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  1. MariaDB Server
  2. MDEV-20946

Hard FTWRL deadlock under user level locks

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Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • 10.4(EOL)
    • 10.4.19
    • Locking
    • None

    Description

      CREATE TABLE t1(a INT);
      		 
      SELECT GET_LOCK("l1", 0);
      		 
       
      		 
      connect(con1,localhost,root,,);
      		 
      LOCK TABLES t1 WRITE;
      		 
       
      		 
      connection default;
      		 
      sleep 1;
      		 
      send FLUSH TABLES WITH READ LOCK;
      		 
       
      		 
      connection con1;
      		 
      sleep 1;
      		 
      send SELECT GET_LOCK("l1", 10);
      		 
       
      		 
      connection default;
      		 
      reap;
      		 
       
      		 
      connection con1;
      		 
      reap;
      		 
      disconnect con1;
      		 
       
      		 
      connection default;
      		 
      SELECT RELEASE_LOCK("l1");
      		 
      UNLOCK TABLES;
      		 
      DROP TABLE t1;

      After MDEV-5336 FTWRL is designed such that it doesn't expect outer MDL locks being held when it is called. Either release user level locks or forbid FTWRL when they're active.

      BACKUP STAGE will likely be affected by this when it receives fixes for some outstanding deadlocks.

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        Issue Links

          is caused by

          Task - A task that needs to be done. MDEV-5336 Implement BACKUP STAGE for safe external backups

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-20945 BACKUP UNLOCK + FTWRL assertion failure | SIGSEGV in I_P_List from MDL_context::release_lock on INSERT w/ BACKUP LOCK (on optimized builds) | Assertion `ticket->m_duration == MDL_EXPLICIT' failed.

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Activity

            People

              monty Michael Widenius
              svoj Sergey Vojtovich
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              Dates

                Created:
                Updated:
                Resolved:

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