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mariadb/sql/sql_db.cc
Dmitry Lenev 378cdc58c1 Patch that refactors global read lock implementation and fixes 
bug #57006 "Deadlock between HANDLER and FLUSH TABLES WITH READ
LOCK" and bug #54673 "It takes too long to get readlock for
'FLUSH TABLES WITH READ LOCK'".

The first bug manifested itself as a deadlock which occurred
when a connection, which had some table open through HANDLER
statement, tried to update some data through DML statement
while another connection tried to execute FLUSH TABLES WITH
READ LOCK concurrently.

What happened was that FTWRL in the second connection managed
to perform first step of GRL acquisition and thus blocked all
upcoming DML. After that it started to wait for table open
through HANDLER statement to be flushed. When the first connection
tried to execute DML it has started to wait for GRL/the second
connection creating deadlock.

The second bug manifested itself as starvation of FLUSH TABLES
WITH READ LOCK statements in cases when there was a constant
stream of concurrent DML statements (in two or more
connections).

This has happened because requests for protection against GRL
which were acquired by DML statements were ignoring presence of
pending GRL and thus the latter was starved.

This patch solves both these problems by re-implementing GRL
using metadata locks.

Similar to the old implementation acquisition of GRL in new
implementation is two-step. During the first step we block
all concurrent DML and DDL statements by acquiring global S
metadata lock (each DML and DDL statement acquires global IX
lock for its duration). During the second step we block commits
by acquiring global S lock in COMMIT namespace (commit code
acquires global IX lock in this namespace).

Note that unlike in old implementation acquisition of
protection against GRL in DML and DDL is semi-automatic.
We assume that any statement which should be blocked by GRL
will either open and acquires write-lock on tables or acquires
metadata locks on objects it is going to modify. For any such
statement global IX metadata lock is automatically acquired
for its duration.

The first problem is solved because waits for GRL become
visible to deadlock detector in metadata locking subsystem
and thus deadlocks like one in the first bug become impossible.

The second problem is solved because global S locks which
are used for GRL implementation are given preference over
IX locks which are acquired by concurrent DML (and we can
switch to fair scheduling in future if needed).

Important change:
FTWRL/GRL no longer blocks DML and DDL on temporary tables.
Before this patch behavior was not consistent in this respect:
in some cases DML/DDL statements on temporary tables were
blocked while in others they were not. Since the main use cases
for FTWRL are various forms of backups and temporary tables are
not preserved during backups we have opted for consistently
allowing DML/DDL on temporary tables during FTWRL/GRL.

Important change:
This patch changes thread state names which are used when
DML/DDL of FTWRL is waiting for global read lock. It is now
either "Waiting for global read lock" or "Waiting for commit
lock" depending on the stage on which FTWRL is.

Incompatible change:
To solve deadlock in events code which was exposed by this
patch we have to replace LOCK_event_metadata mutex with
metadata locks on events. As result we have to prohibit
DDL on events under LOCK TABLES.

This patch also adds extensive test coverage for interaction
of DML/DDL and FTWRL.

Performance of new and old global read lock implementations
in sysbench tests were compared. There were no significant
difference between new and old implementations.
2010-11-11 20:11:05 +03:00

