mutex protection. */
-	++trx->rsegs.m_redo.rseg->trx_ref_count;
-	*trx->xid = undo->xid;
-	trx->id = undo->trx_id;
-	trx->rsegs.m_redo.old_insert = undo;
-	trx->is_recovered = true;
-
-	/* This is single-threaded startup code, we do not need the
-	protection of trx->mutex or trx_sys->mutex here. */
-
-	if (undo->state != TRX_UNDO_ACTIVE) {
-
-		/* Prepared transactions are left in the prepared state
-		waiting for a commit or abort decision from MySQL */
-
-		if (undo->state == TRX_UNDO_PREPARED) {
-
-			ib::info() << "Transaction "
-				<< trx_get_id_for_print(trx)
-				<< " was in the XA prepared state.";
-
-			trx->state = TRX_STATE_PREPARED;
-			trx_sys->n_prepared_trx++;
-			trx_sys->n_prepared_recovered_trx++;
-		} else {
-			trx->state = TRX_STATE_COMMITTED_IN_MEMORY;
-		}
-
-		/* We give a dummy value for the trx no; this should have no
-		relevance since purge is not interested in committed
-		transaction numbers, unless they are in the history
-		list, in which case it looks the number from the disk based
-		undo log structure */
-
-		trx->no = trx->id;
-
-	} else {
-		trx->state = TRX_STATE_ACTIVE;
-
-		/* A running transaction always has the number
-		field inited to TRX_ID_MAX */
-
-		trx->no = TRX_ID_MAX;
-	}
-
-	if (undo->dict_operation) {
-		trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);
-		trx->table_id = undo->table_id;
-	}
-
-	if (!undo->empty) {
-		trx->undo_no = undo->top_undo_no + 1;
-		trx->undo_rseg_space = undo->rseg->space;
-	}
-
-	return(trx);
-}
-
-/****************************************************************//**
-Prepared transactions are left in the prepared state waiting for a
-commit or abort decision from MySQL */
-static
-void
-trx_resurrect_update_in_prepared_state(
-/*===================================*/
-	trx_t*			trx,	/*!< in,out: transaction */
-	const trx_undo_t*	undo)	/*!< in: update UNDO record */
-{
-	/* This is single-threaded startup code, we do not need the
-	protection of trx->mutex or trx_sys->mutex here. */
-
-	if (undo->state == TRX_UNDO_PREPARED) {
-		ib::info() << "Transaction " << trx_get_id_for_print(trx)
-			<< " was in the XA prepared state.";
-
-		if (trx_state_eq(trx, TRX_STATE_NOT_STARTED)) {
-			trx_sys->n_prepared_trx++;
-			trx_sys->n_prepared_recovered_trx++;
-		} else {
-			ut_ad(trx_state_eq(trx, TRX_STATE_PREPARED));
-		}
-
-		trx->state = TRX_STATE_PREPARED;
-	} else {
-		trx->state = TRX_STATE_COMMITTED_IN_MEMORY;
-	}
-}
-
-/****************************************************************//**
-Resurrect the transactions that were doing updates the time of the
-crash, they need to be undone. */
-static
-void
-trx_resurrect_update(
-/*=================*/
-	trx_t*		trx,	/*!< in/out: transaction */
-	trx_undo_t*	undo,	/*!< in/out: update UNDO record */
-	trx_rseg_t*	rseg)	/*!< in/out: rollback segment */
-{
-	trx->rsegs.m_redo.rseg = rseg;
-	/* For transactions with active data will not have rseg size = 1
-	or will not qualify for purge limit criteria. So it is safe to increment
-	this trx_ref_count w/o mutex protection. */
-	++trx->rsegs.m_redo.rseg->trx_ref_count;
-	*trx->xid = undo->xid;
-	trx->id = undo->trx_id;
-	trx->rsegs.m_redo.undo = undo;
-	trx->is_recovered = true;
-
-	/* This is single-threaded startup code, we do not need the
-	protection of trx->mutex or trx_sys->mutex here. */
-
-	if (undo->state != TRX_UNDO_ACTIVE) {
-		trx_resurrect_update_in_prepared_state(trx, undo);
-
-		/* We give a dummy value for the trx number */
-
-		trx->no = trx->id;
-
-	} else {
-		trx->state = TRX_STATE_ACTIVE;
-
-		/* A running transaction always has the number field inited to
-		TRX_ID_MAX */
-
-		trx->no = TRX_ID_MAX;
-	}
-
-	if (undo->dict_operation) {
-		trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);
-		trx->table_id = undo->table_id;
-	}
-
-	if (!undo->empty && undo->top_undo_no >= trx->undo_no) {
-
-		trx->undo_no = undo->top_undo_no + 1;
-		trx->undo_rseg_space = undo->rseg->space;
-	}
-}
-
 /** Mapping read-write transactions from id to transaction instance, for
 creating read views and during trx id lookup for MVCC and locking. */
 struct TrxTrack {
@@ -1004,24 +843,86 @@ struct TrxTrackCmp {
 typedef std::set<TrxTrack, TrxTrackCmp, ut_allocator<TrxTrack> >
 	TrxIdSet;
 
