mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-09-26 19:09:13 +02:00
Code Issues Projects Releases Packages Wiki Activity
mariadb/sql/sql_db.cc
Aleksey Midenkov a518e1dd42 MDEV-20865 Store foreign key info in TABLE_SHARE 
1. Access foreign keys via TABLE_SHARE::foreign_keys and
   TABLE_SHARE::referenced_keys;

   foreign_keys and referenced_keys are lists in TABLE_SHARE.

2. Remove handler FK interface:

   - get_foreign_key_list()
   - get_parent_foreign_key_list()
   - referenced_by_foreign_key()

3. Invalidate referenced shares on:

   - RENAME TABLE
   - DROP TABLE
   - RENAME COLUMN
   - ADD FOREIGN KEY

   When foreign table is created or altered by the above operations
   all referenced shares are closed. This blocks the operation while
   any referenced shares are used (when at least one its TABLE
   instance is locked).

4. Update referenced shares on:

   - CREATE TABLE

   On CREATE TABLE add items to referenced_keys of referenced
   shares. States of referenced shares are restored in case of errors.

5. Invalidate foreign shares on:

   - RENAME TABLE
   - RENAME COLUMN

   The above-mentioned blocking takes effect.

6. Check foreign/referenced shares consistency on:

   - CHECK TABLE

7. Temporary change until MDEV-21051:

   InnoDB fill foreign key info at handler open().

FOREIGN_KEY_INFO is refactored to FK_info holding Lex_cstring.

On first TABLE open FK_info is loaded from storage engine into
TABLE_SHARE. All referenced shares (if any exists) are closed. This
leads to blocking of first time foreign table open while referenced
tables are used.

MDEV-21311 Converge Foreign_key and supplemental generated Key together

mysql_prepare_create_table() does data validation and such utilities
as automatic name generation. But it does that only for indexes and
ignores Foreign_key objects. Now as Foreign_key data needs to be
stored in FRM files as well this processing must be done for it like
for any other Key objects.

Replace Key::FOREIGN_KEY type with Key::foreign flag of type
Key::MULTIPLE and Key::generated set to true. Construct one object
with Key::foreign == true instead of two objects of type
Key::FOREIGN_KEY and Key::MULTIPLE.

MDEV-21051 datadict refactorings

- Move read_extra2() to datadict.cc
- Refactored extra2_fields to Extra2_info
- build_frm_image() readability

MDEV-21051 build_table_shadow_filename() refactoring

mysql_prepare_alter_table() leaks fixes

MDEV-21051 amend system tables locking restriction

Table mysql.help_relation has foreign key to mysql.help_keyword. On
bootstrap when help_relation is opened, it preopens help_keyword for
READ and fails in lock_tables_check().

If system table is opened for write then fk references are opened for
write.

Related to: Bug#25422, WL#3984
Tests: main.lock

MDEV-21051 Store and read foreign key info into/from FRM files

1. Introduce Foreign_key_io class which creates/parses binary stream
containing foreign key structures. Referenced tables store there only
hints about foreign tables (their db and name), they restore full info
from the corresponding tables.

Foreign_key_io is stored under new EXTRA2_FOREIGN_KEY_INFO field in
extra2 section of FRM file.

2. Modify mysql_prepare_create_table() to generate names for foreign
keys. Until InnoDB storage of foreign keys is removed, FK names must
be unique across the database: the FK name must be based on table
name.

3. Keep stored data in sync on DDL changes. Referenced tables update
their foreign hints after following operations on foreign tables:

  - RENAME TABLE
  - DROP TABLE
  - CREATE TABLE
  - ADD FOREIGN KEY
  - DROP FOREIGN KEY

Foreign tables update their foreign info after following operations on
referenced tables:

  - RENAME TABLE
  - RENAME COLUMN

4. To achieve 3. there must be ability to rewrite extra2 section of
FRM file without full reparse. FRM binary is built from primary
structures like HA_CREATE_INFO and cannot be built from TABLE_SHARE.

Use shadow write and rename like fast_alter_partition_table()
does. Shadow FRM is new FRM file that replaces the old one.

CREATE TABLE workflow:

  1. Foreign_key is constructed in parser, placed into
     alter_info->key_list;

  2. mysql_prepare_create_table() translates them to FK_info, assigns
     foreign_id if needed;

  3. build_frm_image() writes two FK_info lists into FRM's extra2
     section, for referenced keys it stores only table names (hints);

  4. init_from_binary_frm_image() parses extra2 section and fills
     foreign_keys and referenced_keys of TABLE_SHARE.

     It restores referenced_keys by reading hint list of table names,
     opening corresponding shares and restoring FK_info from their
     foreign_keys. Hints resolution is done only when initializing
     non-temporary shares. Usually temporary share has different
     (temporary) name and it is impossible to resolve foreign keys by
     that name (as we identify them by both foreign and referenced
     table names). Another not unimportant reason is performance: this
     saves spare share acquisitions.