1866 lines
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/* Copyright (C) 2000-2003 MySQL AB, 2008-2009 Sun Microsystems, Inc
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* create and drop of databases */
#include "my_global.h" /* NO_EMBEDDED_ACCESS_CHECKS */
#include "sql_priv.h"
#include "unireg.h"
#include "sql_db.h"
#include "sql_cache.h" // query_cache_*
#include "lock.h" // lock_schema_name
#include "sql_table.h" // build_table_filename,
// filename_to_tablename
#include "sql_rename.h" // mysql_rename_tables
#include "sql_acl.h" // SELECT_ACL, DB_ACLS,
// acl_get, check_grant_db
#include "log_event.h" // Query_log_event
#include <mysys_err.h>
#include "sp.h"
#include "events.h"
#include <my_dir.h>
#include <m_ctype.h>
#include "log.h"
#ifdef __WIN__
#include <direct.h>
#endif
#define MAX_DROP_TABLE_Q_LEN 1024
const char *del_exts[]= {".frm", ".BAK", ".TMD",".opt", NullS};
static TYPELIB deletable_extentions=
{array_elements(del_exts)-1,"del_exts", del_exts, NULL};
static long mysql_rm_known_files(THD *thd, MY_DIR *dirp,
const char *db, const char *path, uint level,
TABLE_LIST **dropped_tables);
long mysql_rm_arc_files(THD *thd, MY_DIR *dirp, const char *org_path);
static my_bool rm_dir_w_symlink(const char *org_path, my_bool send_error);
static void mysql_change_db_impl(THD *thd,
LEX_STRING *new_db_name,
ulong new_db_access,
CHARSET_INFO *new_db_charset);
/* Database options hash */
static HASH dboptions;
static my_bool dboptions_init= 0;
static mysql_rwlock_t LOCK_dboptions;
/* Structure for database options */
typedef struct my_dbopt_st
{
char *name; /* Database name */
uint name_length; /* Database length name */
CHARSET_INFO *charset; /* Database default character set */
} my_dbopt_t;
/*
Function we use in the creation of our hash to get key.
*/
extern "C" uchar* dboptions_get_key(my_dbopt_t *opt, size_t *length,
my_bool not_used);
uchar* dboptions_get_key(my_dbopt_t *opt, size_t *length,
my_bool not_used __attribute__((unused)))
{
*length= opt->name_length;
return (uchar*) opt->name;
}
/*
Helper function to write a query to binlog used by mysql_rm_db()
*/
static inline int write_to_binlog(THD *thd, char *query, uint q_len,
char *db, uint db_len)
{
Query_log_event qinfo(thd, query, q_len, FALSE, TRUE, FALSE, 0);
qinfo.db= db;
qinfo.db_len= db_len;
return mysql_bin_log.write(&qinfo);
}
/*
Function to free dboptions hash element
*/
extern "C" void free_dbopt(void *dbopt);
void free_dbopt(void *dbopt)
{
my_free(dbopt);
}
#ifdef HAVE_PSI_INTERFACE
static PSI_rwlock_key key_rwlock_LOCK_dboptions;
static PSI_rwlock_info all_database_names_rwlocks[]=
{
{ &key_rwlock_LOCK_dboptions, "LOCK_dboptions", PSI_FLAG_GLOBAL}
};
static void init_database_names_psi_keys(void)
{
const char* category= "sql";
int count;
if (PSI_server == NULL)
return;
count= array_elements(all_database_names_rwlocks);
PSI_server->register_rwlock(category, all_database_names_rwlocks, count);
}
#endif
/**
Initialize database option cache.
@note Must be called before any other database function is called.
@retval 0 ok
@retval 1 Fatal error
*/
bool my_dboptions_cache_init(void)
{
#ifdef HAVE_PSI_INTERFACE
init_database_names_psi_keys();
#endif
bool error= 0;
mysql_rwlock_init(key_rwlock_LOCK_dboptions, &LOCK_dboptions);
if (!dboptions_init)
{
dboptions_init= 1;
error= my_hash_init(&dboptions, lower_case_table_names ?
&my_charset_bin : system_charset_info,
32, 0, 0, (my_hash_get_key) dboptions_get_key,
free_dbopt,0);
}
return error;
}
/**
Free database option hash and locked databases hash.
*/
void my_dboptions_cache_free(void)
{
if (dboptions_init)
{
dboptions_init= 0;
my_hash_free(&dboptions);
mysql_rwlock_destroy(&LOCK_dboptions);
}
}
/**
Cleanup cached options.
*/
void my_dbopt_cleanup(void)
{
mysql_rwlock_wrlock(&LOCK_dboptions);
my_hash_free(&dboptions);
my_hash_init(&dboptions, lower_case_table_names ?
&my_charset_bin : system_charset_info,
32, 0, 0, (my_hash_get_key) dboptions_get_key,
free_dbopt,0);
mysql_rwlock_unlock(&LOCK_dboptions);
}
/*
Find database options in the hash.
DESCRIPTION
Search a database options in the hash, usings its path.
Fills "create" on success.
RETURN VALUES
0 on success.
1 on error.
*/
static my_bool get_dbopt(const char *dbname, HA_CREATE_INFO *create)
{
my_dbopt_t *opt;
uint length;
my_bool error= 1;
length= (uint) strlen(dbname);
mysql_rwlock_rdlock(&LOCK_dboptions);
if ((opt= (my_dbopt_t*) my_hash_search(&dboptions, (uchar*) dbname, length)))
{
create->default_table_charset= opt->charset;
error= 0;
}
mysql_rwlock_unlock(&LOCK_dboptions);
return error;
}
/*
Writes database options into the hash.
DESCRIPTION
Inserts database options into the hash, or updates
options if they are already in the hash.
RETURN VALUES
0 on success.
1 on error.
*/
static my_bool put_dbopt(const char *dbname, HA_CREATE_INFO *create)
{
my_dbopt_t *opt;
uint length;
my_bool error= 0;
DBUG_ENTER("put_dbopt");
length= (uint) strlen(dbname);
mysql_rwlock_wrlock(&LOCK_dboptions);
if (!(opt= (my_dbopt_t*) my_hash_search(&dboptions, (uchar*) dbname,
length)))
{
/* Options are not in the hash, insert them */
char *tmp_name;
if (!my_multi_malloc(MYF(MY_WME | MY_ZEROFILL),
&opt, (uint) sizeof(*opt), &tmp_name, (uint) length+1,
NullS))
{
error= 1;
goto end;
}
opt->name= tmp_name;
strmov(opt->name, dbname);
opt->name_length= length;
if ((error= my_hash_insert(&dboptions, (uchar*) opt)))
{
my_free(opt);
goto end;
}
}
/* Update / write options in hash */
opt->charset= create->default_table_charset;
end:
mysql_rwlock_unlock(&LOCK_dboptions);
DBUG_RETURN(error);
}
/*
Deletes database options from the hash.
*/
static void del_dbopt(const char *path)
{
my_dbopt_t *opt;
mysql_rwlock_wrlock(&LOCK_dboptions);
if ((opt= (my_dbopt_t *)my_hash_search(&dboptions, (const uchar*) path,
strlen(path))))
my_hash_delete(&dboptions, (uchar*) opt);
mysql_rwlock_unlock(&LOCK_dboptions);
}
/*
Create database options file:
DESCRIPTION
Currently database default charset is only stored there.
RETURN VALUES
0 ok
1 Could not create file or write to it. Error sent through my_error()
*/
static bool write_db_opt(THD *thd, const char *path, HA_CREATE_INFO *create)
{
register File file;
char buf[256]; // Should be enough for one option
bool error=1;
if (!create->default_table_charset)
create->default_table_charset= thd->variables.collation_server;
if (put_dbopt(path, create))
return 1;
if ((file= mysql_file_create(key_file_dbopt, path, CREATE_MODE,