-static inline void trx_sys_add_trx_at_init(trx_t *trx, trx_undo_t *undo,
-                                           uint64_t *rows_to_undo,
-                                           TrxIdSet *set)
-{
-  ut_ad(trx->id != 0);
-  ut_ad(trx->is_recovered);
 
-  set->insert(TrxTrack(trx->id, trx));
-  if (trx_state_eq(trx, TRX_STATE_ACTIVE) ||
-      trx_state_eq(trx, TRX_STATE_PREPARED))
+/**
+  Resurrect the transactions that were doing inserts/updates the time of the
+  crash, they need to be undone.
+*/
+
+static void trx_resurrect(trx_undo_t *undo, trx_rseg_t *rseg,
+                          ib_time_t start_time, uint64_t *rows_to_undo,
+                          TrxIdSet *set, bool is_old_insert)
+{
+  trx_state_t state;
+  /*
+    This is single-threaded startup code, we do not need the
+    protection of trx->mutex or trx_sys->mutex here.
+  */
+  switch (undo->state)
+  {
+  case TRX_UNDO_ACTIVE:
+    state= TRX_STATE_ACTIVE;
+    break;
+  case TRX_UNDO_PREPARED:
+    /*
+      Prepared transactions are left in the prepared state
+      waiting for a commit or abort decision from MySQL
+    */
+    ib::info() << "Transaction " << undo->trx_id
+               << " was in the XA prepared state.";
+
+    state= TRX_STATE_PREPARED;
+    trx_sys->n_prepared_trx++;
+    trx_sys->n_prepared_recovered_trx++;
+    break;
+  default:
+    if (is_old_insert && srv_force_recovery < SRV_FORCE_NO_TRX_UNDO)
+      trx_undo_commit_cleanup(undo, false);
+    return;
+  }
+
+  trx_t *trx= trx_allocate_for_background();
+  trx->state= state;
+  ut_d(trx->start_file= __FILE__);
+  ut_d(trx->start_line= __LINE__);
+  ut_ad(trx->no == TRX_ID_MAX);
+
+  if (is_old_insert)
+    trx->rsegs.m_redo.old_insert= undo;
+  else
+    trx->rsegs.m_redo.undo= undo;
+
+  if (!undo->empty)
+  {
+    trx->undo_no= undo->top_undo_no + 1;
+    trx->undo_rseg_space= undo->rseg->space;
+  }
+
+  trx->rsegs.m_redo.rseg= rseg;
+  /*
+    For transactions with active data will not have rseg size = 1
+    or will not qualify for purge limit criteria. So it is safe to increment
+    this trx_ref_count w/o mutex protection.
+  */
+  ++trx->rsegs.m_redo.rseg->trx_ref_count;
+  *trx->xid= undo->xid;
+  trx->id= undo->trx_id;
+  trx->is_recovered= true;
+  trx->start_time= start_time;
+
+  if (undo->dict_operation)
   {
+    trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);
+    trx->table_id= undo->table_id;
+  }
+
+  set->insert(TrxTrack(trx->id, trx));
   trx_sys->rw_trx_hash.insert(trx);
   trx_sys->rw_trx_hash.put_pins(trx);
   trx_sys->rw_trx_ids.push_back(trx->id);
   trx_resurrect_table_locks(trx, undo);
   if (trx_state_eq(trx, TRX_STATE_ACTIVE))
     *rows_to_undo+= trx->undo_no;
-  }
 #ifdef UNIV_DEBUG
   trx->in_rw_trx_list= true;
   if (trx->id > trx_sys->rw_max_trx_id)
@@ -1029,6 +930,7 @@ static inline void trx_sys_add_trx_at_init(trx_t *trx, trx_undo_t *undo,
 #endif
 }
 
+
 /** Initialize (resurrect) transactions at startup. */
 void
 trx_lists_init_at_db_start()
@@ -1061,36 +963,50 @@ trx_lists_init_at_db_start()
 
 		/* Resurrect transactions that were doing inserts
 		using the old separate insert_undo log. */
-		for (undo = UT_LIST_GET_FIRST(rseg->old_insert_list);
-		     undo != NULL;
-		     undo = UT_LIST_GET_NEXT(undo_list, undo)) {
-			trx_t*	trx = trx_resurrect_insert(undo, rseg);
-			trx->start_time = start_time;
-			trx_sys_add_trx_at_init(trx, undo, &rows_to_undo,
-						&set);
+		undo = UT_LIST_GET_FIRST(rseg->old_insert_list);
+		while (undo) {
+			trx_undo_t* next = UT_LIST_GET_NEXT(undo_list, undo);
+			trx_resurrect(undo, rseg, start_time, &rows_to_undo,
+				      &set, true);
+			undo = next;
 		}
 
