#At file:///home/dlenev/src/bzr/mysql-6.1-mil14/ based on revid:dlenev@stripped
2740 Dmitry Lenev 2009-05-26
WL#148 "Foreign keys".
Milestone 14 "DDL checks and changes: DROP, TRUNCATE, RENAME".
After-review changes in progress. Extracted DROP TABLE-specific
prelocking process into separate function. Also now DROP TABLE
uses the same approach for checking if table's foreign keys
allow impending operation as TRUNCATE and RENAME TABLE.
modified:
sql/fk_dd.cc
sql/fk_dd.h
sql/mysql_priv.h
sql/sql_class.cc
sql/sql_class.h
sql/sql_delete.cc
sql/sql_rename.cc
sql/sql_table.cc
=== modified file 'sql/fk_dd.cc'
--- a/sql/fk_dd.cc 2009-05-15 12:46:44 +0000
+++ b/sql/fk_dd.cc 2009-05-25 20:19:16 +0000
@@ -2708,3 +2708,116 @@ bool fk_take_mdl_on_fk_names(THD *thd, T
return FALSE;
}
+
+
+/**
+ Check if table which is going to be affected by the statement has certain
+ property (related to its foreign keys) which makes it illegal for use in
+ this statement.
+
+ @param thd Thread context.
+ @param table TABLE_LIST element for the table to be affected.
+ @param error_silencer Object which specifies how errors during opening of
+ table definition should be handled.
+ @param checker Object which specifies what property should be
+ checked and what error should be emitted if table
+ has this property.
+
+ @retval FALSE Tables does not have property specified by 'checker'.
+ Statement can proceed.
+ @retval TRUE It is either illegal to use this table in the statement
+ (an appropriate error was emitted) or we have failed to
+ open table definition.
+*/
+
+bool
+fk_check_if_illegal_statement(THD *thd, TABLE_LIST *table,
+ Silence_open_table_def_error *error_silencer,
+ Table_property_checker *checker)
+{
+ char key[MAX_DBKEY_LENGTH];
+ uint key_length;
+ TABLE_SHARE *share;
+ int error;
+ bool result= FALSE;
+
+
+ key_length= create_table_def_key(thd, key, table, 0);
+
+ thd->push_internal_handler(error_silencer);
+ pthread_mutex_lock(&LOCK_open);
+ share= get_table_share_with_create(thd, table, key, key_length, OPEN_VIEW,
+ &error);
+ pthread_mutex_unlock(&LOCK_open);
+ thd->pop_internal_handler();
+
+ if (share)
+ {
+ result= checker->check(share);
+
+ pthread_mutex_lock(&LOCK_open);
+ release_table_share(share);
+ pthread_mutex_unlock(&LOCK_open);
+ return result;
+ }
+ else
+ {
+ return error_silencer->has_unhandled_errors();
+ }
+}
+
+
+/**
+ Check if table which is going to be affected by the statement has
+ any foreign keys associated with it and if yes emit an error that
+ it is illegal to use such table in the statement.
+
+ @param share TABLE_SHARE for the table to be checked.
+
+ @retval FALSE There are no foreign keys associated. Statement can proceed.
+ @retval TRUE There are foreign keys, error was emitted.
+*/
+
+bool Stmt_illegal_if_fks_checker::check(TABLE_SHARE *share)
+{
+ if (! share->fkeys.fkeys_child.is_empty() ||
+ ! share->fkeys.fkeys_parent.is_empty())
+ {
+ my_error(ER_FK_STATEMENT_ILLEGAL, MYF(0), m_statement, share->table_name.str);
+ return TRUE;
+ }
+ return FALSE;
+}
+
+
+/**
+ Check if table which is going to be affected by TRUNCATE TABLE
+ is a parent table in some non-self-referencing foreign key and
+ if yes emit an error that it is illegal to truncate such table.
+
+ @param share TABLE_SHARE for the table to be checked.
+
+ @retval FALSE This table is not parent in a non-self-referencing foreign
+ key. Statement can proceed.
+ @retval TRUE This table is parent in a non-self-referencing foreign key,
+ error was emitted.
+*/
+
+bool Truncate_illegal_if_parent_checker::check(TABLE_SHARE *share)
+{
+ List_iterator<Foreign_key_parent_share> fk_it(share->fkeys.fkeys_parent);
+ Foreign_key_parent_share *fk_s;
+
+ while ((fk_s= fk_it++))
+ {
+ if (share->db.length != fk_s->child_table_db.length ||
+ strcmp(share->db.str, fk_s->child_table_db.str) ||
+ share->table_name.length != fk_s->child_table_name.length ||
+ strcmp(share->table_name.str, fk_s->child_table_name.str))
+ {
+ my_error(ER_FK_TRUNCATE_ILLEGAL, MYF(0));
+ return TRUE;
+ }
+ }
+ return FALSE;
+}
=== modified file 'sql/fk_dd.h'
--- a/sql/fk_dd.h 2009-05-15 12:46:44 +0000
+++ b/sql/fk_dd.h 2009-05-25 20:19:16 +0000
@@ -213,4 +213,58 @@ protected:
};
+/**
+ Base class for helper classes specifying check to be carried out
+ and error to be emitted by fk_check_if_illegal_statement().
