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all the values derived from oldestXid, not just that field. Brain fade in one of my patches associated with flat file removal, exposed by a report from Fujii Masao. With this change, xidVacLimit should always be valid, so remove a couple of bits of complexity associated with the previous assumption that sometimes it wouldn't get set right away.
8944 lines
264 KiB
C
8944 lines
264 KiB
C
/*-------------------------------------------------------------------------
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*
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* xlog.c
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* PostgreSQL transaction log manager
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*
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*
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* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.374 2010/02/17 03:10:33 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <ctype.h>
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#include <signal.h>
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#include <time.h>
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#include <fcntl.h>
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#include <sys/stat.h>
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#include <sys/time.h>
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#include <sys/wait.h>
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#include <unistd.h>
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#include "access/clog.h"
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#include "access/multixact.h"
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#include "access/subtrans.h"
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#include "access/transam.h"
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#include "access/tuptoaster.h"
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#include "access/twophase.h"
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#include "access/xact.h"
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#include "access/xlog_internal.h"
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#include "access/xlogutils.h"
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#include "catalog/catversion.h"
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#include "catalog/pg_control.h"
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#include "catalog/pg_database.h"
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#include "catalog/pg_type.h"
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#include "funcapi.h"
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#include "libpq/pqsignal.h"
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#include "miscadmin.h"
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#include "pgstat.h"
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#include "postmaster/bgwriter.h"
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#include "replication/walreceiver.h"
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#include "replication/walsender.h"
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#include "storage/bufmgr.h"
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#include "storage/fd.h"
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#include "storage/ipc.h"
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#include "storage/pmsignal.h"
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#include "storage/procarray.h"
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#include "storage/smgr.h"
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#include "storage/spin.h"
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#include "utils/builtins.h"
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#include "utils/guc.h"
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#include "utils/ps_status.h"
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#include "utils/relmapper.h"
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#include "pg_trace.h"
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/* File path names (all relative to $PGDATA) */
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#define BACKUP_LABEL_FILE "backup_label"
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#define BACKUP_LABEL_OLD "backup_label.old"
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#define RECOVERY_COMMAND_FILE "recovery.conf"
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#define RECOVERY_COMMAND_DONE "recovery.done"
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/* User-settable parameters */
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int CheckPointSegments = 3;
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int XLOGbuffers = 8;
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int XLogArchiveTimeout = 0;
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bool XLogArchiveMode = false;
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char *XLogArchiveCommand = NULL;
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bool XLogRequestRecoveryConnections = true;
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int MaxStandbyDelay = 30;
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bool fullPageWrites = true;
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bool log_checkpoints = false;
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int sync_method = DEFAULT_SYNC_METHOD;
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#ifdef WAL_DEBUG
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bool XLOG_DEBUG = false;
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#endif
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/*
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* XLOGfileslop is the maximum number of preallocated future XLOG segments.
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* When we are done with an old XLOG segment file, we will recycle it as a
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* future XLOG segment as long as there aren't already XLOGfileslop future
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* segments; else we'll delete it. This could be made a separate GUC
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* variable, but at present I think it's sufficient to hardwire it as
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* 2*CheckPointSegments+1. Under normal conditions, a checkpoint will free
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* no more than 2*CheckPointSegments log segments, and we want to recycle all
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* of them; the +1 allows boundary cases to happen without wasting a
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* delete/create-segment cycle.
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*/
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#define XLOGfileslop (2*CheckPointSegments + 1)
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/*
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* GUC support
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*/
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const struct config_enum_entry sync_method_options[] = {
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{"fsync", SYNC_METHOD_FSYNC, false},
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#ifdef HAVE_FSYNC_WRITETHROUGH
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{"fsync_writethrough", SYNC_METHOD_FSYNC_WRITETHROUGH, false},
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#endif
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#ifdef HAVE_FDATASYNC
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{"fdatasync", SYNC_METHOD_FDATASYNC, false},
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#endif
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#ifdef OPEN_SYNC_FLAG
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{"open_sync", SYNC_METHOD_OPEN, false},
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#endif
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#ifdef OPEN_DATASYNC_FLAG
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{"open_datasync", SYNC_METHOD_OPEN_DSYNC, false},
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#endif
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{NULL, 0, false}
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};
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/*
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* Statistics for current checkpoint are collected in this global struct.
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* Because only the background writer or a stand-alone backend can perform
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* checkpoints, this will be unused in normal backends.
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*/
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CheckpointStatsData CheckpointStats;
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/*
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* ThisTimeLineID will be same in all backends --- it identifies current
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* WAL timeline for the database system.
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*/
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TimeLineID ThisTimeLineID = 0;
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/*
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* Are we doing recovery from XLOG?
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*
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* This is only ever true in the startup process; it should be read as meaning
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* "this process is replaying WAL records", rather than "the system is in
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* recovery mode". It should be examined primarily by functions that need
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* to act differently when called from a WAL redo function (e.g., to skip WAL
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* logging). To check whether the system is in recovery regardless of which
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* process you're running in, use RecoveryInProgress() but only after shared
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* memory startup and lock initialization.
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*/
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bool InRecovery = false;
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/* Are we in Hot Standby mode? Only valid in startup process, see xlog.h */
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HotStandbyState standbyState = STANDBY_DISABLED;
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static XLogRecPtr LastRec;
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/*
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* Local copy of SharedRecoveryInProgress variable. True actually means "not
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* known, need to check the shared state".
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*/
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static bool LocalRecoveryInProgress = true;
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/*
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* Local state for XLogInsertAllowed():
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* 1: unconditionally allowed to insert XLOG
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* 0: unconditionally not allowed to insert XLOG
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* -1: must check RecoveryInProgress(); disallow until it is false
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* Most processes start with -1 and transition to 1 after seeing that recovery
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* is not in progress. But we can also force the value for special cases.
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* The coding in XLogInsertAllowed() depends on the first two of these states
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* being numerically the same as bool true and false.
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*/
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static int LocalXLogInsertAllowed = -1;
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/* Are we recovering using offline XLOG archives? */
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static bool InArchiveRecovery = false;
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/* Was the last xlog file restored from archive, or local? */
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static bool restoredFromArchive = false;
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/* options taken from recovery.conf for archive recovery */
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static char *recoveryRestoreCommand = NULL;
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static char *recoveryEndCommand = NULL;
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static bool recoveryTarget = false;
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static bool recoveryTargetExact = false;
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static bool recoveryTargetInclusive = true;
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static TransactionId recoveryTargetXid;
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static TimestampTz recoveryTargetTime;
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static TimestampTz recoveryLastXTime = 0;
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/* options taken from recovery.conf for XLOG streaming */
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static bool StandbyMode = false;
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static char *PrimaryConnInfo = NULL;
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char *TriggerFile = NULL;
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/* if recoveryStopsHere returns true, it saves actual stop xid/time here */
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static TransactionId recoveryStopXid;
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static TimestampTz recoveryStopTime;
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static bool recoveryStopAfter;
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/*
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* During normal operation, the only timeline we care about is ThisTimeLineID.
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* During recovery, however, things are more complicated. To simplify life
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* for rmgr code, we keep ThisTimeLineID set to the "current" timeline as we
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* scan through the WAL history (that is, it is the line that was active when
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* the currently-scanned WAL record was generated). We also need these
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* timeline values:
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*
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* recoveryTargetTLI: the desired timeline that we want to end in.
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*
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* expectedTLIs: an integer list of recoveryTargetTLI and the TLIs of
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* its known parents, newest first (so recoveryTargetTLI is always the
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* first list member). Only these TLIs are expected to be seen in the WAL
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* segments we read, and indeed only these TLIs will be considered as
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* candidate WAL files to open at all.
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*
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* curFileTLI: the TLI appearing in the name of the current input WAL file.
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* (This is not necessarily the same as ThisTimeLineID, because we could
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* be scanning data that was copied from an ancestor timeline when the current
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* file was created.) During a sequential scan we do not allow this value
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* to decrease.
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*/
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static TimeLineID recoveryTargetTLI;
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static List *expectedTLIs;
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static TimeLineID curFileTLI;
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/*
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* ProcLastRecPtr points to the start of the last XLOG record inserted by the
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* current backend. It is updated for all inserts. XactLastRecEnd points to
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* end+1 of the last record, and is reset when we end a top-level transaction,
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* or start a new one; so it can be used to tell if the current transaction has
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* created any XLOG records.
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*/
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static XLogRecPtr ProcLastRecPtr = {0, 0};
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XLogRecPtr XactLastRecEnd = {0, 0};
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/*
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* RedoRecPtr is this backend's local copy of the REDO record pointer
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* (which is almost but not quite the same as a pointer to the most recent
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* CHECKPOINT record). We update this from the shared-memory copy,
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* XLogCtl->Insert.RedoRecPtr, whenever we can safely do so (ie, when we
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* hold the Insert lock). See XLogInsert for details. We are also allowed
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* to update from XLogCtl->Insert.RedoRecPtr if we hold the info_lck;
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* see GetRedoRecPtr. A freshly spawned backend obtains the value during
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* InitXLOGAccess.
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*/
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static XLogRecPtr RedoRecPtr;
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/*
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* RedoStartLSN points to the checkpoint's REDO location which is specified
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* in a backup label file, backup history file or control file. In standby
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* mode, XLOG streaming usually starts from the position where an invalid
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* record was found. But if we fail to read even the initial checkpoint
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* record, we use the REDO location instead of the checkpoint location as
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* the start position of XLOG streaming. Otherwise we would have to jump
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* backwards to the REDO location after reading the checkpoint record,
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* because the REDO record can precede the checkpoint record.
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*/
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static XLogRecPtr RedoStartLSN = {0, 0};
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/*----------
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* Shared-memory data structures for XLOG control
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*
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* LogwrtRqst indicates a byte position that we need to write and/or fsync
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* the log up to (all records before that point must be written or fsynced).
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* LogwrtResult indicates the byte positions we have already written/fsynced.
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* These structs are identical but are declared separately to indicate their
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* slightly different functions.
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*
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* We do a lot of pushups to minimize the amount of access to lockable
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* shared memory values. There are actually three shared-memory copies of
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* LogwrtResult, plus one unshared copy in each backend. Here's how it works:
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* XLogCtl->LogwrtResult is protected by info_lck
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* XLogCtl->Write.LogwrtResult is protected by WALWriteLock
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* XLogCtl->Insert.LogwrtResult is protected by WALInsertLock
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* One must hold the associated lock to read or write any of these, but
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* of course no lock is needed to read/write the unshared LogwrtResult.
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*
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* XLogCtl->LogwrtResult and XLogCtl->Write.LogwrtResult are both "always
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* right", since both are updated by a write or flush operation before
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* it releases WALWriteLock. The point of keeping XLogCtl->Write.LogwrtResult
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* is that it can be examined/modified by code that already holds WALWriteLock
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* without needing to grab info_lck as well.
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*
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* XLogCtl->Insert.LogwrtResult may lag behind the reality of the other two,
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* but is updated when convenient. Again, it exists for the convenience of
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* code that is already holding WALInsertLock but not the other locks.
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*
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* The unshared LogwrtResult may lag behind any or all of these, and again
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* is updated when convenient.
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*
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* The request bookkeeping is simpler: there is a shared XLogCtl->LogwrtRqst
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* (protected by info_lck), but we don't need to cache any copies of it.
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*
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* Note that this all works because the request and result positions can only
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* advance forward, never back up, and so we can easily determine which of two
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* values is "more up to date".
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*
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* info_lck is only held long enough to read/update the protected variables,
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* so it's a plain spinlock. The other locks are held longer (potentially
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* over I/O operations), so we use LWLocks for them. These locks are:
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*
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* WALInsertLock: must be held to insert a record into the WAL buffers.
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*
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* WALWriteLock: must be held to write WAL buffers to disk (XLogWrite or
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* XLogFlush).
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*
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* ControlFileLock: must be held to read/update control file or create
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* new log file.
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*
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* CheckpointLock: must be held to do a checkpoint or restartpoint (ensures
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* only one checkpointer at a time; currently, with all checkpoints done by
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* the bgwriter, this is just pro forma).
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*
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*----------
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*/
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typedef struct XLogwrtRqst
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{
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XLogRecPtr Write; /* last byte + 1 to write out */
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XLogRecPtr Flush; /* last byte + 1 to flush */
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} XLogwrtRqst;
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typedef struct XLogwrtResult
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{
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XLogRecPtr Write; /* last byte + 1 written out */
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XLogRecPtr Flush; /* last byte + 1 flushed */
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} XLogwrtResult;
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/*
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* Shared state data for XLogInsert.
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*/
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typedef struct XLogCtlInsert
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{
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XLogwrtResult LogwrtResult; /* a recent value of LogwrtResult */
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XLogRecPtr PrevRecord; /* start of previously-inserted record */
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int curridx; /* current block index in cache */
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XLogPageHeader currpage; /* points to header of block in cache */
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char *currpos; /* current insertion point in cache */
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XLogRecPtr RedoRecPtr; /* current redo point for insertions */
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bool forcePageWrites; /* forcing full-page writes for PITR? */
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} XLogCtlInsert;
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/*
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* Shared state data for XLogWrite/XLogFlush.
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*/
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typedef struct XLogCtlWrite
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{
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XLogwrtResult LogwrtResult; /* current value of LogwrtResult */
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int curridx; /* cache index of next block to write */
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pg_time_t lastSegSwitchTime; /* time of last xlog segment switch */
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} XLogCtlWrite;
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/*
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* Total shared-memory state for XLOG.
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*/
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typedef struct XLogCtlData
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{
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/* Protected by WALInsertLock: */
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XLogCtlInsert Insert;
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/* Protected by info_lck: */
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XLogwrtRqst LogwrtRqst;
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XLogwrtResult LogwrtResult;
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uint32 ckptXidEpoch; /* nextXID & epoch of latest checkpoint */
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TransactionId ckptXid;
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XLogRecPtr asyncCommitLSN; /* LSN of newest async commit */
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/* Protected by WALWriteLock: */
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XLogCtlWrite Write;
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/*
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* These values do not change after startup, although the pointed-to pages
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* and xlblocks values certainly do. Permission to read/write the pages
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* and xlblocks values depends on WALInsertLock and WALWriteLock.
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*/
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char *pages; /* buffers for unwritten XLOG pages */
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XLogRecPtr *xlblocks; /* 1st byte ptr-s + XLOG_BLCKSZ */
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int XLogCacheBlck; /* highest allocated xlog buffer index */
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TimeLineID ThisTimeLineID;
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TimeLineID RecoveryTargetTLI;
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/*
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* SharedRecoveryInProgress indicates if we're still in crash or archive
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* recovery. Protected by info_lck.
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*/
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bool SharedRecoveryInProgress;
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/*
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* During recovery, we keep a copy of the latest checkpoint record here.
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* Used by the background writer when it wants to create a restartpoint.
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*
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* Protected by info_lck.
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*/
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XLogRecPtr lastCheckPointRecPtr;
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CheckPoint lastCheckPoint;
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/* end+1 of the last record replayed (or being replayed) */
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XLogRecPtr replayEndRecPtr;
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/* timestamp of last record replayed (or being replayed) */
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TimestampTz recoveryLastXTime;
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/* end+1 of the last record replayed */
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XLogRecPtr recoveryLastRecPtr;
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slock_t info_lck; /* locks shared variables shown above */
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} XLogCtlData;
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static XLogCtlData *XLogCtl = NULL;
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/*
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* We maintain an image of pg_control in shared memory.
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*/
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static ControlFileData *ControlFile = NULL;
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/*
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* Macros for managing XLogInsert state. In most cases, the calling routine
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* has local copies of XLogCtl->Insert and/or XLogCtl->Insert->curridx,
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* so these are passed as parameters instead of being fetched via XLogCtl.
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*/
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/* Free space remaining in the current xlog page buffer */
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#define INSERT_FREESPACE(Insert) \
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(XLOG_BLCKSZ - ((Insert)->currpos - (char *) (Insert)->currpage))
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/* Construct XLogRecPtr value for current insertion point */
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#define INSERT_RECPTR(recptr,Insert,curridx) \
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( \
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(recptr).xlogid = XLogCtl->xlblocks[curridx].xlogid, \
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(recptr).xrecoff = \
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XLogCtl->xlblocks[curridx].xrecoff - INSERT_FREESPACE(Insert) \
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)
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#define PrevBufIdx(idx) \
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(((idx) == 0) ? XLogCtl->XLogCacheBlck : ((idx) - 1))
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#define NextBufIdx(idx) \
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(((idx) == XLogCtl->XLogCacheBlck) ? 0 : ((idx) + 1))
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/*
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* Private, possibly out-of-date copy of shared LogwrtResult.
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* See discussion above.
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*/
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static XLogwrtResult LogwrtResult = {{0, 0}, {0, 0}};
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/*
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* openLogFile is -1 or a kernel FD for an open log file segment.
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* When it's open, openLogOff is the current seek offset in the file.
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* openLogId/openLogSeg identify the segment. These variables are only
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* used to write the XLOG, and so will normally refer to the active segment.
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*/
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static int openLogFile = -1;
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static uint32 openLogId = 0;
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static uint32 openLogSeg = 0;
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static uint32 openLogOff = 0;
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/*
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* These variables are used similarly to the ones above, but for reading
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* the XLOG. Note, however, that readOff generally represents the offset
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* of the page just read, not the seek position of the FD itself, which
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* will be just past that page. readLen indicates how much of the current
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* page has been read into readBuf.
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*/
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static int readFile = -1;
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static uint32 readId = 0;
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static uint32 readSeg = 0;
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static uint32 readOff = 0;
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static uint32 readLen = 0;
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/* Is the currently open segment being streamed from primary? */
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static bool readStreamed = false;
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/* Buffer for currently read page (XLOG_BLCKSZ bytes) */
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static char *readBuf = NULL;
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/* Buffer for current ReadRecord result (expandable) */
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static char *readRecordBuf = NULL;
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static uint32 readRecordBufSize = 0;
|
|
|
|
/* State information for XLOG reading */
|
|
static XLogRecPtr ReadRecPtr; /* start of last record read */
|
|
static XLogRecPtr EndRecPtr; /* end+1 of last record read */
|
|
static TimeLineID lastPageTLI = 0;
|
|
|
|
static XLogRecPtr minRecoveryPoint; /* local copy of
|
|
* ControlFile->minRecoveryPoint */
|
|
static bool updateMinRecoveryPoint = true;
|
|
|
|
static bool InRedo = false;
|
|
|
|
/*
|
|
* Flags set by interrupt handlers for later service in the redo loop.
|
|
*/
|
|
static volatile sig_atomic_t got_SIGHUP = false;
|
|
static volatile sig_atomic_t shutdown_requested = false;
|
|
|
|
/*
|
|
* Flag set when executing a restore command, to tell SIGTERM signal handler
|
|
* that it's safe to just proc_exit.
|
|
*/
|
|
static volatile sig_atomic_t in_restore_command = false;
|
|
|
|
|
|
static void XLogArchiveNotify(const char *xlog);
|
|
static void XLogArchiveNotifySeg(uint32 log, uint32 seg);
|
|
static bool XLogArchiveCheckDone(const char *xlog);
|
|
static bool XLogArchiveIsBusy(const char *xlog);
|
|
static void XLogArchiveCleanup(const char *xlog);
|
|
static void readRecoveryCommandFile(void);
|
|
static void exitArchiveRecovery(TimeLineID endTLI,
|
|
uint32 endLogId, uint32 endLogSeg);
|
|
static bool recoveryStopsHere(XLogRecord *record, bool *includeThis);
|
|
static void CheckRequiredParameterValues(CheckPoint checkPoint);
|
|
static void LocalSetXLogInsertAllowed(void);
|
|
static void CheckPointGuts(XLogRecPtr checkPointRedo, int flags);
|
|
|
|
static bool XLogCheckBuffer(XLogRecData *rdata, bool doPageWrites,
|
|
XLogRecPtr *lsn, BkpBlock *bkpb);
|
|
static bool AdvanceXLInsertBuffer(bool new_segment);
|
|
static void XLogWrite(XLogwrtRqst WriteRqst, bool flexible, bool xlog_switch);
|
|
static bool InstallXLogFileSegment(uint32 *log, uint32 *seg, char *tmppath,
|
|
bool find_free, int *max_advance,
|
|
bool use_lock);
|
|
static int XLogFileRead(uint32 log, uint32 seg, int emode, TimeLineID tli,
|
|
bool fromArchive, bool notexistOk);
|
|
static int XLogFileReadAnyTLI(uint32 log, uint32 seg, int emode,
|
|
bool fromArchive);
|
|
static bool XLogPageRead(XLogRecPtr *RecPtr, int emode, bool fetching_ckpt,
|
|
bool randAccess);
|
|
static void XLogFileClose(void);
|
|
static bool RestoreArchivedFile(char *path, const char *xlogfname,
|
|
const char *recovername, off_t expectedSize);
|
|
static void ExecuteRecoveryEndCommand(void);
|
|
static void PreallocXlogFiles(XLogRecPtr endptr);
|
|
static void RemoveOldXlogFiles(uint32 log, uint32 seg, XLogRecPtr endptr);
|
|
static void ValidateXLOGDirectoryStructure(void);
|
|
static void CleanupBackupHistory(void);
|
|
static void UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force);
|
|
static XLogRecord *ReadRecord(XLogRecPtr *RecPtr, int emode, bool fetching_ckpt);
|
|
static bool ValidXLOGHeader(XLogPageHeader hdr, int emode);
|
|
static XLogRecord *ReadCheckpointRecord(XLogRecPtr RecPtr, int whichChkpt);
|
|
static List *readTimeLineHistory(TimeLineID targetTLI);
|
|
static bool existsTimeLineHistory(TimeLineID probeTLI);
|
|
static TimeLineID findNewestTimeLine(TimeLineID startTLI);
|
|
static void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
|
|
TimeLineID endTLI,
|
|
uint32 endLogId, uint32 endLogSeg);
|
|
static void WriteControlFile(void);
|
|
static void ReadControlFile(void);
|
|
static char *str_time(pg_time_t tnow);
|
|
static bool CheckForStandbyTrigger(void);
|
|
|
|
#ifdef WAL_DEBUG
|
|
static void xlog_outrec(StringInfo buf, XLogRecord *record);
|
|
#endif
|
|
static void pg_start_backup_callback(int code, Datum arg);
|
|
static bool read_backup_label(XLogRecPtr *checkPointLoc);
|
|
static void rm_redo_error_callback(void *arg);
|
|
static int get_sync_bit(int method);
|
|
|
|
|
|
/*
|
|
* Insert an XLOG record having the specified RMID and info bytes,
|
|
* with the body of the record being the data chunk(s) described by
|
|
* the rdata chain (see xlog.h for notes about rdata).
|
|
*
|
|
* Returns XLOG pointer to end of record (beginning of next record).
|
|
* This can be used as LSN for data pages affected by the logged action.
|
|
* (LSN is the XLOG point up to which the XLOG must be flushed to disk
|
|
* before the data page can be written out. This implements the basic
|
|
* WAL rule "write the log before the data".)
|
|
*
|
|
* NB: this routine feels free to scribble on the XLogRecData structs,
|
|
* though not on the data they reference. This is OK since the XLogRecData
|
|
* structs are always just temporaries in the calling code.
|
|
*/
|
|
XLogRecPtr
|
|
XLogInsert(RmgrId rmid, uint8 info, XLogRecData *rdata)
|
|
{
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
XLogRecord *record;
|
|
XLogContRecord *contrecord;
|
|
XLogRecPtr RecPtr;
|
|
XLogRecPtr WriteRqst;
|
|
uint32 freespace;
|
|
int curridx;
|
|
XLogRecData *rdt;
|
|
Buffer dtbuf[XLR_MAX_BKP_BLOCKS];
|
|
bool dtbuf_bkp[XLR_MAX_BKP_BLOCKS];
|
|
BkpBlock dtbuf_xlg[XLR_MAX_BKP_BLOCKS];
|
|
XLogRecPtr dtbuf_lsn[XLR_MAX_BKP_BLOCKS];
|
|
XLogRecData dtbuf_rdt1[XLR_MAX_BKP_BLOCKS];
|
|
XLogRecData dtbuf_rdt2[XLR_MAX_BKP_BLOCKS];
|
|
XLogRecData dtbuf_rdt3[XLR_MAX_BKP_BLOCKS];
|
|
pg_crc32 rdata_crc;
|
|
uint32 len,
|
|
write_len;
|
|
unsigned i;
|
|
bool updrqst;
|
|
bool doPageWrites;
|
|
bool isLogSwitch = (rmid == RM_XLOG_ID && info == XLOG_SWITCH);
|
|
|
|
/* cross-check on whether we should be here or not */
|
|
if (!XLogInsertAllowed())
|
|
elog(ERROR, "cannot make new WAL entries during recovery");
|
|
|
|
/* info's high bits are reserved for use by me */
|
|
if (info & XLR_INFO_MASK)
|
|
elog(PANIC, "invalid xlog info mask %02X", info);
|
|
|
|
TRACE_POSTGRESQL_XLOG_INSERT(rmid, info);
|
|
|
|
/*
|
|
* In bootstrap mode, we don't actually log anything but XLOG resources;
|
|
* return a phony record pointer.
|
|
*/
|
|
if (IsBootstrapProcessingMode() && rmid != RM_XLOG_ID)
|
|
{
|
|
RecPtr.xlogid = 0;
|
|
RecPtr.xrecoff = SizeOfXLogLongPHD; /* start of 1st chkpt record */
|
|
return RecPtr;
|
|
}
|
|
|
|
/*
|
|
* Here we scan the rdata chain, determine which buffers must be backed
|
|
* up, and compute the CRC values for the data. Note that the record
|
|
* header isn't added into the CRC initially since we don't know the final
|
|
* length or info bits quite yet. Thus, the CRC will represent the CRC of
|
|
* the whole record in the order "rdata, then backup blocks, then record
|
|
* header".
|
|
*
|
|
* We may have to loop back to here if a race condition is detected below.
|
|
* We could prevent the race by doing all this work while holding the
|
|
* insert lock, but it seems better to avoid doing CRC calculations while
|
|
* holding the lock. This means we have to be careful about modifying the
|
|
* rdata chain until we know we aren't going to loop back again. The only
|
|
* change we allow ourselves to make earlier is to set rdt->data = NULL in
|
|
* chain items we have decided we will have to back up the whole buffer
|
|
* for. This is OK because we will certainly decide the same thing again
|
|
* for those items if we do it over; doing it here saves an extra pass
|
|
* over the chain later.
|
|
*/
|
|
begin:;
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
dtbuf[i] = InvalidBuffer;
|
|
dtbuf_bkp[i] = false;
|
|
}
|
|
|
|
/*
|
|
* Decide if we need to do full-page writes in this XLOG record: true if
|
|
* full_page_writes is on or we have a PITR request for it. Since we
|
|
* don't yet have the insert lock, forcePageWrites could change under us,
|
|
* but we'll recheck it once we have the lock.
|
|
*/
|
|
doPageWrites = fullPageWrites || Insert->forcePageWrites;
|
|
|
|
INIT_CRC32(rdata_crc);
|
|
len = 0;
|
|
for (rdt = rdata;;)
|
|
{
|
|
if (rdt->buffer == InvalidBuffer)
|
|
{
|
|
/* Simple data, just include it */
|
|
len += rdt->len;
|
|
COMP_CRC32(rdata_crc, rdt->data, rdt->len);
|
|
}
|
|
else
|
|
{
|
|
/* Find info for buffer */
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (rdt->buffer == dtbuf[i])
|
|
{
|
|
/* Buffer already referenced by earlier chain item */
|
|
if (dtbuf_bkp[i])
|
|
rdt->data = NULL;
|
|
else if (rdt->data)
|
|
{
|
|
len += rdt->len;
|
|
COMP_CRC32(rdata_crc, rdt->data, rdt->len);
|
|
}
|
|
break;
|
|
}
|
|
if (dtbuf[i] == InvalidBuffer)
|
|
{
|
|
/* OK, put it in this slot */
|
|
dtbuf[i] = rdt->buffer;
|
|
if (XLogCheckBuffer(rdt, doPageWrites,
|
|
&(dtbuf_lsn[i]), &(dtbuf_xlg[i])))
|
|
{
|
|
dtbuf_bkp[i] = true;
|
|
rdt->data = NULL;
|
|
}
|
|
else if (rdt->data)
|
|
{
|
|
len += rdt->len;
|
|
COMP_CRC32(rdata_crc, rdt->data, rdt->len);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
if (i >= XLR_MAX_BKP_BLOCKS)
|
|
elog(PANIC, "can backup at most %d blocks per xlog record",
|
|
XLR_MAX_BKP_BLOCKS);
|
|
}
|
|
/* Break out of loop when rdt points to last chain item */
|
|
if (rdt->next == NULL)
|
|
break;
|
|
rdt = rdt->next;
|
|
}
|
|
|
|
/*
|
|
* Now add the backup block headers and data into the CRC
|
|
*/
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (dtbuf_bkp[i])
|
|
{
|
|
BkpBlock *bkpb = &(dtbuf_xlg[i]);
|
|
char *page;
|
|
|
|
COMP_CRC32(rdata_crc,
|
|
(char *) bkpb,
|
|
sizeof(BkpBlock));
|
|
page = (char *) BufferGetBlock(dtbuf[i]);
|
|
if (bkpb->hole_length == 0)
|
|
{
|
|
COMP_CRC32(rdata_crc,
|
|
page,
|
|
BLCKSZ);
|
|
}
|
|
else
|
|
{
|
|
/* must skip the hole */
|
|
COMP_CRC32(rdata_crc,
|
|
page,
|
|
bkpb->hole_offset);
|
|
COMP_CRC32(rdata_crc,
|
|
page + (bkpb->hole_offset + bkpb->hole_length),
|
|
BLCKSZ - (bkpb->hole_offset + bkpb->hole_length));
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* NOTE: We disallow len == 0 because it provides a useful bit of extra
|
|
* error checking in ReadRecord. This means that all callers of
|
|
* XLogInsert must supply at least some not-in-a-buffer data. However, we
|
|
* make an exception for XLOG SWITCH records because we don't want them to
|
|
* ever cross a segment boundary.
|
|
*/
|
|
if (len == 0 && !isLogSwitch)
|
|
elog(PANIC, "invalid xlog record length %u", len);
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/* Now wait to get insert lock */
|
|
LWLockAcquire(WALInsertLock, LW_EXCLUSIVE);
|
|
|
|
/*
|
|
* Check to see if my RedoRecPtr is out of date. If so, may have to go
|
|
* back and recompute everything. This can only happen just after a
|
|
* checkpoint, so it's better to be slow in this case and fast otherwise.
|
|
*
|
|
* If we aren't doing full-page writes then RedoRecPtr doesn't actually
|
|
* affect the contents of the XLOG record, so we'll update our local copy
|
|
* but not force a recomputation.
|
|
*/
|
|
if (!XLByteEQ(RedoRecPtr, Insert->RedoRecPtr))
|
|
{
|
|
Assert(XLByteLT(RedoRecPtr, Insert->RedoRecPtr));
|
|
RedoRecPtr = Insert->RedoRecPtr;
|
|
|
|
if (doPageWrites)
|
|
{
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (dtbuf[i] == InvalidBuffer)
|
|
continue;
|
|
if (dtbuf_bkp[i] == false &&
|
|
XLByteLE(dtbuf_lsn[i], RedoRecPtr))
|
|
{
|
|
/*
|
|
* Oops, this buffer now needs to be backed up, but we
|
|
* didn't think so above. Start over.
|
|
*/
|
|
LWLockRelease(WALInsertLock);
|
|
END_CRIT_SECTION();
|
|
goto begin;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Also check to see if forcePageWrites was just turned on; if we weren't
|
|
* already doing full-page writes then go back and recompute. (If it was
|
|
* just turned off, we could recompute the record without full pages, but
|
|
* we choose not to bother.)
|
|
*/
|
|
if (Insert->forcePageWrites && !doPageWrites)
|
|
{
|
|
/* Oops, must redo it with full-page data */
|
|
LWLockRelease(WALInsertLock);
|
|
END_CRIT_SECTION();
|
|
goto begin;
|
|
}
|
|
|
|
/*
|
|
* Make additional rdata chain entries for the backup blocks, so that we
|
|
* don't need to special-case them in the write loop. Note that we have
|
|
* now irrevocably changed the input rdata chain. At the exit of this
|
|
* loop, write_len includes the backup block data.
|
|
*
|
|
* Also set the appropriate info bits to show which buffers were backed
|
|
* up. The i'th XLR_SET_BKP_BLOCK bit corresponds to the i'th distinct
|
|
* buffer value (ignoring InvalidBuffer) appearing in the rdata chain.
|
|
*/
|
|
write_len = len;
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
BkpBlock *bkpb;
|
|
char *page;
|
|
|
|
if (!dtbuf_bkp[i])
|
|
continue;
|
|
|
|
info |= XLR_SET_BKP_BLOCK(i);
|
|
|
|
bkpb = &(dtbuf_xlg[i]);
|
|
page = (char *) BufferGetBlock(dtbuf[i]);
|
|
|
|
rdt->next = &(dtbuf_rdt1[i]);
|
|
rdt = rdt->next;
|
|
|
|
rdt->data = (char *) bkpb;
|
|
rdt->len = sizeof(BkpBlock);
|
|
write_len += sizeof(BkpBlock);
|
|
|
|
rdt->next = &(dtbuf_rdt2[i]);
|
|
rdt = rdt->next;
|
|
|
|
if (bkpb->hole_length == 0)
|
|
{
|
|
rdt->data = page;
|
|
rdt->len = BLCKSZ;
|
|
write_len += BLCKSZ;
|
|
rdt->next = NULL;
|
|
}
|
|
else
|
|
{
|
|
/* must skip the hole */
|
|
rdt->data = page;
|
|
rdt->len = bkpb->hole_offset;
|
|
write_len += bkpb->hole_offset;
|
|
|
|
rdt->next = &(dtbuf_rdt3[i]);
|
|
rdt = rdt->next;
|
|
|
|
rdt->data = page + (bkpb->hole_offset + bkpb->hole_length);
|
|
rdt->len = BLCKSZ - (bkpb->hole_offset + bkpb->hole_length);
|
|
write_len += rdt->len;
|
|
rdt->next = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we backed up any full blocks and online backup is not in progress,
|
|
* mark the backup blocks as removable. This allows the WAL archiver to
|
|
* know whether it is safe to compress archived WAL data by transforming
|
|
* full-block records into the non-full-block format.