 		/* Ressurrect other transactions. */
 		for (undo = UT_LIST_GET_FIRST(rseg->undo_list);
 		     undo != NULL;
 		     undo = UT_LIST_GET_NEXT(undo_list, undo)) {
+			trx_t *trx = trx_sys->rw_trx_hash.find(undo->trx_id);
+			if (!trx) {
+				trx_resurrect(undo, rseg, start_time,
+					      &rows_to_undo, &set, false);
+			} else {
+				ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE) ||
+				      trx_state_eq(trx, TRX_STATE_PREPARED));
+				ut_ad(trx->start_time == start_time);
+				ut_ad(trx->is_recovered);
+				ut_ad(trx->rsegs.m_redo.rseg == rseg);
+				ut_ad(trx->rsegs.m_redo.rseg->trx_ref_count);
 
-			/* Check if trx_id was already registered first. */
-			TrxIdSet::iterator it =
-				set.find(TrxTrack(undo->trx_id));
-			trx_t *trx= it == set.end() ? 0 : it->m_trx;
-
-			if (trx == NULL) {
-				trx = trx_allocate_for_background();
-				trx->start_time = start_time;
-
-				ut_d(trx->start_file = __FILE__);
-				ut_d(trx->start_line = __LINE__);
+				trx->rsegs.m_redo.undo = undo;
+				if (!undo->empty
+				    && undo->top_undo_no >= trx->undo_no) {
+					if (trx_state_eq(trx,
+							 TRX_STATE_ACTIVE)) {
+						rows_to_undo -= trx->undo_no;
+						rows_to_undo +=
+							undo->top_undo_no + 1;
 					}
 
-			trx_resurrect_update(trx, undo, rseg);
-			trx_sys_add_trx_at_init(trx, undo, &rows_to_undo,
-						&set);
+					trx->undo_no = undo->top_undo_no + 1;
+					trx->undo_rseg_space =
+						undo->rseg->space;
+				}
+				trx_resurrect_table_locks(trx, undo);
+				if (trx_state_eq(trx, TRX_STATE_PREPARED)) {
+					trx_sys->n_prepared_trx++;
+					trx_sys->n_prepared_recovered_trx++;
+				}
+			}
 		}
 	}
 
@@ -2046,50 +1962,6 @@ trx_commit(
 	trx_commit_low(trx, mtr);
 }
 
-/****************************************************************//**
-Cleans up a transaction at database startup. The cleanup is needed if
-the transaction already got to the middle of a commit when the database
-crashed, and we cannot roll it back. */
-void
-trx_cleanup_at_db_startup(
-/*======================*/
-	trx_t*	trx)	/*!< in: transaction */
-{
-	ut_ad(trx->is_recovered);
-	ut_ad(!trx->rsegs.m_noredo.undo);
-	ut_ad(!trx->rsegs.m_redo.undo);
-
-	if (trx_undo_t*& undo = trx->rsegs.m_redo.old_insert) {
-		ut_ad(undo->rseg == trx->rsegs.m_redo.rseg);
-		trx_undo_commit_cleanup(undo, false);
-		undo = NULL;
-	}
-
-	memset(&trx->rsegs, 0x0, sizeof(trx->rsegs));
-	trx->undo_no = 0;
-	trx->undo_rseg_space = 0;
-	trx->last_sql_stat_start.least_undo_no = 0;
-
-	trx_sys_mutex_enter();
-
-	ut_a(!trx->read_only);
-
-	UT_LIST_REMOVE(trx_sys->rw_trx_list, trx);
-
-	ut_d(trx->in_rw_trx_list = FALSE);
-
-	trx_sys_mutex_exit();
-
-	/* Change the transaction state without mutex protection, now
-	that it no longer is in the trx_list. Recovered transactions
-	are never placed in the mysql_trx_list. */
-	ut_ad(trx->is_recovered);
-	ut_ad(!trx->in_rw_trx_list);
-	ut_ad(!trx->in_mysql_trx_list);
-	DBUG_LOG("trx", "Cleanup at startup: " << trx);
-	trx->state = TRX_STATE_NOT_STARTED;
-}
-
 /********************************************************************//**
 Assigns a read view for a consistent read query. All the consistent reads
 within the same transaction will get the same read view, which is created

storage/innobase/trx/trx0undo.cc

@@ -1643,7 +1643,6 @@ trx_undo_free_prepared(
 			/* fall through */
 		case TRX_UNDO_ACTIVE:
 			/* lock_trx_release_locks() assigns
-			trx->is_recovered=false and
 			trx->state = TRX_STATE_COMMITTED_IN_MEMORY,
 			also for transactions that we faked
 			to TRX_STATE_PREPARED in trx_rollback_resurrected(). */
@@ -1673,7 +1672,6 @@ trx_undo_free_prepared(
 			/* fall through */
 		case TRX_UNDO_ACTIVE:
 			/* lock_trx_release_locks() assigns
-			trx->is_recovered=false and
 			trx->state = TRX_STATE_COMMITTED_IN_MEMORY,
 			also for transactions that we faked
 			to TRX_STATE_PREPARED in trx_rollback_resurrected(). */