ALTER TABLE workflow:

  1. Foreign_key is constructed in parser, placed into
     alter_info->key_list;

  2. mysql_prepare_alter_table() prepares action lists and share list
     of foreigns/references;

  3. mysql_prepare_alter_table() locks list of foreigns/references by
     MDL_INTENTION_EXCLUSIVE, acquires shares;

  4. prepare_create_table() converts key_list into FK_list, assigns
     foreign_id;

  5. shadow FRM of altered table is created;

  6. data is copied;

  7. altered table is locked by MDL_EXCLUSIVE;

  8. fk_handle_alter() processes action lists, creates FK backups,
     modifies shares, writes shadow FRMs;

  9. altered table is closed;

  10. shadow FRMs are installed;

  11. altered table is renamed, FRM backup deleted;

  12. (TBD in MDEV-21053) shadow FRMs installation log closed, backups
      deleted;

On FK backup system:

In case of failed DDL operation all shares that was modified must be
restored into original state. This is done by FK_ddl_backup (CREATE,
DROP), FK_rename_backup (RENAME), FK_alter_backup (ALTER).

On STL usage:

STL is used for utility not performance-critical algorithms, core
structures hold native List. A wrapper was made to convert STL
exception into bool error status or NULL value.

MDEV-20865 fk_check_consistency() in CHECK TABLE

Self-refs fix

Test table_flags fix: "debug" deviation is now gone.