+*/
+
+class Table_property_checker
+{
+public:
+
+ virtual ~Table_property_checker() {}
+
+ virtual bool check(TABLE_SHARE *share) = 0;
+};
+
+
+/**
+ Helper class which allows to check if table participates in some
+ foreign keys and therefore it is illegal to use this table in
+ this statement.
+*/
+
+class Stmt_illegal_if_fks_checker : public Table_property_checker
+{
+public:
+
+ Stmt_illegal_if_fks_checker(const char *statement)
+ : m_statement(statement)
+ {}
+
+ virtual bool check(TABLE_SHARE *share);
+
+private:
+ const char *m_statement;
+};
+
+
+/**
+ Helper class which allows to check if table on which TRUNCATE TABLE
+ is going to be performed is parent table in some non-self-referencing
+ foreign key and therefore it is illegal to truncate it.
+*/
+
+class Truncate_illegal_if_parent_checker : public Table_property_checker
+{
+public:
+
+ virtual bool check(TABLE_SHARE *share);
+};
+
+bool
+fk_check_if_illegal_statement(THD *thd, TABLE_LIST *table,
+ Silence_open_table_def_error *error_silencer,
+ Table_property_checker *checker);
+
#endif
=== modified file 'sql/mysql_priv.h'
--- a/sql/mysql_priv.h 2009-05-19 05:21:08 +0000
+++ b/sql/mysql_priv.h 2009-05-25 20:19:16 +0000
@@ -1079,12 +1079,6 @@ bool mysql_rm_db(THD *thd,char *db,bool
bool mysql_upgrade_db(THD *thd, LEX_STRING *old_db);
void mysql_binlog_send(THD* thd, char* log_ident, my_off_t pos, ushort flags);
void mysql_client_binlog_statement(THD *thd);
-bool fk_stmt_illegal_if_has_fks(TABLE_SHARE *share, const char *statement);
-bool fk_truncate_illegal_if_parent(TABLE_SHARE *share, const char *statement);
-bool
-fk_check_if_illegal_statement(THD *thd, TABLE_LIST *table,
- bool (*check_func)(TABLE_SHARE *, const char *),
- const char *statement);
bool mysql_rm_table(THD *thd,TABLE_LIST *tables, my_bool if_exists,
my_bool drop_temporary);
int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
=== modified file 'sql/sql_class.cc'
--- a/sql/sql_class.cc 2009-05-05 04:45:37 +0000
+++ b/sql/sql_class.cc 2009-05-25 20:19:16 +0000
@@ -466,6 +466,62 @@ bool Drop_table_error_handler::handle_co
}
+/**
+ Do not silence any errors.
+*/
+
+bool
+Silence_no_error::handle_condition(THD *, uint, const char *,
+ MYSQL_ERROR::enum_warning_level,
+ const char *,
+ MYSQL_ERROR **condition)
+{
+ *condition= NULL;
+ m_has_unhandled_errors++;
+ return FALSE;
+}
+
+
+/**
+ Silence ER_NO_SUCH_TABLE errors, e.g. during opening of table definition.
+*/
+
+bool
+Silence_no_such_table_error::handle_condition(THD *,
+ uint sql_errno,
+ const char *,
+ MYSQL_ERROR::enum_warning_level,
+ const char *,
+ MYSQL_ERROR **condition)
+{
+ *condition= NULL;
+ if (sql_errno == ER_NO_SUCH_TABLE)
+ return TRUE;
+ m_has_unhandled_errors++;
+ return FALSE;
+}
+
+
+/**
+ Silence all non-fatal, non-transient errors which can occur, e.g. during
+ opening of table definition.
+*/
+
+bool Silence_non_fatal_non_transient_error::
+handle_condition(THD *thd, uint sql_errno, const char *,
+ MYSQL_ERROR::enum_warning_level, const char *,
+ MYSQL_ERROR **condition)
+{
+ *condition= NULL;
+ if (thd->is_fatal_error || sql_errno == ER_CANT_OPEN_FILE)
+ {
+ m_has_unhandled_errors++;
+ return FALSE;
+ }
+ return TRUE;
+}
+
+
THD::THD()
:Statement(&main_lex, &main_mem_root, CONVENTIONAL_EXECUTION,
/* statement id */ 0),
=== modified file 'sql/sql_class.h'
--- a/sql/sql_class.h 2009-05-15 12:06:19 +0000
+++ b/sql/sql_class.h 2009-05-25 20:19:16 +0000
@@ -1572,6 +1572,76 @@ private:
/**
+ Base class for internal error handler used for silencing errors
+ which can occur, e.g. during opening of table definition.
