Merge bk-internal.mysql.com:/home/bk/mysql-4.1

into  mysql.com:/home/dlenev/src/mysql-4.1-bg12423


sql/mysqld.cc:
  Auto merged
sql/sql_acl.cc:
  Auto merged
sql/sql_parse.cc:
  Auto merged
mysql-test/r/grant2.result:
  Manual merge.
mysql-test/t/grant2.test:
  Manual merge.

mysql-test/r/grant2.result

@@ -122,3 +122,12 @@ flush privileges;
 drop database mysqltest_1;
 set password = password("changed");
 ERROR 42000: Access denied for user ''@'localhost' to database 'mysql'
+lock table mysql.user write;
+ flush privileges;
+ grant all on *.* to 'mysqltest_1'@'localhost';
+unlock tables;
+lock table mysql.user write;
+ set password for 'mysqltest_1'@'localhost' = password('');
+ revoke all on *.* from 'mysqltest_1'@'localhost';
+unlock tables;
+drop user 'mysqltest_1'@'localhost';

mysql-test/t/grant2.test

@@ -163,4 +163,47 @@ set password = password("changed");
 disconnect n5;
 connection default;
 
+
+# Bug #12423 "Deadlock when doing FLUSH PRIVILEGES and GRANT in 
+# multi-threaded environment". We should be able to execute FLUSH
+# PRIVILEGES and SET PASSWORD simultaneously with other account
+# management commands (such as GRANT and REVOKE) without causing
+# deadlocks. To achieve this we should ensure that all account
+# management commands take table and internal locks in the same order.
+connect (con2root,localhost,root,,);
+connect (con3root,localhost,root,,);
+# Check that we can execute FLUSH PRIVILEGES and GRANT simultaneously
+# This will check that locks are taken in proper order during both
+# user/db-level and table/column-level privileges reloading.
+connection default;
+lock table mysql.user write;
+connection con2root;
+send flush privileges;
+connection con3root;
+send grant all on *.* to 'mysqltest_1'@'localhost';
+connection default;
+unlock tables;
+connection con2root;
+reap;
+connection con3root;
+reap;
+# Check for simultaneous SET PASSWORD and REVOKE.
+connection default;
+lock table mysql.user write;
+connection con2root;
+send set password for 'mysqltest_1'@'localhost' = password('');
+connection con3root;
+send revoke all on *.* from 'mysqltest_1'@'localhost';
+connection default;
+unlock tables;
+connection con2root;
+reap;
+connection con3root;
+reap;
+connection default;
+# Clean-up
+drop user 'mysqltest_1'@'localhost';
+disconnect con2root;
+disconnect con3root;
+
 # End of 4.1 tests

sql/mysqld.cc

@@ -3080,7 +3080,7 @@ we force server id to 2, but this MySQL server will not act as a slave.");
   */
   error_handler_hook = my_message_sql;
   start_signal_handler();				// Creates pidfile
-  if (acl_init((THD *)0, opt_noacl) || 
+  if (acl_init(opt_noacl) ||
       my_tz_init((THD *)0, default_tz_name, opt_bootstrap))
   {
     abort_loop=1;
@@ -3097,7 +3097,7 @@ we force server id to 2, but this MySQL server will not act as a slave.");
     exit(1);
   }
   if (!opt_noacl)
-    (void) grant_init((THD *)0);
+    (void) grant_init();
 
 #ifdef HAVE_DLOPEN
   if (!opt_noacl)

sql/sql_acl.h

@@ -134,8 +134,8 @@ public:
 /* prototypes */
 
 bool hostname_requires_resolving(const char *hostname);
-my_bool  acl_init(THD *thd, bool dont_read_acl_tables);
-void acl_reload(THD *thd);
+my_bool  acl_init(bool dont_read_acl_tables);
+my_bool acl_reload(THD *thd);
 void acl_free(bool end=0);
 ulong acl_get(const char *host, const char *ip,
 	      const char *user, const char *db, my_bool db_is_pattern);
@@ -151,9 +151,9 @@ int mysql_grant(THD *thd, const char *db, List <LEX_USER> &user_list,
 int mysql_table_grant(THD *thd, TABLE_LIST *table, List <LEX_USER> &user_list,
 		      List <LEX_COLUMN> &column_list, ulong rights,
 		      bool revoke);
-my_bool grant_init(THD *thd);
+my_bool grant_init();
 void grant_free(void);
-void grant_reload(THD *thd);
+my_bool grant_reload(THD *thd);
 bool check_grant(THD *thd, ulong want_access, TABLE_LIST *tables,
 		 uint show_command, uint number, bool dont_print_error);
 bool check_grant_column (THD *thd,TABLE *table, const char *name, uint length,

sql/sql_parse.cc

@@ -4988,10 +4988,27 @@ bool reload_acl_and_cache(THD *thd, ulong options, TABLE_LIST *tables,
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   if (options & REFRESH_GRANT)
   {
-    acl_reload(thd);
-    grant_reload(thd);
-    if (mqh_used)
-      reset_mqh(thd,(LEX_USER *) NULL,TRUE);
+    THD *tmp_thd= 0;
+    /*
+      If reload_acl_and_cache() is called from SIGHUP handler we have to
+      allocate temporary THD for execution of acl_reload()/grant_reload().
+    */
+    if (!thd && (thd= (tmp_thd= new THD)))
+      thd->store_globals();
+    if (thd)
+    {
+      (void)acl_reload(thd);
+      (void)grant_reload(thd);
+      if (mqh_used)
+        reset_mqh(thd, (LEX_USER *) NULL, TRUE);
+    }
+    if (tmp_thd)
+    {
+      delete tmp_thd;
+      /* Remember that we don't have a THD */
+      my_pthread_setspecific_ptr(THR_THD,  0);
+      thd= 0;
+    }
   }
 #endif
   if (options & REFRESH_LOG)