@ -8,12 +8,11 @@
*
*
* IDENTIFICATION
* $ Header : / cvsroot / pgsql / src / backend / commands / dbcommands . c , v 1.66 2000 / 11 / 12 20 : 51 : 50 tgl Exp $
* $ Header : / cvsroot / pgsql / src / backend / commands / dbcommands . c , v 1.67 2000 / 11 / 14 18 : 37 : 41 tgl Exp $
*
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
# include "postgres.h"
# include "commands/dbcommands.h"
# include <errno.h>
# include <fcntl.h>
@ -27,6 +26,7 @@
# include "catalog/pg_database.h"
# include "catalog/pg_shadow.h"
# include "commands/comment.h"
# include "commands/dbcommands.h"
# include "miscadmin.h"
# include "storage/sinval.h" /* for DatabaseHasActiveBackends */
# include "utils/builtins.h"
@ -35,29 +35,40 @@
/* non-export function prototypes */
static bool get_db_info ( const char * name , Oid * dbIdP , int4 * ownerIdP ,
int * encodingP , bool * dbIsTemplateP ,
Oid * dbLastSysOidP , char * dbpath ) ;
static bool get_user_info ( Oid use_sysid , bool * use_super , bool * use_createdb ) ;
static bool get_db_info ( const char * name , char * dbpath , Oid * dbIdP , int4 * ownerIdP ) ;
static char * resolve_alt_dbpath ( const char * dbpath , Oid dboid ) ;
static bool remove_dbdirs ( const char * real_loc , const char * altloc ) ;
static char * resolve_alt_dbpath ( const char * dbpath , Oid dboid ) ;
static bool remove_dbdirs ( const char * real_loc , const char * altloc ) ;
/*
* CREATE DATABASE
*/
void
createdb ( const char * dbname , const char * dbpath , int encoding )
createdb ( const char * dbname , const char * dbpath ,
const char * dbtemplate , int encoding )
{
char * nominal_loc ;
char * alt_loc ;
char * target_dir ;
char src_loc [ MAXPGPATH ] ;
char buf [ 2 * MAXPGPATH + 100 ] ;
char * altloc ;
char * real_loc ;
int ret ;
bool use_super ,
use_createdb ;
Oid src_dboid ;
int4 src_owner ;
int src_encoding ;
bool src_istemplate ;
Oid src_lastsysoid ;
char src_dbpath [ MAXPGPATH ] ;
Relation pg_database_rel ;
HeapTuple tuple ;
TupleDesc pg_database_dsc ;
Datum new_record [ Natts_pg_database ] ;
char new_record_nulls [ Natts_pg_database ] = { ' ' , ' ' , ' ' , ' ' , ' ' } ;
char new_record_nulls [ Natts_pg_database ] ;
Oid dboid ;
if ( ! get_user_info ( GetUserId ( ) , & use_super , & use_createdb ) )
@ -66,122 +77,195 @@ createdb(const char *dbname, const char *dbpath, int encoding)
if ( ! use_createdb & & ! use_super )
elog ( ERROR , " CREATE DATABASE: permission denied " ) ;
if ( get_db_info ( dbname , NULL , NULL , NULL ) )
elog ( ERROR , " CREATE DATABASE: database \" %s \" already exists " , dbname ) ;
/* don't call this in a transaction block */
if ( IsTransactionBlock ( ) )
elog ( ERROR , " CREATE DATABASE: may not be called in a transaction block " ) ;
/*
* Insert a new tuple into pg_database
* Check for db name conflict . There is a race condition here , since
* another backend could create the same DB name before we commit .
* However , holding an exclusive lock on pg_database for the whole time
* we are copying the source database doesn ' t seem like a good idea ,
* so accept possibility of race to create . We will check again after
* we grab the exclusive lock .
*/
pg_database_rel = heap_openr ( DatabaseRelationName , AccessExclusiveLock ) ;
pg_database_dsc = RelationGetDescr ( pg_database_rel ) ;
if ( get_db_info ( dbname , NULL , NULL , NULL , NULL , NULL , NULL ) )
elog ( ERROR , " CREATE DATABASE: database \" %s \" already exists " , dbname ) ;
/*
* Preassign OID for pg_database tuple , so that we know current
* OID counter value
/*
* Lookup database ( template ) to be cloned .
