@ -28,13 +28,36 @@
# include "replication/walreceiver.h"
# include "storage/smgr.h"
# include "utils/builtins.h"
# include "utils/memutils.h"
# include "utils/numeric.h"
# include "utils/guc.h"
# include "utils/pg_lsn.h"
# include "utils/timestamp.h"
# include "utils/tuplestore.h"
# include "storage/fd.h"
# include "storage/ipc.h"
/*
* Store label file and tablespace map during non - exclusive backups .
*/
static StringInfo label_file ;
static StringInfo tblspc_map_file ;
static bool exclusive_backup_running = false ;
static bool nonexclusive_backup_running = false ;
/*
* Called when the backend exits with a running non - exclusive base backup ,
* to clean up state .
*/
static void
nonexclusive_base_backup_cleanup ( int code , Datum arg )
{
do_pg_abort_backup ( ) ;
ereport ( WARNING ,
( errmsg ( " aborting backup due to backend exiting before pg_stop_backup was called " ) ) ) ;
}
/*
* pg_start_backup : set up for taking an on - line backup dump
*
@ -49,6 +72,7 @@ pg_start_backup(PG_FUNCTION_ARGS)
{
text * backupid = PG_GETARG_TEXT_P ( 0 ) ;
bool fast = PG_GETARG_BOOL ( 1 ) ;
bool exclusive = PG_GETARG_BOOL ( 2 ) ;
char * backupidstr ;
XLogRecPtr startpoint ;
DIR * dir ;
@ -60,14 +84,42 @@ pg_start_backup(PG_FUNCTION_ARGS)
( errcode ( ERRCODE_INSUFFICIENT_PRIVILEGE ) ,
errmsg ( " must be superuser or replication role to run a backup " ) ) ) ;
if ( exclusive_backup_running | | nonexclusive_backup_running )
ereport ( ERROR ,
( errcode ( ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE ) ,
errmsg ( " a backup is already in progress in this session " ) ) ) ;
/* Make sure we can open the directory with tablespaces in it */
dir = AllocateDir ( " pg_tblspc " ) ;
if ( ! dir )
ereport ( ERROR ,
( errmsg ( " could not open directory \" %s \" : %m " , " pg_tblspc " ) ) ) ;
startpoint = do_pg_start_backup ( backupidstr , fast , NULL , NULL ,
dir , NULL , NULL , false , true ) ;
if ( exclusive )
{
startpoint = do_pg_start_backup ( backupidstr , fast , NULL , NULL ,
dir , NULL , NULL , false , true ) ;
exclusive_backup_running = true ;
}
else
{
MemoryContext oldcontext ;
/*
* Label file and tablespace map file need to be long - lived , since they
* are read in pg_stop_backup .
*/
oldcontext = MemoryContextSwitchTo ( TopMemoryContext ) ;
label_file = makeStringInfo ( ) ;
tblspc_map_file = makeStringInfo ( ) ;
MemoryContextSwitchTo ( oldcontext ) ;
startpoint = do_pg_start_backup ( backupidstr , fast , NULL , label_file ,
dir , NULL , tblspc_map_file , false , true ) ;
nonexclusive_backup_running = true ;
before_shmem_exit ( nonexclusive_base_backup_cleanup , ( Datum ) 0 ) ;
}
FreeDir ( dir ) ;
@ -86,6 +138,10 @@ pg_start_backup(PG_FUNCTION_ARGS)
* record for that and the file is for informational and debug purposes only .
*
* Note : different from CancelBackup which just cancels online backup mode .
*
* Note : this version is only called to stop an exclusive backup . The function
* pg_stop_backup_v2 ( overloaded as pg_stop_backup in SQL ) is called to
* stop non - exclusive backups .
*/
Datum
pg_stop_backup ( PG_FUNCTION_ARGS )
@ -97,11 +153,136 @@ pg_stop_backup(PG_FUNCTION_ARGS)
( errcode ( ERRCODE_INSUFFICIENT_PRIVILEGE ) ,
( errmsg ( " must be superuser or replication role to run a backup " ) ) ) ) ;
if ( nonexclusive_backup_running )
ereport ( ERROR ,
( errcode ( ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE ) ,
errmsg ( " non-exclusive backup in progress " ) ,
errhint ( " did you mean to use pg_stop_backup('f')? " ) ) ) ;
/*
* Exclusive backups were typically started in a different connection ,
* so don ' t try to verify that exclusive_backup_running is set in this one .
* Actual verification that an exclusive backup is in fact running is handled
* inside do_pg_stop_backup .
*/
stoppoint = do_pg_stop_backup ( NULL , true , NULL ) ;
exclusive_backup_running = false ;
PG_RETURN_LSN ( stoppoint ) ;
}
/*
* pg_stop_backup_v2 : finish taking exclusive or nonexclusive on - line backup .