FIXMEs: +16 -1
2025-09-02 13:24:36 +03:00

2164 lines
64 KiB
C++
Raw Permalink Blame History

/*
Copyright (c) 2000, 2014, Oracle and/or its affiliates.
Copyright (c) 2009, 2016, MariaDB Corporation
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
/* create and drop of databases */
#include "mariadb.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
// validate_comment_length
#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 "sql_base.h" // lock_table_names
#include "sql_handler.h" // mysql_ha_rm_tables
#include "sql_class.h"
#include <mysys_err.h>
#include "sp_head.h"
#include "sp.h"
#include "events.h"
#include "sql_handler.h"
#include "sql_statistics.h"
#include "ddl_log.h" // ddl_log functions
#include <my_dir.h>
#include <m_ctype.h>
#include "log.h"
#ifdef _WIN32
#include <direct.h>
#endif
#include "debug.h" // debug_crash_here
#define MAX_DROP_TABLE_Q_LEN 1024
const char *del_exts[]= {".BAK", ".opt", NullS};
static TYPELIB deletable_extensions= CREATE_TYPELIB_FOR(del_exts);
static bool find_db_tables_and_rm_known_files(THD *, MY_DIR *,
const Lex_ident_db_normalized &db,
const char *, TABLE_LIST **);
long mysql_rm_arc_files(THD *thd, MY_DIR *dirp, const char *org_path);
my_bool rm_dir_w_symlink(const char *org_path, my_bool send_error);
static void mysql_change_db_impl(THD *thd,
LEX_CSTRING *new_db_name,
privilege_t new_db_access,
CHARSET_INFO *new_db_charset);
static bool mysql_rm_db_internal(THD *thd, const Lex_ident_db &db,
bool if_exists, bool silent);
/* 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 */
LEX_STRING comment; /* Database comment */
} my_dbopt_t;
/**
Return TRUE if db1_name is equal to db2_name, FALSE otherwise.
The function allows to compare database names according to the MariaDB
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 to db2 in
table_alias_charset
This is the same rules as we use for filenames.
*/
static inline bool
cmp_db_names(const Lex_ident_db &db1_name, const Lex_ident_db &db2_name)
{
return (db1_name.length == 0 && db2_name.length == 0) ||
db1_name.streq(db2_name);
}
#ifdef HAVE_PSI_INTERFACE
static PSI_rwlock_key key_rwlock_LOCK_dboptions;
static PSI_rwlock_key key_rwlock_LOCK_dbnames;
static PSI_rwlock_key key_rwlock_LOCK_rmdir;
static PSI_rwlock_info all_database_names_rwlocks[]= {
{&key_rwlock_LOCK_dboptions, "LOCK_dboptions", PSI_FLAG_GLOBAL},
{&key_rwlock_LOCK_dbnames, "LOCK_dbnames", PSI_FLAG_GLOBAL},
{&key_rwlock_LOCK_rmdir, "LOCK_rmdir",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
static mysql_rwlock_t rmdir_lock;
/*
Cache of C strings for existing database names.
The only use of it is to avoid repeated expensive
my_access() calls.
Provided operations are lookup, insert (after successfull my_access())
and clear (this is called whenever rmdir is called).
*/
struct dbname_cache_t
{
private:
Hash_set<LEX_STRING> m_set;
mysql_rwlock_t m_lock;
static const uchar *get_key(const void *ls_, size_t *sz, my_bool)
{
const LEX_STRING *ls= static_cast<const LEX_STRING*>(ls_);
*sz= ls->length;
return reinterpret_cast<const uchar*>(ls->str);
}
public:
dbname_cache_t()
: m_set(key_memory_dbnames_cache, table_alias_charset, 10, 0,
sizeof(char *), get_key, my_free, 0)
{
mysql_rwlock_init(key_rwlock_LOCK_dbnames, &m_lock);
}
bool contains(const char *s)
{
auto sz= strlen(s);
mysql_rwlock_rdlock(&m_lock);
bool ret= m_set.find(s, sz) != 0;
mysql_rwlock_unlock(&m_lock);
return ret;
}
void insert(const char *s)
{
auto len= strlen(s);
auto ls= (LEX_STRING *) my_malloc(key_memory_dbnames_cache,
sizeof(LEX_STRING) + strlen(s) + 1, 0);
if (!ls)
return;
ls->length= len;
ls->str= (char *) (ls + 1);
memcpy(ls->str, s, len + 1);
mysql_rwlock_wrlock(&m_lock);
bool found= m_set.find(s, len) != 0;
if (!found)
m_set.insert(ls);
mysql_rwlock_unlock(&m_lock);
if (found)
my_free(ls);
}
void clear()
{
mysql_rwlock_wrlock(&m_lock);
m_set.clear();
mysql_rwlock_unlock(&m_lock);
}
~dbname_cache_t()
{
mysql_rwlock_destroy(&m_lock);
}
};
static dbname_cache_t* dbname_cache;
static void dbname_cache_init()
{
static MY_ALIGNED(16) char buf[sizeof(dbname_cache_t)];
DBUG_ASSERT(!dbname_cache);
dbname_cache= new (buf) dbname_cache_t;
mysql_rwlock_init(key_rwlock_LOCK_rmdir, &rmdir_lock);
}
static void dbname_cache_destroy()
{
if (!dbname_cache)
return;
dbname_cache->~dbname_cache_t();
dbname_cache= 0;
mysql_rwlock_destroy(&rmdir_lock);
}
static int my_rmdir(const char *dir)
{
auto ret= rmdir(dir);
if (ret)
return ret;
mysql_rwlock_wrlock(&rmdir_lock);
dbname_cache->clear();
mysql_rwlock_unlock(&rmdir_lock);
return 0;
}
/*
Function we use in the creation of our hash to get key.
*/
extern "C" const uchar *dboptions_get_key(const void *opt, size_t *length,
my_bool);
const uchar *dboptions_get_key(const void *opt_, size_t *length, my_bool)
{
auto opt= static_cast<const my_dbopt_t *>(opt_);
*length= opt->name_length;
return reinterpret_cast<const uchar *>(opt->name);
}
/*
Helper function to write a query to binlog used by mysql_rm_db()
*/
static inline int write_to_binlog(THD *thd, const char *query, size_t q_len,
const char *db, size_t db_len)
{
Query_log_event qinfo(thd, query, q_len, FALSE, TRUE, FALSE, 0);
qinfo.db= db;
qinfo.db_len= (uint32)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);
}
/**
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(key_memory_dboptions_hash, &dboptions,
table_alias_charset, 32, 0, 0, dboptions_get_key,
free_dbopt, 0);
}
dbname_cache_init();
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);