O_RDWR | O_TRUNC, MYF(MY_WME))) >= 0)
{
ulong length;
length= (ulong) (strxnmov(buf, sizeof(buf)-1, "default-character-set=",
create->default_table_charset->csname,
"\ndefault-collation=",
create->default_table_charset->name,
"\n", NullS) - buf);
/* Error is written by mysql_file_write */
if (!mysql_file_write(file, (uchar*) buf, length, MYF(MY_NABP+MY_WME)))
error=0;
mysql_file_close(file, MYF(0));
}
return error;
}
/*
Load database options file
load_db_opt()
path Path for option file
create Where to store the read options
DESCRIPTION
RETURN VALUES
0 File found
1 No database file or could not open it
*/
bool load_db_opt(THD *thd, const char *path, HA_CREATE_INFO *create)
{
File file;
char buf[256];
DBUG_ENTER("load_db_opt");
bool error=1;
uint nbytes;
bzero((char*) create,sizeof(*create));
create->default_table_charset= thd->variables.collation_server;
/* Check if options for this database are already in the hash */
if (!get_dbopt(path, create))
DBUG_RETURN(0);
/* Otherwise, load options from the .opt file */
if ((file= mysql_file_open(key_file_dbopt,
path, O_RDONLY | O_SHARE, MYF(0))) < 0)
goto err1;
IO_CACHE cache;
if (init_io_cache(&cache, file, IO_SIZE, READ_CACHE, 0, 0, MYF(0)))
goto err2;
while ((int) (nbytes= my_b_gets(&cache, (char*) buf, sizeof(buf))) > 0)
{
char *pos= buf+nbytes-1;
/* Remove end space and control characters */
while (pos > buf && !my_isgraph(&my_charset_latin1, pos[-1]))
pos--;
*pos=0;
if ((pos= strchr(buf, '=')))
{
if (!strncmp(buf,"default-character-set", (pos-buf)))
{
/*
Try character set name, and if it fails
try collation name, probably it's an old
4.1.0 db.opt file, which didn't have
separate default-character-set and
default-collation commands.
*/
if (!(create->default_table_charset=
get_charset_by_csname(pos+1, MY_CS_PRIMARY, MYF(0))) &&
!(create->default_table_charset=
get_charset_by_name(pos+1, MYF(0))))
{
sql_print_error("Error while loading database options: '%s':",path);
sql_print_error(ER(ER_UNKNOWN_CHARACTER_SET),pos+1);
create->default_table_charset= default_charset_info;
}
}
else if (!strncmp(buf,"default-collation", (pos-buf)))
{
if (!(create->default_table_charset= get_charset_by_name(pos+1,
MYF(0))))
{
sql_print_error("Error while loading database options: '%s':",path);
sql_print_error(ER(ER_UNKNOWN_COLLATION),pos+1);
create->default_table_charset= default_charset_info;
}
}
}
}
/*
Put the loaded value into the hash.
Note that another thread could've added the same
entry to the hash after we called get_dbopt(),
but it's not an error, as put_dbopt() takes this
possibility into account.
*/
error= put_dbopt(path, create);
end_io_cache(&cache);
err2:
mysql_file_close(file, MYF(0));
err1:
DBUG_RETURN(error);
}
/*
Retrieve database options by name. Load database options file or fetch from
cache.
SYNOPSIS
load_db_opt_by_name()
db_name Database name
db_create_info Where to store the database options
DESCRIPTION
load_db_opt_by_name() is a shortcut for load_db_opt().
NOTE
Although load_db_opt_by_name() (and load_db_opt()) returns status of
the operation, it is useless usually and should be ignored. The problem
is that there are 1) system databases ("mysql") and 2) virtual
databases ("information_schema"), which do not contain options file.
So, load_db_opt[_by_name]() returns FALSE for these databases, but this
is not an error.
load_db_opt[_by_name]() clears db_create_info structure in any case, so
even on failure it contains valid data. So, common use case is just
call load_db_opt[_by_name]() without checking return value and use
db_create_info right after that.
RETURN VALUES (read NOTE!)
FALSE Success
TRUE Failed to retrieve options
*/
bool load_db_opt_by_name(THD *thd, const char *db_name,
HA_CREATE_INFO *db_create_info)
{
char db_opt_path[FN_REFLEN + 1];
/*
Pass an empty file name, and the database options file name as extension
to avoid table name to file name encoding.
*/
(void) build_table_filename(db_opt_path, sizeof(db_opt_path) - 1,
db_name, "", MY_DB_OPT_FILE, 0);
return load_db_opt(thd, db_opt_path, db_create_info);
}
/**
Return default database collation.
@param thd Thread context.
@param db_name Database name.
@return CHARSET_INFO object. The operation always return valid character
set, even if the database does not exist.
*/
CHARSET_INFO *get_default_db_collation(THD *thd, const char *db_name)
{
HA_CREATE_INFO db_info;
if (thd->db != NULL && strcmp(db_name, thd->db) == 0)
return thd->db_charset;
load_db_opt_by_name(thd, db_name, &db_info);
/*
NOTE: even if load_db_opt_by_name() fails,
db_info.default_table_charset contains valid character set
(collation_server). We should not fail if load_db_opt_by_name() fails,
because it is valid case. If a database has been created just by
"mkdir", it does not contain db.opt file, but it is valid database.
*/
return db_info.default_table_charset;
}
/*
Create a database
SYNOPSIS
mysql_create_db()
thd Thread handler
db Name of database to create
Function assumes that this is already validated.
create_info Database create options (like character set)
silent Used by replication when internally creating a database.
In this case the entry should not be logged.
SIDE-EFFECTS
1. Report back to client that command succeeded (my_ok)
2. Report errors to client
3. Log event to binary log
(The 'silent' flags turns off 1 and 3.)
RETURN VALUES
FALSE ok
TRUE Error
*/
int mysql_create_db(THD *thd, char *db, HA_CREATE_INFO *create_info,
bool silent)
{
char path[FN_REFLEN+16];
char tmp_query[FN_REFLEN+16];
long result= 1;
int error= 0;
MY_STAT stat_info;
uint create_options= create_info ? create_info->options : 0;
uint path_len;
DBUG_ENTER("mysql_create_db");
/* do not create 'information_schema' db */
if (is_infoschema_db(db))
{
my_error(ER_DB_CREATE_EXISTS, MYF(0), db);
DBUG_RETURN(-1);
}
if (lock_schema_name(thd, db))
DBUG_RETURN(-1);
/* Check directory */
path_len= build_table_filename(path, sizeof(path) - 1, db, "", "", 0);
path[path_len-1]= 0; // Remove last '/' from path
if (mysql_file_stat(key_file_misc, path, &stat_info, MYF(0)))
{
if (!(create_options & HA_LEX_CREATE_IF_NOT_EXISTS))
{
my_error(ER_DB_CREATE_EXISTS, MYF(0), db);
error= -1;
goto exit;
}
push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
ER_DB_CREATE_EXISTS, ER(ER_DB_CREATE_EXISTS), db);
error= 0;
goto not_silent;
}
else
{
if (my_errno != ENOENT)
{
my_error(EE_STAT, MYF(0), path, my_errno);
goto exit;
}
if (my_mkdir(path,0777,MYF(0)) < 0)
{
my_error(ER_CANT_CREATE_DB, MYF(0), db, my_errno);