*/
dboid = newoid ( ) ;
if ( ! dbtemplate )
dbtemplate = " template1 " ; /* Default template database name */
/* Form tuple */
new_record [ Anum_pg_database_datname - 1 ] =
DirectFunctionCall1 ( namein , CStringGetDatum ( dbname ) ) ;
new_record [ Anum_pg_database_datdba - 1 ] = Int32GetDatum ( GetUserId ( ) ) ;
new_record [ Anum_pg_database_encoding - 1 ] = Int32GetDatum ( encoding ) ;
/* Save current OID val */
new_record [ Anum_pg_database_datlastsysoid - 1 ] = ObjectIdGetDatum ( dboid ) ;
/* no nulls here, GetRawDatabaseInfo doesn't like them */
new_record [ Anum_pg_database_datpath - 1 ] =
DirectFunctionCall1 ( textin , CStringGetDatum ( dbpath ? dbpath : " " ) ) ;
if ( ! get_db_info ( dbtemplate , & src_dboid , & src_owner , & src_encoding ,
& src_istemplate , & src_lastsysoid , src_dbpath ) )
elog ( ERROR , " CREATE DATABASE: template \" %s \" does not exist " ,
dbtemplate ) ;
/*
* Permission check : to copy a DB that ' s not marked datistemplate ,
* you must be superuser or the owner thereof .
*/
if ( ! src_istemplate )
{
if ( ! use_super & & GetUserId ( ) ! = src_owner )
elog ( ERROR , " CREATE DATABASE: permission to copy \" %s \" denied " ,
dbtemplate ) ;
}
/*
* Determine physical path of source database
*/
alt_loc = resolve_alt_dbpath ( src_dbpath , src_dboid ) ;
if ( ! alt_loc )
alt_loc = GetDatabasePath ( src_dboid ) ;
strcpy ( src_loc , alt_loc ) ;
tuple = heap_formtuple ( pg_database_dsc , new_record , new_record_nulls ) ;
/*
* The source DB can ' t have any active backends , except this one
* ( exception is to allow CREATE DB while connected to template1 ) .
* Otherwise we might copy inconsistent data . This check is not
* bulletproof , since someone might connect while we are copying . . .
*/
if ( DatabaseHasActiveBackends ( src_dboid , true ) )
elog ( ERROR , " CREATE DATABASE: source database \" %s \" is being accessed by other users " , dbtemplate ) ;
tuple - > t_data - > t_oid = dboid ; /* override heap_insert */
/* If encoding is defaulted, use source's encoding */
if ( encoding < 0 )
encoding = src_encoding ;
/*
* Preassign OID for pg_database tuple , so that we can compute db path .
*/
dboid = newoid ( ) ;
/*
* Update table
* Compute nominal location ( where we will try to access the database ) ,
* and resolve alternate physical location if one is specified .
*/
heap_insert ( pg_database_rel , tuple ) ;
real_loc = GetDatabasePath ( tuple - > t_data - > t_oid ) ;
altloc = resolve_alt_dbpath ( dbpath , tuple - > t_data - > t_oid ) ;
nominal_loc = GetDatabasePath ( dboid ) ;
alt_loc = resolve_alt_dbpath ( dbpath , dboid ) ;
if ( strchr ( real_loc , ' \' ' ) & & strchr ( altloc , ' \' ' ) )
if ( strchr ( nominal_loc , ' \' ' ) )
elog ( ERROR , " database path may not contain single quotes " ) ;
if ( alt_loc & & strchr ( alt_loc , ' \' ' ) )
elog ( ERROR , " database path may not contain single quotes " ) ;
if ( strchr ( src_loc , ' \' ' ) )
elog ( ERROR , " database path may not contain single quotes " ) ;
/* ... otherwise we'd be open to shell exploits below */
/*
* Update indexes ( there aren ' t any currently )
*/
# ifdef Num_pg_database_indices
if ( RelationGetForm ( pg_database_rel ) - > relhasindex )
{
Relation idescs [ Num_pg_database_indices ] ;
CatalogOpenIndices ( Num_pg_database_indices ,
Name_pg_database_indices , idescs ) ;
CatalogIndexInsert ( idescs , Num_pg_database_indices , pg_database_rel ,
tuple ) ;
CatalogCloseIndices ( Num_pg_database_indices , idescs ) ;
}
# ifdef XLOG
/* Try to force any dirty buffers out to disk */
BufferSync ( ) ;
# endif
heap_close ( pg_database_rel , NoLock ) ;
/*
* Close virtual file descriptors so the kernel has more available for
* the mkdir ( ) and system ( ) calls below .