dbname_cache_destroy();
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(key_memory_dboptions_hash, &dboptions, table_alias_charset, 32,
0, 0, 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(THD *thd, const char *dbname,
Schema_specification_st *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;
if (opt->comment.length)
{
create->schema_comment= thd->make_clex_string(opt->comment.str,
opt->comment.length);
}
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, Schema_specification_st *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;
char *tmp_comment= NULL;
if (!my_multi_malloc(key_memory_dboptions_hash, MYF(MY_WME | MY_ZEROFILL),
&opt, (uint) sizeof(*opt), &tmp_name, (uint) length+1,
&tmp_comment, (uint) DATABASE_COMMENT_MAXLEN+1,
NullS))
{
error= 1;
goto end;
}
opt->name= tmp_name;
strmov(opt->name, dbname);
opt->name_length= length;
opt->comment.str= tmp_comment;
if (unlikely((error= my_hash_insert(&dboptions, (uchar*) opt))))
{
my_free(opt);
goto end;
}
}
/* Update / write options in hash */
opt->charset= create->default_table_charset;
if (create->schema_comment)
{
strmov(opt->comment.str, create->schema_comment->str);
opt->comment.length= create->schema_comment->length;
}
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, default collation
and comment are 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,
Schema_specification_st *create)
{
File file;
char buf[256+DATABASE_COMMENT_MAXLEN];
bool error=1;
if (create->schema_comment)
{
if (validate_comment_length(thd, create->schema_comment,
DATABASE_COMMENT_MAXLEN,
ER_TOO_LONG_DATABASE_COMMENT,
thd->lex->name.str))
return error;
}
if (thd->lex->sql_command == SQLCOM_ALTER_DB &&
(!create->schema_comment || !create->default_table_charset))
{
/* Use existing values of schema_comment and charset for
ALTER DATABASE queries */
Schema_specification_st tmp;
tmp.init();
load_db_opt(thd, path, &tmp);
if (!create->schema_comment)
create->schema_comment= tmp.schema_comment;
if (!create->default_table_charset)
create->default_table_charset= tmp.default_table_charset;
}
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->cs_name.str,
"\ndefault-collation=",
create->default_table_charset->coll_name.str,
"\n", NullS) - buf);
if (create->schema_comment)
length= (ulong) (strxnmov(buf+length, sizeof(buf)-1-length,
"comment=", create->schema_comment->str,
"\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
create->default_table_charset is guaranteed to be alway set
Required by some callers
RETURN VALUES
0 File found
-1 No database file (file was not found or 'empty' file was cached)
1 Could not open it
*/
int load_db_opt(THD *thd, const char *path, Schema_specification_st *create)
{
File file;
char buf[256+DATABASE_COMMENT_MAXLEN];
DBUG_ENTER("load_db_opt");
int error= 0;
size_t nbytes;
myf utf8_flag= thd->get_utf8_flag();
bzero((char*) create,sizeof(*create));
/* Check if options for this database are already in the hash */
if (!get_dbopt(thd, path, create))
{
if (!create->default_table_charset)
error= -1; // db.opt did not exists
goto err1;
}
/* Otherwise, load options from the .opt file */
if ((file= mysql_file_open(key_file_dbopt,
path, O_RDONLY | O_SHARE, MYF(0))) < 0)
{
/*
Create an empty entry, to avoid doing an extra file open for every create
table.
*/
put_dbopt(path, create);
error= -1;
goto err1;
}
IO_CACHE cache;
if (init_io_cache(&cache, file, IO_SIZE, READ_CACHE, 0, 0, MYF(0)))
{
error= 1;
goto err2; // Not cached
}
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(utf8_flag))) &&
!(create->default_table_charset=
get_charset_by_name(pos+1, MYF(utf8_flag))))
{
sql_print_error("Error while loading database options: '%s':",path);
sql_print_error(ER_DEFAULT(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(utf8_flag))))
{
sql_print_error("Error while loading database options: '%s':",path);
sql_print_error(ER_DEFAULT(ER_UNKNOWN_COLLATION),pos+1);
create->default_table_charset= default_charset_info;
}
}
else if (!strncmp(buf, "comment", (pos-buf)))
create->schema_comment= thd->make_clex_string(pos+1, strlen(pos+1));
}
}
/*
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:
if (!create->default_table_charset) // In case of error
create->default_table_charset= thd->variables.collation_server;
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!)
0 File found
-1 No database file (file was not found or 'empty' file was cached)
1 Could not open it
*/
int load_db_opt_by_name(THD *thd, const char *db_name,
Schema_specification_st *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)
{
Schema_specification_st db_info;
if (thd->db.str != NULL && strcmp(db_name, thd->db.str) == 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_internal()
thd Thread handler
db Name of database to create
Function assumes that this is already validated.
options DDL options, e.g. IF NOT EXISTS
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
*/
static int
mysql_create_db_internal(THD *thd, const Lex_ident_db &db,
const DDL_options_st &options,
Schema_specification_st *create_info,
bool silent)
{
char path[FN_REFLEN+16];
MY_STAT stat_info;
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.str);
DBUG_RETURN(-1);
}
const DBNameBuffer dbnorm_buffer(db, lower_case_table_names);
Lex_ident_db_normalized dbnorm(dbnorm_buffer.to_lex_cstring());
if (lock_schema_name(thd, dbnorm))
DBUG_RETURN(-1);
/* Check directory */
path_len= build_table_filename(path, sizeof(path) - 1, db.str, "", "", 0);