|
|
*
|
|
* Note: we could just set the flag whenever !forcePageWrites, but
|
|
* defining it like this leaves the info bit free for some potential other
|
|
* use in records without any backup blocks.
|
|
*/
|
|
if ((info & XLR_BKP_BLOCK_MASK) && !Insert->forcePageWrites)
|
|
info |= XLR_BKP_REMOVABLE;
|
|
|
|
/*
|
|
* If there isn't enough space on the current XLOG page for a record
|
|
* header, advance to the next page (leaving the unused space as zeroes).
|
|
*/
|
|
updrqst = false;
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
if (freespace < SizeOfXLogRecord)
|
|
{
|
|
updrqst = AdvanceXLInsertBuffer(false);
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
}
|
|
|
|
/* Compute record's XLOG location */
|
|
curridx = Insert->curridx;
|
|
INSERT_RECPTR(RecPtr, Insert, curridx);
|
|
|
|
/*
|
|
* If the record is an XLOG_SWITCH, and we are exactly at the start of a
|
|
* segment, we need not insert it (and don't want to because we'd like
|
|
* consecutive switch requests to be no-ops). Instead, make sure
|
|
* everything is written and flushed through the end of the prior segment,
|
|
* and return the prior segment's end address.
|
|
*/
|
|
if (isLogSwitch &&
|
|
(RecPtr.xrecoff % XLogSegSize) == SizeOfXLogLongPHD)
|
|
{
|
|
/* We can release insert lock immediately */
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
RecPtr.xrecoff -= SizeOfXLogLongPHD;
|
|
if (RecPtr.xrecoff == 0)
|
|
{
|
|
/* crossing a logid boundary */
|
|
RecPtr.xlogid -= 1;
|
|
RecPtr.xrecoff = XLogFileSize;
|
|
}
|
|
|
|
LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
|
|
LogwrtResult = XLogCtl->Write.LogwrtResult;
|
|
if (!XLByteLE(RecPtr, LogwrtResult.Flush))
|
|
{
|
|
XLogwrtRqst FlushRqst;
|
|
|
|
FlushRqst.Write = RecPtr;
|
|
FlushRqst.Flush = RecPtr;
|
|
XLogWrite(FlushRqst, false, false);
|
|
}
|
|
LWLockRelease(WALWriteLock);
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
return RecPtr;
|
|
}
|
|
|
|
/* Insert record header */
|
|
|
|
record = (XLogRecord *) Insert->currpos;
|
|
record->xl_prev = Insert->PrevRecord;
|
|
record->xl_xid = GetCurrentTransactionIdIfAny();
|
|
record->xl_tot_len = SizeOfXLogRecord + write_len;
|
|
record->xl_len = len; /* doesn't include backup blocks */
|
|
record->xl_info = info;
|
|
record->xl_rmid = rmid;
|
|
|
|
/* Now we can finish computing the record's CRC */
|
|
COMP_CRC32(rdata_crc, (char *) record + sizeof(pg_crc32),
|
|
SizeOfXLogRecord - sizeof(pg_crc32));
|
|
FIN_CRC32(rdata_crc);
|
|
record->xl_crc = rdata_crc;
|
|
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG)
|
|
{
|
|
StringInfoData buf;
|
|
|
|
initStringInfo(&buf);
|
|
appendStringInfo(&buf, "INSERT @ %X/%X: ",
|
|
RecPtr.xlogid, RecPtr.xrecoff);
|
|
xlog_outrec(&buf, record);
|
|
if (rdata->data != NULL)
|
|
{
|
|
appendStringInfo(&buf, " - ");
|
|
RmgrTable[record->xl_rmid].rm_desc(&buf, record->xl_info, rdata->data);
|
|
}
|
|
elog(LOG, "%s", buf.data);
|
|
pfree(buf.data);
|
|
}
|
|
#endif
|
|
|
|
/* Record begin of record in appropriate places */
|
|
ProcLastRecPtr = RecPtr;
|
|
Insert->PrevRecord = RecPtr;
|
|
|
|
Insert->currpos += SizeOfXLogRecord;
|
|
freespace -= SizeOfXLogRecord;
|
|
|
|
/*
|
|
* Append the data, including backup blocks if any
|
|
*/
|
|
while (write_len)
|
|
{
|
|
while (rdata->data == NULL)
|
|
rdata = rdata->next;
|
|
|
|
if (freespace > 0)
|
|
{
|
|
if (rdata->len > freespace)
|
|
{
|
|
memcpy(Insert->currpos, rdata->data, freespace);
|
|
rdata->data += freespace;
|
|
rdata->len -= freespace;
|
|
write_len -= freespace;
|
|
}
|
|
else
|
|
{
|
|
memcpy(Insert->currpos, rdata->data, rdata->len);
|
|
freespace -= rdata->len;
|
|
write_len -= rdata->len;
|
|
Insert->currpos += rdata->len;
|
|
rdata = rdata->next;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* Use next buffer */
|
|
updrqst = AdvanceXLInsertBuffer(false);
|
|
curridx = Insert->curridx;
|
|
/* Insert cont-record header */
|
|
Insert->currpage->xlp_info |= XLP_FIRST_IS_CONTRECORD;
|
|
contrecord = (XLogContRecord *) Insert->currpos;
|
|
contrecord->xl_rem_len = write_len;
|
|
Insert->currpos += SizeOfXLogContRecord;
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
}
|
|
|
|
/* Ensure next record will be properly aligned */
|
|
Insert->currpos = (char *) Insert->currpage +
|
|
MAXALIGN(Insert->currpos - (char *) Insert->currpage);
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
|
|
/*
|
|
* The recptr I return is the beginning of the *next* record. This will be
|
|
* stored as LSN for changed data pages...
|
|
*/
|
|
INSERT_RECPTR(RecPtr, Insert, curridx);
|
|
|
|
/*
|
|
* If the record is an XLOG_SWITCH, we must now write and flush all the
|
|
* existing data, and then forcibly advance to the start of the next
|
|
* segment. It's not good to do this I/O while holding the insert lock,
|
|
* but there seems too much risk of confusion if we try to release the
|
|
* lock sooner. Fortunately xlog switch needn't be a high-performance
|
|
* operation anyway...
|
|
*/
|
|
if (isLogSwitch)
|
|
{
|
|
XLogCtlWrite *Write = &XLogCtl->Write;
|
|
XLogwrtRqst FlushRqst;
|
|
XLogRecPtr OldSegEnd;
|
|
|
|
TRACE_POSTGRESQL_XLOG_SWITCH();
|
|
|
|
LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
|
|
|
|
/*
|
|
* Flush through the end of the page containing XLOG_SWITCH, and
|
|
* perform end-of-segment actions (eg, notifying archiver).
|
|
*/
|
|
WriteRqst = XLogCtl->xlblocks[curridx];
|
|
FlushRqst.Write = WriteRqst;
|
|
FlushRqst.Flush = WriteRqst;
|
|
XLogWrite(FlushRqst, false, true);
|
|
|
|
/* Set up the next buffer as first page of next segment */
|
|
/* Note: AdvanceXLInsertBuffer cannot need to do I/O here */
|
|
(void) AdvanceXLInsertBuffer(true);
|
|
|
|
/* There should be no unwritten data */
|
|
curridx = Insert->curridx;
|
|
Assert(curridx == Write->curridx);
|
|
|
|
/* Compute end address of old segment */
|
|
OldSegEnd = XLogCtl->xlblocks[curridx];
|
|
OldSegEnd.xrecoff -= XLOG_BLCKSZ;
|
|
if (OldSegEnd.xrecoff == 0)
|
|
{
|
|
/* crossing a logid boundary */
|
|
OldSegEnd.xlogid -= 1;
|
|
OldSegEnd.xrecoff = XLogFileSize;
|
|
}
|
|
|
|
/* Make it look like we've written and synced all of old segment */
|
|
LogwrtResult.Write = OldSegEnd;
|
|
LogwrtResult.Flush = OldSegEnd;
|
|
|
|
/*
|
|
* Update shared-memory status --- this code should match XLogWrite
|
|
*/
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
xlogctl->LogwrtResult = LogwrtResult;
|
|
if (XLByteLT(xlogctl->LogwrtRqst.Write, LogwrtResult.Write))
|
|
xlogctl->LogwrtRqst.Write = LogwrtResult.Write;
|
|
if (XLByteLT(xlogctl->LogwrtRqst.Flush, LogwrtResult.Flush))
|
|
xlogctl->LogwrtRqst.Flush = LogwrtResult.Flush;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
Write->LogwrtResult = LogwrtResult;
|
|
|
|
LWLockRelease(WALWriteLock);
|
|
|
|
updrqst = false; /* done already */
|
|
}
|
|
else
|
|
{
|
|
/* normal case, ie not xlog switch */
|
|
|
|
/* Need to update shared LogwrtRqst if some block was filled up */
|
|
if (freespace < SizeOfXLogRecord)
|
|
{
|
|
/* curridx is filled and available for writing out */
|
|
updrqst = true;
|
|
}
|
|
else
|
|
{
|
|
/* if updrqst already set, write through end of previous buf */
|
|
curridx = PrevBufIdx(curridx);
|
|
}
|
|
WriteRqst = XLogCtl->xlblocks[curridx];
|
|
}
|
|
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
if (updrqst)
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
/* advance global request to include new block(s) */
|
|
if (XLByteLT(xlogctl->LogwrtRqst.Write, WriteRqst))
|
|
xlogctl->LogwrtRqst.Write = WriteRqst;
|
|
/* update local result copy while I have the chance */
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
XactLastRecEnd = RecPtr;
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
return RecPtr;
|
|
}
|
|
|
|
/*
|
|
* Determine whether the buffer referenced by an XLogRecData item has to
|
|
* be backed up, and if so fill a BkpBlock struct for it. In any case
|
|
* save the buffer's LSN at *lsn.
|
|
*/
|
|
static bool
|
|
XLogCheckBuffer(XLogRecData *rdata, bool doPageWrites,
|
|
XLogRecPtr *lsn, BkpBlock *bkpb)
|
|
{
|
|
Page page;
|
|
|
|
page = BufferGetPage(rdata->buffer);
|
|
|
|
/*
|
|
* XXX We assume page LSN is first data on *every* page that can be passed
|
|
* to XLogInsert, whether it otherwise has the standard page layout or
|
|
* not.
|
|
*/
|
|
*lsn = PageGetLSN(page);
|
|
|
|
if (doPageWrites &&
|
|
XLByteLE(PageGetLSN(page), RedoRecPtr))
|
|
{
|
|
/*
|
|
* The page needs to be backed up, so set up *bkpb
|
|
*/
|
|
BufferGetTag(rdata->buffer, &bkpb->node, &bkpb->fork, &bkpb->block);
|
|
|
|
if (rdata->buffer_std)
|
|
{
|
|
/* Assume we can omit data between pd_lower and pd_upper */
|
|
uint16 lower = ((PageHeader) page)->pd_lower;
|
|
uint16 upper = ((PageHeader) page)->pd_upper;
|
|
|
|
if (lower >= SizeOfPageHeaderData &&
|
|
upper > lower &&
|
|
upper <= BLCKSZ)
|
|
{
|
|
bkpb->hole_offset = lower;
|
|
bkpb->hole_length = upper - lower;
|
|
}
|
|
else
|
|
{
|
|
/* No "hole" to compress out */
|
|
bkpb->hole_offset = 0;
|
|
bkpb->hole_length = 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Not a standard page header, don't try to eliminate "hole" */
|
|
bkpb->hole_offset = 0;
|
|
bkpb->hole_length = 0;
|
|
}
|
|
|
|
return true; /* buffer requires backup */
|
|
}
|
|
|
|
return false; /* buffer does not need to be backed up */
|
|
}
|
|
|
|
/*
|
|
* XLogArchiveNotify
|
|
*
|
|
* Create an archive notification file
|
|
*
|
|
* The name of the notification file is the message that will be picked up
|
|
* by the archiver, e.g. we write 0000000100000001000000C6.ready
|
|
* and the archiver then knows to archive XLOGDIR/0000000100000001000000C6,
|
|
* then when complete, rename it to 0000000100000001000000C6.done
|
|
*/
|
|
static void
|
|
XLogArchiveNotify(const char *xlog)
|
|
{
|
|
char archiveStatusPath[MAXPGPATH];
|
|
FILE *fd;
|
|
|
|
/* insert an otherwise empty file called <XLOG>.ready */
|
|
StatusFilePath(archiveStatusPath, xlog, ".ready");
|
|
fd = AllocateFile(archiveStatusPath, "w");
|
|
if (fd == NULL)
|
|
{
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create archive status file \"%s\": %m",
|
|
archiveStatusPath)));
|
|
return;
|
|
}
|
|
if (FreeFile(fd))
|
|
{
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write archive status file \"%s\": %m",
|
|
archiveStatusPath)));
|
|
return;
|
|
}
|
|
|
|
/* Notify archiver that it's got something to do */
|
|
if (IsUnderPostmaster)
|
|
SendPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER);
|
|
}
|
|
|
|
/*
|
|
* Convenience routine to notify using log/seg representation of filename
|
|
*/
|
|
static void
|
|
XLogArchiveNotifySeg(uint32 log, uint32 seg)
|
|
{
|
|
char xlog[MAXFNAMELEN];
|
|
|
|
XLogFileName(xlog, ThisTimeLineID, log, seg);
|
|
XLogArchiveNotify(xlog);
|
|
}
|
|
|
|
/*
|
|
* XLogArchiveCheckDone
|
|
*
|
|
* This is called when we are ready to delete or recycle an old XLOG segment
|
|
* file or backup history file. If it is okay to delete it then return true.
|
|
* If it is not time to delete it, make sure a .ready file exists, and return
|
|
* false.
|
|
*
|
|
* If <XLOG>.done exists, then return true; else if <XLOG>.ready exists,
|
|
* then return false; else create <XLOG>.ready and return false.
|
|
*
|
|
* The reason we do things this way is so that if the original attempt to
|
|
* create <XLOG>.ready fails, we'll retry during subsequent checkpoints.
|
|
*/
|
|
static bool
|
|
XLogArchiveCheckDone(const char *xlog)
|
|
{
|
|
char archiveStatusPath[MAXPGPATH];
|
|
struct stat stat_buf;
|
|
|
|
/* Always deletable if archiving is off */
|
|
if (!XLogArchivingActive())
|
|
return true;
|
|
|
|
/* First check for .done --- this means archiver is done with it */
|
|
StatusFilePath(archiveStatusPath, xlog, ".done");
|
|
if (stat(archiveStatusPath, &stat_buf) == 0)
|
|
return true;
|
|
|
|
/* check for .ready --- this means archiver is still busy with it */
|
|
StatusFilePath(archiveStatusPath, xlog, ".ready");
|
|
if (stat(archiveStatusPath, &stat_buf) == 0)
|
|
return false;
|
|
|
|
/* Race condition --- maybe archiver just finished, so recheck */
|
|
StatusFilePath(archiveStatusPath, xlog, ".done");
|
|
if (stat(archiveStatusPath, &stat_buf) == 0)
|
|
return true;
|
|
|
|
/* Retry creation of the .ready file */
|
|
XLogArchiveNotify(xlog);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* XLogArchiveIsBusy
|
|
*
|
|
* Check to see if an XLOG segment file is still unarchived.
|
|
* This is almost but not quite the inverse of XLogArchiveCheckDone: in
|
|
* the first place we aren't chartered to recreate the .ready file, and
|
|
* in the second place we should consider that if the file is already gone
|
|
* then it's not busy. (This check is needed to handle the race condition
|
|
* that a checkpoint already deleted the no-longer-needed file.)
|
|
*/
|
|
static bool
|
|
XLogArchiveIsBusy(const char *xlog)
|
|
{
|
|
char archiveStatusPath[MAXPGPATH];
|
|
struct stat stat_buf;
|
|
|
|
/* First check for .done --- this means archiver is done with it */
|
|
StatusFilePath(archiveStatusPath, xlog, ".done");
|
|
if (stat(archiveStatusPath, &stat_buf) == 0)
|
|
return false;
|
|
|
|
/* check for .ready --- this means archiver is still busy with it */
|
|
StatusFilePath(archiveStatusPath, xlog, ".ready");
|
|
if (stat(archiveStatusPath, &stat_buf) == 0)
|
|
return true;
|
|
|
|
/* Race condition --- maybe archiver just finished, so recheck */
|
|
StatusFilePath(archiveStatusPath, xlog, ".done");
|
|
if (stat(archiveStatusPath, &stat_buf) == 0)
|
|
return false;
|
|
|
|
/*
|
|
* Check to see if the WAL file has been removed by checkpoint, which
|
|
* implies it has already been archived, and explains why we can't see a
|
|
* status file for it.
|
|
*/
|
|
snprintf(archiveStatusPath, MAXPGPATH, XLOGDIR "/%s", xlog);
|
|
if (stat(archiveStatusPath, &stat_buf) != 0 &&
|
|
errno == ENOENT)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* XLogArchiveCleanup
|
|
*
|
|
* Cleanup archive notification file(s) for a particular xlog segment
|
|
*/
|
|
static void
|
|
XLogArchiveCleanup(const char *xlog)
|
|
{
|
|
char archiveStatusPath[MAXPGPATH];
|
|
|
|
/* Remove the .done file */
|
|
StatusFilePath(archiveStatusPath, xlog, ".done");
|
|
unlink(archiveStatusPath);
|
|
/* should we complain about failure? */
|
|
|
|
/* Remove the .ready file if present --- normally it shouldn't be */
|
|
StatusFilePath(archiveStatusPath, xlog, ".ready");
|
|
unlink(archiveStatusPath);
|
|
/* should we complain about failure? */
|
|
}
|
|
|
|
/*
|
|
* Advance the Insert state to the next buffer page, writing out the next
|
|
* buffer if it still contains unwritten data.
|
|
*
|
|
* If new_segment is TRUE then we set up the next buffer page as the first
|
|
* page of the next xlog segment file, possibly but not usually the next
|
|
* consecutive file page.
|
|
*
|
|
* The global LogwrtRqst.Write pointer needs to be advanced to include the
|
|
* just-filled page. If we can do this for free (without an extra lock),
|
|
* we do so here. Otherwise the caller must do it. We return TRUE if the
|
|
* request update still needs to be done, FALSE if we did it internally.
|
|
*
|
|
* Must be called with WALInsertLock held.
|
|
*/
|
|
static bool
|
|
AdvanceXLInsertBuffer(bool new_segment)
|
|
{
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
XLogCtlWrite *Write = &XLogCtl->Write;
|
|
int nextidx = NextBufIdx(Insert->curridx);
|
|
bool update_needed = true;
|
|
XLogRecPtr OldPageRqstPtr;
|
|
XLogwrtRqst WriteRqst;
|
|
XLogRecPtr NewPageEndPtr;
|
|
XLogPageHeader NewPage;
|
|
|
|
/* Use Insert->LogwrtResult copy if it's more fresh */
|
|
if (XLByteLT(LogwrtResult.Write, Insert->LogwrtResult.Write))
|
|
LogwrtResult = Insert->LogwrtResult;
|
|
|
|
/*
|
|
* Get ending-offset of the buffer page we need to replace (this may be
|
|
* zero if the buffer hasn't been used yet). Fall through if it's already
|
|
* written out.
|
|
*/
|
|
OldPageRqstPtr = XLogCtl->xlblocks[nextidx];
|
|
if (!XLByteLE(OldPageRqstPtr, LogwrtResult.Write))
|
|
{
|
|
/* nope, got work to do... */
|
|
XLogRecPtr FinishedPageRqstPtr;
|
|
|
|
FinishedPageRqstPtr = XLogCtl->xlblocks[Insert->curridx];
|
|
|
|
/* Before waiting, get info_lck and update LogwrtResult */
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
if (XLByteLT(xlogctl->LogwrtRqst.Write, FinishedPageRqstPtr))
|
|
xlogctl->LogwrtRqst.Write = FinishedPageRqstPtr;
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
update_needed = false; /* Did the shared-request update */
|
|
|
|
if (XLByteLE(OldPageRqstPtr, LogwrtResult.Write))
|
|
{
|
|
/* OK, someone wrote it already */
|
|
Insert->LogwrtResult = LogwrtResult;
|
|
}
|
|
else
|
|
{
|
|
/* Must acquire write lock */
|
|
LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
|
|
LogwrtResult = Write->LogwrtResult;
|
|
if (XLByteLE(OldPageRqstPtr, LogwrtResult.Write))
|
|
{
|
|
/* OK, someone wrote it already */
|
|
LWLockRelease(WALWriteLock);
|
|
Insert->LogwrtResult = LogwrtResult;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Have to write buffers while holding insert lock. This is
|
|
* not good, so only write as much as we absolutely must.
|
|
*/
|
|
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_START();
|
|
WriteRqst.Write = OldPageRqstPtr;
|
|
WriteRqst.Flush.xlogid = 0;
|
|
WriteRqst.Flush.xrecoff = 0;
|
|
XLogWrite(WriteRqst, false, false);
|
|
LWLockRelease(WALWriteLock);
|
|
Insert->LogwrtResult = LogwrtResult;
|
|
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now the next buffer slot is free and we can set it up to be the next
|
|
* output page.
|
|
*/
|
|
NewPageEndPtr = XLogCtl->xlblocks[Insert->curridx];
|
|
|
|
if (new_segment)
|
|
{
|
|
/* force it to a segment start point */
|
|
NewPageEndPtr.xrecoff += XLogSegSize - 1;
|
|
NewPageEndPtr.xrecoff -= NewPageEndPtr.xrecoff % XLogSegSize;
|
|
}
|
|
|
|
if (NewPageEndPtr.xrecoff >= XLogFileSize)
|
|
{
|
|
/* crossing a logid boundary */
|
|
NewPageEndPtr.xlogid += 1;
|
|
NewPageEndPtr.xrecoff = XLOG_BLCKSZ;
|
|
}
|
|
else
|
|
NewPageEndPtr.xrecoff += XLOG_BLCKSZ;
|
|
XLogCtl->xlblocks[nextidx] = NewPageEndPtr;
|
|
NewPage = (XLogPageHeader) (XLogCtl->pages + nextidx * (Size) XLOG_BLCKSZ);
|
|
|
|
Insert->curridx = nextidx;
|
|
Insert->currpage = NewPage;
|
|
|
|
Insert->currpos = ((char *) NewPage) +SizeOfXLogShortPHD;
|
|
|
|
/*
|
|
* Be sure to re-zero the buffer so that bytes beyond what we've written
|
|
* will look like zeroes and not valid XLOG records...
|
|
*/
|
|
MemSet((char *) NewPage, 0, XLOG_BLCKSZ);
|
|
|
|
/*
|
|
* Fill the new page's header
|
|
*/
|
|
NewPage ->xlp_magic = XLOG_PAGE_MAGIC;
|
|
|
|
/* NewPage->xlp_info = 0; */ /* done by memset */
|
|
NewPage ->xlp_tli = ThisTimeLineID;
|
|
NewPage ->xlp_pageaddr.xlogid = NewPageEndPtr.xlogid;
|
|
NewPage ->xlp_pageaddr.xrecoff = NewPageEndPtr.xrecoff - XLOG_BLCKSZ;
|
|
|
|
/*
|
|
* If first page of an XLOG segment file, make it a long header.
|
|
*/
|
|
if ((NewPage->xlp_pageaddr.xrecoff % XLogSegSize) == 0)
|
|
{
|
|
XLogLongPageHeader NewLongPage = (XLogLongPageHeader) NewPage;
|
|
|
|
NewLongPage->xlp_sysid = ControlFile->system_identifier;
|
|
NewLongPage->xlp_seg_size = XLogSegSize;
|
|
NewLongPage->xlp_xlog_blcksz = XLOG_BLCKSZ;
|
|
NewPage ->xlp_info |= XLP_LONG_HEADER;
|
|
|
|
Insert->currpos = ((char *) NewPage) +SizeOfXLogLongPHD;
|
|
}
|
|
|
|
return update_needed;
|
|
}
|
|
|
|
/*
|
|
* Check whether we've consumed enough xlog space that a checkpoint is needed.
|
|
*
|
|
* Caller must have just finished filling the open log file (so that
|
|
* openLogId/openLogSeg are valid). We measure the distance from RedoRecPtr
|
|
* to the open log file and see if that exceeds CheckPointSegments.
|
|
*
|
|
* Note: it is caller's responsibility that RedoRecPtr is up-to-date.
|
|
*/
|
|
static bool
|
|
XLogCheckpointNeeded(void)
|
|
{
|
|
/*
|
|
* A straight computation of segment number could overflow 32 bits. Rather
|
|
* than assuming we have working 64-bit arithmetic, we compare the
|
|
* highest-order bits separately, and force a checkpoint immediately when
|
|
* they change.
|
|
*/
|
|
uint32 old_segno,
|
|
new_segno;
|
|
uint32 old_highbits,
|
|
new_highbits;
|
|
|
|
old_segno = (RedoRecPtr.xlogid % XLogSegSize) * XLogSegsPerFile +
|
|
(RedoRecPtr.xrecoff / XLogSegSize);
|
|
old_highbits = RedoRecPtr.xlogid / XLogSegSize;
|
|
new_segno = (openLogId % XLogSegSize) * XLogSegsPerFile + openLogSeg;
|
|
new_highbits = openLogId / XLogSegSize;
|
|
if (new_highbits != old_highbits ||
|
|
new_segno >= old_segno + (uint32) (CheckPointSegments - 1))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Write and/or fsync the log at least as far as WriteRqst indicates.
|
|
*
|
|
* If flexible == TRUE, we don't have to write as far as WriteRqst, but
|
|
* may stop at any convenient boundary (such as a cache or logfile boundary).
|
|
* This option allows us to avoid uselessly issuing multiple writes when a
|
|
* single one would do.
|
|
*
|
|
* If xlog_switch == TRUE, we are intending an xlog segment switch, so
|
|
* perform end-of-segment actions after writing the last page, even if
|
|
* it's not physically the end of its segment. (NB: this will work properly
|
|
* only if caller specifies WriteRqst == page-end and flexible == false,
|
|
* and there is some data to write.)
|
|
*
|
|
* Must be called with WALWriteLock held.
|
|
*/
|
|
static void
|
|
XLogWrite(XLogwrtRqst WriteRqst, bool flexible, bool xlog_switch)
|
|
{
|
|
XLogCtlWrite *Write = &XLogCtl->Write;
|
|
bool ispartialpage;
|
|
bool last_iteration;
|
|
bool finishing_seg;
|
|
bool use_existent;
|
|
int curridx;
|
|
int npages;
|
|
int startidx;
|
|
uint32 startoffset;
|
|
|
|
/* We should always be inside a critical section here */
|
|
Assert(CritSectionCount > 0);
|
|
|
|
/*
|
|
* Update local LogwrtResult (caller probably did this already, but...)
|
|
*/
|
|
LogwrtResult = Write->LogwrtResult;
|
|
|
|
/*
|
|
* Since successive pages in the xlog cache are consecutively allocated,
|
|
* we can usually gather multiple pages together and issue just one
|
|
* write() call. npages is the number of pages we have determined can be
|
|
* written together; startidx is the cache block index of the first one,
|
|
* and startoffset is the file offset at which it should go. The latter
|
|
* two variables are only valid when npages > 0, but we must initialize
|
|
* all of them to keep the compiler quiet.
|
|
*/
|
|
npages = 0;
|
|
startidx = 0;
|
|
startoffset = 0;
|
|
|
|
/*
|
|
* Within the loop, curridx is the cache block index of the page to
|
|
* consider writing. We advance Write->curridx only after successfully
|
|
* writing pages. (Right now, this refinement is useless since we are
|
|
* going to PANIC if any error occurs anyway; but someday it may come in
|
|
* useful.)
|
|
*/
|
|
curridx = Write->curridx;
|
|
|
|
while (XLByteLT(LogwrtResult.Write, WriteRqst.Write))
|
|
{
|
|
/*
|
|
* Make sure we're not ahead of the insert process. This could happen
|
|
* if we're passed a bogus WriteRqst.Write that is past the end of the
|
|
* last page that's been initialized by AdvanceXLInsertBuffer.
|
|
*/
|
|
if (!XLByteLT(LogwrtResult.Write, XLogCtl->xlblocks[curridx]))
|
|
elog(PANIC, "xlog write request %X/%X is past end of log %X/%X",
|
|
LogwrtResult.Write.xlogid, LogwrtResult.Write.xrecoff,
|
|
XLogCtl->xlblocks[curridx].xlogid,
|
|
XLogCtl->xlblocks[curridx].xrecoff);
|
|
|
|
/* Advance LogwrtResult.Write to end of current buffer page */
|
|
LogwrtResult.Write = XLogCtl->xlblocks[curridx];
|
|
ispartialpage = XLByteLT(WriteRqst.Write, LogwrtResult.Write);
|
|
|
|
if (!XLByteInPrevSeg(LogwrtResult.Write, openLogId, openLogSeg))
|
|
{
|
|
/*
|
|
* Switch to new logfile segment. We cannot have any pending
|
|
* pages here (since we dump what we have at segment end).
|
|
*/
|
|
Assert(npages == 0);
|
|
if (openLogFile >= 0)
|
|
XLogFileClose();
|
|
XLByteToPrevSeg(LogwrtResult.Write, openLogId, openLogSeg);
|
|
|
|
/* create/use new log file */
|
|
use_existent = true;
|
|
openLogFile = XLogFileInit(openLogId, openLogSeg,
|
|
&use_existent, true);
|
|
openLogOff = 0;
|
|
}
|
|
|
|
/* Make sure we have the current logfile open */
|
|
if (openLogFile < 0)
|
|
{
|
|
XLByteToPrevSeg(LogwrtResult.Write, openLogId, openLogSeg);
|
|
openLogFile = XLogFileOpen(openLogId, openLogSeg);
|
|
openLogOff = 0;
|
|
}
|
|
|
|
/* Add current page to the set of pending pages-to-dump */
|
|
if (npages == 0)
|
|
{
|
|
/* first of group */
|
|
startidx = curridx;
|
|
startoffset = (LogwrtResult.Write.xrecoff - XLOG_BLCKSZ) % XLogSegSize;
|
|
}
|
|
npages++;
|
|
|
|
/*
|
|
* Dump the set if this will be the last loop iteration, or if we are
|
|
* at the last page of the cache area (since the next page won't be
|
|
* contiguous in memory), or if we are at the end of the logfile
|
|
* segment.
|
|
*/
|
|
last_iteration = !XLByteLT(LogwrtResult.Write, WriteRqst.Write);
|
|
|
|
finishing_seg = !ispartialpage &&
|
|
(startoffset + npages * XLOG_BLCKSZ) >= XLogSegSize;
|
|
|
|
if (last_iteration ||
|
|
curridx == XLogCtl->XLogCacheBlck ||
|
|
finishing_seg)
|
|
{
|
|
char *from;
|
|
Size nbytes;
|
|
|
|
/* Need to seek in the file? */
|
|
if (openLogOff != startoffset)
|
|
{
|
|
if (lseek(openLogFile, (off_t) startoffset, SEEK_SET) < 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not seek in log file %u, "
|
|
"segment %u to offset %u: %m",
|
|
openLogId, openLogSeg, startoffset)));
|
|
openLogOff = startoffset;
|
|
}
|
|
|
|
/* OK to write the page(s) */
|
|
from = XLogCtl->pages + startidx * (Size) XLOG_BLCKSZ;
|
|
nbytes = npages * (Size) XLOG_BLCKSZ;
|
|
errno = 0;
|
|
if (write(openLogFile, from, nbytes) != nbytes)
|
|
{
|
|
/* if write didn't set errno, assume no disk space */
|
|
if (errno == 0)
|
|
errno = ENOSPC;
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to log file %u, segment %u "
|
|
"at offset %u, length %lu: %m",
|
|
openLogId, openLogSeg,
|
|
openLogOff, (unsigned long) nbytes)));
|
|
}
|
|
|
|
/* Update state for write */
|
|
openLogOff += nbytes;
|
|
Write->curridx = ispartialpage ? curridx : NextBufIdx(curridx);
|
|
npages = 0;
|
|
|
|
/*
|
|
* If we just wrote the whole last page of a logfile segment,
|
|
* fsync the segment immediately. This avoids having to go back
|
|
* and re-open prior segments when an fsync request comes along
|
|
* later. Doing it here ensures that one and only one backend will
|
|
* perform this fsync.
|
|
*
|
|
* We also do this if this is the last page written for an xlog
|
|
* switch.
|
|
*
|
|
* This is also the right place to notify the Archiver that the
|
|
* segment is ready to copy to archival storage, and to update the
|
|
* timer for archive_timeout, and to signal for a checkpoint if
|
|
* too many logfile segments have been used since the last
|
|
* checkpoint.
|
|
*/
|
|
if (finishing_seg || (xlog_switch && last_iteration))
|
|
{
|
|
issue_xlog_fsync(openLogFile, openLogId, openLogSeg);
|
|
LogwrtResult.Flush = LogwrtResult.Write; /* end of page */
|
|
|
|
if (XLogArchivingActive())
|
|
XLogArchiveNotifySeg(openLogId, openLogSeg);
|
|
|
|
Write->lastSegSwitchTime = (pg_time_t) time(NULL);
|
|
|
|
/*
|
|
* Signal bgwriter to start a checkpoint if we've consumed too
|
|
* much xlog since the last one. For speed, we first check
|
|
* using the local copy of RedoRecPtr, which might be out of
|
|
* date; if it looks like a checkpoint is needed, forcibly
|
|
* update RedoRecPtr and recheck.
|
|
*/
|
|
if (IsUnderPostmaster &&
|
|
XLogCheckpointNeeded())
|
|
{
|
|
(void) GetRedoRecPtr();
|
|
if (XLogCheckpointNeeded())
|
|
RequestCheckpoint(CHECKPOINT_CAUSE_XLOG);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ispartialpage)
|
|
{
|
|
/* Only asked to write a partial page */
|
|
LogwrtResult.Write = WriteRqst.Write;
|
|
break;
|
|
}
|
|
curridx = NextBufIdx(curridx);
|
|
|
|
/* If flexible, break out of loop as soon as we wrote something */
|
|
if (flexible && npages == 0)
|
|
break;
|
|
}
|
|
|
|
Assert(npages == 0);
|
|
Assert(curridx == Write->curridx);
|
|
|
|
/*
|
|
* If asked to flush, do so
|
|
*/
|
|
if (XLByteLT(LogwrtResult.Flush, WriteRqst.Flush) &&
|
|
XLByteLT(LogwrtResult.Flush, LogwrtResult.Write))
|
|
{
|
|
/*
|
|
* Could get here without iterating above loop, in which case we might
|
|
* have no open file or the wrong one. However, we do not need to
|
|
* fsync more than one file.
