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From:Michael Widenius Date:November 26 1999 2:36am
Subject:Re: 3.23.6a Bug Report
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>>>>> "Joe" == Joe Kislo <kislo@stripped> writes:


Joe> Thanks,
Joe> -----
>> Description:
Joe> If you have two disjoint processes aquire a write table lock on the same
Joe> table, and one of them drops the table from the database, the mysql
Joe> database
Joe> server crashes

Joe> I have been able to repeat this on 3.22.25 and 3.22.27, on both x86
Joe> linux
Joe> 2.2.x and sparc solaris 7.

>> How-To-Repeat:
Joe>         Create two tables
Joe>         establish two mysql connections [in different windows]
Joe>         aquire write lock on both tables in both windows [using 1 sql
Joe> command]
Joe>         one will get the locks, and one will have to wait
Joe>         have the one which got the lock, drop one of the tables it has a
Joe> lock on
Joe>         the Mysql server will immediatly crash, and both connections
Joe> will be
Joe> lost

>> Fix:
Joe>         None, server crashes.  It's corrupted my tables a couple times
Joe> now.

Better fix:

(/my/monty/sql-3.22) diff -c /my/monty/master/mysql-3.22.26a/sql/ .
*** /my/monty/master/mysql-3.22.26a/sql/     Sun Aug  8 20:26:45 1999
--- ./       Fri Nov 26 02:13:06 1999
*** 698,705 ****
      if (!tables || (!db_stat && reopen_table(thd,table,1)))
-       VOID(hash_delete(&open_cache,(byte*) table));
--- 698,705 ----
      if (!tables || (!db_stat && reopen_table(thd,table,1)))
+       VOID(hash_delete(&open_cache,(byte*) table));


PS: Why are are you locking a table that you are going to delete?
    This isn't normally a really good solution...
3.23.6a Bug ReportStephen Taranto25 Nov
  • Re: 3.23.6a Bug Reportsinisa25 Nov
  • 3.23.6a Bug ReportMichael Widenius25 Nov
  • Re: 3.23.6a Bug ReportJoe Kislo25 Nov
    • Re: 3.23.6a Bug ReportMichael Widenius26 Nov
    • Re: 3.23.6a Bug ReportMichael Widenius26 Nov