*/
closeAllVfds ( ) ;
/* Copy the template database to the new location */
/*
* Check we can create the target directory - - - but then remove it
* because we rely on cp ( 1 ) to create it for real .
*/
target_dir = alt_loc ? alt_loc : nominal_loc ;
if ( mkdir ( ( altloc ? altloc : real_loc ) , S_IRWXU ) ! = 0 )
elog ( ERROR , " CREATE DATABASE: unable to create database directory '%s': %s " ,
( altloc ? altloc : real_loc ) , strerror ( errno ) ) ;
if ( mkdir ( target_dir , S_IRWXU ) ! = 0 )
elog ( ERROR , " CREATE DATABASE: unable to create database directory '%s': %m " ,
target_dir ) ;
rmdir ( target_dir ) ;
if ( altloc )
/* Make the symlink, if needed */
if ( alt_loc )
{
if ( symlink ( altloc , re al_loc) ! = 0 )
elog ( ERROR , " CREATE DATABASE: could not link %s to %s: %s " ,
real_loc , altloc , strerror ( errno ) ) ;
if ( symlink ( alt_ loc , nomin al_loc) ! = 0 )
elog ( ERROR , " CREATE DATABASE: could not link '%s' to '%s': %m " ,
nominal_loc , alt_loc ) ;
}
snprintf ( buf , sizeof ( buf ) , " cp '%s'/* '%s' " ,
GetDatabasePath ( TemplateDbOid ) , real_loc ) ;
/* Copy the template database to the new location */
snprintf ( buf , sizeof ( buf ) , " cp -r '%s' '%s' " , src_loc , target_dir ) ;
ret = system ( buf ) ;
/* Some versions of SunOS seem to return ECHILD after a system() call */
if ( ret ! = 0 & & errno ! = ECHILD )
{
if ( remove_dbdirs ( re al_loc, altloc ) )
if ( remove_dbdirs ( nomin al_loc, alt_ loc ) )
elog ( ERROR , " CREATE DATABASE: could not initialize database directory " ) ;
else
elog ( ERROR , " CREATE DATABASE: could not initialize database directory; delete failed as well " ) ;
}
# ifdef XLOG
BufferSync ( ) ;
/*
* Now OK to grab exclusive lock on pg_database .