|
|
*/
|
|
if (sync_method != SYNC_METHOD_OPEN &&
|
|
sync_method != SYNC_METHOD_OPEN_DSYNC)
|
|
{
|
|
if (openLogFile >= 0 &&
|
|
!XLByteInPrevSeg(LogwrtResult.Write, openLogId, openLogSeg))
|
|
XLogFileClose();
|
|
if (openLogFile < 0)
|
|
{
|
|
XLByteToPrevSeg(LogwrtResult.Write, openLogId, openLogSeg);
|
|
openLogFile = XLogFileOpen(openLogId, openLogSeg);
|
|
openLogOff = 0;
|
|
}
|
|
issue_xlog_fsync(openLogFile, openLogId, openLogSeg);
|
|
}
|
|
LogwrtResult.Flush = LogwrtResult.Write;
|
|
}
|
|
|
|
/*
|
|
* Update shared-memory status
|
|
*
|
|
* We make sure that the shared 'request' values do not fall behind the
|
|
* 'result' values. This is not absolutely essential, but it saves some
|
|
* code in a couple of places.
|
|
*/
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
xlogctl->LogwrtResult = LogwrtResult;
|
|
if (XLByteLT(xlogctl->LogwrtRqst.Write, LogwrtResult.Write))
|
|
xlogctl->LogwrtRqst.Write = LogwrtResult.Write;
|
|
if (XLByteLT(xlogctl->LogwrtRqst.Flush, LogwrtResult.Flush))
|
|
xlogctl->LogwrtRqst.Flush = LogwrtResult.Flush;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
Write->LogwrtResult = LogwrtResult;
|
|
}
|
|
|
|
/*
|
|
* Record the LSN for an asynchronous transaction commit.
|
|
* (This should not be called for aborts, nor for synchronous commits.)
|
|
*/
|
|
void
|
|
XLogSetAsyncCommitLSN(XLogRecPtr asyncCommitLSN)
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
if (XLByteLT(xlogctl->asyncCommitLSN, asyncCommitLSN))
|
|
xlogctl->asyncCommitLSN = asyncCommitLSN;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
/*
|
|
* Advance minRecoveryPoint in control file.
|
|
*
|
|
* If we crash during recovery, we must reach this point again before the
|
|
* database is consistent.
|
|
*
|
|
* If 'force' is true, 'lsn' argument is ignored. Otherwise, minRecoveryPoint
|
|
* is only updated if it's not already greater than or equal to 'lsn'.
|
|
*/
|
|
static void
|
|
UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force)
|
|
{
|
|
/* Quick check using our local copy of the variable */
|
|
if (!updateMinRecoveryPoint || (!force && XLByteLE(lsn, minRecoveryPoint)))
|
|
return;
|
|
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
|
|
/* update local copy */
|
|
minRecoveryPoint = ControlFile->minRecoveryPoint;
|
|
|
|
/*
|
|
* An invalid minRecoveryPoint means that we need to recover all the WAL,
|
|
* i.e., we're doing crash recovery. We never modify the control file's
|
|
* value in that case, so we can short-circuit future checks here too.
|
|
*/
|
|
if (minRecoveryPoint.xlogid == 0 && minRecoveryPoint.xrecoff == 0)
|
|
updateMinRecoveryPoint = false;
|
|
else if (force || XLByteLT(minRecoveryPoint, lsn))
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
XLogRecPtr newMinRecoveryPoint;
|
|
|
|
/*
|
|
* To avoid having to update the control file too often, we update it
|
|
* all the way to the last record being replayed, even though 'lsn'
|
|
* would suffice for correctness. This also allows the 'force' case
|
|
* to not need a valid 'lsn' value.
|
|
*
|
|
* Another important reason for doing it this way is that the passed
|
|
* 'lsn' value could be bogus, i.e., past the end of available WAL,
|
|
* if the caller got it from a corrupted heap page. Accepting such
|
|
* a value as the min recovery point would prevent us from coming up
|
|
* at all. Instead, we just log a warning and continue with recovery.
|
|
* (See also the comments about corrupt LSNs in XLogFlush.)
|
|
*/
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
newMinRecoveryPoint = xlogctl->replayEndRecPtr;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
if (!force && XLByteLT(newMinRecoveryPoint, lsn))
|
|
elog(WARNING,
|
|
"xlog min recovery request %X/%X is past current point %X/%X",
|
|
lsn.xlogid, lsn.xrecoff,
|
|
newMinRecoveryPoint.xlogid, newMinRecoveryPoint.xrecoff);
|
|
|
|
/* update control file */
|
|
if (XLByteLT(ControlFile->minRecoveryPoint, newMinRecoveryPoint))
|
|
{
|
|
ControlFile->minRecoveryPoint = newMinRecoveryPoint;
|
|
UpdateControlFile();
|
|
minRecoveryPoint = newMinRecoveryPoint;
|
|
|
|
ereport(DEBUG2,
|
|
(errmsg("updated min recovery point to %X/%X",
|
|
minRecoveryPoint.xlogid, minRecoveryPoint.xrecoff)));
|
|
}
|
|
}
|
|
LWLockRelease(ControlFileLock);
|
|
}
|
|
|
|
/*
|
|
* Ensure that all XLOG data through the given position is flushed to disk.
|
|
*
|
|
* NOTE: this differs from XLogWrite mainly in that the WALWriteLock is not
|
|
* already held, and we try to avoid acquiring it if possible.
|
|
*/
|
|
void
|
|
XLogFlush(XLogRecPtr record)
|
|
{
|
|
XLogRecPtr WriteRqstPtr;
|
|
XLogwrtRqst WriteRqst;
|
|
|
|
/*
|
|
* During REDO, we are reading not writing WAL. Therefore, instead of
|
|
* trying to flush the WAL, we should update minRecoveryPoint instead.
|
|
* We test XLogInsertAllowed(), not InRecovery, because we need the
|
|
* bgwriter to act this way too, and because when the bgwriter tries
|
|
* to write the end-of-recovery checkpoint, it should indeed flush.
|
|
*/
|
|
if (!XLogInsertAllowed())
|
|
{
|
|
UpdateMinRecoveryPoint(record, false);
|
|
return;
|
|
}
|
|
|
|
/* Quick exit if already known flushed */
|
|
if (XLByteLE(record, LogwrtResult.Flush))
|
|
return;
|
|
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG)
|
|
elog(LOG, "xlog flush request %X/%X; write %X/%X; flush %X/%X",
|
|
record.xlogid, record.xrecoff,
|
|
LogwrtResult.Write.xlogid, LogwrtResult.Write.xrecoff,
|
|
LogwrtResult.Flush.xlogid, LogwrtResult.Flush.xrecoff);
|
|
#endif
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/*
|
|
* Since fsync is usually a horribly expensive operation, we try to
|
|
* piggyback as much data as we can on each fsync: if we see any more data
|
|
* entered into the xlog buffer, we'll write and fsync that too, so that
|
|
* the final value of LogwrtResult.Flush is as large as possible. This
|
|
* gives us some chance of avoiding another fsync immediately after.
|
|
*/
|
|
|
|
/* initialize to given target; may increase below */
|
|
WriteRqstPtr = record;
|
|
|
|
/* read LogwrtResult and update local state */
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
if (XLByteLT(WriteRqstPtr, xlogctl->LogwrtRqst.Write))
|
|
WriteRqstPtr = xlogctl->LogwrtRqst.Write;
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
/* done already? */
|
|
if (!XLByteLE(record, LogwrtResult.Flush))
|
|
{
|
|
/* now wait for the write lock */
|
|
LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
|
|
LogwrtResult = XLogCtl->Write.LogwrtResult;
|
|
if (!XLByteLE(record, LogwrtResult.Flush))
|
|
{
|
|
/* try to write/flush later additions to XLOG as well */
|
|
if (LWLockConditionalAcquire(WALInsertLock, LW_EXCLUSIVE))
|
|
{
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
uint32 freespace = INSERT_FREESPACE(Insert);
|
|
|
|
if (freespace < SizeOfXLogRecord) /* buffer is full */
|
|
WriteRqstPtr = XLogCtl->xlblocks[Insert->curridx];
|
|
else
|
|
{
|
|
WriteRqstPtr = XLogCtl->xlblocks[Insert->curridx];
|
|
WriteRqstPtr.xrecoff -= freespace;
|
|
}
|
|
LWLockRelease(WALInsertLock);
|
|
WriteRqst.Write = WriteRqstPtr;
|
|
WriteRqst.Flush = WriteRqstPtr;
|
|
}
|
|
else
|
|
{
|
|
WriteRqst.Write = WriteRqstPtr;
|
|
WriteRqst.Flush = record;
|
|
}
|
|
XLogWrite(WriteRqst, false, false);
|
|
}
|
|
LWLockRelease(WALWriteLock);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
|
|
/*
|
|
* If we still haven't flushed to the request point then we have a
|
|
* problem; most likely, the requested flush point is past end of XLOG.
|
|
* This has been seen to occur when a disk page has a corrupted LSN.
|
|
*
|
|
* Formerly we treated this as a PANIC condition, but that hurts the
|
|
* system's robustness rather than helping it: we do not want to take down
|
|
* the whole system due to corruption on one data page. In particular, if
|
|
* the bad page is encountered again during recovery then we would be
|
|
* unable to restart the database at all! (This scenario actually
|
|
* happened in the field several times with 7.1 releases.) As of 8.4,
|
|
* bad LSNs encountered during recovery are UpdateMinRecoveryPoint's
|
|
* problem; the only time we can reach here during recovery is while
|
|
* flushing the end-of-recovery checkpoint record, and we don't expect
|
|
* that to have a bad LSN.
|
|
*
|
|
* Note that for calls from xact.c, the ERROR will
|
|
* be promoted to PANIC since xact.c calls this routine inside a critical
|
|
* section. However, calls from bufmgr.c are not within critical sections
|
|
* and so we will not force a restart for a bad LSN on a data page.
|
|
*/
|
|
if (XLByteLT(LogwrtResult.Flush, record))
|
|
elog(ERROR,
|
|
"xlog flush request %X/%X is not satisfied --- flushed only to %X/%X",
|
|
record.xlogid, record.xrecoff,
|
|
LogwrtResult.Flush.xlogid, LogwrtResult.Flush.xrecoff);
|
|
}
|
|
|
|
/*
|
|
* Flush xlog, but without specifying exactly where to flush to.
|
|
*
|
|
* We normally flush only completed blocks; but if there is nothing to do on
|
|
* that basis, we check for unflushed async commits in the current incomplete
|
|
* block, and flush through the latest one of those. Thus, if async commits
|
|
* are not being used, we will flush complete blocks only. We can guarantee
|
|
* that async commits reach disk after at most three cycles; normally only
|
|
* one or two. (We allow XLogWrite to write "flexibly", meaning it can stop
|
|
* at the end of the buffer ring; this makes a difference only with very high
|
|
* load or long wal_writer_delay, but imposes one extra cycle for the worst
|
|
* case for async commits.)
|
|
*
|
|
* This routine is invoked periodically by the background walwriter process.
|
|
*/
|
|
void
|
|
XLogBackgroundFlush(void)
|
|
{
|
|
XLogRecPtr WriteRqstPtr;
|
|
bool flexible = true;
|
|
|
|
/* XLOG doesn't need flushing during recovery */
|
|
if (RecoveryInProgress())
|
|
return;
|
|
|
|
/* read LogwrtResult and update local state */
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
WriteRqstPtr = xlogctl->LogwrtRqst.Write;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
/* back off to last completed page boundary */
|
|
WriteRqstPtr.xrecoff -= WriteRqstPtr.xrecoff % XLOG_BLCKSZ;
|
|
|
|
/* if we have already flushed that far, consider async commit records */
|
|
if (XLByteLE(WriteRqstPtr, LogwrtResult.Flush))
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
WriteRqstPtr = xlogctl->asyncCommitLSN;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
flexible = false; /* ensure it all gets written */
|
|
}
|
|
|
|
/* Done if already known flushed */
|
|
if (XLByteLE(WriteRqstPtr, LogwrtResult.Flush))
|
|
return;
|
|
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG)
|
|
elog(LOG, "xlog bg flush request %X/%X; write %X/%X; flush %X/%X",
|
|
WriteRqstPtr.xlogid, WriteRqstPtr.xrecoff,
|
|
LogwrtResult.Write.xlogid, LogwrtResult.Write.xrecoff,
|
|
LogwrtResult.Flush.xlogid, LogwrtResult.Flush.xrecoff);
|
|
#endif
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/* now wait for the write lock */
|
|
LWLockAcquire(WALWriteLock, LW_EXCLUSIVE);
|
|
LogwrtResult = XLogCtl->Write.LogwrtResult;
|
|
if (!XLByteLE(WriteRqstPtr, LogwrtResult.Flush))
|
|
{
|
|
XLogwrtRqst WriteRqst;
|
|
|
|
WriteRqst.Write = WriteRqstPtr;
|
|
WriteRqst.Flush = WriteRqstPtr;
|
|
XLogWrite(WriteRqst, flexible, false);
|
|
}
|
|
LWLockRelease(WALWriteLock);
|
|
|
|
END_CRIT_SECTION();
|
|
}
|
|
|
|
/*
|
|
* Test whether XLOG data has been flushed up to (at least) the given position.
|
|
*
|
|
* Returns true if a flush is still needed. (It may be that someone else
|
|
* is already in process of flushing that far, however.)
|
|
*/
|
|
bool
|
|
XLogNeedsFlush(XLogRecPtr record)
|
|
{
|
|
/*
|
|
* During recovery, we don't flush WAL but update minRecoveryPoint
|
|
* instead. So "needs flush" is taken to mean whether minRecoveryPoint
|
|
* would need to be updated.
|
|
*/
|
|
if (RecoveryInProgress())
|
|
{
|
|
/* Quick exit if already known updated */
|
|
if (XLByteLE(record, minRecoveryPoint) || !updateMinRecoveryPoint)
|
|
return false;
|
|
|
|
/*
|
|
* Update local copy of minRecoveryPoint. But if the lock is busy,
|
|
* just return a conservative guess.
|
|
*/
|
|
if (!LWLockConditionalAcquire(ControlFileLock, LW_SHARED))
|
|
return true;
|
|
minRecoveryPoint = ControlFile->minRecoveryPoint;
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
/*
|
|
* An invalid minRecoveryPoint means that we need to recover all the WAL,
|
|
* i.e., we're doing crash recovery. We never modify the control file's
|
|
* value in that case, so we can short-circuit future checks here too.
|
|
*/
|
|
if (minRecoveryPoint.xlogid == 0 && minRecoveryPoint.xrecoff == 0)
|
|
updateMinRecoveryPoint = false;
|
|
|
|
/* check again */
|
|
if (XLByteLE(record, minRecoveryPoint) || !updateMinRecoveryPoint)
|
|
return false;
|
|
else
|
|
return true;
|
|
}
|
|
|
|
/* Quick exit if already known flushed */
|
|
if (XLByteLE(record, LogwrtResult.Flush))
|
|
return false;
|
|
|
|
/* read LogwrtResult and update local state */
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
/* check again */
|
|
if (XLByteLE(record, LogwrtResult.Flush))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Create a new XLOG file segment, or open a pre-existing one.
|
|
*
|
|
* log, seg: identify segment to be created/opened.
|
|
*
|
|
* *use_existent: if TRUE, OK to use a pre-existing file (else, any
|
|
* pre-existing file will be deleted). On return, TRUE if a pre-existing
|
|
* file was used.
|
|
*
|
|
* use_lock: if TRUE, acquire ControlFileLock while moving file into
|
|
* place. This should be TRUE except during bootstrap log creation. The
|
|
* caller must *not* hold the lock at call.
|
|
*
|
|
* Returns FD of opened file.
|
|
*
|
|
* Note: errors here are ERROR not PANIC because we might or might not be
|
|
* inside a critical section (eg, during checkpoint there is no reason to
|
|
* take down the system on failure). They will promote to PANIC if we are
|
|
* in a critical section.
|
|
*/
|
|
int
|
|
XLogFileInit(uint32 log, uint32 seg,
|
|
bool *use_existent, bool use_lock)
|
|
{
|
|
char path[MAXPGPATH];
|
|
char tmppath[MAXPGPATH];
|
|
char *zbuffer;
|
|
uint32 installed_log;
|
|
uint32 installed_seg;
|
|
int max_advance;
|
|
int fd;
|
|
int nbytes;
|
|
|
|
XLogFilePath(path, ThisTimeLineID, log, seg);
|
|
|
|
/*
|
|
* Try to use existent file (checkpoint maker may have created it already)
|
|
*/
|
|
if (*use_existent)
|
|
{
|
|
fd = BasicOpenFile(path, O_RDWR | PG_BINARY | get_sync_bit(sync_method),
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
}
|
|
else
|
|
return fd;
|
|
}
|
|
|
|
/*
|
|
* Initialize an empty (all zeroes) segment. NOTE: it is possible that
|
|
* another process is doing the same thing. If so, we will end up
|
|
* pre-creating an extra log segment. That seems OK, and better than
|
|
* holding the lock throughout this lengthy process.
|
|
*/
|
|
elog(DEBUG2, "creating and filling new WAL file");
|
|
|
|
snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
|
|
|
|
unlink(tmppath);
|
|
|
|
/* do not use get_sync_bit() here --- want to fsync only at end of fill */
|
|
fd = BasicOpenFile(tmppath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create file \"%s\": %m", tmppath)));
|
|
|
|
/*
|
|
* Zero-fill the file. We have to do this the hard way to ensure that all
|
|
* the file space has really been allocated --- on platforms that allow
|
|
* "holes" in files, just seeking to the end doesn't allocate intermediate
|
|
* space. This way, we know that we have all the space and (after the
|
|
* fsync below) that all the indirect blocks are down on disk. Therefore,
|
|
* fdatasync(2) or O_DSYNC will be sufficient to sync future writes to the
|
|
* log file.
|
|
*
|
|
* Note: palloc zbuffer, instead of just using a local char array, to
|
|
* ensure it is reasonably well-aligned; this may save a few cycles
|
|
* transferring data to the kernel.
|
|
*/
|
|
zbuffer = (char *) palloc0(XLOG_BLCKSZ);
|
|
for (nbytes = 0; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
|
|
{
|
|
errno = 0;
|
|
if ((int) write(fd, zbuffer, XLOG_BLCKSZ) != (int) XLOG_BLCKSZ)
|
|
{
|
|
int save_errno = errno;
|
|
|
|
/*
|
|
* If we fail to make the file, delete it to release disk space
|
|
*/
|
|
unlink(tmppath);
|
|
/* if write didn't set errno, assume problem is no disk space */
|
|
errno = save_errno ? save_errno : ENOSPC;
|
|
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to file \"%s\": %m", tmppath)));
|
|
}
|
|
}
|
|
pfree(zbuffer);
|
|
|
|
if (pg_fsync(fd) != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync file \"%s\": %m", tmppath)));
|
|
|
|
if (close(fd))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close file \"%s\": %m", tmppath)));
|
|
|
|
/*
|
|
* Now move the segment into place with its final name.
|
|
*
|
|
* If caller didn't want to use a pre-existing file, get rid of any
|
|
* pre-existing file. Otherwise, cope with possibility that someone else
|
|
* has created the file while we were filling ours: if so, use ours to
|
|
* pre-create a future log segment.
|
|
*/
|
|
installed_log = log;
|
|
installed_seg = seg;
|
|
max_advance = XLOGfileslop;
|
|
if (!InstallXLogFileSegment(&installed_log, &installed_seg, tmppath,
|
|
*use_existent, &max_advance,
|
|
use_lock))
|
|
{
|
|
/*
|
|
* No need for any more future segments, or InstallXLogFileSegment()
|
|
* failed to rename the file into place. If the rename failed, opening
|
|
* the file below will fail.
|
|
*/
|
|
unlink(tmppath);
|
|
}
|
|
|
|
/* Set flag to tell caller there was no existent file */
|
|
*use_existent = false;
|
|
|
|
/* Now open original target segment (might not be file I just made) */
|
|
fd = BasicOpenFile(path, O_RDWR | PG_BINARY | get_sync_bit(sync_method),
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
|
|
elog(DEBUG2, "done creating and filling new WAL file");
|
|
|
|
return fd;
|
|
}
|
|
|
|
/*
|
|
* Create a new XLOG file segment by copying a pre-existing one.
|
|
*
|
|
* log, seg: identify segment to be created.
|
|
*
|
|
* srcTLI, srclog, srcseg: identify segment to be copied (could be from
|
|
* a different timeline)
|
|
*
|
|
* Currently this is only used during recovery, and so there are no locking
|
|
* considerations. But we should be just as tense as XLogFileInit to avoid
|
|
* emplacing a bogus file.
|
|
*/
|
|
static void
|
|
XLogFileCopy(uint32 log, uint32 seg,
|
|
TimeLineID srcTLI, uint32 srclog, uint32 srcseg)
|
|
{
|
|
char path[MAXPGPATH];
|
|
char tmppath[MAXPGPATH];
|
|
char buffer[XLOG_BLCKSZ];
|
|
int srcfd;
|
|
int fd;
|
|
int nbytes;
|
|
|
|
/*
|
|
* Open the source file
|
|
*/
|
|
XLogFilePath(path, srcTLI, srclog, srcseg);
|
|
srcfd = BasicOpenFile(path, O_RDONLY | PG_BINARY, 0);
|
|
if (srcfd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\": %m", path)));
|
|
|
|
/*
|
|
* Copy into a temp file name.
|
|
*/
|
|
snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
|
|
|
|
unlink(tmppath);
|
|
|
|
/* do not use get_sync_bit() here --- want to fsync only at end of fill */
|
|
fd = BasicOpenFile(tmppath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create file \"%s\": %m", tmppath)));
|
|
|
|
/*
|
|
* Do the data copying.
|
|
*/
|
|
for (nbytes = 0; nbytes < XLogSegSize; nbytes += sizeof(buffer))
|
|
{
|
|
errno = 0;
|
|
if ((int) read(srcfd, buffer, sizeof(buffer)) != (int) sizeof(buffer))
|
|
{
|
|
if (errno != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m", path)));
|
|
else
|
|
ereport(ERROR,
|
|
(errmsg("not enough data in file \"%s\"", path)));
|
|
}
|
|
errno = 0;
|
|
if ((int) write(fd, buffer, sizeof(buffer)) != (int) sizeof(buffer))
|
|
{
|
|
int save_errno = errno;
|
|
|
|
/*
|
|
* If we fail to make the file, delete it to release disk space
|
|
*/
|
|
unlink(tmppath);
|
|
/* if write didn't set errno, assume problem is no disk space */
|
|
errno = save_errno ? save_errno : ENOSPC;
|
|
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to file \"%s\": %m", tmppath)));
|
|
}
|
|
}
|
|
|
|
if (pg_fsync(fd) != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync file \"%s\": %m", tmppath)));
|
|
|
|
if (close(fd))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close file \"%s\": %m", tmppath)));
|
|
|
|
close(srcfd);
|
|
|
|
/*
|
|
* Now move the segment into place with its final name.
|
|
*/
|
|
if (!InstallXLogFileSegment(&log, &seg, tmppath, false, NULL, false))
|
|
elog(ERROR, "InstallXLogFileSegment should not have failed");
|
|
}
|
|
|
|
/*
|
|
* Install a new XLOG segment file as a current or future log segment.
|
|
*
|
|
* This is used both to install a newly-created segment (which has a temp
|
|
* filename while it's being created) and to recycle an old segment.
|
|
*
|
|
* *log, *seg: identify segment to install as (or first possible target).
|
|
* When find_free is TRUE, these are modified on return to indicate the
|
|
* actual installation location or last segment searched.
|
|
*
|
|
* tmppath: initial name of file to install. It will be renamed into place.
|
|
*
|
|
* find_free: if TRUE, install the new segment at the first empty log/seg
|
|
* number at or after the passed numbers. If FALSE, install the new segment
|
|
* exactly where specified, deleting any existing segment file there.
|
|
*
|
|
* *max_advance: maximum number of log/seg slots to advance past the starting
|
|
* point. Fail if no free slot is found in this range. On return, reduced
|
|
* by the number of slots skipped over. (Irrelevant, and may be NULL,
|
|
* when find_free is FALSE.)
|
|
*
|
|
* use_lock: if TRUE, acquire ControlFileLock while moving file into
|
|
* place. This should be TRUE except during bootstrap log creation. The
|
|
* caller must *not* hold the lock at call.
|
|
*
|
|
* Returns TRUE if the file was installed successfully. FALSE indicates that
|
|
* max_advance limit was exceeded, or an error occurred while renaming the
|
|
* file into place.
|
|
*/
|
|
static bool
|
|
InstallXLogFileSegment(uint32 *log, uint32 *seg, char *tmppath,
|
|
bool find_free, int *max_advance,
|
|
bool use_lock)
|
|
{
|
|
char path[MAXPGPATH];
|
|
struct stat stat_buf;
|
|
|
|
XLogFilePath(path, ThisTimeLineID, *log, *seg);
|
|
|
|
/*
|
|
* We want to be sure that only one process does this at a time.
|
|
*/
|
|
if (use_lock)
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
|
|
if (!find_free)
|
|
{
|
|
/* Force installation: get rid of any pre-existing segment file */
|
|
unlink(path);
|
|
}
|
|
else
|
|
{
|
|
/* Find a free slot to put it in */
|
|
while (stat(path, &stat_buf) == 0)
|
|
{
|
|
if (*max_advance <= 0)
|
|
{
|
|
/* Failed to find a free slot within specified range */
|
|
if (use_lock)
|
|
LWLockRelease(ControlFileLock);
|
|
return false;
|
|
}
|
|
NextLogSeg(*log, *seg);
|
|
(*max_advance)--;
|
|
XLogFilePath(path, ThisTimeLineID, *log, *seg);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Prefer link() to rename() here just to be really sure that we don't
|
|
* overwrite an existing logfile. However, there shouldn't be one, so
|
|
* rename() is an acceptable substitute except for the truly paranoid.
|
|
*/
|
|
#if HAVE_WORKING_LINK
|
|
if (link(tmppath, path) < 0)
|
|
{
|
|
if (use_lock)
|
|
LWLockRelease(ControlFileLock);
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not link file \"%s\" to \"%s\" (initialization of log file %u, segment %u): %m",
|
|
tmppath, path, *log, *seg)));
|
|
return false;
|
|
}
|
|
unlink(tmppath);
|
|
#else
|
|
if (rename(tmppath, path) < 0)
|
|
{
|
|
if (use_lock)
|
|
LWLockRelease(ControlFileLock);
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename file \"%s\" to \"%s\" (initialization of log file %u, segment %u): %m",
|
|
tmppath, path, *log, *seg)));
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
if (use_lock)
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Open a pre-existing logfile segment for writing.
|
|
*/
|
|
int
|
|
XLogFileOpen(uint32 log, uint32 seg)
|
|
{
|
|
char path[MAXPGPATH];
|
|
int fd;
|
|
|
|
XLogFilePath(path, ThisTimeLineID, log, seg);
|
|
|
|
fd = BasicOpenFile(path, O_RDWR | PG_BINARY | get_sync_bit(sync_method),
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
|
|
return fd;
|
|
}
|
|
|
|
/*
|
|
* Open a logfile segment for reading (during recovery).
|
|
*
|
|
* If fromArchive is true, the segment is retrieved from archive, otherwise
|
|
* it's read from pg_xlog.
|
|
*/
|
|
static int
|
|
XLogFileRead(uint32 log, uint32 seg, int emode, TimeLineID tli,
|
|
bool fromArchive, bool notfoundOk)
|
|
{
|
|
char xlogfname[MAXFNAMELEN];
|
|
char activitymsg[MAXFNAMELEN + 16];
|
|
char path[MAXPGPATH];
|
|
int fd;
|
|
|
|
XLogFileName(xlogfname, tli, log, seg);
|
|
|
|
if (fromArchive)
|
|
{
|
|
/* Report recovery progress in PS display */
|
|
snprintf(activitymsg, sizeof(activitymsg), "waiting for %s",
|
|
xlogfname);
|
|
set_ps_display(activitymsg, false);
|
|
|
|
restoredFromArchive = RestoreArchivedFile(path, xlogfname,
|
|
"RECOVERYXLOG",
|
|
XLogSegSize);
|
|
if (!restoredFromArchive)
|
|
return -1;
|
|
}
|
|
else
|
|
{
|
|
XLogFilePath(path, tli, log, seg);
|
|
restoredFromArchive = false;
|
|
}
|
|
|
|
fd = BasicOpenFile(path, O_RDONLY | PG_BINARY, 0);
|
|
if (fd >= 0)
|
|
{
|
|
/* Success! */
|
|
curFileTLI = tli;
|
|
|
|
/* Report recovery progress in PS display */
|
|
snprintf(activitymsg, sizeof(activitymsg), "recovering %s",
|
|
xlogfname);
|
|
set_ps_display(activitymsg, false);
|
|
|
|
return fd;
|
|
}
|
|
if (errno != ENOENT || !notfoundOk) /* unexpected failure? */
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Open a logfile segment for reading (during recovery).
|
|
*
|
|
* This version searches for the segment with any TLI listed in expectedTLIs.
|
|
* If not in StandbyMode and fromArchive is true, the segment is also
|
|
* searched in pg_xlog if not found in archive.
|
|
*/
|
|
static int
|
|
XLogFileReadAnyTLI(uint32 log, uint32 seg, int emode, bool fromArchive)
|
|
{
|
|
char path[MAXPGPATH];
|
|
ListCell *cell;
|
|
int fd;
|
|
|
|
/*
|
|
* Loop looking for a suitable timeline ID: we might need to read any of
|
|
* the timelines listed in expectedTLIs.
|
|
*
|
|
* We expect curFileTLI on entry to be the TLI of the preceding file in
|
|
* sequence, or 0 if there was no predecessor. We do not allow curFileTLI
|
|
* to go backwards; this prevents us from picking up the wrong file when a
|
|
* parent timeline extends to higher segment numbers than the child we
|
|
* want to read.
|
|
*/
|
|
foreach(cell, expectedTLIs)
|
|
{
|
|
TimeLineID tli = (TimeLineID) lfirst_int(cell);
|
|
|
|
if (tli < curFileTLI)
|
|
break; /* don't bother looking at too-old TLIs */
|
|
|
|
fd = XLogFileRead(log, seg, emode, tli, fromArchive, true);
|
|
if (fd != -1)
|
|
return fd;
|
|
|
|
/*
|
|
* If not in StandbyMode, fall back to searching pg_xlog. In
|
|
* StandbyMode we're streaming segments from the primary to pg_xlog,
|
|
* and we mustn't confuse the (possibly partial) segments in pg_xlog
|
|
* with complete segments ready to be applied. We rather wait for
|
|
* the records to arrive through streaming.
|
|
*/
|
|
if (!StandbyMode && fromArchive)
|
|
{
|
|
fd = XLogFileRead(log, seg, emode, tli, false, true);
|
|
if (fd != -1)
|
|
return fd;
|
|
}
|
|
}
|
|
|
|
/* Couldn't find it. For simplicity, complain about front timeline */
|
|
XLogFilePath(path, recoveryTargetTLI, log, seg);
|
|
errno = ENOENT;
|
|
ereport(emode,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Close the current logfile segment for writing.
|
|
*/
|
|
static void
|
|
XLogFileClose(void)
|
|
{
|
|
Assert(openLogFile >= 0);
|
|
|
|
/*
|
|
* WAL segment files will not be re-read in normal operation, so we advise
|
|
* the OS to release any cached pages. But do not do so if WAL archiving
|
|
* or streaming is active, because archiver and walsender process could use
|
|
* the cache to read the WAL segment. Also, don't bother with it if we
|
|
* are using O_DIRECT, since the kernel is presumably not caching in that
|
|
* case.
|
|
*/
|
|
#if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
|
|
if (!XLogIsNeeded() &&
|
|
(get_sync_bit(sync_method) & PG_O_DIRECT) == 0)
|
|
(void) posix_fadvise(openLogFile, 0, 0, POSIX_FADV_DONTNEED);
|
|
#endif
|
|
|
|
if (close(openLogFile))
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
openLogFile = -1;
|
|
}
|
|
|
|
/*
|
|
* Attempt to retrieve the specified file from off-line archival storage.
|
|
* If successful, fill "path" with its complete path (note that this will be
|
|
* a temp file name that doesn't follow the normal naming convention), and
|
|
* return TRUE.
|
|
*
|
|
* If not successful, fill "path" with the name of the normal on-line file
|
|
* (which may or may not actually exist, but we'll try to use it), and return
|
|
* FALSE.
|
|
*
|
|
* For fixed-size files, the caller may pass the expected size as an
|
|
* additional crosscheck on successful recovery. If the file size is not
|
|
* known, set expectedSize = 0.
|
|
*/
|
|
static bool
|
|
RestoreArchivedFile(char *path, const char *xlogfname,
|
|
const char *recovername, off_t expectedSize)
|
|
{
|
|
char xlogpath[MAXPGPATH];
|
|
char xlogRestoreCmd[MAXPGPATH];
|
|
char lastRestartPointFname[MAXPGPATH];
|
|
char *dp;
|
|
char *endp;
|
|
const char *sp;
|
|
int rc;
|
|
bool signaled;
|
|
struct stat stat_buf;
|
|
uint32 restartLog;
|
|
uint32 restartSeg;
|
|
|
|
/* In standby mode, restore_command might not be supplied */
|
|
if (recoveryRestoreCommand == NULL)
|
|
goto not_available;
|
|
|
|
/*
|
|
* When doing archive recovery, we always prefer an archived log file even
|
|
* if a file of the same name exists in XLOGDIR. The reason is that the
|
|
* file in XLOGDIR could be an old, un-filled or partly-filled version
|
|
* that was copied and restored as part of backing up $PGDATA.
|
|
*
|
|
* We could try to optimize this slightly by checking the local copy
|
|
* lastchange timestamp against the archived copy, but we have no API to
|
|
* do this, nor can we guarantee that the lastchange timestamp was
|
|
* preserved correctly when we copied to archive. Our aim is robustness,
|
|
* so we elect not to do this.