path[path_len-1]= 0; // Remove last '/' from path
long affected_rows= 1;
if (!mysql_file_stat(key_file_misc, path, &stat_info, MYF(0)))
{
// The database directory does not exist, or my_file_stat() failed
if (my_errno != ENOENT)
{
my_error(EE_STAT, MYF(0), path, my_errno);
DBUG_RETURN(1);
}
}
else if (options.or_replace())
{
if (mysql_rm_db_internal(thd, db, 0, true)) // Removing the old database
DBUG_RETURN(1);
/*
Reset the diagnostics m_status.
It might be set ot DA_OK in mysql_rm_db.
*/
thd->get_stmt_da()->reset_diagnostics_area();
affected_rows= 2;
}
else if (options.if_not_exists())
{
push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
ER_DB_CREATE_EXISTS, ER_THD(thd, ER_DB_CREATE_EXISTS),
db.str);
affected_rows= 0;
goto not_silent;
}
else
{
my_error(ER_DB_CREATE_EXISTS, MYF(0), db.str);
DBUG_RETURN(-1);
}
if (my_mkdir(path, 0777, MYF(0)) < 0)
{
my_error(ER_CANT_CREATE_DB, MYF(0), db.str, my_errno);
DBUG_RETURN(-1);
}
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 (my_rmdir(path) >= 0)
DBUG_RETURN(-1);
/*
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 scenario)
*/
thd->clear_error();
}
/* Log command to ddl log */
backup_log_info ddl_log;
bzero(&ddl_log, sizeof(ddl_log));
ddl_log.query= { C_STRING_WITH_LEN("CREATE") };
ddl_log.org_storage_engine_name= { C_STRING_WITH_LEN("DATABASE") };
ddl_log.org_database= db;
backup_log_ddl(&ddl_log);
not_silent:
if (!silent)
{
char *query;
uint query_length;
query= thd->query();
query_length= thd->query_length();
DBUG_ASSERT(query);
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.str;
qinfo.db_len = (uint32)db.length;
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema
*/
if (mysql_bin_log.write(&qinfo))
DBUG_RETURN(-1);
}
my_ok(thd, affected_rows);
}
DBUG_RETURN(0);
}
/* db-name is already validated when we come here */
static bool
mysql_alter_db_internal(THD *thd, const Lex_ident_db &db,
Schema_specification_st *create_info)
{
char path[FN_REFLEN+16];
long result=1;
int error= 0;
DBUG_ENTER("mysql_alter_db");
const DBNameBuffer dbnorm_buffer(db, lower_case_table_names);
Lex_ident_db_normalized dbnorm(dbnorm_buffer.to_lex_cstring());
if (lock_schema_name(thd, dbnorm))
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.str, "", MY_DB_OPT_FILE, 0);
if (unlikely((error=write_db_opt(thd, path, create_info))))
goto exit;
/* Change options if current database is being altered. */
if (thd->db.str && !cmp(&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;
}
/* Log command to ddl log */
backup_log_info ddl_log;
bzero(&ddl_log, sizeof(ddl_log));
ddl_log.query= { C_STRING_WITH_LEN("ALTER") };
ddl_log.org_storage_engine_name= { C_STRING_WITH_LEN("DATABASE") };
ddl_log.org_database= db;
backup_log_ddl(&ddl_log);
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.str;
qinfo.db_len= (uint) db.length;
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema.
*/
if (unlikely((error= mysql_bin_log.write(&qinfo))))
goto exit;
}
my_ok(thd, result);
exit:
DBUG_RETURN(error);
}
int mysql_create_db(THD *thd, const Lex_ident_db &db, DDL_options_st options,
const Schema_specification_st *create_info)
{
DBUG_ASSERT(create_info->default_table_charset);
/*
As mysql_create_db_internal() may modify Db_create_info structure passed
to it, we need to use a copy to make execution prepared statement- safe.
*/
Schema_specification_st tmp(*create_info);
if (thd->slave_thread &&
slave_ddl_exec_mode_options == SLAVE_EXEC_MODE_IDEMPOTENT)
options.add(DDL_options::OPT_IF_NOT_EXISTS);
return mysql_create_db_internal(thd, db, options, &tmp, false);
}
bool mysql_alter_db(THD *thd, const Lex_ident_db &db,
const Schema_specification_st *create_info)
{
DBUG_ASSERT(create_info->default_table_charset);
/*
As mysql_alter_db_internal() may modify Db_create_info structure passed
to it, we need to use a copy to make execution prepared statement- safe.
*/
Schema_specification_st tmp(*create_info);
return mysql_alter_db_internal(thd, db, &tmp);
}
/**
Drop database objects
@param thd THD object
@param path Path to database (for ha_drop_database)
@param db Normalized database name
@param rm_mysql_schema If the schema is 'mysql', in which case we don't
log the query to binary log or delete related
routines or events.
*/
void drop_database_objects(THD *thd, const LEX_CSTRING *path,
const LEX_CSTRING *db,
bool rm_mysql_schema)
{
debug_crash_here("ddl_log_drop_before_ha_drop_database");
ha_drop_database(path->str);
/*
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.
*/
debug_crash_here("ddl_log_drop_before_drop_db_routines");
query_cache_invalidate1(thd, *db);
if (!rm_mysql_schema)
{
tmp_disable_binlog(thd);
(void) sp_drop_db_routines(thd, *db); /* @todo Do not ignore errors */
#ifdef HAVE_EVENT_SCHEDULER
Events::drop_schema_events(thd, *db);
#endif
reenable_binlog(thd);
}
debug_crash_here("ddl_log_drop_after_drop_db_routines");
}
/**
Drop all tables, routines and events in a database and the database itself.
@param thd Thread handle
@param db Database name in the case given by user
It's already validated and set to lower case
(if needed) when we come here
@param if_exists Don't give error if database doesn't exists
@param silent Don't write the statement to the binary log and don't
send ok packet to the client
@retval false OK (Database dropped)
@retval true Error
*/
static bool
mysql_rm_db_internal(THD *thd, const Lex_ident_db &db, bool if_exists,
bool silent)
{
ulong deleted_tables= 0;
bool error= true, rm_mysql_schema;
char path[FN_REFLEN + 16];
MY_DIR *dirp;