+*/
+
+class Silence_open_table_def_error: public Internal_error_handler
+{
+public:
+
+ Silence_open_table_def_error()
+ : m_has_unhandled_errors(0)
+ {}
+
+ bool has_unhandled_errors() { return m_has_unhandled_errors != 0; }
+
+protected:
+ uint m_has_unhandled_errors;
+};
+
+
+/**
+ Internal error handler which doesn't silence any errors.
+*/
+
+class Silence_no_error: public Silence_open_table_def_error
+{
+public:
+ virtual bool handle_condition(THD *thd,
+ uint sql_errno,
+ const char *sqlstate,
+ MYSQL_ERROR::enum_warning_level level,
+ const char *msg,
+ MYSQL_ERROR **condition);
+};
+
+
+/**
+ Internal error handler which allows to silence ER_NO_SUCH_TABLE
+ errors, e.g. during opening of table definition.
+*/
+
+class Silence_no_such_table_error: public Silence_open_table_def_error
+{
+public:
+ virtual bool handle_condition(THD *thd,
+ uint sql_errno,
+ const char *sqlstate,
+ MYSQL_ERROR::enum_warning_level level,
+ const char *msg,
+ MYSQL_ERROR **condition);
+};
+
+
+/**
+ Internal error handler which allows to silence all non-fatal, non-transient
+ errors which can occur, e.g. during opening of table definition.
+*/
+
+class Silence_non_fatal_non_transient_error: public Silence_open_table_def_error
+{
+public:
+ virtual bool handle_condition(THD *thd,
+ uint sql_errno,
+ const char *sqlstate,
+ MYSQL_ERROR::enum_warning_level level,
+ const char *msg,
+ MYSQL_ERROR **condition);
+};
+
+
+/**
Tables that were locked with LOCK TABLES statement.
Encapsulates a list of TABLE_LIST instances for tables
=== modified file 'sql/sql_delete.cc'
--- a/sql/sql_delete.cc 2009-05-19 05:21:08 +0000
+++ b/sql/sql_delete.cc 2009-05-25 20:19:16 +0000
@@ -26,6 +26,7 @@
#include "sql_trigger.h"
#include "transaction.h"
#include "fk.h"
+#include "fk_dd.h"
/**
@@ -153,11 +154,19 @@ bool mysql_delete(THD *thd, TABLE_LIST *
}
if (thd->lex->sql_command == SQLCOM_TRUNCATE &&
- opt_fk_all_engines &&
- fk_truncate_illegal_if_parent(table->s, "TRUNCATE"))
+ opt_fk_all_engines)
{
- MYSQL_DELETE_DONE(1, 0);
- DBUG_RETURN(TRUE);
+ /*
+ Check that we are not truncating table which is
+ parent for some other table.
+ */
+ Truncate_illegal_if_parent_checker fk_checker;
+
+ if (fk_checker.check(table->s))
+ {
+ MYSQL_DELETE_DONE(1, 0);
+ DBUG_RETURN(TRUE);
+ }
}
thd_proc_info(thd, "init");
@@ -1207,13 +1216,21 @@ bool mysql_truncate(THD *thd, TABLE_LIST
DBUG_RETURN(TRUE);
}
- if (opt_fk_all_engines &&
- fk_check_if_illegal_statement(thd, table_list,
- fk_truncate_illegal_if_parent,
- "TRUNCATE"))
+ if (opt_fk_all_engines)
{
- error= 1;
- goto end;
+ /*
+ Check that we are not going to truncate table which is parent
+ of some other table.
+ */
+ Truncate_illegal_if_parent_checker fk_checker;
+ Silence_no_error no_error_silencer;
+
+ if (fk_check_if_illegal_statement(thd, table_list, &no_error_silencer,
+ &fk_checker))
+ {
+ error= 1;
+ goto end;
+ }
}
pthread_mutex_lock(&LOCK_open);
=== modified file 'sql/sql_rename.cc'
--- a/sql/sql_rename.cc 2009-05-19 05:21:08 +0000
+++ b/sql/sql_rename.cc 2009-05-25 20:19:16 +0000
@@ -19,6 +19,7 @@
#include "mysql_priv.h"
#include "sql_trigger.h"
+#include "fk_dd.h"
static TABLE_LIST *rename_tables(THD *thd, TABLE_LIST *table_list,
@@ -146,12 +147,23 @@ bool mysql_rename_tables(THD *thd, TABLE
if (opt_fk_all_engines)
{
+ /*
+ We have to silence ER_NO_SUCH_TABLE error to allow execution of
+ statements like "RENAME TABLES t1 TO t3, t2 TO t1, t3 TO t1"
+ (i.e. statements in which some table being renamed is not yet
+ exists at the start). It does not make sense to ignore other
+ errors as in this case further execution of the RENAME statement
+ is likely to fail anyway.