|
|
*
|
|
* If we cannot obtain the log file from the archive, however, we will try
|
|
* to use the XLOGDIR file if it exists. This is so that we can make use
|
|
* of log segments that weren't yet transferred to the archive.
|
|
*
|
|
* Notice that we don't actually overwrite any files when we copy back
|
|
* from archive because the recoveryRestoreCommand may inadvertently
|
|
* restore inappropriate xlogs, or they may be corrupt, so we may wish to
|
|
* fallback to the segments remaining in current XLOGDIR later. The
|
|
* copy-from-archive filename is always the same, ensuring that we don't
|
|
* run out of disk space on long recoveries.
|
|
*/
|
|
snprintf(xlogpath, MAXPGPATH, XLOGDIR "/%s", recovername);
|
|
|
|
/*
|
|
* Make sure there is no existing file named recovername.
|
|
*/
|
|
if (stat(xlogpath, &stat_buf) != 0)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not stat file \"%s\": %m",
|
|
xlogpath)));
|
|
}
|
|
else
|
|
{
|
|
if (unlink(xlogpath) != 0)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not remove file \"%s\": %m",
|
|
xlogpath)));
|
|
}
|
|
|
|
/*
|
|
* Calculate the archive file cutoff point for use during log shipping
|
|
* replication. All files earlier than this point can be deleted from the
|
|
* archive, though there is no requirement to do so.
|
|
*
|
|
* We initialise this with the filename of an InvalidXLogRecPtr, which
|
|
* will prevent the deletion of any WAL files from the archive because of
|
|
* the alphabetic sorting property of WAL filenames.
|
|
*
|
|
* Once we have successfully located the redo pointer of the checkpoint
|
|
* from which we start recovery we never request a file prior to the redo
|
|
* pointer of the last restartpoint. When redo begins we know that we have
|
|
* successfully located it, so there is no need for additional status
|
|
* flags to signify the point when we can begin deleting WAL files from
|
|
* the archive.
|
|
*/
|
|
if (InRedo)
|
|
{
|
|
XLByteToSeg(ControlFile->checkPointCopy.redo,
|
|
restartLog, restartSeg);
|
|
XLogFileName(lastRestartPointFname,
|
|
ControlFile->checkPointCopy.ThisTimeLineID,
|
|
restartLog, restartSeg);
|
|
/* we shouldn't need anything earlier than last restart point */
|
|
Assert(strcmp(lastRestartPointFname, xlogfname) <= 0);
|
|
}
|
|
else
|
|
XLogFileName(lastRestartPointFname, 0, 0, 0);
|
|
|
|
/*
|
|
* construct the command to be executed
|
|
*/
|
|
dp = xlogRestoreCmd;
|
|
endp = xlogRestoreCmd + MAXPGPATH - 1;
|
|
*endp = '\0';
|
|
|
|
for (sp = recoveryRestoreCommand; *sp; sp++)
|
|
{
|
|
if (*sp == '%')
|
|
{
|
|
switch (sp[1])
|
|
{
|
|
case 'p':
|
|
/* %p: relative path of target file */
|
|
sp++;
|
|
StrNCpy(dp, xlogpath, endp - dp);
|
|
make_native_path(dp);
|
|
dp += strlen(dp);
|
|
break;
|
|
case 'f':
|
|
/* %f: filename of desired file */
|
|
sp++;
|
|
StrNCpy(dp, xlogfname, endp - dp);
|
|
dp += strlen(dp);
|
|
break;
|
|
case 'r':
|
|
/* %r: filename of last restartpoint */
|
|
sp++;
|
|
StrNCpy(dp, lastRestartPointFname, endp - dp);
|
|
dp += strlen(dp);
|
|
break;
|
|
case '%':
|
|
/* convert %% to a single % */
|
|
sp++;
|
|
if (dp < endp)
|
|
*dp++ = *sp;
|
|
break;
|
|
default:
|
|
/* otherwise treat the % as not special */
|
|
if (dp < endp)
|
|
*dp++ = *sp;
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (dp < endp)
|
|
*dp++ = *sp;
|
|
}
|
|
}
|
|
*dp = '\0';
|
|
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("executing restore command \"%s\"",
|
|
xlogRestoreCmd)));
|
|
|
|
/*
|
|
* Set in_restore_command to tell the signal handler that we should exit
|
|
* right away on SIGTERM. We know that we're at a safe point to do that.
|
|
* Check if we had already received the signal, so that we don't miss a
|
|
* shutdown request received just before this.
|
|
*/
|
|
in_restore_command = true;
|
|
if (shutdown_requested)
|
|
proc_exit(1);
|
|
|
|
/*
|
|
* Copy xlog from archival storage to XLOGDIR
|
|
*/
|
|
rc = system(xlogRestoreCmd);
|
|
|
|
in_restore_command = false;
|
|
|
|
if (rc == 0)
|
|
{
|
|
/*
|
|
* command apparently succeeded, but let's make sure the file is
|
|
* really there now and has the correct size.
|
|
*/
|
|
if (stat(xlogpath, &stat_buf) == 0)
|
|
{
|
|
if (expectedSize > 0 && stat_buf.st_size != expectedSize)
|
|
{
|
|
int elevel;
|
|
|
|
/*
|
|
* If we find a partial file in standby mode, we assume it's
|
|
* because it's just being copied to the archive, and keep
|
|
* trying.
|
|
*
|
|
* Otherwise treat a wrong-sized file as FATAL to ensure the
|
|
* DBA would notice it, but is that too strong? We could try
|
|
* to plow ahead with a local copy of the file ... but the
|
|
* problem is that there probably isn't one, and we'd
|
|
* incorrectly conclude we've reached the end of WAL and
|
|
* we're done recovering ...
|
|
*/
|
|
if (StandbyMode && stat_buf.st_size < expectedSize)
|
|
elevel = DEBUG1;
|
|
else
|
|
elevel = FATAL;
|
|
ereport(elevel,
|
|
(errmsg("archive file \"%s\" has wrong size: %lu instead of %lu",
|
|
xlogfname,
|
|
(unsigned long) stat_buf.st_size,
|
|
(unsigned long) expectedSize)));
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("restored log file \"%s\" from archive",
|
|
xlogfname)));
|
|
strcpy(path, xlogpath);
|
|
return true;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* stat failed */
|
|
if (errno != ENOENT)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not stat file \"%s\": %m",
|
|
xlogpath)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remember, we rollforward UNTIL the restore fails so failure here is
|
|
* just part of the process... that makes it difficult to determine
|
|
* whether the restore failed because there isn't an archive to restore,
|
|
* or because the administrator has specified the restore program
|
|
* incorrectly. We have to assume the former.
|
|
*
|
|
* However, if the failure was due to any sort of signal, it's best to
|
|
* punt and abort recovery. (If we "return false" here, upper levels will
|
|
* assume that recovery is complete and start up the database!) It's
|
|
* essential to abort on child SIGINT and SIGQUIT, because per spec
|
|
* system() ignores SIGINT and SIGQUIT while waiting; if we see one of
|
|
* those it's a good bet we should have gotten it too.
|
|
*
|
|
* On SIGTERM, assume we have received a fast shutdown request, and exit
|
|
* cleanly. It's pure chance whether we receive the SIGTERM first, or the
|
|
* child process. If we receive it first, the signal handler will call
|
|
* proc_exit, otherwise we do it here. If we or the child process received
|
|
* SIGTERM for any other reason than a fast shutdown request, postmaster
|
|
* will perform an immediate shutdown when it sees us exiting
|
|
* unexpectedly.
|
|
*
|
|
* Per the Single Unix Spec, shells report exit status > 128 when a called
|
|
* command died on a signal. Also, 126 and 127 are used to report
|
|
* problems such as an unfindable command; treat those as fatal errors
|
|
* too.
|
|
*/
|
|
if (WIFSIGNALED(rc) && WTERMSIG(rc) == SIGTERM)
|
|
proc_exit(1);
|
|
|
|
signaled = WIFSIGNALED(rc) || WEXITSTATUS(rc) > 125;
|
|
|
|
ereport(signaled ? FATAL : DEBUG2,
|
|
(errmsg("could not restore file \"%s\" from archive: return code %d",
|
|
xlogfname, rc)));
|
|
|
|
not_available:
|
|
/*
|
|
* if an archived file is not available, there might still be a version of
|
|
* this file in XLOGDIR, so return that as the filename to open.
|
|
*
|
|
* In many recovery scenarios we expect this to fail also, but if so that
|
|
* just means we've reached the end of WAL.
|
|
*/
|
|
snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlogfname);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Attempt to execute the recovery_end_command.
|
|
*/
|
|
static void
|
|
ExecuteRecoveryEndCommand(void)
|
|
{
|
|
char xlogRecoveryEndCmd[MAXPGPATH];
|
|
char lastRestartPointFname[MAXPGPATH];
|
|
char *dp;
|
|
char *endp;
|
|
const char *sp;
|
|
int rc;
|
|
bool signaled;
|
|
uint32 restartLog;
|
|
uint32 restartSeg;
|
|
|
|
Assert(recoveryEndCommand);
|
|
|
|
/*
|
|
* Calculate the archive file cutoff point for use during log shipping
|
|
* replication. All files earlier than this point can be deleted from the
|
|
* archive, though there is no requirement to do so.
|
|
*
|
|
* We initialise this with the filename of an InvalidXLogRecPtr, which
|
|
* will prevent the deletion of any WAL files from the archive because of
|
|
* the alphabetic sorting property of WAL filenames.
|
|
*
|
|
* Once we have successfully located the redo pointer of the checkpoint
|
|
* from which we start recovery we never request a file prior to the redo
|
|
* pointer of the last restartpoint. When redo begins we know that we have
|
|
* successfully located it, so there is no need for additional status
|
|
* flags to signify the point when we can begin deleting WAL files from
|
|
* the archive.
|
|
*/
|
|
if (InRedo)
|
|
{
|
|
XLByteToSeg(ControlFile->checkPointCopy.redo,
|
|
restartLog, restartSeg);
|
|
XLogFileName(lastRestartPointFname,
|
|
ControlFile->checkPointCopy.ThisTimeLineID,
|
|
restartLog, restartSeg);
|
|
}
|
|
else
|
|
XLogFileName(lastRestartPointFname, 0, 0, 0);
|
|
|
|
/*
|
|
* construct the command to be executed
|
|
*/
|
|
dp = xlogRecoveryEndCmd;
|
|
endp = xlogRecoveryEndCmd + MAXPGPATH - 1;
|
|
*endp = '\0';
|
|
|
|
for (sp = recoveryEndCommand; *sp; sp++)
|
|
{
|
|
if (*sp == '%')
|
|
{
|
|
switch (sp[1])
|
|
{
|
|
case 'r':
|
|
/* %r: filename of last restartpoint */
|
|
sp++;
|
|
StrNCpy(dp, lastRestartPointFname, endp - dp);
|
|
dp += strlen(dp);
|
|
break;
|
|
case '%':
|
|
/* convert %% to a single % */
|
|
sp++;
|
|
if (dp < endp)
|
|
*dp++ = *sp;
|
|
break;
|
|
default:
|
|
/* otherwise treat the % as not special */
|
|
if (dp < endp)
|
|
*dp++ = *sp;
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (dp < endp)
|
|
*dp++ = *sp;
|
|
}
|
|
}
|
|
*dp = '\0';
|
|
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("executing recovery end command \"%s\"",
|
|
xlogRecoveryEndCmd)));
|
|
|
|
/*
|
|
* execute the constructed command
|
|
*/
|
|
rc = system(xlogRecoveryEndCmd);
|
|
if (rc != 0)
|
|
{
|
|
/*
|
|
* If the failure was due to any sort of signal, it's best to punt and
|
|
* abort recovery. See also detailed comments on signals in
|
|
* RestoreArchivedFile().
|
|
*/
|
|
signaled = WIFSIGNALED(rc) || WEXITSTATUS(rc) > 125;
|
|
|
|
ereport(signaled ? FATAL : WARNING,
|
|
(errmsg("recovery_end_command \"%s\": return code %d",
|
|
xlogRecoveryEndCmd, rc)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Preallocate log files beyond the specified log endpoint.
|
|
*
|
|
* XXX this is currently extremely conservative, since it forces only one
|
|
* future log segment to exist, and even that only if we are 75% done with
|
|
* the current one. This is only appropriate for very low-WAL-volume systems.
|
|
* High-volume systems will be OK once they've built up a sufficient set of
|
|
* recycled log segments, but the startup transient is likely to include
|
|
* a lot of segment creations by foreground processes, which is not so good.
|
|
*/
|
|
static void
|
|
PreallocXlogFiles(XLogRecPtr endptr)
|
|
{
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
int lf;
|
|
bool use_existent;
|
|
|
|
XLByteToPrevSeg(endptr, _logId, _logSeg);
|
|
if ((endptr.xrecoff - 1) % XLogSegSize >=
|
|
(uint32) (0.75 * XLogSegSize))
|
|
{
|
|
NextLogSeg(_logId, _logSeg);
|
|
use_existent = true;
|
|
lf = XLogFileInit(_logId, _logSeg, &use_existent, true);
|
|
close(lf);
|
|
if (!use_existent)
|
|
CheckpointStats.ckpt_segs_added++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Recycle or remove all log files older or equal to passed log/seg#
|
|
*
|
|
* endptr is current (or recent) end of xlog; this is used to determine
|
|
* whether we want to recycle rather than delete no-longer-wanted log files.
|
|
*/
|
|
static void
|
|
RemoveOldXlogFiles(uint32 log, uint32 seg, XLogRecPtr endptr)
|
|
{
|
|
uint32 endlogId;
|
|
uint32 endlogSeg;
|
|
int max_advance;
|
|
DIR *xldir;
|
|
struct dirent *xlde;
|
|
char lastoff[MAXFNAMELEN];
|
|
char path[MAXPGPATH];
|
|
#ifdef WIN32
|
|
char newpath[MAXPGPATH];
|
|
#endif
|
|
struct stat statbuf;
|
|
|
|
/*
|
|
* Initialize info about where to try to recycle to. We allow recycling
|
|
* segments up to XLOGfileslop segments beyond the current XLOG location.
|
|
*/
|
|
XLByteToPrevSeg(endptr, endlogId, endlogSeg);
|
|
max_advance = XLOGfileslop;
|
|
|
|
xldir = AllocateDir(XLOGDIR);
|
|
if (xldir == NULL)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open transaction log directory \"%s\": %m",
|
|
XLOGDIR)));
|
|
|
|
XLogFileName(lastoff, ThisTimeLineID, log, seg);
|
|
|
|
while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
|
|
{
|
|
/*
|
|
* We ignore the timeline part of the XLOG segment identifiers in
|
|
* deciding whether a segment is still needed. This ensures that we
|
|
* won't prematurely remove a segment from a parent timeline. We could
|
|
* probably be a little more proactive about removing segments of
|
|
* non-parent timelines, but that would be a whole lot more
|
|
* complicated.
|
|
*
|
|
* We use the alphanumeric sorting property of the filenames to decide
|
|
* which ones are earlier than the lastoff segment.
|
|
*/
|
|
if (strlen(xlde->d_name) == 24 &&
|
|
strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
|
|
strcmp(xlde->d_name + 8, lastoff + 8) <= 0)
|
|
{
|
|
/*
|
|
* Normally we don't delete old XLOG files during recovery to
|
|
* avoid accidentally deleting a file that looks stale due to a
|
|
* bug or hardware issue, but in fact contains important data.
|
|
* During streaming recovery, however, we will eventually fill the
|
|
* disk if we never clean up, so we have to. That's not an issue
|
|
* with file-based archive recovery because in that case we
|
|
* restore one XLOG file at a time, on-demand, and with a
|
|
* different filename that can't be confused with regular XLOG
|
|
* files.
|
|
*/
|
|
if (WalRcvInProgress() || XLogArchiveCheckDone(xlde->d_name))
|
|
{
|
|
snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlde->d_name);
|
|
|
|
/*
|
|
* Before deleting the file, see if it can be recycled as a
|
|
* future log segment. Only recycle normal files, pg_standby
|
|
* for example can create symbolic links pointing to a
|
|
* separate archive directory.
|
|
*/
|
|
if (lstat(path, &statbuf) == 0 && S_ISREG(statbuf.st_mode) &&
|
|
InstallXLogFileSegment(&endlogId, &endlogSeg, path,
|
|
true, &max_advance, true))
|
|
{
|
|
ereport(DEBUG2,
|
|
(errmsg("recycled transaction log file \"%s\"",
|
|
xlde->d_name)));
|
|
CheckpointStats.ckpt_segs_recycled++;
|
|
/* Needn't recheck that slot on future iterations */
|
|
if (max_advance > 0)
|
|
{
|
|
NextLogSeg(endlogId, endlogSeg);
|
|
max_advance--;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* No need for any more future segments... */
|
|
int rc;
|
|
|
|
ereport(DEBUG2,
|
|
(errmsg("removing transaction log file \"%s\"",
|
|
xlde->d_name)));
|
|
|
|
#ifdef WIN32
|
|
/*
|
|
* On Windows, if another process (e.g another backend)
|
|
* holds the file open in FILE_SHARE_DELETE mode, unlink
|
|
* will succeed, but the file will still show up in
|
|
* directory listing until the last handle is closed.
|
|
* To avoid confusing the lingering deleted file for a
|
|
* live WAL file that needs to be archived, rename it
|
|
* before deleting it.
|
|
*
|
|
* If another process holds the file open without
|
|
* FILE_SHARE_DELETE flag, rename will fail. We'll try
|
|
* again at the next checkpoint.
|
|
*/
|
|
snprintf(newpath, MAXPGPATH, "%s.deleted", path);
|
|
if (rename(path, newpath) != 0)
|
|
{
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename old transaction log file \"%s\": %m",
|
|
path)));
|
|
continue;
|
|
}
|
|
rc = unlink(newpath);
|
|
#else
|
|
rc = unlink(path);
|
|
#endif
|
|
if (rc != 0)
|
|
{
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not remove old transaction log file \"%s\": %m",
|
|
path)));
|
|
continue;
|
|
}
|
|
CheckpointStats.ckpt_segs_removed++;
|
|
}
|
|
|
|
XLogArchiveCleanup(xlde->d_name);
|
|
}
|
|
}
|
|
}
|
|
|
|
FreeDir(xldir);
|
|
}
|
|
|
|
/*
|
|
* Verify whether pg_xlog and pg_xlog/archive_status exist.
|
|
* If the latter does not exist, recreate it.
|
|
*
|
|
* It is not the goal of this function to verify the contents of these
|
|
* directories, but to help in cases where someone has performed a cluster
|
|
* copy for PITR purposes but omitted pg_xlog from the copy.
|
|
*
|
|
* We could also recreate pg_xlog if it doesn't exist, but a deliberate
|
|
* policy decision was made not to. It is fairly common for pg_xlog to be
|
|
* a symlink, and if that was the DBA's intent then automatically making a
|
|
* plain directory would result in degraded performance with no notice.
|
|
*/
|
|
static void
|
|
ValidateXLOGDirectoryStructure(void)
|
|
{
|
|
char path[MAXPGPATH];
|
|
struct stat stat_buf;
|
|
|
|
/* Check for pg_xlog; if it doesn't exist, error out */
|
|
if (stat(XLOGDIR, &stat_buf) != 0 ||
|
|
!S_ISDIR(stat_buf.st_mode))
|
|
ereport(FATAL,
|
|
(errmsg("required WAL directory \"%s\" does not exist",
|
|
XLOGDIR)));
|
|
|
|
/* Check for archive_status */
|
|
snprintf(path, MAXPGPATH, XLOGDIR "/archive_status");
|
|
if (stat(path, &stat_buf) == 0)
|
|
{
|
|
/* Check for weird cases where it exists but isn't a directory */
|
|
if (!S_ISDIR(stat_buf.st_mode))
|
|
ereport(FATAL,
|
|
(errmsg("required WAL directory \"%s\" does not exist",
|
|
path)));
|
|
}
|
|
else
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("creating missing WAL directory \"%s\"", path)));
|
|
if (mkdir(path, 0700) < 0)
|
|
ereport(FATAL,
|
|
(errmsg("could not create missing directory \"%s\": %m",
|
|
path)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove previous backup history files. This also retries creation of
|
|
* .ready files for any backup history files for which XLogArchiveNotify
|
|
* failed earlier.
|
|
*/
|
|
static void
|
|
CleanupBackupHistory(void)
|
|
{
|
|
DIR *xldir;
|
|
struct dirent *xlde;
|
|
char path[MAXPGPATH];
|
|
|
|
xldir = AllocateDir(XLOGDIR);
|
|
if (xldir == NULL)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open transaction log directory \"%s\": %m",
|
|
XLOGDIR)));
|
|
|
|
while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
|
|
{
|
|
if (strlen(xlde->d_name) > 24 &&
|
|
strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
|
|
strcmp(xlde->d_name + strlen(xlde->d_name) - strlen(".backup"),
|
|
".backup") == 0)
|
|
{
|
|
if (XLogArchiveCheckDone(xlde->d_name))
|
|
{
|
|
ereport(DEBUG2,
|
|
(errmsg("removing transaction log backup history file \"%s\"",
|
|
xlde->d_name)));
|
|
snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlde->d_name);
|
|
unlink(path);
|
|
XLogArchiveCleanup(xlde->d_name);
|
|
}
|
|
}
|
|
}
|
|
|
|
FreeDir(xldir);
|
|
}
|
|
|
|
/*
|
|
* Restore the backup blocks present in an XLOG record, if any.
|
|
*
|
|
* We assume all of the record has been read into memory at *record.
|
|
*
|
|
* Note: when a backup block is available in XLOG, we restore it
|
|
* unconditionally, even if the page in the database appears newer.
|
|
* This is to protect ourselves against database pages that were partially
|
|
* or incorrectly written during a crash. We assume that the XLOG data
|
|
* must be good because it has passed a CRC check, while the database
|
|
* page might not be. This will force us to replay all subsequent
|
|
* modifications of the page that appear in XLOG, rather than possibly
|
|
* ignoring them as already applied, but that's not a huge drawback.
|
|
*
|
|
* If 'cleanup' is true, a cleanup lock is used when restoring blocks.
|
|
* Otherwise, a normal exclusive lock is used. During crash recovery, that's
|
|
* just pro forma because there can't be any regular backends in the system,
|
|
* but in hot standby mode the distinction is important. The 'cleanup'
|
|
* argument applies to all backup blocks in the WAL record, that suffices for
|
|
* now.
|
|
*/
|
|
void
|
|
RestoreBkpBlocks(XLogRecPtr lsn, XLogRecord *record, bool cleanup)
|
|
{
|
|
Buffer buffer;
|
|
Page page;
|
|
BkpBlock bkpb;
|
|
char *blk;
|
|
int i;
|
|
|
|
if (!(record->xl_info & XLR_BKP_BLOCK_MASK))
|
|
return;
|
|
|
|
blk = (char *) XLogRecGetData(record) + record->xl_len;
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (!(record->xl_info & XLR_SET_BKP_BLOCK(i)))
|
|
continue;
|
|
|
|
memcpy(&bkpb, blk, sizeof(BkpBlock));
|
|
blk += sizeof(BkpBlock);
|
|
|
|
buffer = XLogReadBufferExtended(bkpb.node, bkpb.fork, bkpb.block,
|
|
RBM_ZERO);
|
|
Assert(BufferIsValid(buffer));
|
|
if (cleanup)
|
|
LockBufferForCleanup(buffer);
|
|
else
|
|
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
|
|
|
|
page = (Page) BufferGetPage(buffer);
|
|
|
|
if (bkpb.hole_length == 0)
|
|
{
|
|
memcpy((char *) page, blk, BLCKSZ);
|
|
}
|
|
else
|
|
{
|
|
/* must zero-fill the hole */
|
|
MemSet((char *) page, 0, BLCKSZ);
|
|
memcpy((char *) page, blk, bkpb.hole_offset);
|
|
memcpy((char *) page + (bkpb.hole_offset + bkpb.hole_length),
|
|
blk + bkpb.hole_offset,
|
|
BLCKSZ - (bkpb.hole_offset + bkpb.hole_length));
|
|
}
|
|
|
|
PageSetLSN(page, lsn);
|
|
PageSetTLI(page, ThisTimeLineID);
|
|
MarkBufferDirty(buffer);
|
|
UnlockReleaseBuffer(buffer);
|
|
|
|
blk += BLCKSZ - bkpb.hole_length;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* CRC-check an XLOG record. We do not believe the contents of an XLOG
|
|
* record (other than to the minimal extent of computing the amount of
|
|
* data to read in) until we've checked the CRCs.
|
|
*
|
|
* We assume all of the record has been read into memory at *record.
|
|
*/
|
|
static bool
|
|
RecordIsValid(XLogRecord *record, XLogRecPtr recptr, int emode)
|
|
{
|
|
pg_crc32 crc;
|
|
int i;
|
|
uint32 len = record->xl_len;
|
|
BkpBlock bkpb;
|
|
char *blk;
|
|
|
|
/* First the rmgr data */
|
|
INIT_CRC32(crc);
|
|
COMP_CRC32(crc, XLogRecGetData(record), len);
|
|
|
|
/* Add in the backup blocks, if any */
|
|
blk = (char *) XLogRecGetData(record) + len;
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
uint32 blen;
|
|
|
|
if (!(record->xl_info & XLR_SET_BKP_BLOCK(i)))
|
|
continue;
|
|
|
|
memcpy(&bkpb, blk, sizeof(BkpBlock));
|
|
if (bkpb.hole_offset + bkpb.hole_length > BLCKSZ)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("incorrect hole size in record at %X/%X",
|
|
recptr.xlogid, recptr.xrecoff)));
|
|
return false;
|
|
}
|
|
blen = sizeof(BkpBlock) + BLCKSZ - bkpb.hole_length;
|
|
COMP_CRC32(crc, blk, blen);
|
|
blk += blen;
|
|
}
|
|
|
|
/* Check that xl_tot_len agrees with our calculation */
|
|
if (blk != (char *) record + record->xl_tot_len)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("incorrect total length in record at %X/%X",
|
|
recptr.xlogid, recptr.xrecoff)));
|
|
return false;
|
|
}
|
|
|
|
/* Finally include the record header */
|
|
COMP_CRC32(crc, (char *) record + sizeof(pg_crc32),
|
|
SizeOfXLogRecord - sizeof(pg_crc32));
|
|
FIN_CRC32(crc);
|
|
|
|
if (!EQ_CRC32(record->xl_crc, crc))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("incorrect resource manager data checksum in record at %X/%X",
|
|
recptr.xlogid, recptr.xrecoff)));
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Attempt to read an XLOG record.
|
|
*
|
|
* If RecPtr is not NULL, try to read a record at that position. Otherwise
|
|
* try to read a record just after the last one previously read.
|
|
*
|
|
* If no valid record is available, returns NULL, or fails if emode is PANIC.
|
|
* (emode must be either PANIC, LOG)
|
|
*
|
|
* The record is copied into readRecordBuf, so that on successful return,
|
|
* the returned record pointer always points there.
|
|
*/
|
|
static XLogRecord *
|
|
ReadRecord(XLogRecPtr *RecPtr, int emode_arg, bool fetching_ckpt)
|
|
{
|
|
XLogRecord *record;
|
|
char *buffer;
|
|
XLogRecPtr tmpRecPtr = EndRecPtr;
|
|
bool randAccess = false;
|
|
uint32 len,
|
|
total_len;
|
|
uint32 targetRecOff;
|
|
uint32 pageHeaderSize;
|
|
int emode;
|
|
|
|
/*
|
|
* We don't expect any invalid records during streaming recovery: we
|
|
* should never hit the end of WAL because we wait for it to be streamed.
|
|
* Therefore treat any broken WAL as PANIC, instead of failing over.
|
|
*/
|
|
if (StandbyMode)
|
|
emode = PANIC;
|
|
else
|
|
emode = emode_arg;
|
|
|
|
if (readBuf == NULL)
|
|
{
|
|
/*
|
|
* First time through, permanently allocate readBuf. We do it this
|
|
* way, rather than just making a static array, for two reasons: (1)
|
|
* no need to waste the storage in most instantiations of the backend;
|
|
* (2) a static char array isn't guaranteed to have any particular
|
|
* alignment, whereas malloc() will provide MAXALIGN'd storage.
|
|
*/
|
|
readBuf = (char *) malloc(XLOG_BLCKSZ);
|
|
Assert(readBuf != NULL);
|
|
}
|
|
|
|
if (RecPtr == NULL)
|
|
{
|
|
RecPtr = &tmpRecPtr;
|
|
|
|
/*
|
|
* Align recptr to next page if no more records can fit on the
|
|
* current page.
|
|
*/
|
|
if (XLOG_BLCKSZ - (RecPtr->xrecoff % XLOG_BLCKSZ) < SizeOfXLogRecord)
|
|
{
|
|
NextLogPage(tmpRecPtr);
|
|
/* We will account for page header size below */
|
|
}
|
|
|
|
if (tmpRecPtr.xrecoff >= XLogFileSize)
|
|
{
|
|
(tmpRecPtr.xlogid)++;
|
|
tmpRecPtr.xrecoff = 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (!XRecOffIsValid(RecPtr->xrecoff))
|
|
ereport(PANIC,
|
|
(errmsg("invalid record offset at %X/%X",
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
|
|
/*
|
|
* Since we are going to a random position in WAL, forget any prior
|
|
* state about what timeline we were in, and allow it to be any
|
|
* timeline in expectedTLIs. We also set a flag to allow curFileTLI
|
|
* to go backwards (but we can't reset that variable right here, since
|
|
* we might not change files at all).
|
|
*/
|
|
lastPageTLI = 0; /* see comment in ValidXLOGHeader */
|
|
randAccess = true; /* allow curFileTLI to go backwards too */
|
|
}
|
|
|
|
/* Read the page containing the record */
|
|
if (!XLogPageRead(RecPtr, emode, fetching_ckpt, randAccess))
|
|
return NULL;
|
|
|
|
pageHeaderSize = XLogPageHeaderSize((XLogPageHeader) readBuf);
|
|
targetRecOff = RecPtr->xrecoff % XLOG_BLCKSZ;
|
|
if (targetRecOff == 0)
|
|
{
|
|
/*
|
|
* Can only get here in the continuing-from-prev-page case, because
|
|
* XRecOffIsValid eliminated the zero-page-offset case otherwise. Need
|
|
* to skip over the new page's header.
|
|
*/
|
|
tmpRecPtr.xrecoff += pageHeaderSize;
|
|
targetRecOff = pageHeaderSize;
|
|
}
|
|
else if (targetRecOff < pageHeaderSize)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("invalid record offset at %X/%X",
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
if ((((XLogPageHeader) readBuf)->xlp_info & XLP_FIRST_IS_CONTRECORD) &&
|
|
targetRecOff == pageHeaderSize)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("contrecord is requested by %X/%X",
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
record = (XLogRecord *) ((char *) readBuf + RecPtr->xrecoff % XLOG_BLCKSZ);
|
|
|
|
/*
|
|
* xl_len == 0 is bad data for everything except XLOG SWITCH, where it is
|
|
* required.
|
|
*/
|
|
if (record->xl_rmid == RM_XLOG_ID && record->xl_info == XLOG_SWITCH)
|
|
{
|
|
if (record->xl_len != 0)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("invalid xlog switch record at %X/%X",
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
}
|
|
else if (record->xl_len == 0)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("record with zero length at %X/%X",
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
if (record->xl_tot_len < SizeOfXLogRecord + record->xl_len ||
|
|
record->xl_tot_len > SizeOfXLogRecord + record->xl_len +
|
|
XLR_MAX_BKP_BLOCKS * (sizeof(BkpBlock) + BLCKSZ))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("invalid record length at %X/%X",
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
if (record->xl_rmid > RM_MAX_ID)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("invalid resource manager ID %u at %X/%X",
|
|
record->xl_rmid, RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
if (randAccess)
|
|
{
|
|
/*
|
|
* We can't exactly verify the prev-link, but surely it should be less
|
|
* than the record's own address.
|
|
*/
|
|
if (!XLByteLT(record->xl_prev, *RecPtr))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("record with incorrect prev-link %X/%X at %X/%X",
|
|
record->xl_prev.xlogid, record->xl_prev.xrecoff,
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Record's prev-link should exactly match our previous location. This
|
|
* check guards against torn WAL pages where a stale but valid-looking
|
|
* WAL record starts on a sector boundary.
|
|
*/
|
|
if (!XLByteEQ(record->xl_prev, ReadRecPtr))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("record with incorrect prev-link %X/%X at %X/%X",
|
|
record->xl_prev.xlogid, record->xl_prev.xrecoff,
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Allocate or enlarge readRecordBuf as needed. To avoid useless small
|
|
* increases, round its size to a multiple of XLOG_BLCKSZ, and make sure
|
|
* it's at least 4*Max(BLCKSZ, XLOG_BLCKSZ) to start with. (That is
|
|
* enough for all "normal" records, but very large commit or abort records
|
|
* might need more space.)