error= -1;
goto exit;
}
}
path[path_len-1]= FN_LIBCHAR;
strmake(path+path_len, MY_DB_OPT_FILE, sizeof(path)-path_len-1);
if (write_db_opt(thd, path, create_info))
{
/*
Could not create options file.
Restore things to beginning.
*/
path[path_len]= 0;
if (rmdir(path) >= 0)
{
error= -1;
goto exit;
}
/*
We come here when we managed to create the database, but not the option
file. In this case it's best to just continue as if nothing has
happened. (This is a very unlikely senario)
*/
thd->clear_error();
}
not_silent:
if (!silent)
{
char *query;
uint query_length;
if (!thd->query()) // Only in replication
{
query= tmp_query;
query_length= (uint) (strxmov(tmp_query,"create database `",
db, "`", NullS) - tmp_query);
}
else
{
query= thd->query();
query_length= thd->query_length();
}
ha_binlog_log_query(thd, 0, LOGCOM_CREATE_DB,
query, query_length,
db, "");
if (mysql_bin_log.is_open())
{
int errcode= query_error_code(thd, TRUE);
Query_log_event qinfo(thd, query, query_length, FALSE, TRUE,
/* suppress_use */ TRUE, errcode);
/*
Write should use the database being created as the "current
database" and not the threads current database, which is the
default. If we do not change the "current database" to the
database being created, the CREATE statement will not be
replicated when using --binlog-do-db to select databases to be
replicated.
An example (--binlog-do-db=sisyfos):
CREATE DATABASE bob; # Not replicated
USE bob; # 'bob' is the current database
CREATE DATABASE sisyfos; # Not replicated since 'bob' is
# current database.
USE sisyfos; # Will give error on slave since
# database does not exist.
*/
qinfo.db = db;
qinfo.db_len = strlen(db);
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema
*/
if (mysql_bin_log.write(&qinfo))
{
error= -1;
goto exit;
}
}
my_ok(thd, result);
}
exit:
DBUG_RETURN(error);
}
/* db-name is already validated when we come here */
bool mysql_alter_db(THD *thd, const char *db, HA_CREATE_INFO *create_info)
{
char path[FN_REFLEN+16];
long result=1;
int error= 0;
DBUG_ENTER("mysql_alter_db");
if (lock_schema_name(thd, db))
DBUG_RETURN(TRUE);
/*
Recreate db options file: /dbpath/.db.opt
We pass MY_DB_OPT_FILE as "extension" to avoid
"table name to file name" encoding.
*/
build_table_filename(path, sizeof(path) - 1, db, "", MY_DB_OPT_FILE, 0);
if ((error=write_db_opt(thd, path, create_info)))
goto exit;
/* Change options if current database is being altered. */
if (thd->db && !strcmp(thd->db,db))
{
thd->db_charset= create_info->default_table_charset ?
create_info->default_table_charset :
thd->variables.collation_server;
thd->variables.collation_database= thd->db_charset;
}
ha_binlog_log_query(thd, 0, LOGCOM_ALTER_DB,
thd->query(), thd->query_length(),
db, "");
if (mysql_bin_log.is_open())
{
int errcode= query_error_code(thd, TRUE);
Query_log_event qinfo(thd, thd->query(), thd->query_length(), FALSE, TRUE,
/* suppress_use */ TRUE, errcode);
/*
Write should use the database being created as the "current
database" and not the threads current database, which is the
default.
*/
qinfo.db = db;
qinfo.db_len = strlen(db);
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema.
*/
if ((error= mysql_bin_log.write(&qinfo)))
goto exit;
}
my_ok(thd, result);
exit:
DBUG_RETURN(error);
}
/*
Drop all tables in a database and the database itself
SYNOPSIS
mysql_rm_db()
thd Thread handle
db Database name in the case given by user
It's already validated and set to lower case
(if needed) when we come here
if_exists Don't give error if database doesn't exists
silent Don't generate errors
RETURN
FALSE ok (Database dropped)
ERROR Error
*/
bool mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent)
{
long deleted=0;
int error= 0;
char path[FN_REFLEN+16];
MY_DIR *dirp;
uint length;
TABLE_LIST* dropped_tables= 0;
DBUG_ENTER("mysql_rm_db");
if (lock_schema_name(thd, db))
DBUG_RETURN(TRUE);
length= build_table_filename(path, sizeof(path) - 1, db, "", "", 0);
strmov(path+length, MY_DB_OPT_FILE); // Append db option file name
del_dbopt(path); // Remove dboption hash entry
path[length]= '\0'; // Remove file name
/* See if the directory exists */
if (!(dirp= my_dir(path,MYF(MY_DONT_SORT))))
{
if (!if_exists)
{
error= -1;
my_error(ER_DB_DROP_EXISTS, MYF(0), db);
goto exit;
}
else
push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
ER_DB_DROP_EXISTS, ER(ER_DB_DROP_EXISTS), db);
}
else
{
Drop_table_error_handler err_handler;
thd->push_internal_handler(&err_handler);
error= -1;
/*
We temporarily disable the binary log while dropping the objects
in the database. Since the DROP DATABASE statement is always
replicated as a statement, execution of it will drop all objects
in the database on the slave as well, so there is no need to
replicate the removal of the individual objects in the database
as well.
This is more of a safety precaution, since normally no objects
should be dropped while the database is being cleaned, but in
the event that a change in the code to remove other objects is
made, these drops should still not be logged.
Notice that the binary log have to be enabled over the call to
ha_drop_database(), since NDB otherwise detects the binary log
as disabled and will not log the drop database statement on any
other connected server.
*/
if ((deleted= mysql_rm_known_files(thd, dirp, db, path, 0,
&dropped_tables)) >= 0)
{
ha_drop_database(path);
tmp_disable_binlog(thd);
query_cache_invalidate1(db);
(void) sp_drop_db_routines(thd, db); /* @todo Do not ignore errors */
#ifdef HAVE_EVENT_SCHEDULER
Events::drop_schema_events(thd, db);
#endif
error = 0;
reenable_binlog(thd);
}
thd->pop_internal_handler();
}
if (!silent && deleted>=0)
{
const char *query;
ulong query_length;
if (!thd->query())
{
/* The client used the old obsolete mysql_drop_db() call */
query= path;
query_length= (uint) (strxmov(path, "drop database `", db, "`",
NullS) - path);
}
else
{
query= thd->query();
query_length= thd->query_length();
}
if (mysql_bin_log.is_open())
{
int errcode= query_error_code(thd, TRUE);
Query_log_event qinfo(thd, query, query_length, FALSE, TRUE,
/* suppress_use */ TRUE, errcode);
/*
Write should use the database being created as the "current
database" and not the threads current database, which is the
default.
*/
qinfo.db = db;
qinfo.db_len = strlen(db);
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema.
*/
if (mysql_bin_log.write(&qinfo))
{
error= -1;
goto exit;
}
}
thd->clear_error();
thd->server_status|= SERVER_STATUS_DB_DROPPED;