uint path_length;
TABLE_LIST *tables= NULL;
TABLE_LIST *table;
DDL_LOG_STATE ddl_log_state;
Drop_table_error_handler err_handler;
DBUG_ENTER("mysql_rm_db");
const DBNameBuffer dbnorm_buffer(db, lower_case_table_names);
Lex_ident_db_normalized dbnorm(dbnorm_buffer.to_lex_cstring());
bzero(&ddl_log_state, sizeof(ddl_log_state));
if (lock_schema_name(thd, dbnorm))
DBUG_RETURN(true);
path_length= build_table_filename(path, sizeof(path) - 1, db.str, "", "", 0);
/* See if the directory exists */
if (!(dirp= my_dir(path,MYF(MY_DONT_SORT))))
{
if (!if_exists)
{
my_error(ER_DB_DROP_EXISTS, MYF(0), db.str);
DBUG_RETURN(true);
}
else
{
push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
ER_DB_DROP_EXISTS, ER_THD(thd, ER_DB_DROP_EXISTS),
db.str);
error= false;
goto update_binlog;
}
}
if (find_db_tables_and_rm_known_files(thd, dirp, dbnorm, path, &tables))
goto exit;
/*
Disable drop of enabled log tables, must be done before name locking.
This check is only needed if we are dropping the "mysql" database.
*/
if ((rm_mysql_schema= MYSQL_SCHEMA_NAME.streq(db)))
{
for (table= tables; table; table= table->next_local)
if (check_if_log_table(table, TRUE, "DROP"))
goto exit;
}
/* Lock all tables and stored routines about to be dropped. */
if (lock_table_names(thd, tables, NULL, thd->variables.lock_wait_timeout,
0) ||
lock_db_routines(thd, dbnorm))
goto exit;
if (!rm_mysql_schema)
{
for (table= tables; table; table= table->next_local)
{
if (table->open_type == OT_BASE_ONLY ||
!thd->find_temporary_table(table))
(void) delete_statistics_for_table(thd, &table->db, &table->table_name);
}
}
/*
Close active HANDLER's for tables in the database.
Note that mysql_ha_rm_tables() requires a non-null TABLE_LIST.
*/
if (tables)
mysql_ha_rm_tables(thd, tables);
for (table= tables; table; table= table->next_local)
deleted_tables++;
thd->push_internal_handler(&err_handler);
if (!thd->killed &&
!(tables &&
mysql_rm_table_no_locks(thd, tables, &dbnorm, &ddl_log_state, true, false,
true, false, true, true, false)))
{
debug_crash_here("ddl_log_drop_after_drop_tables");
LEX_CSTRING cpath{ path, path_length};
ddl_log_drop_db(&ddl_log_state, &dbnorm, &cpath);
drop_database_objects(thd, &cpath, &dbnorm, rm_mysql_schema);
/*
Now remove the db.opt file.
The 'find_db_tables_and_rm_known_files' doesn't remove this file
if there exists a table with the name 'db', so let's just do it
separately. We know this file exists and needs to be deleted anyway.
*/
debug_crash_here("ddl_log_drop_before_drop_option_file");
strmov(path+path_length, MY_DB_OPT_FILE); // Append db option file name
if (mysql_file_delete_with_symlink(key_file_misc, path, "", MYF(0)) &&
my_errno != ENOENT)
{
thd->pop_internal_handler();
my_error(EE_DELETE, MYF(0), path, my_errno);
error= true;
ddl_log_complete(&ddl_log_state);
goto end;
}
del_dbopt(path); // Remove dboption hash entry
path[path_length]= '\0'; // Remove file name
/*
If the directory is a symbolic link, remove the link first, then
remove the directory the symbolic link pointed at
*/
debug_crash_here("ddl_log_drop_before_drop_dir");
error= rm_dir_w_symlink(path, true);
debug_crash_here("ddl_log_drop_after_drop_dir");
}
thd->pop_internal_handler();
update_binlog:
if (likely(!error))
{
/* Log command to ddl log */
backup_log_info ddl_log;
bzero(&ddl_log, sizeof(ddl_log));
ddl_log.query= { C_STRING_WITH_LEN("DROP") };
ddl_log.org_storage_engine_name= { C_STRING_WITH_LEN("DATABASE") };
ddl_log.org_database= db;
backup_log_ddl(&ddl_log);
}
if (!silent && likely(!error))
{
const char *query;
ulong query_length;
query= thd->query();
query_length= thd->query_length();
DBUG_ASSERT(query);
if (mysql_bin_log.is_open())
{
int errcode= query_error_code(thd, TRUE);
int res;
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.str;
qinfo.db_len = (uint32) db.length;
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema.
*/
debug_crash_here("ddl_log_drop_before_binlog");
thd->binlog_xid= thd->query_id;
ddl_log_update_xid(&ddl_log_state, thd->binlog_xid);
res= mysql_bin_log.write(&qinfo);
thd->binlog_xid= 0;
debug_crash_here("ddl_log_drop_after_binlog");
if (res)
{
error= true;
goto exit;
}
}
thd->clear_error();
thd->server_status|= SERVER_STATUS_DB_DROPPED;
my_ok(thd, deleted_tables);
}
else if (mysql_bin_log.is_open() && !silent)
{
char *query, *query_pos, *query_end, *query_data_start;
TABLE_LIST *tbl;
if (!(query= thd->alloc(MAX_DROP_TABLE_Q_LEN)))
goto exit; /* not much else we can do */
query_pos= query_data_start= strmov(query,"DROP TABLE IF EXISTS ");
query_end= query + MAX_DROP_TABLE_Q_LEN;
for (tbl= tables; tbl; tbl= tbl->next_local)
{
size_t tbl_name_len;
char quoted_name[FN_REFLEN+3];
// Only write drop table to the binlog for tables that no longer exist.
if (ha_table_exists(thd, &tbl->db, &tbl->table_name))
continue;
tbl_name_len= my_snprintf(quoted_name, sizeof(quoted_name), "%sQ",
tbl->table_name.str);
tbl_name_len++; /* +1 for the comma */
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, (uint)(query_pos -1 - query), db.str, db.length))
{
error= true;
goto exit;
}
query_pos= query_data_start;
}
query_pos= strmov(query_pos, quoted_name);
*query_pos++ = ',';
}
if (query_pos != query_data_start) // If database was not empty
{
int res;
/*
These DDL methods and logging are protected with the exclusive
metadata lock on the schema.
*/
debug_crash_here("ddl_log_drop_before_binlog");
thd->binlog_xid= thd->query_id;
ddl_log_update_xid(&ddl_log_state, thd->binlog_xid);
