Annamalai Gurusami 7b145111f1 Bug #14556349 RENAME OF COMPRESSED TABLE AND INSERT BUFFER MERGE CAUSE ... HANG Problem Statement: When the operation RENAME TABLE is about rename the tablespace of the table, it will stop all i/o operations on the tablespace temporarily. For this the fil_space_t::stop_ios member is used. Once the fil_space_t::stop_ios member is set to TRUE in the RENAME TABLE operation, it is expected that no new i/o operation will be done on the tablespace and all pending i/o operation can be completed on the tablespace. If the pending i/o operations initiate any new i/o operations then there will be deadlock. The RENAME TABLE operation will be waiting for pending i/o on the tablespace to be completed, and the pending i/o operations will be waiting on the RENAME TABLE operation to set the file_space_t::stop_ios flag to be set to FALSE. But in the given scenario the pending i/o operations did not initiate new i/o. But they where still unnecessarily checking the fil_space_t::stop_ios flag. This resulted in deadlock. Solution: I noticed that this deadlock happens in fil_space_get_size() and fil_space_get_zip_size() in the i/o threads. These functions check the stop_ios flag even when no i/o will be initiated. I modified these functions to ensure that they check the stop_ios flag only when they will be initiating an i/o operation. This solves the problem. rb://1635 (mysql-5.5) rb://1660 (mysql-trunk) approved by Inaam, Jimmy, and ima.		2012-12-20 11:59:36 +05:30
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fil0fil.c	Bug #14556349 RENAME OF COMPRESSED TABLE AND INSERT BUFFER MERGE CAUSE	2012-12-20 11:59:36 +05:30