Commit 51d80960 authored by ingo@mysql.com's avatar ingo@mysql.com

Bug#10224 - ANALYZE TABLE crashing with simultaneous CREATE ... SELECT statement.

1.) Added a new option to mysql_lock_tables() for ignoring FLUSH TABLES.
Used the new option in create_table_from_items().
It is necessary to prevent the SELECT table from being reopend.
It would get new storage assigned for its fields, while the
SELECT part of the command would still use the old (freed) storage.
2.) Protected the CREATE TABLE and CREATE TABLE ... SELECT commands
against a global read lock. This prevents a deadlock in
CREATE TABLE ... SELECT in conjunction with FLUSH TABLES WITH READ LOCK
and avoids the creation of new tables during a global read lock.
3.) Replaced set_protect_against_global_read_lock() and
unset_protect_against_global_read_lock() by
wait_if_global_read_lock() and start_waiting_global_read_lock()
in the INSERT DELAYED handling.
parent db8368fd
...@@ -228,3 +228,11 @@ create table t1 (a int,,b int); ...@@ -228,3 +228,11 @@ create table t1 (a int,,b int);
You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'b int)' at line 1 You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'b int)' at line 1
create table t1 (,b int); create table t1 (,b int);
You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'b int)' at line 1 You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'b int)' at line 1
create table t1 (a int);
create table t1 select * from t1;
INSERT TABLE 't1' isn't allowed in FROM table list
create table t2 union = (t1) select * from t1;
INSERT TABLE 't1' isn't allowed in FROM table list
flush tables with read lock;
unlock tables;
drop table t1;
...@@ -203,3 +203,18 @@ create table t1 (a int,); ...@@ -203,3 +203,18 @@ create table t1 (a int,);
create table t1 (a int,,b int); create table t1 (a int,,b int);
--error 1064 --error 1064
create table t1 (,b int); create table t1 (,b int);
#
# Bug#10224 - ANALYZE TABLE crashing with simultaneous
# CREATE ... SELECT statement.
# This tests two additional possible errors and a hang if
# an improper fix is present.
#
create table t1 (a int);
--error 1093
create table t1 select * from t1;
--error 1093
create table t2 union = (t1) select * from t1;
flush tables with read lock;
unlock tables;
drop table t1;
...@@ -79,8 +79,24 @@ static int unlock_external(THD *thd, TABLE **table,uint count); ...@@ -79,8 +79,24 @@ static int unlock_external(THD *thd, TABLE **table,uint count);
static void print_lock_error(int error); static void print_lock_error(int error);
MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count, /*
bool ignore_global_read_lock) Lock tables.
SYNOPSIS
mysql_lock_tables()
thd The current thread.
tables An array of pointers to the tables to lock.
count The number of tables to lock.
flags Options:
MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK Ignore a global read lock
MYSQL_LOCK_IGNORE_FLUSH Ignore a flush tables.
RETURN
A lock structure pointer on success.
NULL on error.
*/
MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count, uint flags)
{ {
MYSQL_LOCK *sql_lock; MYSQL_LOCK *sql_lock;
TABLE *write_lock_used; TABLE *write_lock_used;
...@@ -91,7 +107,8 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count, ...@@ -91,7 +107,8 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count,
if (!(sql_lock = get_lock_data(thd,tables,count, 0,&write_lock_used))) if (!(sql_lock = get_lock_data(thd,tables,count, 0,&write_lock_used)))
break; break;
if (global_read_lock && write_lock_used && ! ignore_global_read_lock) if (global_read_lock && write_lock_used &&
! (flags & MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK))
{ {
/* /*
Someone has issued LOCK ALL TABLES FOR READ and we want a write lock Someone has issued LOCK ALL TABLES FOR READ and we want a write lock
...@@ -125,7 +142,7 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count, ...@@ -125,7 +142,7 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count,
thd->some_tables_deleted=1; // Try again thd->some_tables_deleted=1; // Try again
sql_lock->lock_count=0; // Locks are alread freed sql_lock->lock_count=0; // Locks are alread freed
} }
else if (!thd->some_tables_deleted) else if (!thd->some_tables_deleted || (flags & MYSQL_LOCK_IGNORE_FLUSH))
{ {
thd->locked=0; thd->locked=0;
break; break;
...@@ -868,47 +885,3 @@ void make_global_read_lock_block_commit(THD *thd) ...@@ -868,47 +885,3 @@ void make_global_read_lock_block_commit(THD *thd)
} }
/*
Set protection against global read lock.
SYNOPSIS
set_protect_against_global_read_lock()
void
RETURN
FALSE OK, no global read lock exists.
TRUE Error, global read lock exists already.