*
* Works the same as pg_stop_backup , except for non - exclusive backups it returns
* the backup label and tablespace map files as text fields in as part of the
* resultset .
*/
Datum
pg_stop_backup_v2 ( PG_FUNCTION_ARGS )
{
ReturnSetInfo * rsinfo = ( ReturnSetInfo * ) fcinfo - > resultinfo ;
TupleDesc tupdesc ;
Tuplestorestate * tupstore ;
MemoryContext per_query_ctx ;
MemoryContext oldcontext ;
Datum values [ 3 ] ;
bool nulls [ 3 ] ;
bool exclusive = PG_GETARG_BOOL ( 0 ) ;
XLogRecPtr stoppoint ;
/* check to see if caller supports us returning a tuplestore */
if ( rsinfo = = NULL | | ! IsA ( rsinfo , ReturnSetInfo ) )
ereport ( ERROR ,
( errcode ( ERRCODE_FEATURE_NOT_SUPPORTED ) ,
errmsg ( " set-valued function called in context that cannot accept a set " ) ) ) ;
if ( ! ( rsinfo - > allowedModes & SFRM_Materialize ) )
ereport ( ERROR ,
( errcode ( ERRCODE_FEATURE_NOT_SUPPORTED ) ,
errmsg ( " materialize mode required, but it is not " \
" allowed in this context " ) ) ) ;
if ( ! superuser ( ) & & ! has_rolreplication ( GetUserId ( ) ) )
ereport ( ERROR ,
( errcode ( ERRCODE_INSUFFICIENT_PRIVILEGE ) ,
( errmsg ( " must be superuser or replication role to run a backup " ) ) ) ) ;
/* Build a tuple descriptor for our result type */
if ( get_call_result_type ( fcinfo , NULL , & tupdesc ) ! = TYPEFUNC_COMPOSITE )
elog ( ERROR , " return type must be a row type " ) ;
per_query_ctx = rsinfo - > econtext - > ecxt_per_query_memory ;
oldcontext = MemoryContextSwitchTo ( per_query_ctx ) ;
tupstore = tuplestore_begin_heap ( true , false , work_mem ) ;
rsinfo - > returnMode = SFRM_Materialize ;
rsinfo - > setResult = tupstore ;
rsinfo - > setDesc = tupdesc ;
MemoryContextSwitchTo ( oldcontext ) ;
MemSet ( values , 0 , sizeof ( values ) ) ;
MemSet ( nulls , 0 , sizeof ( nulls ) ) ;
if ( exclusive )
{
if ( nonexclusive_backup_running )
ereport ( ERROR ,
( errcode ( ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE ) ,
errmsg ( " non-exclusive backup in progress " ) ,
errhint ( " did you mean to use pg_stop_backup('f')? " ) ) ) ;
/*
* Stop the exclusive backup , and since we ' re in an exclusive backup
* return NULL for both backup_label and tablespace_map .
*/
stoppoint = do_pg_stop_backup ( NULL , true , NULL ) ;
exclusive_backup_running = false ;
nulls [ 1 ] = true ;
nulls [ 2 ] = true ;
}
else
{
if ( ! nonexclusive_backup_running )
ereport ( ERROR ,
( errcode ( ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE ) ,
errmsg ( " non-exclusive backup is not in progress " ) ,
errhint ( " did you mean to use pg_stop_backup('t')? " ) ) ) ;
/*
* Stop the non - exclusive backup . Return a copy of the backup
* label and tablespace map so they can be written to disk by
* the caller .
*/
stoppoint = do_pg_stop_backup ( label_file - > data , true , NULL ) ;
nonexclusive_backup_running = false ;
cancel_before_shmem_exit ( nonexclusive_base_backup_cleanup , ( Datum ) 0 ) ;
values [ 1 ] = CStringGetTextDatum ( label_file - > data ) ;
values [ 2 ] = CStringGetTextDatum ( tblspc_map_file - > data ) ;
/* Free structures allocated in TopMemoryContext */
pfree ( label_file - > data ) ;
pfree ( label_file ) ;
label_file = NULL ;
pfree ( tblspc_map_file - > data ) ;
pfree ( tblspc_map_file ) ;
tblspc_map_file = NULL ;
}
/* Stoppoint is included on both exclusive and nonexclusive backups */
values [ 0 ] = LSNGetDatum ( stoppoint ) ;
tuplestore_putvalues ( tupstore , tupdesc , values , nulls ) ;
tuplestore_donestoring ( typstore ) ;
return ( Datum ) 0 ;
}
/*
* pg_switch_xlog : switch to next xlog file
*/
Magnus Hagander
10 years ago