+ */
+ Stmt_illegal_if_fks_checker fk_checker("RENAME TABLE");
+ Silence_no_such_table_error no_such_table_error_silencer;
+
for (ren_table= table_list; ren_table;
ren_table= ren_table->next_local->next_local)
{
if (fk_check_if_illegal_statement(thd, ren_table,
- fk_stmt_illegal_if_has_fks,
- "RENAME TABLE"))
+ &no_such_table_error_silencer,
+ &fk_checker))
{
error= 1;
goto err_unlock;
=== modified file 'sql/sql_table.cc'
--- a/sql/sql_table.cc 2009-05-23 06:58:20 +0000
+++ b/sql/sql_table.cc 2009-05-25 20:19:16 +0000
@@ -1533,172 +1533,6 @@ bool mysql_rm_table(THD *thd,TABLE_LIST
/**
- Check if table which is going to be affected by the statement has
- any foreign keys associated with it and if yes emit an error that
- it is illegal to use such table in the statement.
-
- @param share TABLE_SHARE for the table to be affected.
- @param statement Name of the statement to be used in the error message.
-
- @retval FALSE There are no foreign keys associated. Statement can proceed.
- @retval TRUE There are foreign keys, error was emitted.
-*/
-
-bool fk_stmt_illegal_if_has_fks(TABLE_SHARE *share, const char *statement)
-{
- if (! share->fkeys.fkeys_child.is_empty() ||
- ! share->fkeys.fkeys_parent.is_empty())
- {
- my_error(ER_FK_STATEMENT_ILLEGAL, MYF(0), statement, share->table_name.str);
- return TRUE;
- }
- return FALSE;
-}
-
-
-/**
- Check if table which is going to be affected by the statement is a
- parent table in some non-self-referencing foreign key and if yes
- emit an error that it is illegal to use such table in TRUNCATE TABLE.
-
- @param share TABLE_SHARE for the table to be affected.
- @param statement Name of the statement to be used in the error message.
-
- @retval FALSE This table is not parent in a non-self-referencing foreign
- key. Statement can proceed.
- @retval TRUE There are foreign keys, error was emitted.
-*/
-
-bool fk_truncate_illegal_if_parent(TABLE_SHARE *share, const char *statement)
-{
- List_iterator<Foreign_key_parent_share> fk_it(share->fkeys.fkeys_parent);
- Foreign_key_parent_share *fk_s;
-
- while ((fk_s= fk_it++))
- {
- if (share->db.length != fk_s->child_table_db.length ||
- strcmp(share->db.str, fk_s->child_table_db.str) ||
- share->table_name.length != fk_s->child_table_name.length ||
- strcmp(share->table_name.str, fk_s->child_table_name.str))
- {
- my_error(ER_FK_TRUNCATE_ILLEGAL, MYF(0));
- return TRUE;
- }
- }
- return FALSE;
-}
-
-
-/**
- Silence ER_NO_SUCH_TABLE error during opening of table definition.
-*/
-
-class Silence_no_such_table_error : public Internal_error_handler
-{
-public:
- Silence_no_such_table_error()
- : m_unhandled_errors(0)
- {}
-
- virtual ~Silence_no_such_table_error() {}
-
- virtual bool handle_condition(THD *thd,
- uint sql_errno,
- const char *sqlstate,
- MYSQL_ERROR::enum_warning_level level,
- const char *msg,
- MYSQL_ERROR **condition);
-
- bool not_trapped_errors() { return m_unhandled_errors != 0; }
-
-private:
- int m_unhandled_errors;
-};
-
-
-bool
-Silence_no_such_table_error::handle_condition(THD *,
- uint sql_errno,
- const char *,
- MYSQL_ERROR::enum_warning_level,
- const char *,
- MYSQL_ERROR **condition)
-{
- *condition= NULL;
-
- if (sql_errno == ER_NO_SUCH_TABLE)
- {
- return TRUE;
- }
-
- m_unhandled_errors++;
- return FALSE;
-}
-
-
-/**
- Check if table which is going to be affected by the statement has certain
- property (related to its foreign keys) and if yes emit an appropriate error
- that it is illegal to use such table in the statement.
-
- @param thd Thread context.
- @param table TABLE_LIST element for the table to be affected.
- @param check_func Function which checks if table has certain property
- which makes it illegal to use within particular
- statement and emits appropriate error message.
- @param statement Name of the statement to be used in the error message.
-
- @retval FALSE There are no foreign keys associated. Statement can proceed.
- @retval TRUE There are foreign keys, error was emitted.
