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| author | Dmitry Shulga <Dmitry.Shulga@oracle.com> | 2011-06-23 20:41:04 +0700 |
|---|---|---|
| committer | Dmitry Shulga <Dmitry.Shulga@oracle.com> | 2011-06-23 20:41:04 +0700 |
| commit | 07056eb984573b483576d45d7b8c259ad66dcd66 (patch) | |
| tree | ade6ce3b5681ea2fa357915b4210ff12d7af9d9c /sql/sql_db.cc | |
| parent | b3696af2e66fb4d72815d2d7754740c2fd8043fd (diff) | |
| download | mariadb-git-07056eb984573b483576d45d7b8c259ad66dcd66.tar.gz | |
Fixed Bug#11756013 (formerly known as bug#47870):
BOGUS "THE TABLE MYSQL.PROC IS MISSING,..."
There was a race condition between loading a stored routine
(function/procedure/trigger) specified by fully qualified name
SCHEMA_NAME.PROC_NAME and dropping the stored routine database.
The problem was that there is a window for race condition when one server
thread tries to load a stored routine being executed and the other thread
tries to drop the stored routine schema.
This condition race window exists in implementation of function
mysql_change_db() called by db_load_routine() during loading of stored
routine to cache. Function mysql_change_db() calls check_db_dir_existence()
that might failed because specified database was dropped during concurrent
execution of DROP SCHEMA statement. db_load_routine() calls mysql_change_db()
with flag 'force_switch' set to 'true' value so when referenced db is not found
then my_error() is not called and function mysql_change_db() returns ok.
This shadows information about schema opening error in db_load_routine().
Then db_load_routine() makes attempt to parse stored routine that is failed.
This makes to return error to sp_cache_routines_and_add_tables_aux() but since
during error generation a call to my_error wasn't made and hence
THD::main_da wasn't set we set the generic "mysql.proc table corrupt" error
when running sp_cache_routines_and_add_tables_aux().
The fix is to install an error handler inside db_load_routine() for
the mysql_op_change_db() call, and check later if the ER_BAD_DB_ERROR
was caught.
Diffstat (limited to 'sql/sql_db.cc')
| -rw-r--r-- | sql/sql_db.cc | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/sql/sql_db.cc b/sql/sql_db.cc index d7d7f43a7aa..e0d848321a7 100644 --- a/sql/sql_db.cc +++ b/sql/sql_db.cc @@ -26,6 +26,7 @@ #ifdef __WIN__ #include <direct.h> #endif +#include "debug_sync.h" #define MAX_DROP_TABLE_Q_LEN 1024 @@ -1702,6 +1703,8 @@ bool mysql_change_db(THD *thd, const LEX_STRING *new_db_name, bool force_switch) } #endif + DEBUG_SYNC(thd, "before_db_dir_check"); + if (check_db_dir_existence(new_db_file_name.str)) { if (force_switch) |