|
|
*/
|
|
total_len = record->xl_tot_len;
|
|
if (total_len > readRecordBufSize)
|
|
{
|
|
uint32 newSize = total_len;
|
|
|
|
newSize += XLOG_BLCKSZ - (newSize % XLOG_BLCKSZ);
|
|
newSize = Max(newSize, 4 * Max(BLCKSZ, XLOG_BLCKSZ));
|
|
if (readRecordBuf)
|
|
free(readRecordBuf);
|
|
readRecordBuf = (char *) malloc(newSize);
|
|
if (!readRecordBuf)
|
|
{
|
|
readRecordBufSize = 0;
|
|
/* We treat this as a "bogus data" condition */
|
|
ereport(emode,
|
|
(errmsg("record length %u at %X/%X too long",
|
|
total_len, RecPtr->xlogid, RecPtr->xrecoff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
readRecordBufSize = newSize;
|
|
}
|
|
|
|
buffer = readRecordBuf;
|
|
len = XLOG_BLCKSZ - RecPtr->xrecoff % XLOG_BLCKSZ;
|
|
if (total_len > len)
|
|
{
|
|
/* Need to reassemble record */
|
|
XLogContRecord *contrecord;
|
|
XLogRecPtr pagelsn;
|
|
uint32 gotlen = len;
|
|
|
|
/* Initialize pagelsn to the beginning of the page this record is on */
|
|
pagelsn = *RecPtr;
|
|
pagelsn.xrecoff = (pagelsn.xrecoff / XLOG_BLCKSZ) * XLOG_BLCKSZ;
|
|
|
|
memcpy(buffer, record, len);
|
|
record = (XLogRecord *) buffer;
|
|
buffer += len;
|
|
for (;;)
|
|
{
|
|
/* Calculate pointer to beginning of next page */
|
|
pagelsn.xrecoff += XLOG_BLCKSZ;
|
|
if (pagelsn.xrecoff >= XLogFileSize)
|
|
{
|
|
(pagelsn.xlogid)++;
|
|
pagelsn.xrecoff = 0;
|
|
}
|
|
/* Wait for the next page to become available */
|
|
if (!XLogPageRead(&pagelsn, emode, false, false))
|
|
return NULL;
|
|
|
|
/* Check that the continuation record looks valid */
|
|
if (!(((XLogPageHeader) readBuf)->xlp_info & XLP_FIRST_IS_CONTRECORD))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("there is no contrecord flag in log file %u, segment %u, offset %u",
|
|
readId, readSeg, readOff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
pageHeaderSize = XLogPageHeaderSize((XLogPageHeader) readBuf);
|
|
contrecord = (XLogContRecord *) ((char *) readBuf + pageHeaderSize);
|
|
if (contrecord->xl_rem_len == 0 ||
|
|
total_len != (contrecord->xl_rem_len + gotlen))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("invalid contrecord length %u in log file %u, segment %u, offset %u",
|
|
contrecord->xl_rem_len,
|
|
readId, readSeg, readOff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
len = XLOG_BLCKSZ - pageHeaderSize - SizeOfXLogContRecord;
|
|
if (contrecord->xl_rem_len > len)
|
|
{
|
|
memcpy(buffer, (char *) contrecord + SizeOfXLogContRecord, len);
|
|
gotlen += len;
|
|
buffer += len;
|
|
continue;
|
|
}
|
|
memcpy(buffer, (char *) contrecord + SizeOfXLogContRecord,
|
|
contrecord->xl_rem_len);
|
|
break;
|
|
}
|
|
if (!RecordIsValid(record, *RecPtr, emode))
|
|
goto next_record_is_invalid;
|
|
pageHeaderSize = XLogPageHeaderSize((XLogPageHeader) readBuf);
|
|
EndRecPtr.xlogid = readId;
|
|
EndRecPtr.xrecoff = readSeg * XLogSegSize + readOff +
|
|
pageHeaderSize +
|
|
MAXALIGN(SizeOfXLogContRecord + contrecord->xl_rem_len);
|
|
|
|
ReadRecPtr = *RecPtr;
|
|
/* needn't worry about XLOG SWITCH, it can't cross page boundaries */
|
|
return record;
|
|
}
|
|
|
|
/* Record does not cross a page boundary */
|
|
if (!RecordIsValid(record, *RecPtr, emode))
|
|
goto next_record_is_invalid;
|
|
EndRecPtr.xlogid = RecPtr->xlogid;
|
|
EndRecPtr.xrecoff = RecPtr->xrecoff + MAXALIGN(total_len);
|
|
|
|
ReadRecPtr = *RecPtr;
|
|
memcpy(buffer, record, total_len);
|
|
|
|
/*
|
|
* Special processing if it's an XLOG SWITCH record
|
|
*/
|
|
if (record->xl_rmid == RM_XLOG_ID && record->xl_info == XLOG_SWITCH)
|
|
{
|
|
/* Pretend it extends to end of segment */
|
|
EndRecPtr.xrecoff += XLogSegSize - 1;
|
|
EndRecPtr.xrecoff -= EndRecPtr.xrecoff % XLogSegSize;
|
|
|
|
/*
|
|
* Pretend that readBuf contains the last page of the segment. This is
|
|
* just to avoid Assert failure in StartupXLOG if XLOG ends with this
|
|
* segment.
|
|
*/
|
|
readOff = XLogSegSize - XLOG_BLCKSZ;
|
|
}
|
|
return (XLogRecord *) buffer;
|
|
|
|
next_record_is_invalid:;
|
|
if (readFile >= 0)
|
|
{
|
|
close(readFile);
|
|
readFile = -1;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Check whether the xlog header of a page just read in looks valid.
|
|
*
|
|
* This is just a convenience subroutine to avoid duplicated code in
|
|
* ReadRecord. It's not intended for use from anywhere else.
|
|
*/
|
|
static bool
|
|
ValidXLOGHeader(XLogPageHeader hdr, int emode)
|
|
{
|
|
XLogRecPtr recaddr;
|
|
|
|
if (hdr->xlp_magic != XLOG_PAGE_MAGIC)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("invalid magic number %04X in log file %u, segment %u, offset %u",
|
|
hdr->xlp_magic, readId, readSeg, readOff)));
|
|
return false;
|
|
}
|
|
if ((hdr->xlp_info & ~XLP_ALL_FLAGS) != 0)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("invalid info bits %04X in log file %u, segment %u, offset %u",
|
|
hdr->xlp_info, readId, readSeg, readOff)));
|
|
return false;
|
|
}
|
|
if (hdr->xlp_info & XLP_LONG_HEADER)
|
|
{
|
|
XLogLongPageHeader longhdr = (XLogLongPageHeader) hdr;
|
|
|
|
if (longhdr->xlp_sysid != ControlFile->system_identifier)
|
|
{
|
|
char fhdrident_str[32];
|
|
char sysident_str[32];
|
|
|
|
/*
|
|
* Format sysids separately to keep platform-dependent format code
|
|
* out of the translatable message string.
|
|
*/
|
|
snprintf(fhdrident_str, sizeof(fhdrident_str), UINT64_FORMAT,
|
|
longhdr->xlp_sysid);
|
|
snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
|
|
ControlFile->system_identifier);
|
|
ereport(emode,
|
|
(errmsg("WAL file is from different system"),
|
|
errdetail("WAL file SYSID is %s, pg_control SYSID is %s",
|
|
fhdrident_str, sysident_str)));
|
|
return false;
|
|
}
|
|
if (longhdr->xlp_seg_size != XLogSegSize)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("WAL file is from different system"),
|
|
errdetail("Incorrect XLOG_SEG_SIZE in page header.")));
|
|
return false;
|
|
}
|
|
if (longhdr->xlp_xlog_blcksz != XLOG_BLCKSZ)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("WAL file is from different system"),
|
|
errdetail("Incorrect XLOG_BLCKSZ in page header.")));
|
|
return false;
|
|
}
|
|
}
|
|
else if (readOff == 0)
|
|
{
|
|
/* hmm, first page of file doesn't have a long header? */
|
|
ereport(emode,
|
|
(errmsg("invalid info bits %04X in log file %u, segment %u, offset %u",
|
|
hdr->xlp_info, readId, readSeg, readOff)));
|
|
return false;
|
|
}
|
|
|
|
recaddr.xlogid = readId;
|
|
recaddr.xrecoff = readSeg * XLogSegSize + readOff;
|
|
if (!XLByteEQ(hdr->xlp_pageaddr, recaddr))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("unexpected pageaddr %X/%X in log file %u, segment %u, offset %u",
|
|
hdr->xlp_pageaddr.xlogid, hdr->xlp_pageaddr.xrecoff,
|
|
readId, readSeg, readOff)));
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check page TLI is one of the expected values.
|
|
*/
|
|
if (!list_member_int(expectedTLIs, (int) hdr->xlp_tli))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("unexpected timeline ID %u in log file %u, segment %u, offset %u",
|
|
hdr->xlp_tli,
|
|
readId, readSeg, readOff)));
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Since child timelines are always assigned a TLI greater than their
|
|
* immediate parent's TLI, we should never see TLI go backwards across
|
|
* successive pages of a consistent WAL sequence.
|
|
*
|
|
* Of course this check should only be applied when advancing sequentially
|
|
* across pages; therefore ReadRecord resets lastPageTLI to zero when
|
|
* going to a random page.
|
|
*/
|
|
if (hdr->xlp_tli < lastPageTLI)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("out-of-sequence timeline ID %u (after %u) in log file %u, segment %u, offset %u",
|
|
hdr->xlp_tli, lastPageTLI,
|
|
readId, readSeg, readOff)));
|
|
return false;
|
|
}
|
|
lastPageTLI = hdr->xlp_tli;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Try to read a timeline's history file.
|
|
*
|
|
* If successful, return the list of component TLIs (the given TLI followed by
|
|
* its ancestor TLIs). If we can't find the history file, assume that the
|
|
* timeline has no parents, and return a list of just the specified timeline
|
|
* ID.
|
|
*/
|
|
static List *
|
|
readTimeLineHistory(TimeLineID targetTLI)
|
|
{
|
|
List *result;
|
|
char path[MAXPGPATH];
|
|
char histfname[MAXFNAMELEN];
|
|
char fline[MAXPGPATH];
|
|
FILE *fd;
|
|
|
|
/* Timeline 1 does not have a history file, so no need to check */
|
|
if (targetTLI == 1)
|
|
return list_make1_int((int) targetTLI);
|
|
|
|
if (InArchiveRecovery)
|
|
{
|
|
TLHistoryFileName(histfname, targetTLI);
|
|
RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0);
|
|
}
|
|
else
|
|
TLHistoryFilePath(path, targetTLI);
|
|
|
|
fd = AllocateFile(path, "r");
|
|
if (fd == NULL)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\": %m", path)));
|
|
/* Not there, so assume no parents */
|
|
return list_make1_int((int) targetTLI);
|
|
}
|
|
|
|
result = NIL;
|
|
|
|
/*
|
|
* Parse the file...
|
|
*/
|
|
while (fgets(fline, sizeof(fline), fd) != NULL)
|
|
{
|
|
/* skip leading whitespace and check for # comment */
|
|
char *ptr;
|
|
char *endptr;
|
|
TimeLineID tli;
|
|
|
|
for (ptr = fline; *ptr; ptr++)
|
|
{
|
|
if (!isspace((unsigned char) *ptr))
|
|
break;
|
|
}
|
|
if (*ptr == '\0' || *ptr == '#')
|
|
continue;
|
|
|
|
/* expect a numeric timeline ID as first field of line */
|
|
tli = (TimeLineID) strtoul(ptr, &endptr, 0);
|
|
if (endptr == ptr)
|
|
ereport(FATAL,
|
|
(errmsg("syntax error in history file: %s", fline),
|
|
errhint("Expected a numeric timeline ID.")));
|
|
|
|
if (result &&
|
|
tli <= (TimeLineID) linitial_int(result))
|
|
ereport(FATAL,
|
|
(errmsg("invalid data in history file: %s", fline),
|
|
errhint("Timeline IDs must be in increasing sequence.")));
|
|
|
|
/* Build list with newest item first */
|
|
result = lcons_int((int) tli, result);
|
|
|
|
/* we ignore the remainder of each line */
|
|
}
|
|
|
|
FreeFile(fd);
|
|
|
|
if (result &&
|
|
targetTLI <= (TimeLineID) linitial_int(result))
|
|
ereport(FATAL,
|
|
(errmsg("invalid data in history file \"%s\"", path),
|
|
errhint("Timeline IDs must be less than child timeline's ID.")));
|
|
|
|
result = lcons_int((int) targetTLI, result);
|
|
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("history of timeline %u is %s",
|
|
targetTLI, nodeToString(result))));
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Probe whether a timeline history file exists for the given timeline ID
|
|
*/
|
|
static bool
|
|
existsTimeLineHistory(TimeLineID probeTLI)
|
|
{
|
|
char path[MAXPGPATH];
|
|
char histfname[MAXFNAMELEN];
|
|
FILE *fd;
|
|
|
|
/* Timeline 1 does not have a history file, so no need to check */
|
|
if (probeTLI == 1)
|
|
return false;
|
|
|
|
if (InArchiveRecovery)
|
|
{
|
|
TLHistoryFileName(histfname, probeTLI);
|
|
RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0);
|
|
}
|
|
else
|
|
TLHistoryFilePath(path, probeTLI);
|
|
|
|
fd = AllocateFile(path, "r");
|
|
if (fd != NULL)
|
|
{
|
|
FreeFile(fd);
|
|
return true;
|
|
}
|
|
else
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\": %m", path)));
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Find the newest existing timeline, assuming that startTLI exists.
|
|
*
|
|
* Note: while this is somewhat heuristic, it does positively guarantee
|
|
* that (result + 1) is not a known timeline, and therefore it should
|
|
* be safe to assign that ID to a new timeline.
|
|
*/
|
|
static TimeLineID
|
|
findNewestTimeLine(TimeLineID startTLI)
|
|
{
|
|
TimeLineID newestTLI;
|
|
TimeLineID probeTLI;
|
|
|
|
/*
|
|
* The algorithm is just to probe for the existence of timeline history
|
|
* files. XXX is it useful to allow gaps in the sequence?
|
|
*/
|
|
newestTLI = startTLI;
|
|
|
|
for (probeTLI = startTLI + 1;; probeTLI++)
|
|
{
|
|
if (existsTimeLineHistory(probeTLI))
|
|
{
|
|
newestTLI = probeTLI; /* probeTLI exists */
|
|
}
|
|
else
|
|
{
|
|
/* doesn't exist, assume we're done */
|
|
break;
|
|
}
|
|
}
|
|
|
|
return newestTLI;
|
|
}
|
|
|
|
/*
|
|
* Create a new timeline history file.
|
|
*
|
|
* newTLI: ID of the new timeline
|
|
* parentTLI: ID of its immediate parent
|
|
* endTLI et al: ID of the last used WAL file, for annotation purposes
|
|
*
|
|
* Currently this is only used during recovery, and so there are no locking
|
|
* considerations. But we should be just as tense as XLogFileInit to avoid
|
|
* emplacing a bogus file.
|
|
*/
|
|
static void
|
|
writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
|
|
TimeLineID endTLI, uint32 endLogId, uint32 endLogSeg)
|
|
{
|
|
char path[MAXPGPATH];
|
|
char tmppath[MAXPGPATH];
|
|
char histfname[MAXFNAMELEN];
|
|
char xlogfname[MAXFNAMELEN];
|
|
char buffer[BLCKSZ];
|
|
int srcfd;
|
|
int fd;
|
|
int nbytes;
|
|
|
|
Assert(newTLI > parentTLI); /* else bad selection of newTLI */
|
|
|
|
/*
|
|
* Write into a temp file name.
|
|
*/
|
|
snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
|
|
|
|
unlink(tmppath);
|
|
|
|
/* do not use get_sync_bit() here --- want to fsync only at end of fill */
|
|
fd = BasicOpenFile(tmppath, O_RDWR | O_CREAT | O_EXCL,
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create file \"%s\": %m", tmppath)));
|
|
|
|
/*
|
|
* If a history file exists for the parent, copy it verbatim
|
|
*/
|
|
if (InArchiveRecovery)
|
|
{
|
|
TLHistoryFileName(histfname, parentTLI);
|
|
RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0);
|
|
}
|
|
else
|
|
TLHistoryFilePath(path, parentTLI);
|
|
|
|
srcfd = BasicOpenFile(path, O_RDONLY, 0);
|
|
if (srcfd < 0)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\": %m", path)));
|
|
/* Not there, so assume parent has no parents */
|
|
}
|
|
else
|
|
{
|
|
for (;;)
|
|
{
|
|
errno = 0;
|
|
nbytes = (int) read(srcfd, buffer, sizeof(buffer));
|
|
if (nbytes < 0 || errno != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m", path)));
|
|
if (nbytes == 0)
|
|
break;
|
|
errno = 0;
|
|
if ((int) write(fd, buffer, nbytes) != nbytes)
|
|
{
|
|
int save_errno = errno;
|
|
|
|
/*
|
|
* If we fail to make the file, delete it to release disk
|
|
* space
|
|
*/
|
|
unlink(tmppath);
|
|
|
|
/*
|
|
* if write didn't set errno, assume problem is no disk space
|
|
*/
|
|
errno = save_errno ? save_errno : ENOSPC;
|
|
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to file \"%s\": %m", tmppath)));
|
|
}
|
|
}
|
|
close(srcfd);
|
|
}
|
|
|
|
/*
|
|
* Append one line with the details of this timeline split.
|
|
*
|
|
* If we did have a parent file, insert an extra newline just in case the
|
|
* parent file failed to end with one.
|
|
*/
|
|
XLogFileName(xlogfname, endTLI, endLogId, endLogSeg);
|
|
|
|
snprintf(buffer, sizeof(buffer),
|
|
"%s%u\t%s\t%s transaction %u at %s\n",
|
|
(srcfd < 0) ? "" : "\n",
|
|
parentTLI,
|
|
xlogfname,
|
|
recoveryStopAfter ? "after" : "before",
|
|
recoveryStopXid,
|
|
timestamptz_to_str(recoveryStopTime));
|
|
|
|
nbytes = strlen(buffer);
|
|
errno = 0;
|
|
if ((int) write(fd, buffer, nbytes) != nbytes)
|
|
{
|
|
int save_errno = errno;
|
|
|
|
/*
|
|
* If we fail to make the file, delete it to release disk space
|
|
*/
|
|
unlink(tmppath);
|
|
/* if write didn't set errno, assume problem is no disk space */
|
|
errno = save_errno ? save_errno : ENOSPC;
|
|
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to file \"%s\": %m", tmppath)));
|
|
}
|
|
|
|
if (pg_fsync(fd) != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync file \"%s\": %m", tmppath)));
|
|
|
|
if (close(fd))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close file \"%s\": %m", tmppath)));
|
|
|
|
|
|
/*
|
|
* Now move the completed history file into place with its final name.
|
|
*/
|
|
TLHistoryFilePath(path, newTLI);
|
|
|
|
/*
|
|
* Prefer link() to rename() here just to be really sure that we don't
|
|
* overwrite an existing logfile. However, there shouldn't be one, so
|
|
* rename() is an acceptable substitute except for the truly paranoid.
|
|
*/
|
|
#if HAVE_WORKING_LINK
|
|
if (link(tmppath, path) < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not link file \"%s\" to \"%s\": %m",
|
|
tmppath, path)));
|
|
unlink(tmppath);
|
|
#else
|
|
if (rename(tmppath, path) < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename file \"%s\" to \"%s\": %m",
|
|
tmppath, path)));
|
|
#endif
|
|
|
|
/* The history file can be archived immediately. */
|
|
TLHistoryFileName(histfname, newTLI);
|
|
XLogArchiveNotify(histfname);
|
|
}
|
|
|
|
/*
|
|
* I/O routines for pg_control
|
|
*
|
|
* *ControlFile is a buffer in shared memory that holds an image of the
|
|
* contents of pg_control. WriteControlFile() initializes pg_control
|
|
* given a preloaded buffer, ReadControlFile() loads the buffer from
|
|
* the pg_control file (during postmaster or standalone-backend startup),
|
|
* and UpdateControlFile() rewrites pg_control after we modify xlog state.
|
|
*
|
|
* For simplicity, WriteControlFile() initializes the fields of pg_control
|
|
* that are related to checking backend/database compatibility, and
|
|
* ReadControlFile() verifies they are correct. We could split out the
|
|
* I/O and compatibility-check functions, but there seems no need currently.
|
|
*/
|
|
static void
|
|
WriteControlFile(void)
|
|
{
|
|
int fd;
|
|
char buffer[PG_CONTROL_SIZE]; /* need not be aligned */
|
|
|
|
/*
|
|
* Initialize version and compatibility-check fields
|
|
*/
|
|
ControlFile->pg_control_version = PG_CONTROL_VERSION;
|
|
ControlFile->catalog_version_no = CATALOG_VERSION_NO;
|
|
|
|
ControlFile->maxAlign = MAXIMUM_ALIGNOF;
|
|
ControlFile->floatFormat = FLOATFORMAT_VALUE;
|
|
|
|
ControlFile->blcksz = BLCKSZ;
|
|
ControlFile->relseg_size = RELSEG_SIZE;
|
|
ControlFile->xlog_blcksz = XLOG_BLCKSZ;
|
|
ControlFile->xlog_seg_size = XLOG_SEG_SIZE;
|
|
|
|
ControlFile->nameDataLen = NAMEDATALEN;
|
|
ControlFile->indexMaxKeys = INDEX_MAX_KEYS;
|
|
|
|
ControlFile->toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
|
|
|
|
#ifdef HAVE_INT64_TIMESTAMP
|
|
ControlFile->enableIntTimes = true;
|
|
#else
|
|
ControlFile->enableIntTimes = false;
|
|
#endif
|
|
ControlFile->float4ByVal = FLOAT4PASSBYVAL;
|
|
ControlFile->float8ByVal = FLOAT8PASSBYVAL;
|
|
|
|
/* Contents are protected with a CRC */
|
|
INIT_CRC32(ControlFile->crc);
|
|
COMP_CRC32(ControlFile->crc,
|
|
(char *) ControlFile,
|
|
offsetof(ControlFileData, crc));
|
|
FIN_CRC32(ControlFile->crc);
|
|
|
|
/*
|
|
* We write out PG_CONTROL_SIZE bytes into pg_control, zero-padding the
|
|
* excess over sizeof(ControlFileData). This reduces the odds of
|
|
* premature-EOF errors when reading pg_control. We'll still fail when we
|
|
* check the contents of the file, but hopefully with a more specific
|
|
* error than "couldn't read pg_control".
|
|
*/
|
|
if (sizeof(ControlFileData) > PG_CONTROL_SIZE)
|
|
elog(PANIC, "sizeof(ControlFileData) is larger than PG_CONTROL_SIZE; fix either one");
|
|
|
|
memset(buffer, 0, PG_CONTROL_SIZE);
|
|
memcpy(buffer, ControlFile, sizeof(ControlFileData));
|
|
|
|
fd = BasicOpenFile(XLOG_CONTROL_FILE,
|
|
O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create control file \"%s\": %m",
|
|
XLOG_CONTROL_FILE)));
|
|
|
|
errno = 0;
|
|
if (write(fd, buffer, PG_CONTROL_SIZE) != PG_CONTROL_SIZE)
|
|
{
|
|
/* if write didn't set errno, assume problem is no disk space */
|
|
if (errno == 0)
|
|
errno = ENOSPC;
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to control file: %m")));
|
|
}
|
|
|
|
if (pg_fsync(fd) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync control file: %m")));
|
|
|
|
if (close(fd))
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close control file: %m")));
|
|
}
|
|
|
|
static void
|
|
ReadControlFile(void)
|
|
{
|
|
pg_crc32 crc;
|
|
int fd;
|
|
|
|
/*
|
|
* Read data...
|
|
*/
|
|
fd = BasicOpenFile(XLOG_CONTROL_FILE,
|
|
O_RDWR | PG_BINARY,
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open control file \"%s\": %m",
|
|
XLOG_CONTROL_FILE)));
|
|
|
|
if (read(fd, ControlFile, sizeof(ControlFileData)) != sizeof(ControlFileData))
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from control file: %m")));
|
|
|
|
close(fd);
|
|
|
|
/*
|
|
* Check for expected pg_control format version. If this is wrong, the
|
|
* CRC check will likely fail because we'll be checking the wrong number
|
|
* of bytes. Complaining about wrong version will probably be more
|
|
* enlightening than complaining about wrong CRC.
|
|
*/
|
|
|
|
if (ControlFile->pg_control_version != PG_CONTROL_VERSION && ControlFile->pg_control_version % 65536 == 0 && ControlFile->pg_control_version / 65536 != 0)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with PG_CONTROL_VERSION %d (0x%08x),"
|
|
" but the server was compiled with PG_CONTROL_VERSION %d (0x%08x).",
|
|
ControlFile->pg_control_version, ControlFile->pg_control_version,
|
|
PG_CONTROL_VERSION, PG_CONTROL_VERSION),
|
|
errhint("This could be a problem of mismatched byte ordering. It looks like you need to initdb.")));
|
|
|
|
if (ControlFile->pg_control_version != PG_CONTROL_VERSION)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with PG_CONTROL_VERSION %d,"
|
|
" but the server was compiled with PG_CONTROL_VERSION %d.",
|
|
ControlFile->pg_control_version, PG_CONTROL_VERSION),
|
|
errhint("It looks like you need to initdb.")));
|
|
|
|
/* Now check the CRC. */
|
|
INIT_CRC32(crc);
|
|
COMP_CRC32(crc,
|
|
(char *) ControlFile,
|
|
offsetof(ControlFileData, crc));
|
|
FIN_CRC32(crc);
|
|
|
|
if (!EQ_CRC32(crc, ControlFile->crc))
|
|
ereport(FATAL,
|
|
(errmsg("incorrect checksum in control file")));
|
|
|
|
/*
|
|
* Do compatibility checking immediately. If the database isn't
|
|
* compatible with the backend executable, we want to abort before we can
|
|
* possibly do any damage.
|
|
*/
|
|
if (ControlFile->catalog_version_no != CATALOG_VERSION_NO)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with CATALOG_VERSION_NO %d,"
|
|
" but the server was compiled with CATALOG_VERSION_NO %d.",
|
|
ControlFile->catalog_version_no, CATALOG_VERSION_NO),
|
|
errhint("It looks like you need to initdb.")));
|
|
if (ControlFile->maxAlign != MAXIMUM_ALIGNOF)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with MAXALIGN %d,"
|
|
" but the server was compiled with MAXALIGN %d.",
|
|
ControlFile->maxAlign, MAXIMUM_ALIGNOF),
|
|
errhint("It looks like you need to initdb.")));
|
|
if (ControlFile->floatFormat != FLOATFORMAT_VALUE)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster appears to use a different floating-point number format than the server executable."),
|
|
errhint("It looks like you need to initdb.")));
|
|
if (ControlFile->blcksz != BLCKSZ)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with BLCKSZ %d,"
|
|
" but the server was compiled with BLCKSZ %d.",
|
|
ControlFile->blcksz, BLCKSZ),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
if (ControlFile->relseg_size != RELSEG_SIZE)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with RELSEG_SIZE %d,"
|
|
" but the server was compiled with RELSEG_SIZE %d.",
|
|
ControlFile->relseg_size, RELSEG_SIZE),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
if (ControlFile->xlog_blcksz != XLOG_BLCKSZ)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with XLOG_BLCKSZ %d,"
|
|
" but the server was compiled with XLOG_BLCKSZ %d.",
|
|
ControlFile->xlog_blcksz, XLOG_BLCKSZ),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
if (ControlFile->xlog_seg_size != XLOG_SEG_SIZE)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with XLOG_SEG_SIZE %d,"
|
|
" but the server was compiled with XLOG_SEG_SIZE %d.",
|
|
ControlFile->xlog_seg_size, XLOG_SEG_SIZE),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
if (ControlFile->nameDataLen != NAMEDATALEN)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with NAMEDATALEN %d,"
|
|
" but the server was compiled with NAMEDATALEN %d.",
|
|
ControlFile->nameDataLen, NAMEDATALEN),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
if (ControlFile->indexMaxKeys != INDEX_MAX_KEYS)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with INDEX_MAX_KEYS %d,"
|
|
" but the server was compiled with INDEX_MAX_KEYS %d.",
|
|
ControlFile->indexMaxKeys, INDEX_MAX_KEYS),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
if (ControlFile->toast_max_chunk_size != TOAST_MAX_CHUNK_SIZE)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with TOAST_MAX_CHUNK_SIZE %d,"
|
|
" but the server was compiled with TOAST_MAX_CHUNK_SIZE %d.",
|
|
ControlFile->toast_max_chunk_size, (int) TOAST_MAX_CHUNK_SIZE),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
|
|
#ifdef HAVE_INT64_TIMESTAMP
|
|
if (ControlFile->enableIntTimes != true)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized without HAVE_INT64_TIMESTAMP"
|
|
" but the server was compiled with HAVE_INT64_TIMESTAMP."),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
#else
|
|
if (ControlFile->enableIntTimes != false)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with HAVE_INT64_TIMESTAMP"
|
|
" but the server was compiled without HAVE_INT64_TIMESTAMP."),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
#endif
|
|
|
|
#ifdef USE_FLOAT4_BYVAL
|
|
if (ControlFile->float4ByVal != true)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized without USE_FLOAT4_BYVAL"
|
|
" but the server was compiled with USE_FLOAT4_BYVAL."),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
#else
|
|
if (ControlFile->float4ByVal != false)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with USE_FLOAT4_BYVAL"
|
|
" but the server was compiled without USE_FLOAT4_BYVAL."),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
#endif
|
|
|
|
#ifdef USE_FLOAT8_BYVAL
|
|
if (ControlFile->float8ByVal != true)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized without USE_FLOAT8_BYVAL"
|
|
" but the server was compiled with USE_FLOAT8_BYVAL."),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
#else
|
|
if (ControlFile->float8ByVal != false)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with USE_FLOAT8_BYVAL"
|
|
" but the server was compiled without USE_FLOAT8_BYVAL."),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
#endif
|
|
}
|
|
|
|
void
|
|
UpdateControlFile(void)
|
|
{
|
|
int fd;
|
|
|
|
INIT_CRC32(ControlFile->crc);
|
|
COMP_CRC32(ControlFile->crc,
|
|
(char *) ControlFile,
|
|
offsetof(ControlFileData, crc));
|
|
FIN_CRC32(ControlFile->crc);
|
|
|
|
fd = BasicOpenFile(XLOG_CONTROL_FILE,
|
|
O_RDWR | PG_BINARY,
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open control file \"%s\": %m",
|
|
XLOG_CONTROL_FILE)));
|
|
|
|
errno = 0;
|
|
if (write(fd, ControlFile, sizeof(ControlFileData)) != sizeof(ControlFileData))
|
|
{
|
|
/* if write didn't set errno, assume problem is no disk space */
|
|
if (errno == 0)
|
|
errno = ENOSPC;
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to control file: %m")));
|
|
}
|
|
|
|
if (pg_fsync(fd) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync control file: %m")));
|
|
|
|
if (close(fd))
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close control file: %m")));
|
|
}
|
|
|
|
/*
|
|
* Returns the unique system identifier from control file.
|
|
*/
|
|
uint64
|
|
GetSystemIdentifier(void)
|
|
{
|
|
Assert(ControlFile != NULL);
|
|
return ControlFile->system_identifier;
|
|
}
|
|
|
|
/*
|
|
* Initialization of shared memory for XLOG
|
|
*/
|
|
Size
|
|
XLOGShmemSize(void)
|
|
{
|
|
Size size;
|
|
|
|
/* XLogCtl */
|
|
size = sizeof(XLogCtlData);
|
|
/* xlblocks array */
|
|
size = add_size(size, mul_size(sizeof(XLogRecPtr), XLOGbuffers));
|
|
/* extra alignment padding for XLOG I/O buffers */
|
|
size = add_size(size, ALIGNOF_XLOG_BUFFER);
|
|
/* and the buffers themselves */
|
|
size = add_size(size, mul_size(XLOG_BLCKSZ, XLOGbuffers));
|
|
|
|
/*
|
|
* Note: we don't count ControlFileData, it comes out of the "slop factor"
|
|
* added by CreateSharedMemoryAndSemaphores. This lets us use this
|
|
* routine again below to compute the actual allocation size.
|
|
*/
|
|
|
|
return size;
|
|
}
|
|
|
|
void
|
|
XLOGShmemInit(void)
|
|
{
|
|
bool foundCFile,
|
|
foundXLog;
|
|
char *allocptr;
|
|
|
|
ControlFile = (ControlFileData *)
|
|
ShmemInitStruct("Control File", sizeof(ControlFileData), &foundCFile);
|
|
XLogCtl = (XLogCtlData *)
|
|
ShmemInitStruct("XLOG Ctl", XLOGShmemSize(), &foundXLog);
|
|
|
|
if (foundCFile || foundXLog)
|
|
{
|
|
/* both should be present or neither */
|
|
Assert(foundCFile && foundXLog);
|
|
return;
|
|
}
|
|
|
|
memset(XLogCtl, 0, sizeof(XLogCtlData));
|
|
|
|
/*
|
|
* Since XLogCtlData contains XLogRecPtr fields, its sizeof should be a
|
|
* multiple of the alignment for same, so no extra alignment padding is
|
|
* needed here.
|
|
*/
|
|
allocptr = ((char *) XLogCtl) + sizeof(XLogCtlData);
|
|
XLogCtl->xlblocks = (XLogRecPtr *) allocptr;
|
|
memset(XLogCtl->xlblocks, 0, sizeof(XLogRecPtr) * XLOGbuffers);
|
|
allocptr += sizeof(XLogRecPtr) * XLOGbuffers;
|
|
|
|
/*
|
|
* Align the start of the page buffers to an ALIGNOF_XLOG_BUFFER boundary.
|
|
*/
|
|
allocptr = (char *) TYPEALIGN(ALIGNOF_XLOG_BUFFER, allocptr);
|
|
XLogCtl->pages = allocptr;
|
|
memset(XLogCtl->pages, 0, (Size) XLOG_BLCKSZ * XLOGbuffers);
|
|
|
|
/*
|
|
* Do basic initialization of XLogCtl shared data. (StartupXLOG will fill
|
|
* in additional info.)
|
|
*/
|
|
XLogCtl->XLogCacheBlck = XLOGbuffers - 1;
|
|
XLogCtl->SharedRecoveryInProgress = true;
|
|
XLogCtl->Insert.currpage = (XLogPageHeader) (XLogCtl->pages);
|
|
SpinLockInit(&XLogCtl->info_lck);
|
|
|
|
/*
|
|
* If we are not in bootstrap mode, pg_control should already exist. Read
|
|
* and validate it immediately (see comments in ReadControlFile() for the
|
|
* reasons why).
|
|
*/
|
|
if (!IsBootstrapProcessingMode())
|
|
ReadControlFile();
|
|
}
|
|
|
|
/*
|
|
* This func must be called ONCE on system install. It creates pg_control
|
|
* and the initial XLOG segment.
|
|
*/
|
|
void
|
|
BootStrapXLOG(void)
|
|
{
|
|
CheckPoint checkPoint;
|
|
char *buffer;
|
|
XLogPageHeader page;
|
|
XLogLongPageHeader longpage;
|
|
XLogRecord *record;
|
|
bool use_existent;
|
|
uint64 sysidentifier;
|
|
struct timeval tv;
|
|
pg_crc32 crc;
|
|
|
|
/*
|
|
* Select a hopefully-unique system identifier code for this installation.
