mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2026-04-28 11:15:33 +02:00
Code Issues Projects Releases Packages Wiki Activity

MDEV-6749 - Deadlock between GRANT/REVOKE, SELECT FROM I_S.COLUMNS,

Browse source 
SET slow_query_log and failed connection attempt

A very subtle though valid deadlock. Deadlock chain:
wrlock(LOCK_grant)    -> lock(acl_cache->lock) GRANT/REVOKE CREATE/DROP USER
lock(LOCK_open)       -> rdlock(LOCK_grant)    SELECT * FROM I_S.COLUMNS
wrlock(LOCK_logger)   -> lock(LOCK_open)       SET @@global.slow_query_log='ON'
lock(acl_cache->lock) -> rdlock(LOCK_logger)   Failed connection

Fixed by removing relationship between acl_cache->lock and LOCK_logger
during failed connection attempt.
This commit is contained in:
Sergey Vojtovich 2014-09-18 19:45:06 +04:00
commit d1e46a50bc
1 changed files with 1 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

2
sql/sql_acl.cc
View file

@ -9224,9 +9224,9 @@ bool acl_authenticate(THD *thd, uint connect_errors,
mpvio.auth_info.authenticated_as, TRUE);
if (!acl_proxy_user)
{
mysql_mutex_unlock(&acl_cache->lock);
if (!thd->is_error())
login_failed_error(thd);
mysql_mutex_unlock(&acl_cache->lock);
DBUG_RETURN(1);
}
acl_user= acl_proxy_user->copy(thd->mem_root);