*/
pg_database_rel = heap_openr ( DatabaseRelationName , AccessExclusiveLock ) ;
/* Check to see if someone else created same DB name meanwhile. */
if ( get_db_info ( dbname , NULL , NULL , NULL , NULL , NULL , NULL ) )
{
remove_dbdirs ( nominal_loc , alt_loc ) ;
elog ( ERROR , " CREATE DATABASE: database \" %s \" already exists " , dbname ) ;
}
/*
* Insert a new tuple into pg_database
*/
pg_database_dsc = RelationGetDescr ( pg_database_rel ) ;
/* Form tuple */
new_record [ Anum_pg_database_datname - 1 ] =
DirectFunctionCall1 ( namein , CStringGetDatum ( dbname ) ) ;
new_record [ Anum_pg_database_datdba - 1 ] = Int32GetDatum ( GetUserId ( ) ) ;
new_record [ Anum_pg_database_encoding - 1 ] = Int32GetDatum ( encoding ) ;
new_record [ Anum_pg_database_datistemplate - 1 ] = BoolGetDatum ( false ) ;
new_record [ Anum_pg_database_datallowconn - 1 ] = BoolGetDatum ( true ) ;
new_record [ Anum_pg_database_datlastsysoid - 1 ] = ObjectIdGetDatum ( src_lastsysoid ) ;
/* no nulls here, GetRawDatabaseInfo doesn't like them */
new_record [ Anum_pg_database_datpath - 1 ] =
DirectFunctionCall1 ( textin , CStringGetDatum ( dbpath ? dbpath : " " ) ) ;
memset ( new_record_nulls , ' ' , sizeof ( new_record_nulls ) ) ;
tuple = heap_formtuple ( pg_database_dsc , new_record , new_record_nulls ) ;
tuple - > t_data - > t_oid = dboid ; /* override heap_insert's OID selection */
heap_insert ( pg_database_rel , tuple ) ;
/*
* Update indexes ( there aren ' t any currently )
*/
# ifdef Num_pg_database_indices
if ( RelationGetForm ( pg_database_rel ) - > relhasindex )
{
Relation idescs [ Num_pg_database_indices ] ;
CatalogOpenIndices ( Num_pg_database_indices ,
Name_pg_database_indices , idescs ) ;
CatalogIndexInsert ( idescs , Num_pg_database_indices , pg_database_rel ,
tuple ) ;
CatalogCloseIndices ( Num_pg_database_indices , idescs ) ;
}
# endif
}
/* Close pg_database, but keep lock till commit */
heap_close ( pg_database_rel , NoLock ) ;
}
/*
* DROP DATABASE
*/
void
dropdb ( const char * dbname )
{
int4 db_owner ;
bool db_istemplate ;
bool use_super ;
Oid db_id ;
char * altloc ;
char * real_loc ;
char * alt_ loc ;
char * nomin al_loc;
char dbpath [ MAXPGPATH ] ;
Relation pgdbrel ;
HeapScanDesc pgdbscan ;
@ -190,9 +274,6 @@ dropdb(const char *dbname)
AssertArg ( dbname ) ;
if ( strcmp ( dbname , " template1 " ) = = 0 )
elog ( ERROR , " DROP DATABASE: may not be executed on the template1 database " ) ;
if ( strcmp ( dbname , DatabaseName ) = = 0 )
elog ( ERROR , " DROP DATABASE: cannot be executed on the currently open database " ) ;
@ -202,15 +283,6 @@ dropdb(const char *dbname)
if ( ! get_user_info ( GetUserId ( ) , & use_super , NULL ) )
elog ( ERROR , " current user name is invalid " ) ;
if ( ! get_db_info ( dbname , dbpath , & db_id , & db_owner ) )
elog ( ERROR , " DROP DATABASE: database \" %s \" does not exist " , dbname ) ;
if ( GetUserId ( ) ! = db_owner & & ! use_super )
elog ( ERROR , " DROP DATABASE: permission denied " ) ;
real_loc = GetDatabasePath ( db_id ) ;
altloc = resolve_alt_dbpath ( dbpath , db_id ) ;
/*
* Obtain exclusive lock on pg_database . We need this to ensure that
* no new backend starts up in the target database while we are
@ -222,14 +294,29 @@ dropdb(const char *dbname)
*/
pgdbrel = heap_openr ( DatabaseRelationName , AccessExclusiveLock ) ;
if ( ! get_db_info ( dbname , & db_id , & db_owner , NULL ,
& db_istemplate , NULL , dbpath ) )
elog ( ERROR , " DROP DATABASE: database \" %s \" does not exist " , dbname ) ;
if ( ! use_super & & GetUserId ( ) ! = db_owner )
elog ( ERROR , " DROP DATABASE: permission denied " ) ;
/*
* Disallow dropping a DB that is marked istemplate . This is just
* to prevent people from accidentally dropping template0 or template1 ;
* they can do so if they ' re really determined . . .