*/
my_bool set_protect_against_global_read_lock(void)
{
my_bool global_read_lock_exists;
pthread_mutex_lock(&LOCK_open);
if (! (global_read_lock_exists= test(global_read_lock)))
protect_against_global_read_lock++;
pthread_mutex_unlock(&LOCK_open);
return global_read_lock_exists;
}
/*
Unset protection against global read lock.
SYNOPSIS
unset_protect_against_global_read_lock()
void
RETURN
void
*/
void unset_protect_against_global_read_lock(void)
{
pthread_mutex_lock(&LOCK_open);
protect_against_global_read_lock--;
pthread_mutex_unlock(&LOCK_open);
pthread_cond_broadcast(&COND_refresh);
}
...@@ -766,8 +766,11 @@ extern pthread_t signal_thread; ...@@ -766,8 +766,11 @@ extern pthread_t signal_thread;
extern struct st_VioSSLAcceptorFd * ssl_acceptor_fd; extern struct st_VioSSLAcceptorFd * ssl_acceptor_fd;
#endif /* HAVE_OPENSSL */ #endif /* HAVE_OPENSSL */
MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **table, uint count, MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **table, uint count, uint flags);
bool ignore_global_read_lock= FALSE); /* mysql_lock_tables() flags bits */
#define MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK 0x0001
#define MYSQL_LOCK_IGNORE_FLUSH 0x0002
void mysql_unlock_tables(THD *thd, MYSQL_LOCK *sql_lock); void mysql_unlock_tables(THD *thd, MYSQL_LOCK *sql_lock);
void mysql_unlock_read_tables(THD *thd, MYSQL_LOCK *sql_lock); void mysql_unlock_read_tables(THD *thd, MYSQL_LOCK *sql_lock);
void mysql_unlock_some_tables(THD *thd, TABLE **table,uint count); void mysql_unlock_some_tables(THD *thd, TABLE **table,uint count);
......
...@@ -177,7 +177,7 @@ my_bool acl_init(THD *org_thd, bool dont_read_acl_tables) ...@@ -177,7 +177,7 @@ my_bool acl_init(THD *org_thd, bool dont_read_acl_tables)
ptr[0]= tables[0].table; ptr[0]= tables[0].table;
ptr[1]= tables[1].table; ptr[1]= tables[1].table;
ptr[2]= tables[2].table; ptr[2]= tables[2].table;
if (!(lock=mysql_lock_tables(thd,ptr,3))) if (! (lock= mysql_lock_tables(thd, ptr, 3, 0)))
{ {
sql_print_error("Fatal error: Can't lock privilege tables: %s", sql_print_error("Fatal error: Can't lock privilege tables: %s",
thd->net.last_error); thd->net.last_error);
...@@ -2514,7 +2514,7 @@ my_bool grant_init(THD *org_thd) ...@@ -2514,7 +2514,7 @@ my_bool grant_init(THD *org_thd)
TABLE *ptr[2]; // Lock tables for quick update TABLE *ptr[2]; // Lock tables for quick update
ptr[0]= tables[0].table; ptr[0]= tables[0].table;
ptr[1]= tables[1].table; ptr[1]= tables[1].table;
if (!(lock=mysql_lock_tables(thd,ptr,2))) if (! (lock= mysql_lock_tables(thd, ptr, 2, 0)))
goto end; goto end;
t_table = tables[0].table; c_table = tables[1].table; t_table = tables[0].table; c_table = tables[1].table;
......
...@@ -1161,7 +1161,7 @@ bool reopen_tables(THD *thd,bool get_locks,bool in_refresh) ...@@ -1161,7 +1161,7 @@ bool reopen_tables(THD *thd,bool get_locks,bool in_refresh)
MYSQL_LOCK *lock; MYSQL_LOCK *lock;
/* We should always get these locks */ /* We should always get these locks */
thd->some_tables_deleted=0; thd->some_tables_deleted=0;
if ((lock=mysql_lock_tables(thd,tables,(uint) (tables_ptr-tables)))) if ((lock= mysql_lock_tables(thd, tables, (uint) (tables_ptr-tables), 0)))
{ {
thd->locked_tables=mysql_lock_merge(thd->locked_tables,lock); thd->locked_tables=mysql_lock_merge(thd->locked_tables,lock);
} }
...@@ -1602,7 +1602,7 @@ TABLE *open_ltable(THD *thd, TABLE_LIST *table_list, thr_lock_type lock_type) ...@@ -1602,7 +1602,7 @@ TABLE *open_ltable(THD *thd, TABLE_LIST *table_list, thr_lock_type lock_type)
else else
{ {
if ((table->reginfo.lock_type= lock_type) != TL_UNLOCK) if ((table->reginfo.lock_type= lock_type) != TL_UNLOCK)
if (!(thd->lock=mysql_lock_tables(thd,&table_list->table,1))) if (! (thd->lock= mysql_lock_tables(thd, &table_list->table, 1, 0)))
table= 0; table= 0;
} }
} }
...@@ -1653,7 +1653,7 @@ int lock_tables(THD *thd,TABLE_LIST *tables) ...@@ -1653,7 +1653,7 @@ int lock_tables(THD *thd,TABLE_LIST *tables)
return -1; return -1;
for (table = tables ; table ; table=table->next) for (table = tables ; table ; table=table->next)
*(ptr++)= table->table; *(ptr++)= table->table;
if (!(thd->lock=mysql_lock_tables(thd,start,count))) if (! (thd->lock= mysql_lock_tables(thd, start, count, 0)))
return -1; /* purecov: inspected */ return -1; /* purecov: inspected */
} }
else else
......