-*/
-
-bool
-fk_check_if_illegal_statement(THD *thd, TABLE_LIST *table,
- bool (*check_func)(TABLE_SHARE *, const char *),
- const char *statement)
-{
- char key[MAX_DBKEY_LENGTH];
- uint key_length;
- Silence_no_such_table_error no_such_table_error_silencer;
- TABLE_SHARE *share;
- int error;
- bool result= FALSE;
-
-
- key_length= create_table_def_key(thd, key, table, 0);
-
- /*
- We have to silence ER_NO_SUCH_TABLE error to allow execution of statements
- like "RENAME TABLES t1 TO t3, t2 TO t1, t3 TO t1" (i.e. statements in which
- some table being renamed is not yet exists at the start).
- It does not make sense to ignore other errors as in this case further
- execution of statement calling fk_illegal_statement_if_has_fks() is
- likely to fail anyway.
- */
- thd->push_internal_handler(& no_such_table_error_silencer);
- pthread_mutex_lock(&LOCK_open);
- share= get_table_share_with_create(thd, table, key, key_length, OPEN_VIEW,
- &error);
- pthread_mutex_unlock(&LOCK_open);
- thd->pop_internal_handler();
-
- if (share)
- {
- result= (*check_func)(share, statement);
-
- pthread_mutex_lock(&LOCK_open);
- release_table_share(share);
- pthread_mutex_unlock(&LOCK_open);
- return result;
- }
- else
- {
- return no_such_table_error_silencer.not_trapped_errors();
- }
-}
-
-
-/**
Create TABLE_LIST object representing a parent table for the child
table being dropped and add it to the table list.
@@ -1714,10 +1548,10 @@ fk_check_if_illegal_statement(THD *thd,
@retval TRUE Failure (OOM).
*/
-static bool fk_drop_table_add_parent_table(THD *thd,
- TABLE_LIST **local_table_list,
- const LEX_STRING &db,
- const LEX_STRING &table_name)
+static bool drop_table_add_parent_table(THD *thd,
+ TABLE_LIST **local_table_list,
+ const LEX_STRING &db,
+ const LEX_STRING &table_name)
{
TABLE_LIST *table;
@@ -1848,51 +1682,6 @@ private:
/**
- Silence all non-fatal, non-transient errors which can occur during
- opening of table definition.
-*/
-
-class Silence_non_fatal_non_transient_error : public Internal_error_handler
-{
-public:
- Silence_non_fatal_non_transient_error()
- : m_unhandled_errors(0)
- {}
-
- virtual ~Silence_non_fatal_non_transient_error() {}
-
- virtual bool handle_condition(THD *thd,
- uint sql_errno,
- const char *sqlstate,
- MYSQL_ERROR::enum_warning_level level,
- const char *msg,
- MYSQL_ERROR **condition);
-
- bool not_trapped_errors() { return m_unhandled_errors != 0; }
-
-private:
- int m_unhandled_errors;
-};
-
-
-bool Silence_non_fatal_non_transient_error::
-handle_condition(THD *thd, uint sql_errno, const char *,
- MYSQL_ERROR::enum_warning_level, const char *,
- MYSQL_ERROR **condition)
-{
- *condition= NULL;
-
- if (thd->is_fatal_error || sql_errno == ER_CANT_OPEN_FILE)
- {
- m_unhandled_errors++;
- return FALSE;
- }
-
- return TRUE;
-}
-
-
-/**
Prepare context for drop table operation by preparing Parent_info
objects describing related tables from which foreign keys involving
table being dropped were removed.
@@ -1926,7 +1715,7 @@ Foreign_key_ddl_rcontext::prepare_drop_t
Don't drop foreign keys from .FRMs of temporary tables which are
left from aborted ALTER TABLE.
- See comment in fk_check_tables_before_drop() function.
+ See comment in drop_table_check_locks() function.
*/
if (drop_table->internal_tmp_table)
return FALSE;
@@ -1944,7 +1733,7 @@ Foreign_key_ddl_rcontext::prepare_drop_t
in order to avoid errors when attempting to drop non-existing table
or table with corrupted .FRMs.
- @sa Comment in fk_check_tables_before_drop().
+ @sa Comment in drop_table_check_locks().
*/
m_thd->push_internal_handler(&non_fatal_error_silencer);
pthread_mutex_lock(&LOCK_open);
@@ -1954,7 +1743,7 @@ Foreign_key_ddl_rcontext::prepare_drop_t
if (!share)
{
- return non_fatal_error_silencer.not_trapped_errors();
+ return non_fatal_error_silencer.has_unhandled_errors();
}
List_iterator<Foreign_key_child_share> fkeys_it(share->fkeys.fkeys_child);
@@ -2117,7 +1906,7 @@ Foreign_key_ddl_rcontext::prepare_drop_t
This also covers cases when table needs repair or its definition
in the engine has changed.