my_ok(thd, (ulong) deleted);
thd->server_status&= ~SERVER_STATUS_DB_DROPPED;
}
else if (mysql_bin_log.is_open())
{
char *query, *query_pos, *query_end, *query_data_start;
TABLE_LIST *tbl;
uint db_len;
if (!(query= (char*) thd->alloc(MAX_DROP_TABLE_Q_LEN)))
goto exit; /* not much else we can do */
query_pos= query_data_start= strmov(query,"drop table ");
query_end= query + MAX_DROP_TABLE_Q_LEN;
db_len= strlen(db);
for (tbl= dropped_tables; tbl; tbl= tbl->next_local)
{
uint tbl_name_len;
/* 3 for the quotes and the comma*/
tbl_name_len= strlen(tbl->table_name) + 3;
if (query_pos + tbl_name_len + 1 >= query_end)
{
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema.
*/
if (write_to_binlog(thd, query, query_pos -1 - query, db, db_len))
{
error= -1;
goto exit;
}
query_pos= query_data_start;
}
*query_pos++ = '`';
query_pos= strmov(query_pos,tbl->table_name);
*query_pos++ = '`';
*query_pos++ = ',';
}
if (query_pos != query_data_start)
{
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema.
*/
if (write_to_binlog(thd, query, query_pos -1 - query, db, db_len))
{
error= -1;
goto exit;
}
}
}
exit:
/*
If this database was the client's selected database, we silently
change the client's selected database to nothing (to have an empty
SELECT DATABASE() in the future). For this we free() thd->db and set
it to 0.
*/
if (thd->db && !strcmp(thd->db, db) && error == 0)
mysql_change_db_impl(thd, NULL, 0, thd->variables.collation_server);
DBUG_RETURN(error);
}
/*
Removes files with known extensions plus all found subdirectories that
are 2 hex digits (raid directories).
thd MUST be set when calling this function!
*/
static long mysql_rm_known_files(THD *thd, MY_DIR *dirp, const char *db,
const char *org_path, uint level,
TABLE_LIST **dropped_tables)
{
long deleted=0;
ulong found_other_files=0;
char filePath[FN_REFLEN];
TABLE_LIST *tot_list=0, **tot_list_next_local, **tot_list_next_global;
List<String> raid_dirs;
DBUG_ENTER("mysql_rm_known_files");
DBUG_PRINT("enter",("path: %s", org_path));
tot_list_next_local= tot_list_next_global= &tot_list;
for (uint idx=0 ;
idx < (uint) dirp->number_off_files && !thd->killed ;
idx++)
{
FILEINFO *file=dirp->dir_entry+idx;
char *extension;
DBUG_PRINT("info",("Examining: %s", file->name));
/* skiping . and .. */
if (file->name[0] == '.' && (!file->name[1] ||
(file->name[1] == '.' && !file->name[2])))
continue;
/* Check if file is a raid directory */
if ((my_isdigit(system_charset_info, file->name[0]) ||
(file->name[0] >= 'a' && file->name[0] <= 'f')) &&
(my_isdigit(system_charset_info, file->name[1]) ||
(file->name[1] >= 'a' && file->name[1] <= 'f')) &&
!file->name[2] && !level)
{
char newpath[FN_REFLEN], *copy_of_path;
MY_DIR *new_dirp;
String *dir;
uint length;
strxmov(newpath,org_path,"/",file->name,NullS);
length= unpack_filename(newpath,newpath);
if ((new_dirp = my_dir(newpath,MYF(MY_DONT_SORT))))
{
DBUG_PRINT("my",("New subdir found: %s", newpath));
if ((mysql_rm_known_files(thd, new_dirp, NullS, newpath,1,0)) < 0)
goto err;
if (!(copy_of_path= (char*) thd->memdup(newpath, length+1)) ||
!(dir= new (thd->mem_root) String(copy_of_path, length,
&my_charset_bin)) ||
raid_dirs.push_back(dir))
goto err;
continue;
}
found_other_files++;
continue;
}
else if (file->name[0] == 'a' && file->name[1] == 'r' &&
file->name[2] == 'c' && file->name[3] == '\0')
{
/* .frm archive:
Those archives are obsolete, but following code should
exist to remove existent "arc" directories.
*/
char newpath[FN_REFLEN];
MY_DIR *new_dirp;
strxmov(newpath, org_path, "/", "arc", NullS);
(void) unpack_filename(newpath, newpath);
if ((new_dirp = my_dir(newpath, MYF(MY_DONT_SORT))))
{
DBUG_PRINT("my",("Archive subdir found: %s", newpath));
if ((mysql_rm_arc_files(thd, new_dirp, newpath)) < 0)
goto err;
continue;
}
found_other_files++;
continue;
}
if (!(extension= strrchr(file->name, '.')))
extension= strend(file->name);
if (find_type(extension, &deletable_extentions,1+2) <= 0)
{
if (find_type(extension, ha_known_exts(),1+2) <= 0)
found_other_files++;
continue;
}
/* just for safety we use files_charset_info */
if (db && !my_strcasecmp(files_charset_info,
extension, reg_ext))
{
/* Drop the table nicely */
*extension= 0; // Remove extension
TABLE_LIST *table_list=(TABLE_LIST*)
thd->calloc(sizeof(*table_list) +
strlen(db) + 1 +
MYSQL50_TABLE_NAME_PREFIX_LENGTH +
strlen(file->name) + 1);
if (!table_list)
goto err;
table_list->db= (char*) (table_list+1);
table_list->db_length= strmov(table_list->db, db) - table_list->db;
table_list->table_name= table_list->db + table_list->db_length + 1;
table_list->table_name_length= filename_to_tablename(file->name,
table_list->table_name,
MYSQL50_TABLE_NAME_PREFIX_LENGTH +
strlen(file->name) + 1);
table_list->open_type= OT_BASE_ONLY;
/* To be able to correctly look up the table in the table cache. */
if (lower_case_table_names)
table_list->table_name_length= my_casedn_str(files_charset_info,
table_list->table_name);
table_list->alias= table_list->table_name; // If lower_case_table_names=2
table_list->internal_tmp_table= is_prefix(file->name, tmp_file_prefix);
table_list->mdl_request.init(MDL_key::TABLE, table_list->db,
table_list->table_name, MDL_EXCLUSIVE,
MDL_TRANSACTION);
/* Link into list */
(*tot_list_next_local)= table_list;
(*tot_list_next_global)= table_list;
tot_list_next_local= &table_list->next_local;
tot_list_next_global= &table_list->next_global;
deleted++;
}
else
{
strxmov(filePath, org_path, "/", file->name, NullS);
if (mysql_file_delete_with_symlink(key_file_misc, filePath, MYF(MY_WME)))
{
goto err;
}
}
}
if (thd->killed ||
(tot_list && mysql_rm_table_part2(thd, tot_list, 1, 0, 1, 1)))
goto err;
/* Remove RAID directories */
{
List_iterator<String> it(raid_dirs);
String *dir;
while ((dir= it++))
if (rmdir(dir->c_ptr()) < 0)
found_other_files++;
}
my_dirend(dirp);
if (dropped_tables)
*dropped_tables= tot_list;
/*
If the directory is a symbolic link, remove the link first, then
remove the directory the symbolic link pointed at
*/
if (found_other_files)
{
my_error(ER_DB_DROP_RMDIR, MYF(0), org_path, EEXIST);
DBUG_RETURN(-1);
}
else
{
/* Don't give errors if we can't delete 'RAID' directory */
if (rm_dir_w_symlink(org_path, level == 0))
DBUG_RETURN(-1);
}
DBUG_RETURN(deleted);
err:
my_dirend(dirp);
DBUG_RETURN(-1);
}
/*
Remove directory with symlink
SYNOPSIS
rm_dir_w_symlink()
org_path path of derictory
send_error send errors
RETURN
0 OK
1 ERROR
*/