...@@ -448,7 +448,7 @@ int mysql_ha_read(THD *thd, TABLE_LIST *tables, ...@@ -448,7 +448,7 @@ int mysql_ha_read(THD *thd, TABLE_LIST *tables,
send_fields(thd,list,1); send_fields(thd,list,1);
HANDLER_TABLES_HACK(thd); HANDLER_TABLES_HACK(thd);
lock= mysql_lock_tables(thd, &tables->table, 1); lock= mysql_lock_tables(thd, &tables->table, 1, 0);
HANDLER_TABLES_HACK(thd); HANDLER_TABLES_HACK(thd);
byte *key; byte *key;
......
...@@ -674,10 +674,13 @@ static TABLE *delayed_get_table(THD *thd,TABLE_LIST *table_list) ...@@ -674,10 +674,13 @@ static TABLE *delayed_get_table(THD *thd,TABLE_LIST *table_list)
Avoid that a global read lock steps in while we are creating the Avoid that a global read lock steps in while we are creating the
new thread. It would block trying to open the table. Hence, the new thread. It would block trying to open the table. Hence, the
DI thread and this thread would wait until after the global DI thread and this thread would wait until after the global
readlock is gone. If the read lock exists already, we leave with readlock is gone. Since the insert thread needs to wait for a
no table and then switch to non-delayed insert. global read lock anyway, we do it right now. Note that
wait_if_global_read_lock() sets a protection against a new
global read lock when it succeeds. This needs to be released by
start_waiting_global_read_lock().
*/ */
if (set_protect_against_global_read_lock()) if (wait_if_global_read_lock(thd, 0, 1))
goto err; goto err;
if (!(tmp=new delayed_insert())) if (!(tmp=new delayed_insert()))
{ {
...@@ -719,7 +722,11 @@ static TABLE *delayed_get_table(THD *thd,TABLE_LIST *table_list) ...@@ -719,7 +722,11 @@ static TABLE *delayed_get_table(THD *thd,TABLE_LIST *table_list)
pthread_cond_wait(&tmp->cond_client,&tmp->mutex); pthread_cond_wait(&tmp->cond_client,&tmp->mutex);
} }
pthread_mutex_unlock(&tmp->mutex); pthread_mutex_unlock(&tmp->mutex);
unset_protect_against_global_read_lock(); /*
Release the protection against the global read lock and wake
everyone, who might want to set a global read lock.
*/
start_waiting_global_read_lock(thd);
thd->proc_info="got old table"; thd->proc_info="got old table";
if (tmp->thd.killed) if (tmp->thd.killed)
{ {
...@@ -755,7 +762,11 @@ static TABLE *delayed_get_table(THD *thd,TABLE_LIST *table_list) ...@@ -755,7 +762,11 @@ static TABLE *delayed_get_table(THD *thd,TABLE_LIST *table_list)
err1: err1:
thd->fatal_error= 1; thd->fatal_error= 1;
unset_protect_against_global_read_lock(); /*
Release the protection against the global read lock and wake
everyone, who might want to set a global read lock.
*/
start_waiting_global_read_lock(thd);
err: err:
pthread_mutex_unlock(&LOCK_delayed_create); pthread_mutex_unlock(&LOCK_delayed_create);
DBUG_RETURN(0); // Continue with normal insert DBUG_RETURN(0); // Continue with normal insert
...@@ -1105,7 +1116,8 @@ extern "C" pthread_handler_decl(handle_delayed_insert,arg) ...@@ -1105,7 +1116,8 @@ extern "C" pthread_handler_decl(handle_delayed_insert,arg)
handler will close the table and finish when the outstanding handler will close the table and finish when the outstanding
inserts are done. inserts are done.
*/ */
if (! (thd->lock= mysql_lock_tables(thd, &di->table, 1, TRUE))) if (! (thd->lock= mysql_lock_tables(thd, &di->table, 1,
MYSQL_LOCK_IGNORE_GLOBAL_READ_LOCK)))
{ {
di->dead=thd->killed=1; // Fatal error di->dead=thd->killed=1; // Fatal error
} }
......