*/
- if (no_such_table_error_silencer.not_trapped_errors())
+ if (no_such_table_error_silencer.has_unhandled_errors())
return TRUE;
/* In case of ER_NO_SUCH_TABLE simply remove table from the list. */
tab_it.remove();
@@ -2200,10 +1989,6 @@ void Foreign_key_ddl_rcontext::cleanup()
@param parents Additional tables to lock.
@param fk_names List of foreign key names to lock.
- @note Unlike for tables from the first list for tables from
- 'parents' list this functions assumes that meta-data lock
- requests objects are allocated by caller.
-
@retval FALSE Success.
@retval TRUE Failure.
*/
@@ -2364,11 +2149,9 @@ err_tables:
/**
- Check if among tables being dropped there are tables which participate
- as a parent in foreign key and for which corresponding child table is
- not dropped. Also find out if we have all necessary metadata locks for
- this operation and create list of tables and foreign key names to be
- additionally locked if not.
+ Find out if we have all necessary metadata locks for dropping tables
+ and create list of tables and foreign key names to be additionally
+ locked if not.
@param[in] thd Thread context.
@param[in] tables List of tables to be dropped.
@@ -2389,13 +2172,12 @@ err_tables:
*/
static bool
-fk_check_tables_before_drop(THD *thd,
- TABLE_LIST *tables,
- TABLE_LIST **parents_to_lock,
- List<Foreign_key_name> *fk_names_to_lock,
- bool *has_not_locked_parent_or_fk_name)
+drop_table_check_locks(THD *thd, TABLE_LIST *tables,
+ TABLE_LIST **parents_to_lock,
+ List<Foreign_key_name> *fk_names_to_lock,
+ bool *has_not_locked_parent_or_fk_name)
{
- TABLE_LIST *table, *tab;
+ TABLE_LIST *table;
TABLE_SHARE *share;
char key[MAX_DBKEY_LENGTH];
uint key_length;
@@ -2449,7 +2231,7 @@ fk_check_tables_before_drop(THD *thd,
pthread_mutex_unlock(&LOCK_open);
thd->pop_internal_handler();
- if (!share && non_fatal_error_silencer.not_trapped_errors())
+ if (!share && non_fatal_error_silencer.has_unhandled_errors())
return TRUE;
if (share)
@@ -2458,26 +2240,8 @@ fk_check_tables_before_drop(THD *thd,
fkeys.fkeys_parent);
Foreign_key_parent_share *fk_p_s;
- /*
- For all foreign keys in which table to be dropped serves as parent
- check that we also going to drop child table.
- */
while ((fk_p_s= fkeys_p_it++))
{
- if (! (tab= find_table_in_local_list(tables, fk_p_s->child_table_db.str,
- fk_p_s->child_table_name.str)) ||
- tab->drop_table_rctx->is_temporary)
- {
- my_error(ER_FK_CHILD_TABLE_EXISTS, MYF(0), fk_p_s->name.str,
- thd->lex->sql_command == SQLCOM_DROP_DB ? "DROP DATABASE" :
- "DROP TABLE",
- table->table_name);
- pthread_mutex_lock(&LOCK_open);
- release_table_share(share);
- pthread_mutex_unlock(&LOCK_open);
- return TRUE;
- }
-
/*
Adding name of foreign key to the list of names to be locked
when processing Foreign_key_parent_share is needed in order
@@ -2523,9 +2287,9 @@ fk_check_tables_before_drop(THD *thd,
table->db, fk_c_s->name.str)))
*has_not_locked_parent_or_fk_name= TRUE;
- if (fk_drop_table_add_parent_table(thd, parents_to_lock,
- fk_c_s->parent_table_db,
- fk_c_s->parent_table_name))
+ if (drop_table_add_parent_table(thd, parents_to_lock,
+ fk_c_s->parent_table_db,
+ fk_c_s->parent_table_name))
{
pthread_mutex_lock(&LOCK_open);
release_table_share(share);
@@ -2559,12 +2323,10 @@ fk_check_tables_before_drop(THD *thd,
/**
- Check if among tables being dropped there are tables which participate
- as a parent in foreign key and for which corresponding child table is
- not dropped. Also find out if we have all necessary table-level locks
- on parent tables for this operation. Create list of parent tables which
- are not among tables to be dropped and list of foreign key names with
- appropriate metadata locks.
+ Find out if we have all necessary table-level locks on parent tables for
+ tables to be dropped. Create list of parent tables which are not among
+ tables to be dropped and list of foreign key names with appropriate
+ metadata locks.
@param[in] thd Thread context.
@param[in] tables List of tables to be dropped.