*/
if ( db_istemplate )
elog ( ERROR , " DROP DATABASE: database is marked as a template " ) ;
nominal_loc = GetDatabasePath ( db_id ) ;
alt_loc = resolve_alt_dbpath ( dbpath , db_id ) ;
/*
* Check for active backends in the target database .
*/
if ( DatabaseHasActiveBackends ( db_id , false ) )
{
heap_close ( pgdbrel , AccessExclusiveLock ) ;
elog ( ERROR , " DROP DATABASE: database \" %s \" is being accessed by other users " , dbname ) ;
}
/*
* Find the database ' s tuple by OID ( should be unique , we trust ) .
@ -242,8 +329,6 @@ dropdb(const char *dbname)
tup = heap_getnext ( pgdbscan , 0 ) ;
if ( ! HeapTupleIsValid ( tup ) )
{
heap_close ( pgdbrel , AccessExclusiveLock ) ;
/*
* This error should never come up since the existence of the
* database is checked earlier
@ -252,9 +337,6 @@ dropdb(const char *dbname)
dbname ) ;
}
/* Delete any comments associated with the database */
DeleteComments ( db_id ) ;
/* Remove the database's tuple from pg_database */
heap_delete ( pgdbrel , & tup - > t_self , NULL ) ;
@ -266,6 +348,9 @@ dropdb(const char *dbname)
*/
heap_close ( pgdbrel , NoLock ) ;
/* Delete any comments associated with the database */
DeleteComments ( db_id ) ;
/*
* Drop pages for this database that are in the shared buffer cache .
* This is important to ensure that no remaining backend tries to
@ -273,16 +358,10 @@ dropdb(const char *dbname)
*/
DropBuffers ( db_id ) ;
/*
* Close virtual file descriptors so the kernel has more available for
* the system ( ) call below .
*/
closeAllVfds ( ) ;
/*
* Remove the database ' s subdirectory and everything in it .
*/
remove_dbdirs ( re al_loc, altloc ) ;
remove_dbdirs ( nominal_loc , alt_loc ) ;
}
@ -292,28 +371,32 @@ dropdb(const char *dbname)
*/
static bool
get_db_info ( const char * name , char * dbpath , Oid * dbIdP , int4 * ownerIdP )
get_db_info ( const char * name , Oid * dbIdP , int4 * ownerIdP ,
int * encodingP , bool * dbIsTemplateP ,
Oid * dbLastSysOidP , char * dbpath )
{
Relation relation ;
HeapTuple tuple ;
ScanKeyData scanKey ;
HeapScanDesc scan ;
HeapTuple tuple ;
AssertArg ( name ) ;
relation = heap_openr ( DatabaseRelationName , AccessExclusiveLock /* ??? */ ) ;
/* Caller may wish to grab a better lock on pg_database beforehand... */
relation = heap_openr ( DatabaseRelationName , AccessShareLock ) ;
ScanKeyEntryInitialize ( & scanKey , 0 , Anum_pg_database_datname ,
F_NAMEEQ , NameGetDatum ( name ) ) ;
scan = heap_beginscan ( relation , 0 , SnapshotNow , 1 , & scanKey ) ;
if ( ! HeapScanIsValid ( scan ) )
elog ( ERROR , " Cannot begin scan of %s. " , DatabaseRelationName ) ;
elog ( ERROR , " Cannot begin scan of %s " , DatabaseRelationName ) ;
tuple = heap_getnext ( scan , 0 ) ;
if ( HeapTupleIsValid ( tuple ) )
{
Form_pg_database dbform = ( Form_pg_database ) GETSTRUCT ( tuple ) ;
text * tmptext ;
bool isnull ;
@ -322,22 +405,23 @@ get_db_info(const char *name, char *dbpath, Oid *dbIdP, int4 *ownerIdP)
* dbIdP = tuple - > t_data - > t_oid ;
/* uid of the owner */
if ( ownerIdP )
{
* ownerIdP = ( int4 ) heap_getattr ( tuple ,
Anum_pg_database_datdba ,
RelationGetDescr ( relation ) ,