res= write_to_binlog(thd, query, (uint)(query_pos -1 - query), db.str,
db.length);
thd->binlog_xid= 0;
debug_crash_here("ddl_log_drop_after_binlog");
if (res)
{
error= true;
goto exit;
}
}
}
exit:
ddl_log_complete(&ddl_log_state);
/*
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 (unlikely(thd->db.str &&
cmp_db_names(Lex_ident_db(thd->db), db) && !error))
{
mysql_change_db_impl(thd, NULL, NO_ACL, thd->variables.collation_server);
thd->session_tracker.current_schema.mark_as_changed(thd);
}
end:
my_dirend(dirp);
DBUG_RETURN(error);
}
bool mysql_rm_db(THD *thd, const Lex_ident_db &db, bool if_exists)
{
if (thd->slave_thread &&
slave_ddl_exec_mode_options == SLAVE_EXEC_MODE_IDEMPOTENT)
if_exists= true;
return mysql_rm_db_internal(thd, db, if_exists, false);
}
static bool find_db_tables_and_rm_known_files(THD *thd, MY_DIR *dirp,
const Lex_ident_db_normalized &db,
const char *path,
TABLE_LIST **tables)
{
char filePath[FN_REFLEN];
TABLE_LIST *tot_list=0, **tot_list_next_local, **tot_list_next_global;
DBUG_ENTER("find_db_tables_and_rm_known_files");
DBUG_PRINT("enter",("path: %s", path));
/* first, get the list of tables */
Dynamic_array<LEX_CSTRING*> files(PSI_INSTRUMENT_MEM, dirp->number_of_files);
Discovered_table_list tl(thd, &files);
if (ha_discover_table_names(thd, &db, dirp, &tl, true))
DBUG_RETURN(1);
/* Now put the tables in the list */
tot_list_next_local= tot_list_next_global= &tot_list;
for (size_t idx=0; idx < files.elements(); idx++)
{
const LEX_CSTRING *table= files.at(idx);
/* Drop the table nicely */
TABLE_LIST *table_list= thd->calloc<TABLE_LIST>(1);
if (!table_list)
DBUG_RETURN(true);
table_list->db= db;
/*
On the case-insensitive file systems table is opened
with the lowercased file name. So we should lowercase
as well to look up the cache properly.
*/
table_list->table_name= lower_case_file_system ?
Lex_ident_table(thd->make_ident_casedn(*table)) :
Lex_ident_table(*table);
table_list->open_type= OT_BASE_ONLY;
table_list->alias= table_list->table_name; // If lower_case_table_names=2
MDL_REQUEST_INIT(&table_list->mdl_request, MDL_key::TABLE,
table_list->db.str, table_list->table_name.str,
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;
}
*tables= tot_list;
/* and at last delete all non-table files */
for (size_t idx=0; idx < dirp->number_of_files && !thd->killed; idx++)
{
FILEINFO *file=dirp->dir_entry+idx;
char *extension;
DBUG_PRINT("info",("Examining: %s", file->name));
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, 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)
DBUG_RETURN(true);
}
continue;
}
if (!(extension= strrchr(file->name, '.')))
extension= strend(file->name);
if (find_type(extension, &deletable_extensions, FIND_TYPE_NO_PREFIX) > 0)
{
strxmov(filePath, path, "/", file->name, NullS);
/*
We ignore ENOENT error in order to skip files that was deleted
by concurrently running statement like REPAIR TABLE ...
*/
if (mysql_file_delete_with_symlink(key_file_misc, filePath, "", MYF(0)) &&
my_errno != ENOENT)
{
my_error(EE_DELETE, MYF(0), filePath, my_errno);
DBUG_RETURN(true);
}
}
}
DBUG_RETURN(false);
}
/*
Remove directory with symlink
SYNOPSIS
rm_dir_w_symlink()
org_path path of directory
send_error send errors
RETURN
0 OK
1 ERROR
*/
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);
/* Remove end FN_LIBCHAR as this causes problem on Linux and OS/2 */
pos= strend(path);
if (pos > path && pos[-1] == FN_LIBCHAR)
*--pos=0;
#ifdef HAVE_READLINK
int error;
char tmp2_path[FN_REFLEN];
if (unlikely((error= my_readlink(tmp2_path, path,
MYF(send_error ? MY_WME : 0))) < 0))
DBUG_RETURN(1);
if (likely(!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
if (unlikely(my_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 (size_t idx=0; idx < dirp->number_of_files && !thd->killed; idx++)
{
FILEINFO *file=dirp->dir_entry+idx;
char *extension, *revision;
DBUG_PRINT("info",("Examining: %s", file->name));
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_CSTRING *new_db_name,
privilege_t 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_clex_str);
}
else if (new_db_name->str == INFORMATION_SCHEMA_NAME.str)
{
/*
Here we must use THD::set_db(), because we want to copy
INFORMATION_SCHEMA_NAME constant.
*/
thd->set_db(&INFORMATION_SCHEMA_NAME);
}
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.
*/
thd->set_db(&null_clex_str);
thd->reset_db(new_db_name);
}
/* 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)
{
DBUG_ASSERT(saved_db_name->length >= SAFE_NAME_LEN +1);
if (!thd->db.str)
{
/* No current (default) database selected. */
saved_db_name->str= 0;
saved_db_name->length= 0;
}
else
{
memcpy(saved_db_name->str, thd->db.str, thd->db.length + 1);
saved_db_name->length= thd->db.length;
}
}
/**
@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
(Lex_ident_db::check_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
(Lex_ident_db::check_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 error code (ER_XXX)
@retval 0 Success
@retval >0 Error
*/
uint mysql_change_db(THD *thd, const LEX_CSTRING *new_db_name,
bool force_switch)
{
DBNameBuffer new_db_buff;
LEX_CSTRING new_db_file_name;
Security_context *sctx= thd->security_ctx;
privilege_t db_access(sctx->db_access);
CHARSET_INFO *db_default_cl;
DBUG_ENTER("mysql_change_db");
if (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.
In case of stored program, new_db_name->str == "" and
new_db_name->length == 0.
*/
mysql_change_db_impl(thd, NULL, NO_ACL, thd->variables.collation_server);