|
|
* We use the result of gettimeofday(), including the fractional seconds
|
|
* field, as being about as unique as we can easily get. (Think not to
|
|
* use random(), since it hasn't been seeded and there's no portable way
|
|
* to seed it other than the system clock value...) The upper half of the
|
|
* uint64 value is just the tv_sec part, while the lower half is the XOR
|
|
* of tv_sec and tv_usec. This is to ensure that we don't lose uniqueness
|
|
* unnecessarily if "uint64" is really only 32 bits wide. A person
|
|
* knowing this encoding can determine the initialization time of the
|
|
* installation, which could perhaps be useful sometimes.
|
|
*/
|
|
gettimeofday(&tv, NULL);
|
|
sysidentifier = ((uint64) tv.tv_sec) << 32;
|
|
sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
|
|
|
|
/* First timeline ID is always 1 */
|
|
ThisTimeLineID = 1;
|
|
|
|
/* page buffer must be aligned suitably for O_DIRECT */
|
|
buffer = (char *) palloc(XLOG_BLCKSZ + ALIGNOF_XLOG_BUFFER);
|
|
page = (XLogPageHeader) TYPEALIGN(ALIGNOF_XLOG_BUFFER, buffer);
|
|
memset(page, 0, XLOG_BLCKSZ);
|
|
|
|
/* Set up information for the initial checkpoint record */
|
|
checkPoint.redo.xlogid = 0;
|
|
checkPoint.redo.xrecoff = SizeOfXLogLongPHD;
|
|
checkPoint.ThisTimeLineID = ThisTimeLineID;
|
|
checkPoint.nextXidEpoch = 0;
|
|
checkPoint.nextXid = FirstNormalTransactionId;
|
|
checkPoint.nextOid = FirstBootstrapObjectId;
|
|
checkPoint.nextMulti = FirstMultiXactId;
|
|
checkPoint.nextMultiOffset = 0;
|
|
checkPoint.oldestXid = FirstNormalTransactionId;
|
|
checkPoint.oldestXidDB = TemplateDbOid;
|
|
checkPoint.time = (pg_time_t) time(NULL);
|
|
checkPoint.oldestActiveXid = InvalidTransactionId;
|
|
|
|
ShmemVariableCache->nextXid = checkPoint.nextXid;
|
|
ShmemVariableCache->nextOid = checkPoint.nextOid;
|
|
ShmemVariableCache->oidCount = 0;
|
|
MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
|
|
SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
|
|
|
|
/* Set up the XLOG page header */
|
|
page->xlp_magic = XLOG_PAGE_MAGIC;
|
|
page->xlp_info = XLP_LONG_HEADER;
|
|
page->xlp_tli = ThisTimeLineID;
|
|
page->xlp_pageaddr.xlogid = 0;
|
|
page->xlp_pageaddr.xrecoff = 0;
|
|
longpage = (XLogLongPageHeader) page;
|
|
longpage->xlp_sysid = sysidentifier;
|
|
longpage->xlp_seg_size = XLogSegSize;
|
|
longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
|
|
|
|
/* Insert the initial checkpoint record */
|
|
record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
|
|
record->xl_prev.xlogid = 0;
|
|
record->xl_prev.xrecoff = 0;
|
|
record->xl_xid = InvalidTransactionId;
|
|
record->xl_tot_len = SizeOfXLogRecord + sizeof(checkPoint);
|
|
record->xl_len = sizeof(checkPoint);
|
|
record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
|
|
record->xl_rmid = RM_XLOG_ID;
|
|
memcpy(XLogRecGetData(record), &checkPoint, sizeof(checkPoint));
|
|
|
|
INIT_CRC32(crc);
|
|
COMP_CRC32(crc, &checkPoint, sizeof(checkPoint));
|
|
COMP_CRC32(crc, (char *) record + sizeof(pg_crc32),
|
|
SizeOfXLogRecord - sizeof(pg_crc32));
|
|
FIN_CRC32(crc);
|
|
record->xl_crc = crc;
|
|
|
|
/* Create first XLOG segment file */
|
|
use_existent = false;
|
|
openLogFile = XLogFileInit(0, 0, &use_existent, false);
|
|
|
|
/* Write the first page with the initial record */
|
|
errno = 0;
|
|
if (write(openLogFile, page, XLOG_BLCKSZ) != XLOG_BLCKSZ)
|
|
{
|
|
/* if write didn't set errno, assume problem is no disk space */
|
|
if (errno == 0)
|
|
errno = ENOSPC;
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write bootstrap transaction log file: %m")));
|
|
}
|
|
|
|
if (pg_fsync(openLogFile) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync bootstrap transaction log file: %m")));
|
|
|
|
if (close(openLogFile))
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close bootstrap transaction log file: %m")));
|
|
|
|
openLogFile = -1;
|
|
|
|
/* Now create pg_control */
|
|
|
|
memset(ControlFile, 0, sizeof(ControlFileData));
|
|
/* Initialize pg_control status fields */
|
|
ControlFile->system_identifier = sysidentifier;
|
|
ControlFile->state = DB_SHUTDOWNED;
|
|
ControlFile->time = checkPoint.time;
|
|
ControlFile->checkPoint = checkPoint.redo;
|
|
ControlFile->checkPointCopy = checkPoint;
|
|
/* some additional ControlFile fields are set in WriteControlFile() */
|
|
|
|
WriteControlFile();
|
|
|
|
/* Bootstrap the commit log, too */
|
|
BootStrapCLOG();
|
|
BootStrapSUBTRANS();
|
|
BootStrapMultiXact();
|
|
|
|
pfree(buffer);
|
|
}
|
|
|
|
static char *
|
|
str_time(pg_time_t tnow)
|
|
{
|
|
static char buf[128];
|
|
|
|
pg_strftime(buf, sizeof(buf),
|
|
"%Y-%m-%d %H:%M:%S %Z",
|
|
pg_localtime(&tnow, log_timezone));
|
|
|
|
return buf;
|
|
}
|
|
|
|
/*
|
|
* See if there is a recovery command file (recovery.conf), and if so
|
|
* read in parameters for archive recovery and XLOG streaming.
|
|
*
|
|
* XXX longer term intention is to expand this to
|
|
* cater for additional parameters and controls
|
|
* possibly use a flex lexer similar to the GUC one
|
|
*/
|
|
static void
|
|
readRecoveryCommandFile(void)
|
|
{
|
|
FILE *fd;
|
|
char cmdline[MAXPGPATH];
|
|
TimeLineID rtli = 0;
|
|
bool rtliGiven = false;
|
|
bool syntaxError = false;
|
|
|
|
fd = AllocateFile(RECOVERY_COMMAND_FILE, "r");
|
|
if (fd == NULL)
|
|
{
|
|
if (errno == ENOENT)
|
|
return; /* not there, so no archive recovery */
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open recovery command file \"%s\": %m",
|
|
RECOVERY_COMMAND_FILE)));
|
|
}
|
|
|
|
/*
|
|
* Parse the file...
|
|
*/
|
|
while (fgets(cmdline, sizeof(cmdline), fd) != NULL)
|
|
{
|
|
/* skip leading whitespace and check for # comment */
|
|
char *ptr;
|
|
char *tok1;
|
|
char *tok2;
|
|
|
|
for (ptr = cmdline; *ptr; ptr++)
|
|
{
|
|
if (!isspace((unsigned char) *ptr))
|
|
break;
|
|
}
|
|
if (*ptr == '\0' || *ptr == '#')
|
|
continue;
|
|
|
|
/* identify the quoted parameter value */
|
|
tok1 = strtok(ptr, "'");
|
|
if (!tok1)
|
|
{
|
|
syntaxError = true;
|
|
break;
|
|
}
|
|
tok2 = strtok(NULL, "'");
|
|
if (!tok2)
|
|
{
|
|
syntaxError = true;
|
|
break;
|
|
}
|
|
/* reparse to get just the parameter name */
|
|
tok1 = strtok(ptr, " \t=");
|
|
if (!tok1)
|
|
{
|
|
syntaxError = true;
|
|
break;
|
|
}
|
|
|
|
if (strcmp(tok1, "restore_command") == 0)
|
|
{
|
|
recoveryRestoreCommand = pstrdup(tok2);
|
|
ereport(DEBUG2,
|
|
(errmsg("restore_command = '%s'",
|
|
recoveryRestoreCommand)));
|
|
}
|
|
else if (strcmp(tok1, "recovery_end_command") == 0)
|
|
{
|
|
recoveryEndCommand = pstrdup(tok2);
|
|
ereport(DEBUG2,
|
|
(errmsg("recovery_end_command = '%s'",
|
|
recoveryEndCommand)));
|
|
}
|
|
else if (strcmp(tok1, "recovery_target_timeline") == 0)
|
|
{
|
|
rtliGiven = true;
|
|
if (strcmp(tok2, "latest") == 0)
|
|
rtli = 0;
|
|
else
|
|
{
|
|
errno = 0;
|
|
rtli = (TimeLineID) strtoul(tok2, NULL, 0);
|
|
if (errno == EINVAL || errno == ERANGE)
|
|
ereport(FATAL,
|
|
(errmsg("recovery_target_timeline is not a valid number: \"%s\"",
|
|
tok2)));
|
|
}
|
|
if (rtli)
|
|
ereport(DEBUG2,
|
|
(errmsg("recovery_target_timeline = %u", rtli)));
|
|
else
|
|
ereport(DEBUG2,
|
|
(errmsg("recovery_target_timeline = latest")));
|
|
}
|
|
else if (strcmp(tok1, "recovery_target_xid") == 0)
|
|
{
|
|
errno = 0;
|
|
recoveryTargetXid = (TransactionId) strtoul(tok2, NULL, 0);
|
|
if (errno == EINVAL || errno == ERANGE)
|
|
ereport(FATAL,
|
|
(errmsg("recovery_target_xid is not a valid number: \"%s\"",
|
|
tok2)));
|
|
ereport(DEBUG2,
|
|
(errmsg("recovery_target_xid = %u",
|
|
recoveryTargetXid)));
|
|
recoveryTarget = true;
|
|
recoveryTargetExact = true;
|
|
}
|
|
else if (strcmp(tok1, "recovery_target_time") == 0)
|
|
{
|
|
/*
|
|
* if recovery_target_xid specified, then this overrides
|
|
* recovery_target_time
|
|
*/
|
|
if (recoveryTargetExact)
|
|
continue;
|
|
recoveryTarget = true;
|
|
recoveryTargetExact = false;
|
|
|
|
/*
|
|
* Convert the time string given by the user to TimestampTz form.
|
|
*/
|
|
recoveryTargetTime =
|
|
DatumGetTimestampTz(DirectFunctionCall3(timestamptz_in,
|
|
CStringGetDatum(tok2),
|
|
ObjectIdGetDatum(InvalidOid),
|
|
Int32GetDatum(-1)));
|
|
ereport(DEBUG2,
|
|
(errmsg("recovery_target_time = '%s'",
|
|
timestamptz_to_str(recoveryTargetTime))));
|
|
}
|
|
else if (strcmp(tok1, "recovery_target_inclusive") == 0)
|
|
{
|
|
/*
|
|
* does nothing if a recovery_target is not also set
|
|
*/
|
|
if (!parse_bool(tok2, &recoveryTargetInclusive))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("parameter \"recovery_target_inclusive\" requires a Boolean value")));
|
|
ereport(DEBUG2,
|
|
(errmsg("recovery_target_inclusive = %s", tok2)));
|
|
}
|
|
else if (strcmp(tok1, "standby_mode") == 0)
|
|
{
|
|
if (!parse_bool(tok2, &StandbyMode))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("parameter \"standby_mode\" requires a Boolean value")));
|
|
ereport(DEBUG2,
|
|
(errmsg("standby_mode = '%s'", tok2)));
|
|
}
|
|
else if (strcmp(tok1, "primary_conninfo") == 0)
|
|
{
|
|
PrimaryConnInfo = pstrdup(tok2);
|
|
ereport(DEBUG2,
|
|
(errmsg("primary_conninfo = '%s'",
|
|
PrimaryConnInfo)));
|
|
}
|
|
else if (strcmp(tok1, "trigger_file") == 0)
|
|
{
|
|
TriggerFile = pstrdup(tok2);
|
|
ereport(DEBUG2,
|
|
(errmsg("trigger_file = '%s'",
|
|
TriggerFile)));
|
|
}
|
|
else
|
|
ereport(FATAL,
|
|
(errmsg("unrecognized recovery parameter \"%s\"",
|
|
tok1)));
|
|
}
|
|
|
|
FreeFile(fd);
|
|
|
|
if (syntaxError)
|
|
ereport(FATAL,
|
|
(errmsg("syntax error in recovery command file: %s",
|
|
cmdline),
|
|
errhint("Lines should have the format parameter = 'value'.")));
|
|
|
|
/* If not in standby mode, restore_command must be supplied */
|
|
if (!StandbyMode && recoveryRestoreCommand == NULL)
|
|
ereport(FATAL,
|
|
(errmsg("recovery command file \"%s\" did not specify restore_command nor standby_mode",
|
|
RECOVERY_COMMAND_FILE)));
|
|
|
|
/* Enable fetching from archive recovery area */
|
|
InArchiveRecovery = true;
|
|
|
|
/*
|
|
* If user specified recovery_target_timeline, validate it or compute the
|
|
* "latest" value. We can't do this until after we've gotten the restore
|
|
* command and set InArchiveRecovery, because we need to fetch timeline
|
|
* history files from the archive.
|
|
*/
|
|
if (rtliGiven)
|
|
{
|
|
if (rtli)
|
|
{
|
|
/* Timeline 1 does not have a history file, all else should */
|
|
if (rtli != 1 && !existsTimeLineHistory(rtli))
|
|
ereport(FATAL,
|
|
(errmsg("recovery target timeline %u does not exist",
|
|
rtli)));
|
|
recoveryTargetTLI = rtli;
|
|
}
|
|
else
|
|
{
|
|
/* We start the "latest" search from pg_control's timeline */
|
|
recoveryTargetTLI = findNewestTimeLine(recoveryTargetTLI);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Exit archive-recovery state
|
|
*/
|
|
static void
|
|
exitArchiveRecovery(TimeLineID endTLI, uint32 endLogId, uint32 endLogSeg)
|
|
{
|
|
char recoveryPath[MAXPGPATH];
|
|
char xlogpath[MAXPGPATH];
|
|
XLogRecPtr InvalidXLogRecPtr = {0, 0};
|
|
|
|
/*
|
|
* We are no longer in archive recovery state.
|
|
*/
|
|
InArchiveRecovery = false;
|
|
|
|
/*
|
|
* Update min recovery point one last time.
|
|
*/
|
|
UpdateMinRecoveryPoint(InvalidXLogRecPtr, true);
|
|
|
|
/*
|
|
* If the ending log segment is still open, close it (to avoid
|
|
* problems on Windows with trying to rename or delete an open file).
|
|
*/
|
|
if (readFile >= 0)
|
|
{
|
|
close(readFile);
|
|
readFile = -1;
|
|
}
|
|
|
|
/*
|
|
* If the segment was fetched from archival storage, we want to replace
|
|
* the existing xlog segment (if any) with the archival version. This is
|
|
* because whatever is in XLOGDIR is very possibly older than what we have
|
|
* from the archives, since it could have come from restoring a PGDATA
|
|
* backup. In any case, the archival version certainly is more
|
|
* descriptive of what our current database state is, because that is what
|
|
* we replayed from.
|
|
*
|
|
* Note that if we are establishing a new timeline, ThisTimeLineID is
|
|
* already set to the new value, and so we will create a new file instead
|
|
* of overwriting any existing file. (This is, in fact, always the case
|
|
* at present.)
|
|
*/
|
|
snprintf(recoveryPath, MAXPGPATH, XLOGDIR "/RECOVERYXLOG");
|
|
XLogFilePath(xlogpath, ThisTimeLineID, endLogId, endLogSeg);
|
|
|
|
if (restoredFromArchive)
|
|
{
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("moving last restored xlog to \"%s\"",
|
|
xlogpath)));
|
|
unlink(xlogpath); /* might or might not exist */
|
|
if (rename(recoveryPath, xlogpath) != 0)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename file \"%s\" to \"%s\": %m",
|
|
recoveryPath, xlogpath)));
|
|
/* XXX might we need to fix permissions on the file? */
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If the latest segment is not archival, but there's still a
|
|
* RECOVERYXLOG laying about, get rid of it.
|
|
*/
|
|
unlink(recoveryPath); /* ignore any error */
|
|
|
|
/*
|
|
* If we are establishing a new timeline, we have to copy data from
|
|
* the last WAL segment of the old timeline to create a starting WAL
|
|
* segment for the new timeline.
|
|
*
|
|
* Notify the archiver that the last WAL segment of the old timeline
|
|
* is ready to copy to archival storage. Otherwise, it is not archived
|
|
* for a while.
|
|
*/
|
|
if (endTLI != ThisTimeLineID)
|
|
{
|
|
XLogFileCopy(endLogId, endLogSeg,
|
|
endTLI, endLogId, endLogSeg);
|
|
|
|
if (XLogArchivingActive())
|
|
{
|
|
XLogFileName(xlogpath, endTLI, endLogId, endLogSeg);
|
|
XLogArchiveNotify(xlogpath);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Let's just make real sure there are not .ready or .done flags posted
|
|
* for the new segment.
|
|
*/
|
|
XLogFileName(xlogpath, ThisTimeLineID, endLogId, endLogSeg);
|
|
XLogArchiveCleanup(xlogpath);
|
|
|
|
/* Get rid of any remaining recovered timeline-history file, too */
|
|
snprintf(recoveryPath, MAXPGPATH, XLOGDIR "/RECOVERYHISTORY");
|
|
unlink(recoveryPath); /* ignore any error */
|
|
|
|
/*
|
|
* Rename the config file out of the way, so that we don't accidentally
|
|
* re-enter archive recovery mode in a subsequent crash.
|
|
*/
|
|
unlink(RECOVERY_COMMAND_DONE);
|
|
if (rename(RECOVERY_COMMAND_FILE, RECOVERY_COMMAND_DONE) != 0)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename file \"%s\" to \"%s\": %m",
|
|
RECOVERY_COMMAND_FILE, RECOVERY_COMMAND_DONE)));
|
|
|
|
ereport(LOG,
|
|
(errmsg("archive recovery complete")));
|
|
}
|
|
|
|
/*
|
|
* For point-in-time recovery, this function decides whether we want to
|
|
* stop applying the XLOG at or after the current record.
|
|
*
|
|
* Returns TRUE if we are stopping, FALSE otherwise. On TRUE return,
|
|
* *includeThis is set TRUE if we should apply this record before stopping.
|
|
*
|
|
* We also track the timestamp of the latest applied COMMIT/ABORT record
|
|
* in recoveryLastXTime, for logging purposes.
|
|
* Also, some information is saved in recoveryStopXid et al for use in
|
|
* annotating the new timeline's history file.
|
|
*/
|
|
static bool
|
|
recoveryStopsHere(XLogRecord *record, bool *includeThis)
|
|
{
|
|
bool stopsHere;
|
|
uint8 record_info;
|
|
TimestampTz recordXtime;
|
|
|
|
/* We only consider stopping at COMMIT or ABORT records */
|
|
if (record->xl_rmid == RM_XACT_ID)
|
|
{
|
|
record_info = record->xl_info & ~XLR_INFO_MASK;
|
|
if (record_info == XLOG_XACT_COMMIT)
|
|
{
|
|
xl_xact_commit *recordXactCommitData;
|
|
|
|
recordXactCommitData = (xl_xact_commit *) XLogRecGetData(record);
|
|
recordXtime = recordXactCommitData->xact_time;
|
|
}
|
|
else if (record_info == XLOG_XACT_ABORT)
|
|
{
|
|
xl_xact_abort *recordXactAbortData;
|
|
|
|
recordXactAbortData = (xl_xact_abort *) XLogRecGetData(record);
|
|
recordXtime = recordXactAbortData->xact_time;
|
|
}
|
|
else
|
|
return false;
|
|
}
|
|
else if (record->xl_rmid == RM_XLOG_ID)
|
|
{
|
|
record_info = record->xl_info & ~XLR_INFO_MASK;
|
|
if (record_info == XLOG_CHECKPOINT_SHUTDOWN ||
|
|
record_info == XLOG_CHECKPOINT_ONLINE)
|
|
{
|
|
CheckPoint checkPoint;
|
|
|
|
memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
|
|
recoveryLastXTime = checkPoint.time;
|
|
}
|
|
|
|
/*
|
|
* We don't want to stop recovery on a checkpoint record, but we do
|
|
* want to update recoveryLastXTime. So return is unconditional.
|
|
*/
|
|
return false;
|
|
}
|
|
else
|
|
return false;
|
|
|
|
/* Do we have a PITR target at all? */
|
|
if (!recoveryTarget)
|
|
{
|
|
recoveryLastXTime = recordXtime;
|
|
return false;
|
|
}
|
|
|
|
if (recoveryTargetExact)
|
|
{
|
|
/*
|
|
* there can be only one transaction end record with this exact
|
|
* transactionid
|
|
*
|
|
* when testing for an xid, we MUST test for equality only, since
|
|
* transactions are numbered in the order they start, not the order
|
|
* they complete. A higher numbered xid will complete before you about
|
|
* 50% of the time...
|
|
*/
|
|
stopsHere = (record->xl_xid == recoveryTargetXid);
|
|
if (stopsHere)
|
|
*includeThis = recoveryTargetInclusive;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* there can be many transactions that share the same commit time, so
|
|
* we stop after the last one, if we are inclusive, or stop at the
|
|
* first one if we are exclusive
|
|
*/
|
|
if (recoveryTargetInclusive)
|
|
stopsHere = (recordXtime > recoveryTargetTime);
|
|
else
|
|
stopsHere = (recordXtime >= recoveryTargetTime);
|
|
if (stopsHere)
|
|
*includeThis = false;
|
|
}
|
|
|
|
if (stopsHere)
|
|
{
|
|
recoveryStopXid = record->xl_xid;
|
|
recoveryStopTime = recordXtime;
|
|
recoveryStopAfter = *includeThis;
|
|
|
|
if (record_info == XLOG_XACT_COMMIT)
|
|
{
|
|
if (recoveryStopAfter)
|
|
ereport(LOG,
|
|
(errmsg("recovery stopping after commit of transaction %u, time %s",
|
|
recoveryStopXid,
|
|
timestamptz_to_str(recoveryStopTime))));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("recovery stopping before commit of transaction %u, time %s",
|
|
recoveryStopXid,
|
|
timestamptz_to_str(recoveryStopTime))));
|
|
}
|
|
else
|
|
{
|
|
if (recoveryStopAfter)
|
|
ereport(LOG,
|
|
(errmsg("recovery stopping after abort of transaction %u, time %s",
|
|
recoveryStopXid,
|
|
timestamptz_to_str(recoveryStopTime))));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("recovery stopping before abort of transaction %u, time %s",
|
|
recoveryStopXid,
|
|
timestamptz_to_str(recoveryStopTime))));
|
|
}
|
|
|
|
if (recoveryStopAfter)
|
|
recoveryLastXTime = recordXtime;
|
|
}
|
|
else
|
|
recoveryLastXTime = recordXtime;
|
|
|
|
return stopsHere;
|
|
}
|
|
|
|
/*
|
|
* Returns bool with current recovery mode, a global state.
|
|
*/
|
|
Datum
|
|
pg_is_in_recovery(PG_FUNCTION_ARGS)
|
|
{
|
|
PG_RETURN_BOOL(RecoveryInProgress());
|
|
}
|
|
|
|
/*
|
|
* Returns timestamp of last recovered commit/abort record.
|
|
*/
|
|
TimestampTz
|
|
GetLatestXLogTime(void)
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
recoveryLastXTime = xlogctl->recoveryLastXTime;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
return recoveryLastXTime;
|
|
}
|
|
|
|
/*
|
|
* Note that text field supplied is a parameter name and does not require translation
|
|
*/
|
|
#define RecoveryRequiresIntParameter(param_name, currValue, checkpointValue) \
|
|
{ \
|
|
if (currValue < checkpointValue) \
|
|
ereport(ERROR, \
|
|
(errmsg("recovery connections cannot continue because " \
|
|
"%s = %u is a lower setting than on WAL source server (value was %u)", \
|
|
param_name, \
|
|
currValue, \
|
|
checkpointValue))); \
|
|
}
|
|
|
|
/*
|
|
* Check to see if required parameters are set high enough on this server
|
|
* for various aspects of recovery operation.
|
|
*/
|
|
static void
|
|
CheckRequiredParameterValues(CheckPoint checkPoint)
|
|
{
|
|
/* We ignore autovacuum_max_workers when we make this test. */
|
|
RecoveryRequiresIntParameter("max_connections",
|
|
MaxConnections, checkPoint.MaxConnections);
|
|
|
|
RecoveryRequiresIntParameter("max_prepared_xacts",
|
|
max_prepared_xacts, checkPoint.max_prepared_xacts);
|
|
RecoveryRequiresIntParameter("max_locks_per_xact",
|
|
max_locks_per_xact, checkPoint.max_locks_per_xact);
|
|
|
|
if (!checkPoint.XLogStandbyInfoMode)
|
|
ereport(ERROR,
|
|
(errmsg("recovery connections cannot start because the recovery_connections "
|
|
"parameter is disabled on the WAL source server")));
|
|
}
|
|
|
|
/*
|
|
* This must be called ONCE during postmaster or standalone-backend startup
|
|
*/
|
|
void
|
|
StartupXLOG(void)
|
|
{
|
|
XLogCtlInsert *Insert;
|
|
CheckPoint checkPoint;
|
|
bool wasShutdown;
|
|
bool reachedStopPoint = false;
|
|
bool haveBackupLabel = false;
|
|
XLogRecPtr RecPtr,
|
|
checkPointLoc,
|
|
EndOfLog;
|
|
uint32 endLogId;
|
|
uint32 endLogSeg;
|
|
XLogRecord *record;
|
|
uint32 freespace;
|
|
TransactionId oldestActiveXID;
|
|
bool bgwriterLaunched = false;
|
|
bool backendsAllowed = false;
|
|
|
|
/*
|
|
* Read control file and check XLOG status looks valid.
|
|
*
|
|
* Note: in most control paths, *ControlFile is already valid and we need
|
|
* not do ReadControlFile() here, but might as well do it to be sure.
|
|
*/
|
|
ReadControlFile();
|
|
|
|
if (ControlFile->state < DB_SHUTDOWNED ||
|
|
ControlFile->state > DB_IN_PRODUCTION ||
|
|
!XRecOffIsValid(ControlFile->checkPoint.xrecoff))
|
|
ereport(FATAL,
|
|
(errmsg("control file contains invalid data")));
|
|
|
|
if (ControlFile->state == DB_SHUTDOWNED)
|
|
ereport(LOG,
|
|
(errmsg("database system was shut down at %s",
|
|
str_time(ControlFile->time))));
|
|
else if (ControlFile->state == DB_SHUTDOWNING)
|
|
ereport(LOG,
|
|
(errmsg("database system shutdown was interrupted; last known up at %s",
|
|
str_time(ControlFile->time))));
|
|
else if (ControlFile->state == DB_IN_CRASH_RECOVERY)
|
|
ereport(LOG,
|
|
(errmsg("database system was interrupted while in recovery at %s",
|
|
str_time(ControlFile->time)),
|
|
errhint("This probably means that some data is corrupted and"
|
|
" you will have to use the last backup for recovery.")));
|
|
else if (ControlFile->state == DB_IN_ARCHIVE_RECOVERY)
|
|
ereport(LOG,
|
|
(errmsg("database system was interrupted while in recovery at log time %s",
|
|
str_time(ControlFile->checkPointCopy.time)),
|
|
errhint("If this has occurred more than once some data might be corrupted"
|
|
" and you might need to choose an earlier recovery target.")));
|
|
else if (ControlFile->state == DB_IN_PRODUCTION)
|
|
ereport(LOG,
|
|
(errmsg("database system was interrupted; last known up at %s",
|
|
str_time(ControlFile->time))));
|
|
|
|
/* This is just to allow attaching to startup process with a debugger */
|
|
#ifdef XLOG_REPLAY_DELAY
|
|
if (ControlFile->state != DB_SHUTDOWNED)
|
|
pg_usleep(60000000L);
|
|
#endif
|
|
|
|
/*
|
|
* Verify that pg_xlog and pg_xlog/archive_status exist. In cases where
|
|
* someone has performed a copy for PITR, these directories may have been
|
|
* excluded and need to be re-created.
|
|
*/
|
|
ValidateXLOGDirectoryStructure();
|
|
|
|
/*
|
|
* Clear out any old relcache cache files. This is *necessary* if we
|
|
* do any WAL replay, since that would probably result in the cache files
|
|
* being out of sync with database reality. In theory we could leave
|
|
* them in place if the database had been cleanly shut down, but it
|
|
* seems safest to just remove them always and let them be rebuilt
|
|
* during the first backend startup.
|
|
*/
|
|
RelationCacheInitFileRemove();
|
|
|
|
/*
|
|
* Initialize on the assumption we want to recover to the same timeline
|
|
* that's active according to pg_control.
|
|
*/
|
|
recoveryTargetTLI = ControlFile->checkPointCopy.ThisTimeLineID;
|
|
|
|
/*
|
|
* Check for recovery control file, and if so set up state for offline
|
|
* recovery
|
|
*/
|
|
readRecoveryCommandFile();
|
|
|
|
/* Now we can determine the list of expected TLIs */
|
|
expectedTLIs = readTimeLineHistory(recoveryTargetTLI);
|
|
|
|
/*
|
|
* If pg_control's timeline is not in expectedTLIs, then we cannot
|
|
* proceed: the backup is not part of the history of the requested
|
|
* timeline.
|
|
*/
|
|
if (!list_member_int(expectedTLIs,
|
|
(int) ControlFile->checkPointCopy.ThisTimeLineID))
|
|
ereport(FATAL,
|
|
(errmsg("requested timeline %u is not a child of database system timeline %u",
|
|
recoveryTargetTLI,
|
|
ControlFile->checkPointCopy.ThisTimeLineID)));
|
|
|
|
/* Save the selected recovery target timeline ID in shared memory */
|
|
XLogCtl->RecoveryTargetTLI = recoveryTargetTLI;
|
|
|
|
if (read_backup_label(&checkPointLoc))
|
|
{
|
|
/*
|
|
* When a backup_label file is present, we want to roll forward from
|
|
* the checkpoint it identifies, rather than using pg_control.
|
|
*/
|
|
record = ReadCheckpointRecord(checkPointLoc, 0);
|
|
if (record != NULL)
|
|
{
|
|
ereport(DEBUG1,
|
|
(errmsg("checkpoint record is at %X/%X",
|
|
checkPointLoc.xlogid, checkPointLoc.xrecoff)));
|
|
InRecovery = true; /* force recovery even if SHUTDOWNED */
|
|
}
|
|
else
|
|
{
|
|
ereport(PANIC,
|
|
(errmsg("could not locate required checkpoint record"),
|
|
errhint("If you are not restoring from a backup, try removing the file \"%s/backup_label\".", DataDir)));
|
|
}
|
|
/* set flag to delete it later */
|
|
haveBackupLabel = true;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Get the last valid checkpoint record. If the latest one according
|
|
* to pg_control is broken, try the next-to-last one.
|
|
*/
|
|
checkPointLoc = ControlFile->checkPoint;
|
|
RedoStartLSN = ControlFile->checkPointCopy.redo;
|
|
record = ReadCheckpointRecord(checkPointLoc, 1);
|
|
if (record != NULL)
|
|
{
|
|
ereport(DEBUG1,
|
|
(errmsg("checkpoint record is at %X/%X",
|
|
checkPointLoc.xlogid, checkPointLoc.xrecoff)));
|
|
}
|
|
else if (StandbyMode)
|
|
{
|
|
/*
|
|
* The last valid checkpoint record required for a streaming
|
|
* recovery exists in neither standby nor the primary.
|
|
*/
|
|
ereport(PANIC,
|
|
(errmsg("could not locate a valid checkpoint record")));
|
|
}
|
|
else
|
|
{
|
|
checkPointLoc = ControlFile->prevCheckPoint;
|
|
record = ReadCheckpointRecord(checkPointLoc, 2);
|
|
if (record != NULL)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("using previous checkpoint record at %X/%X",
|
|
checkPointLoc.xlogid, checkPointLoc.xrecoff)));
|
|
InRecovery = true; /* force recovery even if SHUTDOWNED */
|
|
}
|
|
else
|
|
ereport(PANIC,
|
|
(errmsg("could not locate a valid checkpoint record")));
|
|
}
|
|
}
|
|
|
|
LastRec = RecPtr = checkPointLoc;
|
|
memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
|
|
wasShutdown = (record->xl_info == XLOG_CHECKPOINT_SHUTDOWN);
|
|
|
|
ereport(DEBUG1,
|
|
(errmsg("redo record is at %X/%X; shutdown %s",
|
|
checkPoint.redo.xlogid, checkPoint.redo.xrecoff,
|
|
wasShutdown ? "TRUE" : "FALSE")));
|
|
ereport(DEBUG1,
|
|
(errmsg("next transaction ID: %u/%u; next OID: %u",
|
|
checkPoint.nextXidEpoch, checkPoint.nextXid,
|
|
checkPoint.nextOid)));
|
|
ereport(DEBUG1,
|
|
(errmsg("next MultiXactId: %u; next MultiXactOffset: %u",
|
|
checkPoint.nextMulti, checkPoint.nextMultiOffset)));
|
|
ereport(DEBUG1,
|
|
(errmsg("oldest unfrozen transaction ID: %u, in database %u",
|
|
checkPoint.oldestXid, checkPoint.oldestXidDB)));
|
|
if (!TransactionIdIsNormal(checkPoint.nextXid))
|
|
ereport(PANIC,
|
|
(errmsg("invalid next transaction ID")));
|
|
|
|
ShmemVariableCache->nextXid = checkPoint.nextXid;
|
|
ShmemVariableCache->nextOid = checkPoint.nextOid;
|
|
ShmemVariableCache->oidCount = 0;
|
|
MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
|
|
SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
|
|
|
|
/*
|
|
* We must replay WAL entries using the same TimeLineID they were created
|
|
* under, so temporarily adopt the TLI indicated by the checkpoint (see
|
|
* also xlog_redo()).
