MDEV-39303: Skip ibuf_upgrade() if innodb_force_recovery=6

ibuf_upgrade_needed(): Pretend that no upgrade is needed when
innodb_force_recovery=6.

srv_load_tables(): Test the least likely condition first.

srv_start(): Remove a message that is duplicating one at the start
of recv_recovery_from_checkpoint_start().

This was tested by starting up a server on an empty data directory
that had been created by MariaDB Server 10.6.

Reviewed by: Thirunarayanan Balathandayuthapani

Author: dr-m

storage/innobase/ibuf/ibuf0ibuf.cc

@@ -1025,6 +1025,9 @@ ATTRIBUTE_COLD dberr_t ibuf_upgrade()
 
 dberr_t ibuf_upgrade_needed()
 {
+  if (srv_force_recovery == SRV_FORCE_NO_LOG_REDO)
+    return DB_SUCCESS;
+
   mtr_t mtr{nullptr};
   mtr.start();
   mtr.x_lock_space(fil_system.sys_space);
@@ -1035,8 +1038,6 @@ dberr_t ibuf_upgrade_needed()
   {
   err_exit:
     sql_print_error("InnoDB: The change buffer is corrupted");
-    if (srv_force_recovery == SRV_FORCE_NO_LOG_REDO)
-      err= DB_SUCCESS;
   func_exit:
     mtr.commit();
     return err;
@@ -1067,7 +1068,7 @@ dberr_t ibuf_upgrade_needed()
                     " of the change buffer");
     err= DB_READ_ONLY;
   }
-  else if (srv_force_recovery != SRV_FORCE_NO_LOG_REDO)
+  else
     err= DB_FAIL;
 
   goto func_exit;

storage/innobase/srv/srv0start.cc

@@ -1217,8 +1217,8 @@ static dberr_t srv_load_tables(bool must_upgrade_ibuf) noexcept
   dberr_t err = dict_load_indexes(&mtr, dict_sys.sys_tables, false, heap,
                                   DICT_ERR_IGNORE_NONE);
   mem_heap_empty(heap);
-  if ((err == DB_SUCCESS || srv_force_recovery >= SRV_FORCE_NO_DDL_UNDO) &&
-      UNIV_UNLIKELY(must_upgrade_ibuf))
+  if (UNIV_UNLIKELY(must_upgrade_ibuf) &&
+      (err == DB_SUCCESS || srv_force_recovery >= SRV_FORCE_NO_DDL_UNDO))
   {
     dict_sys.unlock();
     dict_load_tablespaces(nullptr, true);
@@ -1412,10 +1412,7 @@ dberr_t srv_start(bool create_new_db)
 		      || srv_operation == SRV_OPERATION_RESTORE_EXPORT);
 		ut_ad(!recv_sys.recovery_on);
 
-		if (srv_force_recovery >= SRV_FORCE_NO_LOG_REDO) {
-			sql_print_information("InnoDB: innodb_force_recovery=6"
-					      " skips redo log apply");
-		} else {
+		if (srv_force_recovery < SRV_FORCE_NO_LOG_REDO) {
 			log_sys.latch.wr_lock();
 			err = recv_sys.find_checkpoint();
 			log_sys.latch.wr_unlock();