goto done;
}
else
{
my_message(ER_NO_DB_ERROR, ER_THD(thd, ER_NO_DB_ERROR), MYF(0));
DBUG_RETURN(ER_NO_DB_ERROR);
}
}
DBUG_PRINT("enter",("name: '%s'", new_db_name->str));
if (is_infoschema_db(new_db_name))
{
/* Switch the current database to INFORMATION_SCHEMA. */
mysql_change_db_impl(thd, &INFORMATION_SCHEMA_NAME, SELECT_ACL,
system_charset_info);
goto done;
}
new_db_file_name= lower_case_table_names == 1 ?
new_db_buff.copy_casedn(&my_charset_utf8mb3_general_ci,
*new_db_name).to_lex_cstring() :
*new_db_name;
/*
NOTE: if Lex_ident_db::check_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.
The cast below ok here as new_db_file_name was just allocated
*/
if (Lex_ident_db::check_name_with_error(new_db_file_name))
{
if (force_switch)
mysql_change_db_impl(thd, NULL, NO_ACL, thd->variables.collation_server);
DBUG_RETURN(ER_WRONG_DB_NAME);
}
DBUG_PRINT("info",("Use database: %s", new_db_file_name.str));
#ifndef NO_EMBEDDED_ACCESS_CHECKS
if (test_all_bits(sctx->master_access, DB_ACLS))
{
db_access= DB_ACLS;
}
else
{
db_access= acl_get_all3(sctx, new_db_file_name.str, FALSE);
db_access|= 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_THD(thd, ER_DBACCESS_DENIED_ERROR),
sctx->priv_user, sctx->priv_host, new_db_file_name.str);
DBUG_RETURN(ER_DBACCESS_DENIED_ERROR);
}
#endif
DEBUG_SYNC(thd, "before_db_dir_check");
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, Sql_condition::WARN_LEVEL_NOTE,
ER_BAD_DB_ERROR, ER_THD(thd, ER_BAD_DB_ERROR),
new_db_file_name.str);
/* Change db to NULL. */
mysql_change_db_impl(thd, NULL, NO_ACL, thd->variables.collation_server);
/* The operation succeed. */
goto done;
}
else
{
/* Report an error and free new_db_file_name. */
my_error(ER_BAD_DB_ERROR, MYF(0), new_db_file_name.str);
/* The operation failed. */
DBUG_RETURN(ER_BAD_DB_ERROR);
}
}
db_default_cl= get_default_db_collation(thd, new_db_file_name.str);
/*
new_db_file_name allocated memory on the stack.
mysql_change_db_impl() expects a my_alloc-ed memory.
NOTE: in mysql_change_db_impl() new_db_file_name is assigned to THD
attributes and will be freed in THD::~THD().
*/
if (const char *tmp= my_strndup(key_memory_THD_db,
new_db_file_name.str,
new_db_file_name.length, MYF(MY_WME)))
{
LEX_CSTRING new_db_malloced({tmp, new_db_file_name.length});
mysql_change_db_impl(thd, &new_db_malloced, db_access, db_default_cl);
}
else
DBUG_RETURN(ER_OUT_OF_RESOURCES); /* the error is set */
done:
thd->session_tracker.current_schema.mark_as_changed(thd);
thd->session_tracker.state_change.mark_as_changed(thd);
DBUG_RETURN(0);
}
/**
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_CSTRING *new_db_name,
LEX_STRING *saved_db_name,
bool force_switch,
bool *cur_db_changed)
{
*cur_db_changed= !cmp_db_names(Lex_ident_db(thd->db),
Lex_ident_db(*new_db_name));
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, const Lex_ident_db &old_db)
{
bool error= 0, change_to_newdb= 0;
char path[FN_REFLEN+16];
uint length;
Schema_specification_st create_info;
MY_DIR *dirp;
TABLE_LIST *table_list;
SELECT_LEX *sl= thd->lex->current_select;
Lex_ident_db 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= Lex_ident_db(old_db.str + MYSQL50_TABLE_NAME_PREFIX_LENGTH,
old_db.length - MYSQL50_TABLE_NAME_PREFIX_LENGTH);
const DBNameBuffer dbnorm_buffer_old(old_db, lower_case_table_names);
Lex_ident_db_normalized old_dbnorm(dbnorm_buffer_old.to_lex_cstring());
/* Lock the old name, the new name will be locked by mysql_create_db().*/
if (lock_schema_name(thd, old_dbnorm))
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.str && !cmp(&thd->db, &old_db))
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 (unlikely((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 (unlikely((error= mysql_create_db_internal(thd, new_db,
DDL_options(), &create_info,
1))))
goto exit;
/* Step2: Move tables to the new database */
if ((dirp = my_dir(path,MYF(MY_DONT_SORT))))
{
size_t nfiles= dirp->number_of_files;
for (size_t idx=0 ; idx < nfiles && !thd->killed ; idx++)
{
FILEINFO *file= dirp->dir_entry + idx;
char *extension, tname[FN_REFLEN + 1];
LEX_CSTRING table_str;
DBUG_PRINT("info",("Examining: %s", file->name));
/* skipping non-FRM files */
if (!(extension= (char*) fn_frm_ext(file->name)))
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*) thd->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, 0)))
{
/*
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 guarantees we never lose 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 '\'
my_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 explicitly 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))))
{
size_t nfiles= dirp->number_of_files;
for (size_t 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));
/* skipping MY_DB_OPT_FILE */
if (!files_charset_info->strnncoll(Lex_cstring_strlen(file->name),
Lex_cstring_strlen(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_internal(thd, old_db, 0, true);
/* 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) != 0;
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;
if (dbname_cache->contains(db_name))
return 0;
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.
The locking is to prevent creating permanent stale
entries for deleted databases, in case of
race condition with my_rmdir.
*/
mysql_rwlock_rdlock(&rmdir_lock);
int ret= my_access(db_dir_path, F_OK);
if (!ret)
dbname_cache->insert(db_name);
mysql_rwlock_unlock(&rmdir_lock);
return ret;
}
Reference in a new issue View git blame Copy permalink