static my_bool rm_dir_w_symlink(const char *org_path, my_bool send_error)
{
char tmp_path[FN_REFLEN], *pos;
char *path= tmp_path;
DBUG_ENTER("rm_dir_w_symlink");
unpack_filename(tmp_path, org_path);
#ifdef HAVE_READLINK
int error;
char tmp2_path[FN_REFLEN];
/* Remove end FN_LIBCHAR as this causes problem on Linux in readlink */
pos= strend(path);
if (pos > path && pos[-1] == FN_LIBCHAR)
*--pos=0;
if ((error= my_readlink(tmp2_path, path, MYF(MY_WME))) < 0)
DBUG_RETURN(1);
if (!error)
{
if (mysql_file_delete(key_file_misc, path, MYF(send_error ? MY_WME : 0)))
{
DBUG_RETURN(send_error);
}
/* Delete directory symbolic link pointed at */
path= tmp2_path;
}
#endif
/* Remove last FN_LIBCHAR to not cause a problem on OS/2 */
pos= strend(path);
if (pos > path && pos[-1] == FN_LIBCHAR)
*--pos=0;
if (rmdir(path) < 0 && send_error)
{
my_error(ER_DB_DROP_RMDIR, MYF(0), path, errno);
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
/*
Remove .frm archives from directory
SYNOPSIS
thd thread handler
dirp list of files in archive directory
db data base name
org_path path of archive directory
RETURN
> 0 number of removed files
-1 error
NOTE
A support of "arc" directories is obsolete, however this
function should exist to remove existent "arc" directories.
*/
long mysql_rm_arc_files(THD *thd, MY_DIR *dirp, const char *org_path)
{
long deleted= 0;
ulong found_other_files= 0;
char filePath[FN_REFLEN];
DBUG_ENTER("mysql_rm_arc_files");
DBUG_PRINT("enter", ("path: %s", org_path));
for (uint idx=0 ;
idx < (uint) dirp->number_off_files && !thd->killed ;
idx++)
{
FILEINFO *file=dirp->dir_entry+idx;
char *extension, *revision;
DBUG_PRINT("info",("Examining: %s", file->name));
/* skiping . and .. */
if (file->name[0] == '.' && (!file->name[1] ||
(file->name[1] == '.' && !file->name[2])))
continue;
extension= fn_ext(file->name);
if (extension[0] != '.' ||
extension[1] != 'f' || extension[2] != 'r' ||
extension[3] != 'm' || extension[4] != '-')
{
found_other_files++;
continue;
}
revision= extension+5;
while (*revision && my_isdigit(system_charset_info, *revision))
revision++;
if (*revision)
{
found_other_files++;
continue;
}
strxmov(filePath, org_path, "/", file->name, NullS);
if (mysql_file_delete_with_symlink(key_file_misc, filePath, MYF(MY_WME)))
{
goto err;
}
deleted++;
}
if (thd->killed)
goto err;
my_dirend(dirp);
/*
If the directory is a symbolic link, remove the link first, then
remove the directory the symbolic link pointed at
*/
if (!found_other_files &&
rm_dir_w_symlink(org_path, 0))
DBUG_RETURN(-1);
DBUG_RETURN(deleted);
err:
my_dirend(dirp);
DBUG_RETURN(-1);
}
/**
@brief Internal implementation: switch current database to a valid one.
@param thd Thread context.
@param new_db_name Name of the database to switch to. The function will
take ownership of the name (the caller must not free
the allocated memory). If the name is NULL, we're
going to switch to NULL db.
@param new_db_access Privileges of the new database.
@param new_db_charset Character set of the new database.
*/
static void mysql_change_db_impl(THD *thd,
LEX_STRING *new_db_name,
ulong new_db_access,
CHARSET_INFO *new_db_charset)
{
/* 1. Change current database in THD. */
if (new_db_name == NULL)
{
/*
THD::set_db() does all the job -- it frees previous database name and
sets the new one.
*/
thd->set_db(NULL, 0);
}
else if (new_db_name == &INFORMATION_SCHEMA_NAME)
{
/*
Here we must use THD::set_db(), because we want to copy
INFORMATION_SCHEMA_NAME constant.
*/
thd->set_db(INFORMATION_SCHEMA_NAME.str, INFORMATION_SCHEMA_NAME.length);
}
else
{
/*
Here we already have a copy of database name to be used in THD. So,
we just call THD::reset_db(). Since THD::reset_db() does not releases
the previous database name, we should do it explicitly.
*/
my_free(thd->db);
thd->reset_db(new_db_name->str, new_db_name->length);
}
/* 2. Update security context. */
#ifndef NO_EMBEDDED_ACCESS_CHECKS
thd->security_ctx->db_access= new_db_access;
#endif
/* 3. Update db-charset environment variables. */
thd->db_charset= new_db_charset;
thd->variables.collation_database= new_db_charset;
}
/**
Backup the current database name before switch.
@param[in] thd thread handle
@param[in, out] saved_db_name IN: "str" points to a buffer where to store
the old database name, "length" contains the
buffer size
OUT: if the current (default) database is
not NULL, its name is copied to the
buffer pointed at by "str"
and "length" is updated accordingly.
Otherwise "str" is set to NULL and
"length" is set to 0.
*/
static void backup_current_db_name(THD *thd,
LEX_STRING *saved_db_name)
{
if (!thd->db)
{
/* No current (default) database selected. */
saved_db_name->str= NULL;
saved_db_name->length= 0;
}
else
{
strmake(saved_db_name->str, thd->db, saved_db_name->length - 1);
saved_db_name->length= thd->db_length;
}
}
/**
Return TRUE if db1_name is equal to db2_name, FALSE otherwise.
The function allows to compare database names according to the MySQL
rules. The database names db1 and db2 are equal if:
- db1 is NULL and db2 is NULL;
or
- db1 is not-NULL, db2 is not-NULL, db1 is equal (ignoring case) to
db2 in system character set (UTF8).
*/
static inline bool
cmp_db_names(const char *db1_name,
const char *db2_name)
{
return
/* db1 is NULL and db2 is NULL */
(!db1_name && !db2_name) ||
/* db1 is not-NULL, db2 is not-NULL, db1 == db2. */
(db1_name && db2_name &&
my_strcasecmp(system_charset_info, db1_name, db2_name) == 0);
}
/**
@brief Change the current database and its attributes unconditionally.
@param thd thread handle
@param new_db_name database name
@param force_switch if force_switch is FALSE, then the operation will fail if
- new_db_name is NULL or empty;
- OR new database name is invalid
(check_db_name() failed);
- OR user has no privilege on the new database;
- OR new database does not exist;
if force_switch is TRUE, then
- if new_db_name is NULL or empty, the current
database will be NULL, @@collation_database will
be set to @@collation_server, the operation will
succeed.
- if new database name is invalid
(check_db_name() failed), the current database
will be NULL, @@collation_database will be set to
@@collation_server, but the operation will fail;
- user privileges will not be checked
(THD::db_access however is updated);
TODO: is this really the intention?
(see sp-security.test).
- if new database does not exist,the current database
will be NULL, @@collation_database will be set to
@@collation_server, a warning will be thrown, the