|
|
*/
|
|
ThisTimeLineID = checkPoint.ThisTimeLineID;
|
|
|
|
RedoRecPtr = XLogCtl->Insert.RedoRecPtr = checkPoint.redo;
|
|
|
|
if (XLByteLT(RecPtr, checkPoint.redo))
|
|
ereport(PANIC,
|
|
(errmsg("invalid redo in checkpoint record")));
|
|
|
|
/*
|
|
* Check whether we need to force recovery from WAL. If it appears to
|
|
* have been a clean shutdown and we did not have a recovery.conf file,
|
|
* then assume no recovery needed.
|
|
*/
|
|
if (XLByteLT(checkPoint.redo, RecPtr))
|
|
{
|
|
if (wasShutdown)
|
|
ereport(PANIC,
|
|
(errmsg("invalid redo record in shutdown checkpoint")));
|
|
InRecovery = true;
|
|
}
|
|
else if (ControlFile->state != DB_SHUTDOWNED)
|
|
InRecovery = true;
|
|
else if (InArchiveRecovery)
|
|
{
|
|
/* force recovery due to presence of recovery.conf */
|
|
InRecovery = true;
|
|
}
|
|
|
|
/* REDO */
|
|
if (InRecovery)
|
|
{
|
|
int rmid;
|
|
|
|
/*
|
|
* Update pg_control to show that we are recovering and to show the
|
|
* selected checkpoint as the place we are starting from. We also mark
|
|
* pg_control with any minimum recovery stop point obtained from a
|
|
* backup history file.
|
|
*/
|
|
if (InArchiveRecovery)
|
|
{
|
|
if (StandbyMode)
|
|
ereport(LOG,
|
|
(errmsg("entering standby mode")));
|
|
else if (recoveryTarget)
|
|
{
|
|
if (recoveryTargetExact)
|
|
ereport(LOG,
|
|
(errmsg("starting point-in-time recovery to XID %u",
|
|
recoveryTargetXid)));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("starting point-in-time recovery to %s",
|
|
timestamptz_to_str(recoveryTargetTime))));
|
|
}
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("starting archive recovery")));
|
|
ControlFile->state = DB_IN_ARCHIVE_RECOVERY;
|
|
}
|
|
else
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("database system was not properly shut down; "
|
|
"automatic recovery in progress")));
|
|
ControlFile->state = DB_IN_CRASH_RECOVERY;
|
|
}
|
|
ControlFile->prevCheckPoint = ControlFile->checkPoint;
|
|
ControlFile->checkPoint = checkPointLoc;
|
|
ControlFile->checkPointCopy = checkPoint;
|
|
if (InArchiveRecovery)
|
|
{
|
|
/* initialize minRecoveryPoint if not set yet */
|
|
if (XLByteLT(ControlFile->minRecoveryPoint, checkPoint.redo))
|
|
ControlFile->minRecoveryPoint = checkPoint.redo;
|
|
}
|
|
/*
|
|
* set backupStartupPoint if we're starting archive recovery from a
|
|
* base backup
|
|
*/
|
|
if (haveBackupLabel)
|
|
ControlFile->backupStartPoint = checkPoint.redo;
|
|
ControlFile->time = (pg_time_t) time(NULL);
|
|
/* No need to hold ControlFileLock yet, we aren't up far enough */
|
|
UpdateControlFile();
|
|
|
|
/* initialize our local copy of minRecoveryPoint */
|
|
minRecoveryPoint = ControlFile->minRecoveryPoint;
|
|
|
|
/*
|
|
* Reset pgstat data, because it may be invalid after recovery.
|
|
*/
|
|
pgstat_reset_all();
|
|
|
|
/*
|
|
* If there was a backup label file, it's done its job and the info
|
|
* has now been propagated into pg_control. We must get rid of the
|
|
* label file so that if we crash during recovery, we'll pick up at
|
|
* the latest recovery restartpoint instead of going all the way back
|
|
* to the backup start point. It seems prudent though to just rename
|
|
* the file out of the way rather than delete it completely.
|
|
*/
|
|
if (haveBackupLabel)
|
|
{
|
|
unlink(BACKUP_LABEL_OLD);
|
|
if (rename(BACKUP_LABEL_FILE, BACKUP_LABEL_OLD) != 0)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename file \"%s\" to \"%s\": %m",
|
|
BACKUP_LABEL_FILE, BACKUP_LABEL_OLD)));
|
|
}
|
|
|
|
/*
|
|
* Initialize recovery connections, if enabled. We won't let backends
|
|
* in yet, not until we've reached the min recovery point specified
|
|
* in control file and we've established a recovery snapshot from a
|
|
* running-xacts WAL record.
|
|
*/
|
|
if (InArchiveRecovery && XLogRequestRecoveryConnections)
|
|
{
|
|
TransactionId *xids;
|
|
int nxids;
|
|
|
|
CheckRequiredParameterValues(checkPoint);
|
|
|
|
ereport(DEBUG1,
|
|
(errmsg("initializing recovery connections")));
|
|
|
|
InitRecoveryTransactionEnvironment();
|
|
|
|
if (wasShutdown)
|
|
oldestActiveXID = PrescanPreparedTransactions(&xids, &nxids);
|
|
else
|
|
oldestActiveXID = checkPoint.oldestActiveXid;
|
|
Assert(TransactionIdIsValid(oldestActiveXID));
|
|
|
|
/* Startup commit log and related stuff */
|
|
StartupCLOG();
|
|
StartupSUBTRANS(oldestActiveXID);
|
|
StartupMultiXact();
|
|
|
|
ProcArrayInitRecoveryInfo(oldestActiveXID);
|
|
}
|
|
|
|
/* Initialize resource managers */
|
|
for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
|
|
{
|
|
if (RmgrTable[rmid].rm_startup != NULL)
|
|
RmgrTable[rmid].rm_startup();
|
|
}
|
|
|
|
/*
|
|
* Find the first record that logically follows the checkpoint --- it
|
|
* might physically precede it, though.
|
|
*/
|
|
if (XLByteLT(checkPoint.redo, RecPtr))
|
|
{
|
|
/* back up to find the record */
|
|
record = ReadRecord(&(checkPoint.redo), PANIC, false);
|
|
}
|
|
else
|
|
{
|
|
/* just have to read next record after CheckPoint */
|
|
record = ReadRecord(NULL, LOG, false);
|
|
}
|
|
|
|
if (record != NULL)
|
|
{
|
|
bool recoveryContinue = true;
|
|
bool recoveryApply = true;
|
|
bool reachedMinRecoveryPoint = false;
|
|
ErrorContextCallback errcontext;
|
|
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
/* initialize shared replayEndRecPtr and recoveryLastRecPtr */
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
xlogctl->replayEndRecPtr = ReadRecPtr;
|
|
xlogctl->recoveryLastRecPtr = ReadRecPtr;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
InRedo = true;
|
|
|
|
ereport(LOG,
|
|
(errmsg("redo starts at %X/%X",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff)));
|
|
|
|
/*
|
|
* Let postmaster know we've started redo now, so that it can
|
|
* launch bgwriter to perform restartpoints. We don't bother
|
|
* during crash recovery as restartpoints can only be performed
|
|
* during archive recovery. And we'd like to keep crash recovery
|
|
* simple, to avoid introducing bugs that could you from
|
|
* recovering after crash.
|
|
*
|
|
* After this point, we can no longer assume that we're the only
|
|
* process in addition to postmaster! Also, fsync requests are
|
|
* subsequently to be handled by the bgwriter, not locally.
|
|
*/
|
|
if (InArchiveRecovery && IsUnderPostmaster)
|
|
{
|
|
SetForwardFsyncRequests();
|
|
SendPostmasterSignal(PMSIGNAL_RECOVERY_STARTED);
|
|
bgwriterLaunched = true;
|
|
}
|
|
|
|
/*
|
|
* main redo apply loop
|
|
*/
|
|
do
|
|
{
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG ||
|
|
(rmid == RM_XACT_ID && trace_recovery_messages <= DEBUG2) ||
|
|
(rmid != RM_XACT_ID && trace_recovery_messages <= DEBUG3))
|
|
{
|
|
StringInfoData buf;
|
|
|
|
initStringInfo(&buf);
|
|
appendStringInfo(&buf, "REDO @ %X/%X; LSN %X/%X: ",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff,
|
|
EndRecPtr.xlogid, EndRecPtr.xrecoff);
|
|
xlog_outrec(&buf, record);
|
|
appendStringInfo(&buf, " - ");
|
|
RmgrTable[record->xl_rmid].rm_desc(&buf,
|
|
record->xl_info,
|
|
XLogRecGetData(record));
|
|
elog(LOG, "%s", buf.data);
|
|
pfree(buf.data);
|
|
}
|
|
#endif
|
|
|
|
/* Handle interrupt signals of startup process */
|
|
HandleStartupProcInterrupts();
|
|
|
|
/*
|
|
* Have we passed our safe starting point?
|
|
*/
|
|
if (!reachedMinRecoveryPoint &&
|
|
XLByteLE(minRecoveryPoint, EndRecPtr) &&
|
|
XLogRecPtrIsInvalid(ControlFile->backupStartPoint))
|
|
{
|
|
reachedMinRecoveryPoint = true;
|
|
ereport(LOG,
|
|
(errmsg("consistent recovery state reached at %X/%X",
|
|
EndRecPtr.xlogid, EndRecPtr.xrecoff)));
|
|
}
|
|
|
|
/*
|
|
* Have we got a valid starting snapshot that will allow
|
|
* queries to be run? If so, we can tell postmaster that
|
|
* the database is consistent now, enabling connections.
|
|
*/
|
|
if (standbyState == STANDBY_SNAPSHOT_READY &&
|
|
!backendsAllowed &&
|
|
reachedMinRecoveryPoint &&
|
|
IsUnderPostmaster)
|
|
{
|
|
backendsAllowed = true;
|
|
SendPostmasterSignal(PMSIGNAL_RECOVERY_CONSISTENT);
|
|
}
|
|
|
|
/*
|
|
* Have we reached our recovery target?
|
|
*/
|
|
if (recoveryStopsHere(record, &recoveryApply))
|
|
{
|
|
reachedStopPoint = true; /* see below */
|
|
recoveryContinue = false;
|
|
if (!recoveryApply)
|
|
break;
|
|
}
|
|
|
|
/* Setup error traceback support for ereport() */
|
|
errcontext.callback = rm_redo_error_callback;
|
|
errcontext.arg = (void *) record;
|
|
errcontext.previous = error_context_stack;
|
|
error_context_stack = &errcontext;
|
|
|
|
/* nextXid must be beyond record's xid */
|
|
if (TransactionIdFollowsOrEquals(record->xl_xid,
|
|
ShmemVariableCache->nextXid))
|
|
{
|
|
ShmemVariableCache->nextXid = record->xl_xid;
|
|
TransactionIdAdvance(ShmemVariableCache->nextXid);
|
|
}
|
|
|
|
/*
|
|
* Update shared replayEndRecPtr before replaying this record,
|
|
* so that XLogFlush will update minRecoveryPoint correctly.
|
|
*/
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
xlogctl->replayEndRecPtr = EndRecPtr;
|
|
xlogctl->recoveryLastXTime = recoveryLastXTime;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
/* In Hot Standby mode, keep track of XIDs we've seen */
|
|
if (InHotStandby && TransactionIdIsValid(record->xl_xid))
|
|
RecordKnownAssignedTransactionIds(record->xl_xid);
|
|
|
|
RmgrTable[record->xl_rmid].rm_redo(EndRecPtr, record);
|
|
|
|
/* Pop the error context stack */
|
|
error_context_stack = errcontext.previous;
|
|
|
|
/*
|
|
* Update shared recoveryLastRecPtr after this record has been
|
|
* replayed.
|
|
*/
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
xlogctl->recoveryLastRecPtr = EndRecPtr;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
LastRec = ReadRecPtr;
|
|
|
|
record = ReadRecord(NULL, LOG, false);
|
|
} while (record != NULL && recoveryContinue);
|
|
|
|
/*
|
|
* end of main redo apply loop
|
|
*/
|
|
|
|
ereport(LOG,
|
|
(errmsg("redo done at %X/%X",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff)));
|
|
if (recoveryLastXTime)
|
|
ereport(LOG,
|
|
(errmsg("last completed transaction was at log time %s",
|
|
timestamptz_to_str(recoveryLastXTime))));
|
|
InRedo = false;
|
|
}
|
|
else
|
|
{
|
|
/* there are no WAL records following the checkpoint */
|
|
ereport(LOG,
|
|
(errmsg("redo is not required")));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we launched a WAL receiver, it should be gone by now. It will trump
|
|
* over the startup checkpoint and subsequent records if it's still alive,
|
|
* so be extra sure that it's gone.
|
|
*/
|
|
if (WalRcvInProgress())
|
|
elog(PANIC, "wal receiver still active");
|
|
|
|
/*
|
|
* We are now done reading the xlog from stream. Turn off streaming
|
|
* recovery to force fetching the files (which would be required
|
|
* at end of recovery, e.g., timeline history file) from archive or
|
|
* pg_xlog.
|
|
*/
|
|
StandbyMode = false;
|
|
|
|
/*
|
|
* Re-fetch the last valid or last applied record, so we can identify the
|
|
* exact endpoint of what we consider the valid portion of WAL.
|
|
*/
|
|
record = ReadRecord(&LastRec, PANIC, false);
|
|
EndOfLog = EndRecPtr;
|
|
XLByteToPrevSeg(EndOfLog, endLogId, endLogSeg);
|
|
|
|
/*
|
|
* Complain if we did not roll forward far enough to render the backup
|
|
* dump consistent. Note: it is indeed okay to look at the local variable
|
|
* minRecoveryPoint here, even though ControlFile->minRecoveryPoint might
|
|
* be further ahead --- ControlFile->minRecoveryPoint cannot have been
|
|
* advanced beyond the WAL we processed.
|
|
*/
|
|
if (InArchiveRecovery &&
|
|
(XLByteLT(EndOfLog, minRecoveryPoint) ||
|
|
!XLogRecPtrIsInvalid(ControlFile->backupStartPoint)))
|
|
{
|
|
if (reachedStopPoint) /* stopped because of stop request */
|
|
ereport(FATAL,
|
|
(errmsg("requested recovery stop point is before consistent recovery point")));
|
|
else /* ran off end of WAL */
|
|
ereport(FATAL,
|
|
(errmsg("WAL ends before consistent recovery point")));
|
|
}
|
|
|
|
/*
|
|
* Consider whether we need to assign a new timeline ID.
|
|
*
|
|
* If we are doing an archive recovery, we always assign a new ID. This
|
|
* handles a couple of issues. If we stopped short of the end of WAL
|
|
* during recovery, then we are clearly generating a new timeline and must
|
|
* assign it a unique new ID. Even if we ran to the end, modifying the
|
|
* current last segment is problematic because it may result in trying to
|
|
* overwrite an already-archived copy of that segment, and we encourage
|
|
* DBAs to make their archive_commands reject that. We can dodge the
|
|
* problem by making the new active segment have a new timeline ID.
|
|
*
|
|
* In a normal crash recovery, we can just extend the timeline we were in.
|
|
*/
|
|
if (InArchiveRecovery)
|
|
{
|
|
ThisTimeLineID = findNewestTimeLine(recoveryTargetTLI) + 1;
|
|
ereport(LOG,
|
|
(errmsg("selected new timeline ID: %u", ThisTimeLineID)));
|
|
writeTimeLineHistory(ThisTimeLineID, recoveryTargetTLI,
|
|
curFileTLI, endLogId, endLogSeg);
|
|
}
|
|
|
|
/* Save the selected TimeLineID in shared memory, too */
|
|
XLogCtl->ThisTimeLineID = ThisTimeLineID;
|
|
|
|
/*
|
|
* We are now done reading the old WAL. Turn off archive fetching if it
|
|
* was active, and make a writable copy of the last WAL segment. (Note
|
|
* that we also have a copy of the last block of the old WAL in readBuf;
|
|
* we will use that below.)
|
|
*/
|
|
if (InArchiveRecovery)
|
|
exitArchiveRecovery(curFileTLI, endLogId, endLogSeg);
|
|
|
|
/*
|
|
* Prepare to write WAL starting at EndOfLog position, and init xlog
|
|
* buffer cache using the block containing the last record from the
|
|
* previous incarnation.
|
|
*/
|
|
openLogId = endLogId;
|
|
openLogSeg = endLogSeg;
|
|
openLogFile = XLogFileOpen(openLogId, openLogSeg);
|
|
openLogOff = 0;
|
|
Insert = &XLogCtl->Insert;
|
|
Insert->PrevRecord = LastRec;
|
|
XLogCtl->xlblocks[0].xlogid = openLogId;
|
|
XLogCtl->xlblocks[0].xrecoff =
|
|
((EndOfLog.xrecoff - 1) / XLOG_BLCKSZ + 1) * XLOG_BLCKSZ;
|
|
|
|
/*
|
|
* Tricky point here: readBuf contains the *last* block that the LastRec
|
|
* record spans, not the one it starts in. The last block is indeed the
|
|
* one we want to use.
|
|
*/
|
|
Assert(readOff == (XLogCtl->xlblocks[0].xrecoff - XLOG_BLCKSZ) % XLogSegSize);
|
|
memcpy((char *) Insert->currpage, readBuf, XLOG_BLCKSZ);
|
|
Insert->currpos = (char *) Insert->currpage +
|
|
(EndOfLog.xrecoff + XLOG_BLCKSZ - XLogCtl->xlblocks[0].xrecoff);
|
|
|
|
LogwrtResult.Write = LogwrtResult.Flush = EndOfLog;
|
|
|
|
XLogCtl->Write.LogwrtResult = LogwrtResult;
|
|
Insert->LogwrtResult = LogwrtResult;
|
|
XLogCtl->LogwrtResult = LogwrtResult;
|
|
|
|
XLogCtl->LogwrtRqst.Write = EndOfLog;
|
|
XLogCtl->LogwrtRqst.Flush = EndOfLog;
|
|
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
if (freespace > 0)
|
|
{
|
|
/* Make sure rest of page is zero */
|
|
MemSet(Insert->currpos, 0, freespace);
|
|
XLogCtl->Write.curridx = 0;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Whenever Write.LogwrtResult points to exactly the end of a page,
|
|
* Write.curridx must point to the *next* page (see XLogWrite()).
|
|
*
|
|
* Note: it might seem we should do AdvanceXLInsertBuffer() here, but
|
|
* this is sufficient. The first actual attempt to insert a log
|
|
* record will advance the insert state.
|
|
*/
|
|
XLogCtl->Write.curridx = NextBufIdx(0);
|
|
}
|
|
|
|
/* Pre-scan prepared transactions to find out the range of XIDs present */
|
|
oldestActiveXID = PrescanPreparedTransactions(NULL, NULL);
|
|
|
|
if (InRecovery)
|
|
{
|
|
int rmid;
|
|
|
|
/*
|
|
* Resource managers might need to write WAL records, eg, to record
|
|
* index cleanup actions. So temporarily enable XLogInsertAllowed in
|
|
* this process only.
|
|
*/
|
|
LocalSetXLogInsertAllowed();
|
|
|
|
/*
|
|
* Allow resource managers to do any required cleanup.
|
|
*/
|
|
for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
|
|
{
|
|
if (RmgrTable[rmid].rm_cleanup != NULL)
|
|
RmgrTable[rmid].rm_cleanup();
|
|
}
|
|
|
|
/* Disallow XLogInsert again */
|
|
LocalXLogInsertAllowed = -1;
|
|
|
|
/*
|
|
* Check to see if the XLOG sequence contained any unresolved
|
|
* references to uninitialized pages.
|
|
*/
|
|
XLogCheckInvalidPages();
|
|
|
|
/*
|
|
* Perform a checkpoint to update all our recovery activity to disk.
|
|
*
|
|
* Note that we write a shutdown checkpoint rather than an on-line
|
|
* one. This is not particularly critical, but since we may be
|
|
* assigning a new TLI, using a shutdown checkpoint allows us to have
|
|
* the rule that TLI only changes in shutdown checkpoints, which
|
|
* allows some extra error checking in xlog_redo.
|
|
*/
|
|
if (bgwriterLaunched)
|
|
RequestCheckpoint(CHECKPOINT_END_OF_RECOVERY |
|
|
CHECKPOINT_IMMEDIATE |
|
|
CHECKPOINT_WAIT);
|
|
else
|
|
CreateCheckPoint(CHECKPOINT_END_OF_RECOVERY | CHECKPOINT_IMMEDIATE);
|
|
|
|
/*
|
|
* And finally, execute the recovery_end_command, if any.
|
|
*/
|
|
if (recoveryEndCommand)
|
|
ExecuteRecoveryEndCommand();
|
|
}
|
|
|
|
/*
|
|
* Preallocate additional log files, if wanted.
|
|
*/
|
|
PreallocXlogFiles(EndOfLog);
|
|
|
|
/*
|
|
* Okay, we're officially UP.
|
|
*/
|
|
InRecovery = false;
|
|
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
ControlFile->state = DB_IN_PRODUCTION;
|
|
ControlFile->time = (pg_time_t) time(NULL);
|
|
UpdateControlFile();
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
/* start the archive_timeout timer running */
|
|
XLogCtl->Write.lastSegSwitchTime = (pg_time_t) time(NULL);
|
|
|
|
/* initialize shared-memory copy of latest checkpoint XID/epoch */
|
|
XLogCtl->ckptXidEpoch = ControlFile->checkPointCopy.nextXidEpoch;
|
|
XLogCtl->ckptXid = ControlFile->checkPointCopy.nextXid;
|
|
|
|
/* also initialize latestCompletedXid, to nextXid - 1 */
|
|
ShmemVariableCache->latestCompletedXid = ShmemVariableCache->nextXid;
|
|
TransactionIdRetreat(ShmemVariableCache->latestCompletedXid);
|
|
|
|
/*
|
|
* Start up the commit log and related stuff, too. In hot standby mode
|
|
* we did this already before WAL replay.
|
|
*/
|
|
if (standbyState == STANDBY_DISABLED)
|
|
{
|
|
StartupCLOG();
|
|
StartupSUBTRANS(oldestActiveXID);
|
|
StartupMultiXact();
|
|
}
|
|
|
|
/* Reload shared-memory state for prepared transactions */
|
|
RecoverPreparedTransactions();
|
|
|
|
/*
|
|
* Shutdown the recovery environment. This must occur after
|
|
* RecoverPreparedTransactions(), see notes for lock_twophase_recover()
|
|
*/
|
|
if (standbyState != STANDBY_DISABLED)
|
|
ShutdownRecoveryTransactionEnvironment();
|
|
|
|
/* Shut down readFile facility, free space */
|
|
if (readFile >= 0)
|
|
{
|
|
close(readFile);
|
|
readFile = -1;
|
|
}
|
|
if (readBuf)
|
|
{
|
|
free(readBuf);
|
|
readBuf = NULL;
|
|
}
|
|
if (readRecordBuf)
|
|
{
|
|
free(readRecordBuf);
|
|
readRecordBuf = NULL;
|
|
readRecordBufSize = 0;
|
|
}
|
|
|
|
/*
|
|
* All done. Allow backends to write WAL. (Although the bool flag is
|
|
* probably atomic in itself, we use the info_lck here to ensure that
|
|
* there are no race conditions concerning visibility of other recent
|
|
* updates to shared memory.)
|
|
*/
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
xlogctl->SharedRecoveryInProgress = false;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Is the system still in recovery?
|
|
*
|
|
* Unlike testing InRecovery, this works in any process that's connected to
|
|
* shared memory.
|
|
*
|
|
* As a side-effect, we initialize the local TimeLineID and RedoRecPtr
|
|
* variables the first time we see that recovery is finished.
|
|
*/
|
|
bool
|
|
RecoveryInProgress(void)
|
|
{
|
|
/*
|
|
* We check shared state each time only until we leave recovery mode.
|
|
* We can't re-enter recovery, so there's no need to keep checking after
|
|
* the shared variable has once been seen false.
|
|
*/
|
|
if (!LocalRecoveryInProgress)
|
|
return false;
|
|
else
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
/* spinlock is essential on machines with weak memory ordering! */
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
LocalRecoveryInProgress = xlogctl->SharedRecoveryInProgress;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
/*
|
|
* Initialize TimeLineID and RedoRecPtr when we discover that recovery
|
|
* is finished. InitPostgres() relies upon this behaviour to ensure
|
|
* that InitXLOGAccess() is called at backend startup. (If you change
|
|
* this, see also LocalSetXLogInsertAllowed.)
|
|
*/
|
|
if (!LocalRecoveryInProgress)
|
|
InitXLOGAccess();
|
|
|
|
return LocalRecoveryInProgress;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Is this process allowed to insert new WAL records?
|
|
*
|
|
* Ordinarily this is essentially equivalent to !RecoveryInProgress().
|
|
* But we also have provisions for forcing the result "true" or "false"
|
|
* within specific processes regardless of the global state.
|
|
*/
|
|
bool
|
|
XLogInsertAllowed(void)
|
|
{
|
|
/*
|
|
* If value is "unconditionally true" or "unconditionally false",
|
|
* just return it. This provides the normal fast path once recovery
|
|
* is known done.
|
|
*/
|
|
if (LocalXLogInsertAllowed >= 0)
|
|
return (bool) LocalXLogInsertAllowed;
|
|
|
|
/*
|
|
* Else, must check to see if we're still in recovery.
|
|
*/
|
|
if (RecoveryInProgress())
|
|
return false;
|
|
|
|
/*
|
|
* On exit from recovery, reset to "unconditionally true", since there
|
|
* is no need to keep checking.
|
|
*/
|
|
LocalXLogInsertAllowed = 1;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Make XLogInsertAllowed() return true in the current process only.
|
|
*
|
|
* Note: it is allowed to switch LocalXLogInsertAllowed back to -1 later,
|
|
* and even call LocalSetXLogInsertAllowed() again after that.
|
|
*/
|
|
static void
|
|
LocalSetXLogInsertAllowed(void)
|
|
{
|
|
Assert(LocalXLogInsertAllowed == -1);
|
|
LocalXLogInsertAllowed = 1;
|
|
|
|
/* Initialize as RecoveryInProgress() would do when switching state */
|
|
InitXLOGAccess();
|
|
}
|
|
|
|
/*
|
|
* Subroutine to try to fetch and validate a prior checkpoint record.
|
|
*
|
|
* whichChkpt identifies the checkpoint (merely for reporting purposes).
|
|
* 1 for "primary", 2 for "secondary", 0 for "other" (backup_label)
|
|
*/
|
|
static XLogRecord *
|
|
ReadCheckpointRecord(XLogRecPtr RecPtr, int whichChkpt)
|
|
{
|
|
XLogRecord *record;
|
|
|
|
if (!XRecOffIsValid(RecPtr.xrecoff))
|
|
{
|
|
switch (whichChkpt)
|
|
{
|
|
case 1:
|
|
ereport(LOG,
|
|
(errmsg("invalid primary checkpoint link in control file")));
|
|
break;
|
|
case 2:
|
|
ereport(LOG,
|
|
(errmsg("invalid secondary checkpoint link in control file")));
|
|
break;
|
|
default:
|
|
ereport(LOG,
|
|
(errmsg("invalid checkpoint link in backup_label file")));
|
|
break;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
record = ReadRecord(&RecPtr, LOG, true);
|
|
|
|
if (record == NULL)
|
|
{
|
|
switch (whichChkpt)
|
|
{
|
|
case 1:
|
|
ereport(LOG,
|
|
(errmsg("invalid primary checkpoint record")));
|
|
break;
|
|
case 2:
|
|
ereport(LOG,
|
|
(errmsg("invalid secondary checkpoint record")));
|
|
break;
|
|
default:
|
|
ereport(LOG,
|
|
(errmsg("invalid checkpoint record")));
|
|
break;
|
|
}
|
|
return NULL;
|
|
}
|
|
if (record->xl_rmid != RM_XLOG_ID)
|
|
{
|
|
switch (whichChkpt)
|
|
{
|
|
case 1:
|
|
ereport(LOG,
|
|
(errmsg("invalid resource manager ID in primary checkpoint record")));
|
|
break;
|
|
case 2:
|
|
ereport(LOG,
|
|
(errmsg("invalid resource manager ID in secondary checkpoint record")));
|
|
break;
|
|
default:
|
|
ereport(LOG,
|
|
(errmsg("invalid resource manager ID in checkpoint record")));
|
|
break;
|
|
}
|
|
return NULL;
|
|
}
|
|
if (record->xl_info != XLOG_CHECKPOINT_SHUTDOWN &&
|
|
record->xl_info != XLOG_CHECKPOINT_ONLINE)
|
|
{
|
|
switch (whichChkpt)
|
|
{
|
|
case 1:
|
|
ereport(LOG,
|
|
(errmsg("invalid xl_info in primary checkpoint record")));
|
|
break;
|
|
case 2:
|
|
ereport(LOG,
|
|
(errmsg("invalid xl_info in secondary checkpoint record")));
|
|
break;
|
|
default:
|
|
ereport(LOG,
|
|
(errmsg("invalid xl_info in checkpoint record")));
|
|
break;
|
|
}
|
|
return NULL;
|
|
}
|
|
if (record->xl_len != sizeof(CheckPoint) ||
|
|
record->xl_tot_len != SizeOfXLogRecord + sizeof(CheckPoint))
|
|
{
|
|
switch (whichChkpt)
|
|
{
|
|
case 1:
|
|
ereport(LOG,
|
|
(errmsg("invalid length of primary checkpoint record")));
|
|
break;
|
|
case 2:
|
|
ereport(LOG,
|
|
(errmsg("invalid length of secondary checkpoint record")));
|
|
break;
|
|
default:
|
|
ereport(LOG,
|
|
(errmsg("invalid length of checkpoint record")));
|
|
break;
|
|
}
|
|
return NULL;
|
|
}
|
|
return record;
|
|
}
|
|
|
|
/*
|
|
* This must be called during startup of a backend process, except that
|
|
* it need not be called in a standalone backend (which does StartupXLOG
|
|
* instead). We need to initialize the local copies of ThisTimeLineID and
|
|
* RedoRecPtr.
|
|
*
|
|
* Note: before Postgres 8.0, we went to some effort to keep the postmaster
|
|
* process's copies of ThisTimeLineID and RedoRecPtr valid too. This was
|
|
* unnecessary however, since the postmaster itself never touches XLOG anyway.
|
|
*/
|
|
void
|
|
InitXLOGAccess(void)
|
|
{
|
|
/* ThisTimeLineID doesn't change so we need no lock to copy it */
|
|
ThisTimeLineID = XLogCtl->ThisTimeLineID;
|
|
Assert(ThisTimeLineID != 0 || IsBootstrapProcessingMode());
|
|
|
|
/* Use GetRedoRecPtr to copy the RedoRecPtr safely */
|
|
(void) GetRedoRecPtr();
|
|
}
|
|
|
|
/*
|
|
* Once spawned, a backend may update its local RedoRecPtr from
|
|
* XLogCtl->Insert.RedoRecPtr; it must hold the insert lock or info_lck
|
|
* to do so. This is done in XLogInsert() or GetRedoRecPtr().
|
|
*/
|
|
XLogRecPtr
|
|
GetRedoRecPtr(void)
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
Assert(XLByteLE(RedoRecPtr, xlogctl->Insert.RedoRecPtr));
|
|
RedoRecPtr = xlogctl->Insert.RedoRecPtr;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
return RedoRecPtr;
|
|
}
|
|
|
|
/*
|
|
* GetInsertRecPtr -- Returns the current insert position.
|
|
*
|
|
* NOTE: The value *actually* returned is the position of the last full
|
|
* xlog page. It lags behind the real insert position by at most 1 page.
|
|
* For that, we don't need to acquire WALInsertLock which can be quite
|
|
* heavily contended, and an approximation is enough for the current
|
|
* usage of this function.
|
|
*/
|
|
XLogRecPtr
|
|
GetInsertRecPtr(void)
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
XLogRecPtr recptr;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
recptr = xlogctl->LogwrtRqst.Write;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
return recptr;
|
|
}
|
|
|
|
/*
|
|
* GetWriteRecPtr -- Returns the current write position.
|
|
*
|
|
* NOTE: The value returned lags behind the real write position. But,
|
|
* an approximation is enough for the current usage of this function.
|
|
*/
|
|
XLogRecPtr
|
|
GetWriteRecPtr(void)
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
XLogRecPtr recptr;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
recptr = xlogctl->LogwrtResult.Write;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
return recptr;
|
|
}
|
|
|
|
/*
|
|
* Get the time of the last xlog segment switch
|
|
*/
|
|
pg_time_t
|
|
GetLastSegSwitchTime(void)
|
|
{
|
|
pg_time_t result;
|
|
|
|
/* Need WALWriteLock, but shared lock is sufficient */
|
|
LWLockAcquire(WALWriteLock, LW_SHARED);
|
|
result = XLogCtl->Write.lastSegSwitchTime;
|
|
LWLockRelease(WALWriteLock);
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* GetNextXidAndEpoch - get the current nextXid value and associated epoch
|
|
*
|
|
* This is exported for use by code that would like to have 64-bit XIDs.
|
|
* We don't really support such things, but all XIDs within the system
|
|
* can be presumed "close to" the result, and thus the epoch associated
|
|
* with them can be determined.
|
|
*/
|
|
void
|
|
GetNextXidAndEpoch(TransactionId *xid, uint32 *epoch)
|
|
{
|
|
uint32 ckptXidEpoch;
|
|
TransactionId ckptXid;
|
|
TransactionId nextXid;
|
|
|
|
/* Must read checkpoint info first, else have race condition */
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
ckptXidEpoch = xlogctl->ckptXidEpoch;
|
|
ckptXid = xlogctl->ckptXid;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
/* Now fetch current nextXid */
|
|
nextXid = ReadNewTransactionId();
|
|
|
|
/*
|
|
* nextXid is certainly logically later than ckptXid. So if it's
|
|
* numerically less, it must have wrapped into the next epoch.
|
|
*/
|
|
if (nextXid < ckptXid)
|
|
ckptXidEpoch++;
|
|
|
|
*xid = nextXid;
|
|
*epoch = ckptXidEpoch;
|
|
}
|
|
|
|
/*
|
|
* GetRecoveryTargetTLI - get the recovery target timeline ID
|
|
*/
|
|
TimeLineID
|
|
GetRecoveryTargetTLI(void)
|
|
{
|
|
/* RecoveryTargetTLI doesn't change so we need no lock to copy it */
|
|
return XLogCtl->RecoveryTargetTLI;
|
|
}
|
|
|
|
/*
|
|
* This must be called ONCE during postmaster or standalone-backend shutdown
|
|
*/
|
|
void
|
|
ShutdownXLOG(int code, Datum arg)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("shutting down")));
|
|
|
|
if (RecoveryInProgress())
|
|
CreateRestartPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_IMMEDIATE);
|
|
else
|
|
{
|
|
/*
|
|
* If archiving is enabled, rotate the last XLOG file so that all the
|
|
* remaining records are archived (postmaster wakes up the archiver
|
|
* process one more time at the end of shutdown). The checkpoint
|
|
* record will go to the next XLOG file and won't be archived (yet).