@@ -2579,9 +2341,9 @@ fk_check_tables_before_drop(THD *thd,
*/
static bool
-fk_check_tables_before_drop(THD *thd,
- TABLE_LIST *tables, TABLE_LIST **parents_locked,
- List<Foreign_key_name> *fk_names_locked)
+drop_table_check_locks(THD *thd, TABLE_LIST *tables,
+ TABLE_LIST **parents_locked,
+ List<Foreign_key_name> *fk_names_locked)
{
TABLE_LIST *table, *tab;
TABLE_SHARE *share;
@@ -2595,24 +2357,6 @@ fk_check_tables_before_drop(THD *thd,
share= table->table->s;
- List_iterator<Foreign_key_parent_share> fkeys_p_it(share->
- fkeys.fkeys_parent);
- Foreign_key_parent_share *fk_p_s;
-
- while ((fk_p_s= fkeys_p_it++))
- {
- if (! (tab= find_table_in_local_list(tables, fk_p_s->child_table_db.str,
- fk_p_s->child_table_name.str)) ||
- tab->drop_table_rctx->is_temporary)
- {
- my_error(ER_FK_CHILD_TABLE_EXISTS, MYF(0), fk_p_s->name.str,
- thd->lex->sql_command == SQLCOM_DROP_DB ? "DROP DATABASE" :
- "DROP TABLE",
- table->table_name);
- return TRUE;
- }
- }
-
List_iterator<Foreign_key_child_share> fkeys_c_it(share->fkeys.fkeys_child);
Foreign_key_child_share *fk_c_s;
@@ -2626,9 +2370,9 @@ fk_check_tables_before_drop(THD *thd,
fk_c_s->parent_table_db.str,
fk_c_s->parent_table_name.str))
{
- if (fk_drop_table_add_parent_table(thd, parents_locked,
- fk_c_s->parent_table_db,
- fk_c_s->parent_table_name))
+ if (drop_table_add_parent_table(thd, parents_locked,
+ fk_c_s->parent_table_db,
+ fk_c_s->parent_table_name))
return TRUE;
if (! ((*parents_locked)->table=
@@ -2660,6 +2404,117 @@ fk_check_tables_before_drop(THD *thd,
}
+/**
+ Get all necessary metadata locks for dropping tables (including
+ modification of .FRMs of parent tables), create list of tables
+ which were locked in addition to tables being dropped and similar
+ list of foreign key names.
+
+ @param[in] thd Thread context.
+ @param[in] tables List of tables to be dropped.
+ @param[out] parents_locked List of parent tables which were additionally
+ locked.
+ @param[out] fk_names_locked List of foreign key names which were locked.
+
+ @retval FALSE Success.
+ @retval TRUE Failure (e.g OOM, connection/statement was killed).
+*/
+
+static bool drop_table_lock_tables(THD *thd, TABLE_LIST *tables,
+ TABLE_LIST **parents_locked,
+ List<Foreign_key_name> *fk_names_locked)
+{
+ TABLE_LIST *parents_to_lock= NULL;
+ List<Foreign_key_name> fk_names_to_lock;
+ bool has_not_locked_parent_or_fk_name;
+
+ while (1)
+ {
+ if (lock_dropped_and_parent_tables(thd, tables, parents_to_lock,
+ fk_names_to_lock))
+ return TRUE;
+ *parents_locked= parents_to_lock;
+ *fk_names_locked= fk_names_to_lock;
+
+ if (opt_fk_all_engines)
+ {
+ if (drop_table_check_locks(thd, tables,
+ &parents_to_lock, &fk_names_to_lock,
+ &has_not_locked_parent_or_fk_name))
+ return TRUE;
+
+ if (has_not_locked_parent_or_fk_name)
+ {
+ thd->mdl_context.release_all_locks();
+ thd->mdl_context.remove_all_requests();
+ /* Retry acquiring all necessary metadata locks. */
+ continue;
+ }
+ }
+ break;
+ }
+ return FALSE;
+}
+
+
+/**
+ Helper class which allows to perform check that DROP TABLE/DATABASE
+ statement doesn't try to drop table which is parent for some other
+ table not to be dropped.
+*/
+
+class Drop_table_illegal_if_parent_checker : public Table_property_checker
+{
+public:
+
+ Drop_table_illegal_if_parent_checker(const char *statement,
+ TABLE_LIST *tables)
+ : m_statement(statement), m_dropped_tables(tables)
+ {}
+
+ virtual bool check(TABLE_SHARE *share);
+
+private:
+ const char *m_statement;
+ TABLE_LIST *m_dropped_tables;
+};
+
+
+/**
+ Check if table which is going to be dropped is a parent table for
+ some table which is not dropped. If yes emit an error that it is
+ illegal to do that in DROP TABLE/DATABASE statement.
+
+ @param share TABLE_SHARE for the table to be checked.
+
+ @retval FALSE This table is not parent for some table which is not
+ to be dropped. Statement can proceed.
+ @retval TRUE This table is parent table for some table which is
+ not to be dropped. Error was emitted.