operation will succeed.
@details The function checks that the database name corresponds to a
valid and existent database, checks access rights and changes the current
database with database attributes (@@collation_database session variable,
THD::db_access).
This function is not the only way to switch the database that is
currently employed. When the replication slave thread switches the
database before executing a query, it calls thd->set_db directly.
However, if the query, in turn, uses a stored routine, the stored routine
will use this function, even if it's run on the slave.
This function allocates the name of the database on the system heap: this
is necessary to be able to uniformly change the database from any module
of the server. Up to 5.0 different modules were using different memory to
store the name of the database, and this led to memory corruption:
a stack pointer set by Stored Procedures was used by replication after
the stack address was long gone.
@return Operation status
@retval FALSE Success
@retval TRUE Error
*/
bool mysql_change_db(THD *thd, const LEX_STRING *new_db_name, bool force_switch)
{
LEX_STRING new_db_file_name;
Security_context *sctx= thd->security_ctx;
ulong db_access= sctx->db_access;
CHARSET_INFO *db_default_cl;
DBUG_ENTER("mysql_change_db");
DBUG_PRINT("enter",("name: '%s'", new_db_name->str));
if (new_db_name == NULL ||
new_db_name->length == 0)
{
if (force_switch)
{
/*
This can happen only if we're switching the current database back
after loading stored program. The thing is that loading of stored
program can happen when there is no current database.
TODO: actually, new_db_name and new_db_name->str seem to be always
non-NULL. In case of stored program, new_db_name->str == "" and
new_db_name->length == 0.
*/
mysql_change_db_impl(thd, NULL, 0, thd->variables.collation_server);
DBUG_RETURN(FALSE);
}
else
{
my_message(ER_NO_DB_ERROR, ER(ER_NO_DB_ERROR), MYF(0));
DBUG_RETURN(TRUE);
}
}
if (is_infoschema_db(new_db_name->str, new_db_name->length))
{
/* Switch the current database to INFORMATION_SCHEMA. */
mysql_change_db_impl(thd, &INFORMATION_SCHEMA_NAME, SELECT_ACL,
system_charset_info);
DBUG_RETURN(FALSE);
}
/*
Now we need to make a copy because check_db_name requires a
non-constant argument. Actually, it takes database file name.
TODO: fix check_db_name().
*/
new_db_file_name.str= my_strndup(new_db_name->str, new_db_name->length,
MYF(MY_WME));
new_db_file_name.length= new_db_name->length;
if (new_db_file_name.str == NULL)
DBUG_RETURN(TRUE); /* the error is set */
/*
NOTE: if check_db_name() fails, we should throw an error in any case,
even if we are called from sp_head::execute().
It's next to impossible however to get this error when we are called
from sp_head::execute(). But let's switch the current database to NULL
in this case to be sure.
*/
if (check_db_name(&new_db_file_name))
{
my_error(ER_WRONG_DB_NAME, MYF(0), new_db_file_name.str);
my_free(new_db_file_name.str);
if (force_switch)
mysql_change_db_impl(thd, NULL, 0, thd->variables.collation_server);
DBUG_RETURN(TRUE);
}
DBUG_PRINT("info",("Use database: %s", new_db_file_name.str));
#ifndef NO_EMBEDDED_ACCESS_CHECKS
db_access=
test_all_bits(sctx->master_access, DB_ACLS) ?
DB_ACLS :
acl_get(sctx->host,
sctx->ip,
sctx->priv_user,
new_db_file_name.str,
FALSE) | sctx->master_access;
if (!force_switch &&
!(db_access & DB_ACLS) &&
check_grant_db(thd, new_db_file_name.str))
{
my_error(ER_DBACCESS_DENIED_ERROR, MYF(0),
sctx->priv_user,
sctx->priv_host,
new_db_file_name.str);
general_log_print(thd, COM_INIT_DB, ER(ER_DBACCESS_DENIED_ERROR),
sctx->priv_user, sctx->priv_host, new_db_file_name.str);
my_free(new_db_file_name.str);
DBUG_RETURN(TRUE);
}
#endif
if (check_db_dir_existence(new_db_file_name.str))
{
if (force_switch)
{
/* Throw a warning and free new_db_file_name. */
push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
ER_BAD_DB_ERROR, ER(ER_BAD_DB_ERROR),
new_db_file_name.str);
my_free(new_db_file_name.str);
/* Change db to NULL. */
mysql_change_db_impl(thd, NULL, 0, thd->variables.collation_server);
/* The operation succeed. */
DBUG_RETURN(FALSE);
}
else
{
/* Report an error and free new_db_file_name. */
my_error(ER_BAD_DB_ERROR, MYF(0), new_db_file_name.str);
my_free(new_db_file_name.str);
/* The operation failed. */
DBUG_RETURN(TRUE);
}
}
/*
NOTE: in mysql_change_db_impl() new_db_file_name is assigned to THD
attributes and will be freed in THD::~THD().
*/
db_default_cl= get_default_db_collation(thd, new_db_file_name.str);
mysql_change_db_impl(thd, &new_db_file_name, db_access, db_default_cl);
DBUG_RETURN(FALSE);
}
/**
Change the current database and its attributes if needed.
@param thd thread handle
@param new_db_name database name
@param[in, out] saved_db_name IN: "str" points to a buffer where to store
the old database name, "length" contains the
buffer size
OUT: if the current (default) database is
not NULL, its name is copied to the
buffer pointed at by "str"
and "length" is updated accordingly.
Otherwise "str" is set to NULL and
"length" is set to 0.
@param force_switch @see mysql_change_db()
@param[out] cur_db_changed out-flag to indicate whether the current
database has been changed (valid only if
the function suceeded)
*/
bool mysql_opt_change_db(THD *thd,
const LEX_STRING *new_db_name,
LEX_STRING *saved_db_name,
bool force_switch,
bool *cur_db_changed)
{
*cur_db_changed= !cmp_db_names(thd->db, new_db_name->str);
if (!*cur_db_changed)
return FALSE;
backup_current_db_name(thd, saved_db_name);
return mysql_change_db(thd, new_db_name, force_switch);
}
/**
Upgrade a 5.0 database.
This function is invoked whenever an ALTER DATABASE UPGRADE query is executed:
ALTER DATABASE 'olddb' UPGRADE DATA DIRECTORY NAME.
If we have managed to rename (move) tables to the new database
but something failed on a later step, then we store the
RENAME DATABASE event in the log. mysql_rename_db() is atomic in
the sense that it will rename all or none of the tables.
@param thd Current thread
@param old_db 5.0 database name, in #mysql50#name format
@return 0 on success, 1 on error
*/
bool mysql_upgrade_db(THD *thd, LEX_STRING *old_db)
{
int error= 0, change_to_newdb= 0;
char path[FN_REFLEN+16];
uint length;
HA_CREATE_INFO create_info;
MY_DIR *dirp;
TABLE_LIST *table_list;
SELECT_LEX *sl= thd->lex->current_select;
LEX_STRING new_db;
DBUG_ENTER("mysql_upgrade_db");
if ((old_db->length <= MYSQL50_TABLE_NAME_PREFIX_LENGTH) ||
(strncmp(old_db->str,
