4809 Annamalai Gurusami 2012-12-20 [merge]
Null merge from mysql-5.5 to mysql-5.6.
4808 Annamalai Gurusami 2012-12-20
Bug #14556349 RENAME OF COMPRESSED TABLE AND INSERT BUFFER MERGE CAUSE
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
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.
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://1660 (mysql-trunk) approved by Inaam, Jimmy, and ima.
No bundle (reason: useless for push emails).
|• bzr push into mysql-5.6 branch (annamalai.gurusami:4808 to 4809) ||Annamalai Gurusami||20 Dec|