& isnull ) ;
if ( isnull )
* ownerIdP = - 1 ; /* hopefully no one has that id already ;) */
}
* ownerIdP = dbform - > datdba ;
/* multibyte encoding */
if ( encodingP )
* encodingP = dbform - > encoding ;
/* allowed as template? */
if ( dbIsTemplateP )
* dbIsTemplateP = dbform - > datistemplate ;
/* last system OID used in database */
if ( dbLastSysOidP )
* dbLastSysOidP = dbform - > datlastsysoid ;
/* database path (as registered in pg_database) */
if ( dbpath )
{
tmptext = ( text * ) heap_getattr ( tuple ,
Anum_pg_database_datpath ,
RelationGetDescr ( relation ) ,
& isnull ) ;
tmptext = DatumGetTextP ( heap_getattr ( tuple ,
Anum_pg_database_datpath ,
RelationGetDescr ( relation ) ,
& isnull ) ) ;
if ( ! isnull )
{
Assert ( VARSIZE ( tmptext ) - VARHDRSZ < MAXPGPATH ) ;
@ -349,16 +433,9 @@ get_db_info(const char *name, char *dbpath, Oid *dbIdP, int4 *ownerIdP)
strcpy ( dbpath , " " ) ;
}
}
else
{
if ( dbIdP )
* dbIdP = InvalidOid ;
}
heap_endscan ( scan ) ;
/* We will keep the lock on the relation until end of transaction. */
heap_close ( relation , NoLock ) ;
heap_close ( relation , AccessShareLock ) ;
return HeapTupleIsValid ( tuple ) ;
}
@ -396,6 +473,8 @@ resolve_alt_dbpath(const char * dbpath, Oid dboid)
if ( strchr ( dbpath , ' / ' ) )
{
if ( dbpath [ 0 ] ! = ' / ' )
elog ( ERROR , " Relative paths are not allowed as database locations " ) ;
# ifndef ALLOW_ABSOLUTE_DBPATHS
elog ( ERROR , " Absolute paths are not allowed as database locations " ) ;
# endif
@ -406,9 +485,9 @@ resolve_alt_dbpath(const char * dbpath, Oid dboid)
/* must be environment variable */
char * var = getenv ( dbpath ) ;
if ( ! var )
elog ( ERROR , " environment variable %s not set " , dbpath ) ;
elog ( ERROR , " Postmaster environment variable ' %s' not set" , dbpath ) ;
if ( var [ 0 ] ! = ' / ' )
elog ( ERROR , " environment variable %s must be absolute path " , dbpath ) ;
elog ( ERROR , " Postmaster environment variable ' %s' must be absolute path" , dbpath ) ;
prefix = var ;
}
@ -421,24 +500,36 @@ resolve_alt_dbpath(const char * dbpath, Oid dboid)
static bool
remove_dbdirs ( const char * re al_loc, const char * altloc )
remove_dbdirs ( const char * nomin al_loc, const char * alt_ loc )
{
const char * target_dir ;
char buf [ MAXPGPATH + 100 ] ;
bool success = true ;
if ( altloc )
target_dir = alt_loc ? alt_loc : nominal_loc ;
/*
* Close virtual file descriptors so the kernel has more available for
* the system ( ) call below .
*/
closeAllVfds ( ) ;
if ( alt_loc )
{
/* remove symlink */
if ( unlink ( real_loc ) ! = 0 )
if ( unlink ( nomin al_loc) ! = 0 )
{
elog ( NOTICE , " could not remove '%s': %s " , real_loc , strerror ( errno ) ) ;
elog ( NOTICE , " could not remove '%s': %m " , nominal_loc ) ;
success = false ;
}
}
snprintf ( buf , sizeof ( buf ) , " rm -rf '%s' " , target_dir ) ;
snprintf ( buf , sizeof ( buf ) , " rm -rf '%s' " , altloc ? altloc : real_loc ) ;
if ( system ( buf ) ! = 0 & & errno ! = ECHILD )
{
elog ( NOTICE , " database directory '%s' could not be removed " ,
altloc ? altloc : real_loc ) ;
target_dir ) ;
success = false ;
}
Tom Lane
25 years ago