...@@ -1673,6 +1673,24 @@ mysql_execute_command(void) ...@@ -1673,6 +1673,24 @@ mysql_execute_command(void)
break; break;
} }
#endif #endif
/*
The create-select command will open and read-lock the select table
and then create, open and write-lock the new table. If a global
read lock steps in, we get a deadlock. The write lock waits for
the global read lock, while the global read lock waits for the
select table to be closed. So we wait until the global readlock is
gone before starting both steps. Note that
wait_if_global_read_lock() sets a protection against a new global
read lock when it succeeds. This needs to be released by
start_waiting_global_read_lock(). We protect the normal CREATE
TABLE in the same way. That way we avoid that a new table is
created during a gobal read lock.
*/
if (wait_if_global_read_lock(thd, 0, 1))
{
res= -1;
break;
}
if (select_lex->item_list.elements) // With select if (select_lex->item_list.elements) // With select
{ {
select_result *result; select_result *result;
...@@ -1681,7 +1699,7 @@ mysql_execute_command(void) ...@@ -1681,7 +1699,7 @@ mysql_execute_command(void)
check_dup(tables->db, tables->real_name, tables->next)) check_dup(tables->db, tables->real_name, tables->next))
{ {
net_printf(&thd->net,ER_INSERT_TABLE_USED,tables->real_name); net_printf(&thd->net,ER_INSERT_TABLE_USED,tables->real_name);
DBUG_VOID_RETURN; goto error1;
} }
if (lex->create_info.used_fields & HA_CREATE_USED_UNION) if (lex->create_info.used_fields & HA_CREATE_USED_UNION)
{ {
...@@ -1692,7 +1710,7 @@ mysql_execute_command(void) ...@@ -1692,7 +1710,7 @@ mysql_execute_command(void)
(TABLE_LIST*)lex->create_info.merge_list.first)) (TABLE_LIST*)lex->create_info.merge_list.first))
{ {
net_printf(&thd->net, ER_INSERT_TABLE_USED, tab->real_name); net_printf(&thd->net, ER_INSERT_TABLE_USED, tab->real_name);
DBUG_VOID_RETURN; goto error1;
} }
} }
} }
...@@ -1700,7 +1718,7 @@ mysql_execute_command(void) ...@@ -1700,7 +1718,7 @@ mysql_execute_command(void)
{ {
TABLE_LIST *table; TABLE_LIST *table;
if (check_table_access(thd, SELECT_ACL, tables->next)) if (check_table_access(thd, SELECT_ACL, tables->next))
goto error; // Error message is given goto error1; // Error message is given
/* TODO: Delete the following loop when locks is set by sql_yacc */ /* TODO: Delete the following loop when locks is set by sql_yacc */
for (table = tables->next ; table ; table=table->next) for (table = tables->next ; table ; table=table->next)
table->lock_type= lex->lock_option; table->lock_type= lex->lock_option;
...@@ -1737,6 +1755,11 @@ mysql_execute_command(void) ...@@ -1737,6 +1755,11 @@ mysql_execute_command(void)
if (!res) if (!res)
send_ok(&thd->net); send_ok(&thd->net);
} }
/*
Release the protection against the global read lock and wake
everyone, who might want to set a global read lock.
*/
start_waiting_global_read_lock(thd);
break; break;
} }
case SQLCOM_CREATE_INDEX: case SQLCOM_CREATE_INDEX:
...@@ -2674,6 +2697,14 @@ error: ...@@ -2674,6 +2697,14 @@ error:
thd->lock= 0; thd->lock= 0;
} }
DBUG_VOID_RETURN; DBUG_VOID_RETURN;
error1:
/*
Release the protection against the global read lock and wake
everyone, who might want to set a global read lock.
*/
start_waiting_global_read_lock(thd);
DBUG_VOID_RETURN;
} }
......
...@@ -896,7 +896,7 @@ TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info, ...@@ -896,7 +896,7 @@ TABLE *create_table_from_items(THD *thd, HA_CREATE_INFO *create_info,
if (!table) if (!table)
DBUG_RETURN(0); DBUG_RETURN(0);
table->reginfo.lock_type=TL_WRITE; table->reginfo.lock_type=TL_WRITE;
if (!((*lock)=mysql_lock_tables(thd,&table,1))) if (! ((*lock)= mysql_lock_tables(thd, &table, 1, MYSQL_LOCK_IGNORE_FLUSH)))
{ {
VOID(pthread_mutex_lock(&LOCK_open)); VOID(pthread_mutex_lock(&LOCK_open));
hash_delete(&open_cache,(byte*) table); hash_delete(&open_cache,(byte*) table);
......
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