MYSQL50_TABLE_NAME_PREFIX,
MYSQL50_TABLE_NAME_PREFIX_LENGTH) != 0))
{
my_error(ER_WRONG_USAGE, MYF(0),
"ALTER DATABASE UPGRADE DATA DIRECTORY NAME",
"name");
DBUG_RETURN(1);
}
/* `#mysql50#<name>` converted to encoded `<name>` */
new_db.str= old_db->str + MYSQL50_TABLE_NAME_PREFIX_LENGTH;
new_db.length= old_db->length - MYSQL50_TABLE_NAME_PREFIX_LENGTH;
/* Lock the old name, the new name will be locked by mysql_create_db().*/
if (lock_schema_name(thd, old_db->str))
DBUG_RETURN(-1);
/*
Let's remember if we should do "USE newdb" afterwards.
thd->db will be cleared in mysql_rename_db()
*/
if (thd->db && !strcmp(thd->db, old_db->str))
change_to_newdb= 1;
build_table_filename(path, sizeof(path)-1,
old_db->str, "", MY_DB_OPT_FILE, 0);
if ((load_db_opt(thd, path, &create_info)))
create_info.default_table_charset= thd->variables.collation_server;
length= build_table_filename(path, sizeof(path)-1, old_db->str, "", "", 0);
if (length && path[length-1] == FN_LIBCHAR)
path[length-1]=0; // remove ending '\'
if ((error= my_access(path,F_OK)))
{
my_error(ER_BAD_DB_ERROR, MYF(0), old_db->str);
goto exit;
}
/* Step1: Create the new database */
if ((error= mysql_create_db(thd, new_db.str, &create_info, 1)))
goto exit;
/* Step2: Move tables to the new database */
if ((dirp = my_dir(path,MYF(MY_DONT_SORT))))
{
uint nfiles= (uint) dirp->number_off_files;
for (uint idx=0 ; idx < nfiles && !thd->killed ; idx++)
{
FILEINFO *file= dirp->dir_entry + idx;
char *extension, tname[FN_REFLEN + 1];
LEX_STRING table_str;
DBUG_PRINT("info",("Examining: %s", file->name));
/* skiping non-FRM files */
if (my_strcasecmp(files_charset_info,
(extension= fn_rext(file->name)), reg_ext))
continue;
/* A frm file found, add the table info rename list */
*extension= '\0';
table_str.length= filename_to_tablename(file->name,
tname, sizeof(tname)-1);
table_str.str= (char*) sql_memdup(tname, table_str.length + 1);
Table_ident *old_ident= new Table_ident(thd, *old_db, table_str, 0);
Table_ident *new_ident= new Table_ident(thd, new_db, table_str, 0);
if (!old_ident || !new_ident ||
!sl->add_table_to_list(thd, old_ident, NULL,
TL_OPTION_UPDATING, TL_IGNORE,
MDL_EXCLUSIVE) ||
!sl->add_table_to_list(thd, new_ident, NULL,
TL_OPTION_UPDATING, TL_IGNORE,
MDL_EXCLUSIVE))
{
error= 1;
my_dirend(dirp);
goto exit;
}
}
my_dirend(dirp);
}
if ((table_list= thd->lex->query_tables) &&
(error= mysql_rename_tables(thd, table_list, 1)))
{
/*
Failed to move all tables from the old database to the new one.
In the best case mysql_rename_tables() moved all tables back to the old
database. In the worst case mysql_rename_tables() moved some tables
to the new database, then failed, then started to move the tables back,
and then failed again. In this situation we have some tables in the
old database and some tables in the new database.
Let's delete the option file, and then the new database directory.
If some tables were left in the new directory, rmdir() will fail.
It garantees we never loose any tables.
*/
build_table_filename(path, sizeof(path)-1,
new_db.str,"",MY_DB_OPT_FILE, 0);
mysql_file_delete(key_file_dbopt, path, MYF(MY_WME));
length= build_table_filename(path, sizeof(path)-1, new_db.str, "", "", 0);
if (length && path[length-1] == FN_LIBCHAR)
path[length-1]=0; // remove ending '\'
rmdir(path);
goto exit;
}
/*
Step3: move all remaining files to the new db's directory.
Skip db opt file: it's been created by mysql_create_db() in
the new directory, and will be dropped by mysql_rm_db() in the old one.
Trigger TRN and TRG files are be moved as regular files at the moment,
without any special treatment.
Triggers without explicit database qualifiers in table names work fine:
use d1;
create trigger trg1 before insert on t2 for each row set @a:=1
rename database d1 to d2;
TODO: Triggers, having the renamed database explicitely written
in the table qualifiers.
1. when the same database is renamed:
create trigger d1.trg1 before insert on d1.t1 for each row set @a:=1;
rename database d1 to d2;
Problem: After database renaming, the trigger's body
still points to the old database d1.
2. when another database is renamed:
create trigger d3.trg1 before insert on d3.t1 for each row
insert into d1.t1 values (...);
rename database d1 to d2;
Problem: After renaming d1 to d2, the trigger's body
in the database d3 still points to database d1.
*/
if ((dirp = my_dir(path,MYF(MY_DONT_SORT))))
{
uint nfiles= (uint) dirp->number_off_files;
for (uint idx=0 ; idx < nfiles ; idx++)
{
FILEINFO *file= dirp->dir_entry + idx;
char oldname[FN_REFLEN + 1], newname[FN_REFLEN + 1];
DBUG_PRINT("info",("Examining: %s", file->name));
/* skiping . and .. and MY_DB_OPT_FILE */
if ((file->name[0] == '.' &&
(!file->name[1] || (file->name[1] == '.' && !file->name[2]))) ||
!my_strcasecmp(files_charset_info, file->name, MY_DB_OPT_FILE))
continue;
/* pass empty file name, and file->name as extension to avoid encoding */
build_table_filename(oldname, sizeof(oldname)-1,
old_db->str, "", file->name, 0);
build_table_filename(newname, sizeof(newname)-1,
new_db.str, "", file->name, 0);
mysql_file_rename(key_file_misc, oldname, newname, MYF(MY_WME));
}
my_dirend(dirp);
}
/*
Step7: drop the old database.
query_cache_invalidate(olddb) is done inside mysql_rm_db(), no need
to execute them again.
mysql_rm_db() also "unuses" if we drop the current database.
*/
error= mysql_rm_db(thd, old_db->str, 0, 1);
/* Step8: logging */
if (mysql_bin_log.is_open())
{
int errcode= query_error_code(thd, TRUE);
Query_log_event qinfo(thd, thd->query(), thd->query_length(),
FALSE, TRUE, TRUE, errcode);
thd->clear_error();
error|= mysql_bin_log.write(&qinfo);
}
/* Step9: Let's do "use newdb" if we renamed the current database */
if (change_to_newdb)
error|= mysql_change_db(thd, & new_db, FALSE);
exit:
DBUG_RETURN(error);
}
/*
Check if there is directory for the database name.
SYNOPSIS
check_db_dir_existence()
db_name database name
RETURN VALUES
FALSE There is directory for the specified database name.
TRUE The directory does not exist.
*/
bool check_db_dir_existence(const char *db_name)
{
char db_dir_path[FN_REFLEN + 1];
uint db_dir_path_len;
db_dir_path_len= build_table_filename(db_dir_path, sizeof(db_dir_path) - 1,
db_name, "", "", 0);
if (db_dir_path_len && db_dir_path[db_dir_path_len - 1] == FN_LIBCHAR)
db_dir_path[db_dir_path_len - 1]= 0;
/* Check access. */
return my_access(db_dir_path, F_OK);
}
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