+*/
+
+bool Drop_table_illegal_if_parent_checker::check(TABLE_SHARE *share)
+{
+ List_iterator<Foreign_key_parent_share> fk_it(share->fkeys.fkeys_parent);
+ Foreign_key_parent_share *fk_s;
+ TABLE_LIST *tab;
+
+ while ((fk_s= fk_it++))
+ {
+ if (! (tab= find_table_in_local_list(m_dropped_tables,
+ fk_s->child_table_db.str,
+ fk_s->child_table_name.str)) ||
+ tab->drop_table_rctx->is_temporary)
+ {
+ my_error(ER_FK_CHILD_TABLE_EXISTS, MYF(0), fk_s->name.str, m_statement,
+ share->table_name.str);
+ return TRUE;
+ }
+ }
+ return FALSE;
+}
+
+
/*
Execute the drop of a normal or temporary table
@@ -2702,9 +2557,8 @@ int mysql_rm_table_part2(THD *thd, TABLE
int non_temp_tables_count= 0;
bool some_tables_deleted=0, tmp_table_deleted=0, foreign_key_error=0;
String built_query;
- bool has_not_locked_parent_or_fk_name;
- TABLE_LIST *parents_to_lock= NULL, *parents_locked= NULL;
- List<Foreign_key_name> fk_names_to_lock, fk_names_locked;
+ TABLE_LIST *parents_locked= NULL;
+ List<Foreign_key_name> fk_names_locked;
List_iterator<Foreign_key_name> fk_names_it(fk_names_locked);
Foreign_key_name *fk_name;
DBUG_ENTER("mysql_rm_table_part2");
@@ -2779,25 +2633,36 @@ int mysql_rm_table_part2(THD *thd, TABLE
if (!thd->locked_tables_mode)
{
-retry_lock:
- if (lock_dropped_and_parent_tables(thd, tables,
- parents_to_lock, fk_names_to_lock))
+ if (drop_table_lock_tables(thd, tables, &parents_locked,
+ &fk_names_locked))
DBUG_RETURN(1);
- parents_locked= parents_to_lock;
- fk_names_locked= fk_names_to_lock;
if (opt_fk_all_engines)
{
- if (fk_check_tables_before_drop(thd, tables,
- &parents_to_lock, &fk_names_to_lock,
- &has_not_locked_parent_or_fk_name))
- DBUG_RETURN(1);
+ /*
+ For all foreign keys in which table to be dropped serves as parent
+ check that we also going to drop child table.
+
+ Ignore ER_NO_SUCH_TABLE and other non-fatal, non-transient errors
+ in order to be able to drop non-existing or corrupted tables.
+ */
+ Drop_table_illegal_if_parent_checker checker(((thd->lex->sql_command ==
+ SQLCOM_DROP_DB) ?
+ "DROP DATABASE" :
+ "DROP TABLE"),
+ tables);
+ Silence_non_fatal_non_transient_error non_fatal_error_silencer;
- if (has_not_locked_parent_or_fk_name)
+ for (table= tables; table; table= table->next_local)
{
- thd->mdl_context.release_all_locks();
- thd->mdl_context.remove_all_requests();
- goto retry_lock;
+ if (! table->drop_table_rctx->is_temporary &&
+ ! table->internal_tmp_table)
+ {
+ if (fk_check_if_illegal_statement(thd, table,
+ &non_fatal_error_silencer,
+ &checker))
+ DBUG_RETURN(1);
+ }
}
}
}
@@ -2820,16 +2685,28 @@ retry_lock:
}
}
+ if (opt_fk_all_engines)
+ {
+ /*
+ Check that we are not dropping parent tables without dropping
+ child tables.
+ */
+ Drop_table_illegal_if_parent_checker fk_checker("DROP TABLE", tables);
+
+ for (table= tables; table; table= table->next_local)
+ if (fk_checker.check(table->table->s))
+ DBUG_RETURN(1);
+ }
+
/*
- Check that we are not dropping parent tables withour dropping child
- tables and that for all parent tables for child tables being dropped
+ Check that that for all parent tables for child tables being dropped
we have a write lock so we can safely upgrade meta-data lock before
- changing their .FRM. Finally, create list of parent tables which are
- not among tables to be dropped to use for this upgrade.
+ changing their .FRM. Also create list of parent tables which are not
+ among tables to be dropped to use for this upgrade.
*/
if (opt_fk_all_engines &&
- fk_check_tables_before_drop(thd, tables, &parents_locked,
- &fk_names_locked))
+ drop_table_check_locks(thd, tables, &parents_locked,
+ &fk_names_locked))
DBUG_RETURN(1);
/*
Attachment: [text/bzr-bundle] bzr/dlenev@mysql.com-20090525201916-9rm2b8e6axf1233b.bundle
| Thread |
|---|
| • bzr commit into mysql-6.1-fk branch (dlenev:2740) WL#148 | Dmitry Lenev | 25 May |
