Prevent reenabling logging by thread which tries to lock table used by bulk insert.

      Scenario of the BUG#40731 ("Maria: hang (probably in page cache) under concurrency"):
      T1: Disable logging for the table
      T1: Start inserting into the table
      T2: Tries to lock the table so waits.
      T2: Tries unlock and relock during the process see that the table has disabled logging and reenables it
      T1: Got DBUG_ASSERT because suddenly start use table with transaction switched on which is not expected during bulk insert

storage/maria/ma_pagecache.c:
  Page type print added for debugging purposes.
storage/maria/ma_recovery.c:
  Check that it was this thred which switched off logging (transactional mode).
storage/maria/maria_def.h:
  Flag for controling which thread switched off transactiona mode for the table added.

storage/maria/ma_pagecache.c

@@ -99,7 +99,7 @@
   DBUG_PRINT("info", \
              ("block: 0x%lx  fd: %lu  page: %lu  s: %0x  hshL: " \
               " 0x%lx  req: %u/%u wrlocks: %u  rdlocks %u  " \
-              "rdlocks_q: %u  pins: %u  status: %u", \
+              "rdlocks_q: %u  pins: %u  status: %u  type: %s", \
               (ulong)(B), \
               (ulong)((B)->hash_link ? \
                       (B)->hash_link->file.file : \
@@ -114,7 +114,8 @@
                      (B)->hash_link->requests : \
                        0), \
               block->wlocks, block->rlocks, block->rlocks_queue, \
-              (uint)(B)->pins, (uint)(B)->status))
+              (uint)(B)->pins, (uint)(B)->status, \
+              page_cache_page_type_str[(B)->type]))
 
 /* TODO: put it to my_static.c */
 my_bool my_disable_flush_pagecache_blocks= 0;

storage/maria/ma_recovery.c

@@ -3243,6 +3243,7 @@ void _ma_tmp_disable_logging_for_table(MARIA_HA *info,
    */
   share->state.common= *info->state;
   info->state= &share->state.common;
+  info->switched_transactional= TRUE;
 
   /*
     Some code in ma_blockrec.c assumes a trn even if !now_transactional but in
@@ -3273,8 +3274,10 @@ my_bool _ma_reenable_logging_for_table(MARIA_HA *info, my_bool flush_pages)
   MARIA_SHARE *share= info->s;
   DBUG_ENTER("_ma_reenable_logging_for_table");
 
-  if (share->now_transactional == share->base.born_transactional)
+  if (share->now_transactional == share->base.born_transactional ||
+      !info->switched_transactional)
     DBUG_RETURN(0);
+  info->switched_transactional= FALSE;
 
   if ((share->now_transactional= share->base.born_transactional))
   {

storage/maria/maria_def.h

@@ -548,6 +548,8 @@ struct st_maria_handler
   /* If info->keyread_buff has to be re-read for rnext */
   my_bool keyread_buff_used;
   my_bool once_flags;			/* For MARIA_MRG */
+  /* For bulk insert enable/disable transactions control */
+  my_bool switched_transactional;
 #ifdef __WIN__
   my_bool owned_by_merge;               /* This Maria table is part of a merge union */
 #endif