|
|
*/
|
|
if (XLogArchivingActive() && XLogArchiveCommandSet())
|
|
RequestXLogSwitch();
|
|
|
|
CreateCheckPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_IMMEDIATE);
|
|
}
|
|
ShutdownCLOG();
|
|
ShutdownSUBTRANS();
|
|
ShutdownMultiXact();
|
|
|
|
ereport(LOG,
|
|
(errmsg("database system is shut down")));
|
|
}
|
|
|
|
/*
|
|
* Log start of a checkpoint.
|
|
*/
|
|
static void
|
|
LogCheckpointStart(int flags, bool restartpoint)
|
|
{
|
|
const char *msg;
|
|
|
|
/*
|
|
* XXX: This is hopelessly untranslatable. We could call gettext_noop for
|
|
* the main message, but what about all the flags?
|
|
*/
|
|
if (restartpoint)
|
|
msg = "restartpoint starting:%s%s%s%s%s%s%s";
|
|
else
|
|
msg = "checkpoint starting:%s%s%s%s%s%s%s";
|
|
|
|
elog(LOG, msg,
|
|
(flags & CHECKPOINT_IS_SHUTDOWN) ? " shutdown" : "",
|
|
(flags & CHECKPOINT_END_OF_RECOVERY) ? " end-of-recovery" : "",
|
|
(flags & CHECKPOINT_IMMEDIATE) ? " immediate" : "",
|
|
(flags & CHECKPOINT_FORCE) ? " force" : "",
|
|
(flags & CHECKPOINT_WAIT) ? " wait" : "",
|
|
(flags & CHECKPOINT_CAUSE_XLOG) ? " xlog" : "",
|
|
(flags & CHECKPOINT_CAUSE_TIME) ? " time" : "");
|
|
}
|
|
|
|
/*
|
|
* Log end of a checkpoint.
|
|
*/
|
|
static void
|
|
LogCheckpointEnd(bool restartpoint)
|
|
{
|
|
long write_secs,
|
|
sync_secs,
|
|
total_secs;
|
|
int write_usecs,
|
|
sync_usecs,
|
|
total_usecs;
|
|
|
|
CheckpointStats.ckpt_end_t = GetCurrentTimestamp();
|
|
|
|
TimestampDifference(CheckpointStats.ckpt_start_t,
|
|
CheckpointStats.ckpt_end_t,
|
|
&total_secs, &total_usecs);
|
|
|
|
TimestampDifference(CheckpointStats.ckpt_write_t,
|
|
CheckpointStats.ckpt_sync_t,
|
|
&write_secs, &write_usecs);
|
|
|
|
TimestampDifference(CheckpointStats.ckpt_sync_t,
|
|
CheckpointStats.ckpt_sync_end_t,
|
|
&sync_secs, &sync_usecs);
|
|
|
|
if (restartpoint)
|
|
elog(LOG, "restartpoint complete: wrote %d buffers (%.1f%%); "
|
|
"write=%ld.%03d s, sync=%ld.%03d s, total=%ld.%03d s",
|
|
CheckpointStats.ckpt_bufs_written,
|
|
(double) CheckpointStats.ckpt_bufs_written * 100 / NBuffers,
|
|
write_secs, write_usecs / 1000,
|
|
sync_secs, sync_usecs / 1000,
|
|
total_secs, total_usecs / 1000);
|
|
else
|
|
elog(LOG, "checkpoint complete: wrote %d buffers (%.1f%%); "
|
|
"%d transaction log file(s) added, %d removed, %d recycled; "
|
|
"write=%ld.%03d s, sync=%ld.%03d s, total=%ld.%03d s",
|
|
CheckpointStats.ckpt_bufs_written,
|
|
(double) CheckpointStats.ckpt_bufs_written * 100 / NBuffers,
|
|
CheckpointStats.ckpt_segs_added,
|
|
CheckpointStats.ckpt_segs_removed,
|
|
CheckpointStats.ckpt_segs_recycled,
|
|
write_secs, write_usecs / 1000,
|
|
sync_secs, sync_usecs / 1000,
|
|
total_secs, total_usecs / 1000);
|
|
}
|
|
|
|
/*
|
|
* Perform a checkpoint --- either during shutdown, or on-the-fly
|
|
*
|
|
* flags is a bitwise OR of the following:
|
|
* CHECKPOINT_IS_SHUTDOWN: checkpoint is for database shutdown.
|
|
* CHECKPOINT_END_OF_RECOVERY: checkpoint is for end of WAL recovery.
|
|
* CHECKPOINT_IMMEDIATE: finish the checkpoint ASAP,
|
|
* ignoring checkpoint_completion_target parameter.
|
|
* CHECKPOINT_FORCE: force a checkpoint even if no XLOG activity has occured
|
|
* since the last one (implied by CHECKPOINT_IS_SHUTDOWN or
|
|
* CHECKPOINT_END_OF_RECOVERY).
|
|
*
|
|
* Note: flags contains other bits, of interest here only for logging purposes.
|
|
* In particular note that this routine is synchronous and does not pay
|
|
* attention to CHECKPOINT_WAIT.
|
|
*/
|
|
void
|
|
CreateCheckPoint(int flags)
|
|
{
|
|
bool shutdown;
|
|
CheckPoint checkPoint;
|
|
XLogRecPtr recptr;
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
XLogRecData rdata;
|
|
uint32 freespace;
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
TransactionId *inCommitXids;
|
|
int nInCommit;
|
|
|
|
/*
|
|
* An end-of-recovery checkpoint is really a shutdown checkpoint, just
|
|
* issued at a different time.
|
|
*/
|
|
if (flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY))
|
|
shutdown = true;
|
|
else
|
|
shutdown = false;
|
|
|
|
/* sanity check */
|
|
if (RecoveryInProgress() && (flags & CHECKPOINT_END_OF_RECOVERY) == 0)
|
|
elog(ERROR, "can't create a checkpoint during recovery");
|
|
|
|
/*
|
|
* Acquire CheckpointLock to ensure only one checkpoint happens at a time.
|
|
* (This is just pro forma, since in the present system structure there is
|
|
* only one process that is allowed to issue checkpoints at any given
|
|
* time.)
|
|
*/
|
|
LWLockAcquire(CheckpointLock, LW_EXCLUSIVE);
|
|
|
|
/*
|
|
* Prepare to accumulate statistics.
|
|
*
|
|
* Note: because it is possible for log_checkpoints to change while a
|
|
* checkpoint proceeds, we always accumulate stats, even if
|
|
* log_checkpoints is currently off.
|
|
*/
|
|
MemSet(&CheckpointStats, 0, sizeof(CheckpointStats));
|
|
CheckpointStats.ckpt_start_t = GetCurrentTimestamp();
|
|
|
|
/*
|
|
* Use a critical section to force system panic if we have trouble.
|
|
*/
|
|
START_CRIT_SECTION();
|
|
|
|
if (shutdown)
|
|
{
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
ControlFile->state = DB_SHUTDOWNING;
|
|
ControlFile->time = (pg_time_t) time(NULL);
|
|
UpdateControlFile();
|
|
LWLockRelease(ControlFileLock);
|
|
}
|
|
|
|
/*
|
|
* Let smgr prepare for checkpoint; this has to happen before we determine
|
|
* the REDO pointer. Note that smgr must not do anything that'd have to
|
|
* be undone if we decide no checkpoint is needed.
|
|
*/
|
|
smgrpreckpt();
|
|
|
|
/* Begin filling in the checkpoint WAL record */
|
|
MemSet(&checkPoint, 0, sizeof(checkPoint));
|
|
checkPoint.time = (pg_time_t) time(NULL);
|
|
|
|
/* Set important parameter values for use when replaying WAL */
|
|
checkPoint.MaxConnections = MaxConnections;
|
|
checkPoint.max_prepared_xacts = max_prepared_xacts;
|
|
checkPoint.max_locks_per_xact = max_locks_per_xact;
|
|
checkPoint.XLogStandbyInfoMode = XLogStandbyInfoActive();
|
|
|
|
/*
|
|
* We must hold WALInsertLock while examining insert state to determine
|
|
* the checkpoint REDO pointer.
|
|
*/
|
|
LWLockAcquire(WALInsertLock, LW_EXCLUSIVE);
|
|
|
|
/*
|
|
* If this isn't a shutdown or forced checkpoint, and we have not inserted
|
|
* any XLOG records since the start of the last checkpoint, skip the
|
|
* checkpoint. The idea here is to avoid inserting duplicate checkpoints
|
|
* when the system is idle. That wastes log space, and more importantly it
|
|
* exposes us to possible loss of both current and previous checkpoint
|
|
* records if the machine crashes just as we're writing the update.
|
|
* (Perhaps it'd make even more sense to checkpoint only when the previous
|
|
* checkpoint record is in a different xlog page?)
|
|
*
|
|
* We have to make two tests to determine that nothing has happened since
|
|
* the start of the last checkpoint: current insertion point must match
|
|
* the end of the last checkpoint record, and its redo pointer must point
|
|
* to itself.
|
|
*/
|
|
if ((flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY |
|
|
CHECKPOINT_FORCE)) == 0)
|
|
{
|
|
XLogRecPtr curInsert;
|
|
|
|
INSERT_RECPTR(curInsert, Insert, Insert->curridx);
|
|
if (curInsert.xlogid == ControlFile->checkPoint.xlogid &&
|
|
curInsert.xrecoff == ControlFile->checkPoint.xrecoff +
|
|
MAXALIGN(SizeOfXLogRecord + sizeof(CheckPoint)) &&
|
|
ControlFile->checkPoint.xlogid ==
|
|
ControlFile->checkPointCopy.redo.xlogid &&
|
|
ControlFile->checkPoint.xrecoff ==
|
|
ControlFile->checkPointCopy.redo.xrecoff)
|
|
{
|
|
LWLockRelease(WALInsertLock);
|
|
LWLockRelease(CheckpointLock);
|
|
END_CRIT_SECTION();
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* An end-of-recovery checkpoint is created before anyone is allowed to
|
|
* write WAL. To allow us to write the checkpoint record, temporarily
|
|
* enable XLogInsertAllowed. (This also ensures ThisTimeLineID is
|
|
* initialized, which we need here and in AdvanceXLInsertBuffer.)
|
|
*/
|
|
if (flags & CHECKPOINT_END_OF_RECOVERY)
|
|
LocalSetXLogInsertAllowed();
|
|
|
|
checkPoint.ThisTimeLineID = ThisTimeLineID;
|
|
|
|
/*
|
|
* Compute new REDO record ptr = location of next XLOG record.
|
|
*
|
|
* NB: this is NOT necessarily where the checkpoint record itself will be,
|
|
* since other backends may insert more XLOG records while we're off doing
|
|
* the buffer flush work. Those XLOG records are logically after the
|
|
* checkpoint, even though physically before it. Got that?
|
|
*/
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
if (freespace < SizeOfXLogRecord)
|
|
{
|
|
(void) AdvanceXLInsertBuffer(false);
|
|
/* OK to ignore update return flag, since we will do flush anyway */
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
}
|
|
INSERT_RECPTR(checkPoint.redo, Insert, Insert->curridx);
|
|
|
|
/*
|
|
* Here we update the shared RedoRecPtr for future XLogInsert calls; this
|
|
* must be done while holding the insert lock AND the info_lck.
|
|
*
|
|
* Note: if we fail to complete the checkpoint, RedoRecPtr will be left
|
|
* pointing past where it really needs to point. This is okay; the only
|
|
* consequence is that XLogInsert might back up whole buffers that it
|
|
* didn't really need to. We can't postpone advancing RedoRecPtr because
|
|
* XLogInserts that happen while we are dumping buffers must assume that
|
|
* their buffer changes are not included in the checkpoint.
|
|
*/
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
RedoRecPtr = xlogctl->Insert.RedoRecPtr = checkPoint.redo;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
/*
|
|
* Now we can release WAL insert lock, allowing other xacts to proceed
|
|
* while we are flushing disk buffers.
|
|
*/
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
/*
|
|
* If enabled, log checkpoint start. We postpone this until now so as not
|
|
* to log anything if we decided to skip the checkpoint.
|
|
*/
|
|
if (log_checkpoints)
|
|
LogCheckpointStart(flags, false);
|
|
|
|
TRACE_POSTGRESQL_CHECKPOINT_START(flags);
|
|
|
|
/*
|
|
* Before flushing data, we must wait for any transactions that are
|
|
* currently in their commit critical sections. If an xact inserted its
|
|
* commit record into XLOG just before the REDO point, then a crash
|
|
* restart from the REDO point would not replay that record, which means
|
|
* that our flushing had better include the xact's update of pg_clog. So
|
|
* we wait till he's out of his commit critical section before proceeding.
|
|
* See notes in RecordTransactionCommit().
|
|
*
|
|
* Because we've already released WALInsertLock, this test is a bit fuzzy:
|
|
* it is possible that we will wait for xacts we didn't really need to
|
|
* wait for. But the delay should be short and it seems better to make
|
|
* checkpoint take a bit longer than to hold locks longer than necessary.
|
|
* (In fact, the whole reason we have this issue is that xact.c does
|
|
* commit record XLOG insertion and clog update as two separate steps
|
|
* protected by different locks, but again that seems best on grounds of
|
|
* minimizing lock contention.)
|
|
*
|
|
* A transaction that has not yet set inCommit when we look cannot be at
|
|
* risk, since he's not inserted his commit record yet; and one that's
|
|
* already cleared it is not at risk either, since he's done fixing clog
|
|
* and we will correctly flush the update below. So we cannot miss any
|
|
* xacts we need to wait for.
|
|
*/
|
|
nInCommit = GetTransactionsInCommit(&inCommitXids);
|
|
if (nInCommit > 0)
|
|
{
|
|
do
|
|
{
|
|
pg_usleep(10000L); /* wait for 10 msec */
|
|
} while (HaveTransactionsInCommit(inCommitXids, nInCommit));
|
|
}
|
|
pfree(inCommitXids);
|
|
|
|
/*
|
|
* Get the other info we need for the checkpoint record.
|
|
*/
|
|
LWLockAcquire(XidGenLock, LW_SHARED);
|
|
checkPoint.nextXid = ShmemVariableCache->nextXid;
|
|
checkPoint.oldestXid = ShmemVariableCache->oldestXid;
|
|
checkPoint.oldestXidDB = ShmemVariableCache->oldestXidDB;
|
|
LWLockRelease(XidGenLock);
|
|
|
|
/* Increase XID epoch if we've wrapped around since last checkpoint */
|
|
checkPoint.nextXidEpoch = ControlFile->checkPointCopy.nextXidEpoch;
|
|
if (checkPoint.nextXid < ControlFile->checkPointCopy.nextXid)
|
|
checkPoint.nextXidEpoch++;
|
|
|
|
LWLockAcquire(OidGenLock, LW_SHARED);
|
|
checkPoint.nextOid = ShmemVariableCache->nextOid;
|
|
if (!shutdown)
|
|
checkPoint.nextOid += ShmemVariableCache->oidCount;
|
|
LWLockRelease(OidGenLock);
|
|
|
|
MultiXactGetCheckptMulti(shutdown,
|
|
&checkPoint.nextMulti,
|
|
&checkPoint.nextMultiOffset);
|
|
|
|
/*
|
|
* Having constructed the checkpoint record, ensure all shmem disk buffers
|
|
* and commit-log buffers are flushed to disk.
|
|
*
|
|
* This I/O could fail for various reasons. If so, we will fail to
|
|
* complete the checkpoint, but there is no reason to force a system
|
|
* panic. Accordingly, exit critical section while doing it.
|
|
*/
|
|
END_CRIT_SECTION();
|
|
|
|
CheckPointGuts(checkPoint.redo, flags);
|
|
|
|
/*
|
|
* Take a snapshot of running transactions and write this to WAL.
|
|
* This allows us to reconstruct the state of running transactions
|
|
* during archive recovery, if required. Skip, if this info disabled.
|
|
*
|
|
* If we are shutting down, or Startup process is completing crash
|
|
* recovery we don't need to write running xact data.
|
|
*
|
|
* Update checkPoint.nextXid since we have a later value
|
|
*/
|
|
if (!shutdown && XLogStandbyInfoActive())
|
|
LogStandbySnapshot(&checkPoint.oldestActiveXid, &checkPoint.nextXid);
|
|
else
|
|
checkPoint.oldestActiveXid = InvalidTransactionId;
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/*
|
|
* Now insert the checkpoint record into XLOG.
|
|
*/
|
|
rdata.data = (char *) (&checkPoint);
|
|
rdata.len = sizeof(checkPoint);
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.next = NULL;
|
|
|
|
recptr = XLogInsert(RM_XLOG_ID,
|
|
shutdown ? XLOG_CHECKPOINT_SHUTDOWN :
|
|
XLOG_CHECKPOINT_ONLINE,
|
|
&rdata);
|
|
|
|
XLogFlush(recptr);
|
|
|
|
/*
|
|
* We mustn't write any new WAL after a shutdown checkpoint, or it will
|
|
* be overwritten at next startup. No-one should even try, this just
|
|
* allows sanity-checking. In the case of an end-of-recovery checkpoint,
|
|
* we want to just temporarily disable writing until the system has exited
|
|
* recovery.
|
|
*/
|
|
if (shutdown)
|
|
{
|
|
if (flags & CHECKPOINT_END_OF_RECOVERY)
|
|
LocalXLogInsertAllowed = -1; /* return to "check" state */
|
|
else
|
|
LocalXLogInsertAllowed = 0; /* never again write WAL */
|
|
}
|
|
|
|
/*
|
|
* We now have ProcLastRecPtr = start of actual checkpoint record, recptr
|
|
* = end of actual checkpoint record.
|
|
*/
|
|
if (shutdown && !XLByteEQ(checkPoint.redo, ProcLastRecPtr))
|
|
ereport(PANIC,
|
|
(errmsg("concurrent transaction log activity while database system is shutting down")));
|
|
|
|
/*
|
|
* Select point at which we can truncate the log, which we base on the
|
|
* prior checkpoint's earliest info.
|
|
*/
|
|
XLByteToSeg(ControlFile->checkPointCopy.redo, _logId, _logSeg);
|
|
|
|
/*
|
|
* Update the control file.
|
|
*/
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
if (shutdown)
|
|
ControlFile->state = DB_SHUTDOWNED;
|
|
ControlFile->prevCheckPoint = ControlFile->checkPoint;
|
|
ControlFile->checkPoint = ProcLastRecPtr;
|
|
ControlFile->checkPointCopy = checkPoint;
|
|
ControlFile->time = (pg_time_t) time(NULL);
|
|
/* crash recovery should always recover to the end of WAL */
|
|
MemSet(&ControlFile->minRecoveryPoint, 0, sizeof(XLogRecPtr));
|
|
UpdateControlFile();
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
/* Update shared-memory copy of checkpoint XID/epoch */
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
xlogctl->ckptXidEpoch = checkPoint.nextXidEpoch;
|
|
xlogctl->ckptXid = checkPoint.nextXid;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
/*
|
|
* We are now done with critical updates; no need for system panic if we
|
|
* have trouble while fooling with old log segments.
|
|
*/
|
|
END_CRIT_SECTION();
|
|
|
|
/*
|
|
* Let smgr do post-checkpoint cleanup (eg, deleting old files).
|
|
*/
|
|
smgrpostckpt();
|
|
|
|
/*
|
|
* If there's connected standby servers doing XLOG streaming, don't
|
|
* delete XLOG files that have not been streamed to all of them yet.
|
|
* This does nothing to prevent them from being deleted when the
|
|
* standby is disconnected (e.g because of network problems), but at
|
|
* least it avoids an open replication connection from failing because
|
|
* of that.
|
|
*/
|
|
if ((_logId || _logSeg) && MaxWalSenders > 0)
|
|
{
|
|
XLogRecPtr oldest;
|
|
uint32 log;
|
|
uint32 seg;
|
|
|
|
oldest = GetOldestWALSendPointer();
|
|
if (oldest.xlogid != 0 || oldest.xrecoff != 0)
|
|
{
|
|
XLByteToSeg(oldest, log, seg);
|
|
if (log < _logId || (log == _logId && seg < _logSeg))
|
|
{
|
|
_logId = log;
|
|
_logSeg = seg;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Delete old log files (those no longer needed even for
|
|
* previous checkpoint or the standbys in XLOG streaming).
|
|
*/
|
|
if (_logId || _logSeg)
|
|
{
|
|
PrevLogSeg(_logId, _logSeg);
|
|
RemoveOldXlogFiles(_logId, _logSeg, recptr);
|
|
}
|
|
|
|
/*
|
|
* Make more log segments if needed. (Do this after recycling old log
|
|
* segments, since that may supply some of the needed files.)
|
|
*/
|
|
if (!shutdown)
|
|
PreallocXlogFiles(recptr);
|
|
|
|
/*
|
|
* Truncate pg_subtrans if possible. We can throw away all data before
|
|
* the oldest XMIN of any running transaction. No future transaction will
|
|
* attempt to reference any pg_subtrans entry older than that (see Asserts
|
|
* in subtrans.c). During recovery, though, we mustn't do this because
|
|
* StartupSUBTRANS hasn't been called yet.
|
|
*/
|
|
if (!RecoveryInProgress())
|
|
TruncateSUBTRANS(GetOldestXmin(true, false));
|
|
|
|
/* All real work is done, but log before releasing lock. */
|
|
if (log_checkpoints)
|
|
LogCheckpointEnd(false);
|
|
|
|
TRACE_POSTGRESQL_CHECKPOINT_DONE(CheckpointStats.ckpt_bufs_written,
|
|
NBuffers,
|
|
CheckpointStats.ckpt_segs_added,
|
|
CheckpointStats.ckpt_segs_removed,
|
|
CheckpointStats.ckpt_segs_recycled);
|
|
|
|
LWLockRelease(CheckpointLock);
|
|
}
|
|
|
|
/*
|
|
* Flush all data in shared memory to disk, and fsync
|
|
*
|
|
* This is the common code shared between regular checkpoints and
|
|
* recovery restartpoints.
|
|
*/
|
|
static void
|
|
CheckPointGuts(XLogRecPtr checkPointRedo, int flags)
|
|
{
|
|
CheckPointCLOG();
|
|
CheckPointSUBTRANS();
|
|
CheckPointMultiXact();
|
|
CheckPointRelationMap();
|
|
CheckPointBuffers(flags); /* performs all required fsyncs */
|
|
/* We deliberately delay 2PC checkpointing as long as possible */
|
|
CheckPointTwoPhase(checkPointRedo);
|
|
}
|
|
|
|
/*
|
|
* Save a checkpoint for recovery restart if appropriate
|
|
*
|
|
* This function is called each time a checkpoint record is read from XLOG.
|
|
* It must determine whether the checkpoint represents a safe restartpoint or
|
|
* not. If so, the checkpoint record is stashed in shared memory so that
|
|
* CreateRestartPoint can consult it. (Note that the latter function is
|
|
* executed by the bgwriter, while this one will be executed by the startup
|
|
* process.)
|
|
*/
|
|
static void
|
|
RecoveryRestartPoint(const CheckPoint *checkPoint)
|
|
{
|
|
int rmid;
|
|
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
/*
|
|
* Is it safe to checkpoint? We must ask each of the resource managers
|
|
* whether they have any partial state information that might prevent a
|
|
* correct restart from this point. If so, we skip this opportunity, but
|
|
* return at the next checkpoint record for another try.
|
|
*/
|
|
for (rmid = 0; rmid <= RM_MAX_ID; rmid++)
|
|
{
|
|
if (RmgrTable[rmid].rm_safe_restartpoint != NULL)
|
|
if (!(RmgrTable[rmid].rm_safe_restartpoint()))
|
|
{
|
|
elog(trace_recovery(DEBUG2), "RM %d not safe to record restart point at %X/%X",
|
|
rmid,
|
|
checkPoint->redo.xlogid,
|
|
checkPoint->redo.xrecoff);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy the checkpoint record to shared memory, so that bgwriter can use
|
|
* it the next time it wants to perform a restartpoint.
|
|
*/
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
XLogCtl->lastCheckPointRecPtr = ReadRecPtr;
|
|
memcpy(&XLogCtl->lastCheckPoint, checkPoint, sizeof(CheckPoint));
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
/*
|
|
* Establish a restartpoint if possible.
|
|
*
|
|
* This is similar to CreateCheckPoint, but is used during WAL recovery
|
|
* to establish a point from which recovery can roll forward without
|
|
* replaying the entire recovery log.
|
|
*
|
|
* Returns true if a new restartpoint was established. We can only establish
|
|
* a restartpoint if we have replayed a safe checkpoint record since last
|
|
* restartpoint.
|
|
*/
|
|
bool
|
|
CreateRestartPoint(int flags)
|
|
{
|
|
XLogRecPtr lastCheckPointRecPtr;
|
|
CheckPoint lastCheckPoint;
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
/*
|
|
* Acquire CheckpointLock to ensure only one restartpoint or checkpoint
|
|
* happens at a time.
|
|
*/
|
|
LWLockAcquire(CheckpointLock, LW_EXCLUSIVE);
|
|
|
|
/* Get a local copy of the last safe checkpoint record. */
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
lastCheckPointRecPtr = xlogctl->lastCheckPointRecPtr;
|
|
memcpy(&lastCheckPoint, &XLogCtl->lastCheckPoint, sizeof(CheckPoint));
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
/*
|
|
* Check that we're still in recovery mode. It's ok if we exit recovery
|
|
* mode after this check, the restart point is valid anyway.
|
|
*/
|
|
if (!RecoveryInProgress())
|
|
{
|
|
ereport(DEBUG2,
|
|
(errmsg("skipping restartpoint, recovery has already ended")));
|
|
LWLockRelease(CheckpointLock);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* If the last checkpoint record we've replayed is already our last
|
|
* restartpoint, we can't perform a new restart point. We still update
|
|
* minRecoveryPoint in that case, so that if this is a shutdown restart
|
|
* point, we won't start up earlier than before. That's not strictly
|
|
* necessary, but when we get hot standby capability, it would be rather
|
|
* weird if the database opened up for read-only connections at a
|
|
* point-in-time before the last shutdown. Such time travel is still
|
|
* possible in case of immediate shutdown, though.
|
|
*
|
|
* We don't explicitly advance minRecoveryPoint when we do create a
|
|
* restartpoint. It's assumed that flushing the buffers will do that as a
|
|
* side-effect.
|
|
*/
|
|
if (XLogRecPtrIsInvalid(lastCheckPointRecPtr) ||
|
|
XLByteLE(lastCheckPoint.redo, ControlFile->checkPointCopy.redo))
|
|
{
|
|
XLogRecPtr InvalidXLogRecPtr = {0, 0};
|
|
|
|
ereport(DEBUG2,
|
|
(errmsg("skipping restartpoint, already performed at %X/%X",
|
|
lastCheckPoint.redo.xlogid, lastCheckPoint.redo.xrecoff)));
|
|
|
|
UpdateMinRecoveryPoint(InvalidXLogRecPtr, true);
|
|
LWLockRelease(CheckpointLock);
|
|
return false;
|
|
}
|
|
|
|
if (log_checkpoints)
|
|
{
|
|
/*
|
|
* Prepare to accumulate statistics.
|
|
*/
|
|
MemSet(&CheckpointStats, 0, sizeof(CheckpointStats));
|
|
CheckpointStats.ckpt_start_t = GetCurrentTimestamp();
|
|
|
|
LogCheckpointStart(flags, true);
|
|
}
|
|
|
|
CheckPointGuts(lastCheckPoint.redo, flags);
|
|
|
|
/*
|
|
* Select point at which we can truncate the xlog, which we base on the
|
|
* prior checkpoint's earliest info.
|
|
*/
|
|
XLByteToSeg(ControlFile->checkPointCopy.redo, _logId, _logSeg);
|
|
|
|
/*
|
|
* Update pg_control, using current time. Check that it still shows
|
|
* IN_ARCHIVE_RECOVERY state and an older checkpoint, else do nothing;
|
|
* this is a quick hack to make sure nothing really bad happens if
|
|
* somehow we get here after the end-of-recovery checkpoint.
|
|
*/
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
if (ControlFile->state == DB_IN_ARCHIVE_RECOVERY &&
|
|
XLByteLT(ControlFile->checkPointCopy.redo, lastCheckPoint.redo))
|
|
{
|
|
ControlFile->prevCheckPoint = ControlFile->checkPoint;
|
|
ControlFile->checkPoint = lastCheckPointRecPtr;
|
|
ControlFile->checkPointCopy = lastCheckPoint;
|
|
ControlFile->time = (pg_time_t) time(NULL);
|
|
UpdateControlFile();
|
|
}
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
/*
|
|
* Delete old log files (those no longer needed even for previous
|
|
* checkpoint/restartpoint) to prevent the disk holding the xlog from
|
|
* growing full. We don't need do this during normal recovery, but during
|
|
* streaming recovery we have to or the disk will eventually fill up from
|
|
* old log files streamed from master.
|
|
*/
|
|
if (WalRcvInProgress() && (_logId || _logSeg))
|
|
{
|
|
XLogRecPtr endptr;
|
|
|
|
/* Get the current (or recent) end of xlog */
|
|
endptr = GetWalRcvWriteRecPtr();
|
|
|
|
PrevLogSeg(_logId, _logSeg);
|
|
RemoveOldXlogFiles(_logId, _logSeg, endptr);
|
|
|
|
/*
|
|
* Make more log segments if needed. (Do this after recycling old log
|
|
* segments, since that may supply some of the needed files.)
|
|
*/
|
|
PreallocXlogFiles(endptr);
|
|
}
|
|
|
|
/*
|
|
* Currently, there is no need to truncate pg_subtrans during recovery. If
|
|
* we did do that, we will need to have called StartupSUBTRANS() already
|
|
* and then TruncateSUBTRANS() would go here.
|
|
*/
|
|
|
|
/* All real work is done, but log before releasing lock. */
|
|
if (log_checkpoints)
|
|
LogCheckpointEnd(true);
|
|
|
|
ereport((log_checkpoints ? LOG : DEBUG2),
|
|
(errmsg("recovery restart point at %X/%X with latest known log time %s",
|
|
lastCheckPoint.redo.xlogid, lastCheckPoint.redo.xrecoff,
|
|
timestamptz_to_str(GetLatestXLogTime()))));
|
|
|
|
LWLockRelease(CheckpointLock);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Write a NEXTOID log record
|
|
*/
|
|
void
|
|
XLogPutNextOid(Oid nextOid)
|
|
{
|
|
XLogRecData rdata;
|
|
|
|
rdata.data = (char *) (&nextOid);
|
|
rdata.len = sizeof(Oid);
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.next = NULL;
|
|
(void) XLogInsert(RM_XLOG_ID, XLOG_NEXTOID, &rdata);
|
|
|
|
/*
|
|
* We need not flush the NEXTOID record immediately, because any of the
|
|
* just-allocated OIDs could only reach disk as part of a tuple insert or
|
|
* update that would have its own XLOG record that must follow the NEXTOID
|
|
* record. Therefore, the standard buffer LSN interlock applied to those
|
|
* records will ensure no such OID reaches disk before the NEXTOID record
|
|
* does.
|
|
*
|
|
* Note, however, that the above statement only covers state "within" the
|
|
* database. When we use a generated OID as a file or directory name, we
|
|
* are in a sense violating the basic WAL rule, because that filesystem
|
|
* change may reach disk before the NEXTOID WAL record does. The impact
|
|
* of this is that if a database crash occurs immediately afterward, we
|
|
* might after restart re-generate the same OID and find that it conflicts
|
|
* with the leftover file or directory. But since for safety's sake we
|
|
* always loop until finding a nonconflicting filename, this poses no real
|
|
* problem in practice. See pgsql-hackers discussion 27-Sep-2006.
|
|
*/
|
|
}
|
|
|
|
/*
|
|
* Write an XLOG SWITCH record.
|
|
*
|
|
* Here we just blindly issue an XLogInsert request for the record.
|
|
* All the magic happens inside XLogInsert.
|
|
*
|
|
* The return value is either the end+1 address of the switch record,
|
|
* or the end+1 address of the prior segment if we did not need to
|
|
* write a switch record because we are already at segment start.
|
|
*/
|
|
XLogRecPtr
|
|
RequestXLogSwitch(void)
|
|
{
|
|
XLogRecPtr RecPtr;
|
|
XLogRecData rdata;
|
|
|
|
/* XLOG SWITCH, alone among xlog record types, has no data */
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.data = NULL;
|
|
rdata.len = 0;
|
|
rdata.next = NULL;
|
|
|
|
RecPtr = XLogInsert(RM_XLOG_ID, XLOG_SWITCH, &rdata);
|
|
|
|
return RecPtr;
|
|
}
|
|
|
|
/*
|
|
* Write an XLOG UNLOGGED record, indicating that some operation was
|
|
* performed on data that we fsync()'d directly to disk, skipping
|
|
* WAL-logging.
|
|
*
|
|
* Such operations screw up archive recovery, so we complain if we see
|
|
* these records during archive recovery. That shouldn't happen in a
|
|
* correctly configured server, but you can induce it by temporarily
|
|
* disabling archiving and restarting, so it's good to at least get a
|
|
* warning of silent data loss in such cases. These records serve no
|
|
* other purpose and are simply ignored during crash recovery.
|
|
*/
|
|
void
|
|
XLogReportUnloggedStatement(char *reason)
|
|
{
|
|
XLogRecData rdata;
|
|
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.data = reason;
|
|
rdata.len = strlen(reason) + 1;
|
|
rdata.next = NULL;
|
|
|
|
XLogInsert(RM_XLOG_ID, XLOG_UNLOGGED, &rdata);
|
|
}
|
|
|
|
/*
|
|
* XLOG resource manager's routines
|
|
*
|
|
* Definitions of info values are in include/catalog/pg_control.h, though
|
|
* not all record types are related to control file updates.
|
|
*/
|
|
void
|
|
xlog_redo(XLogRecPtr lsn, XLogRecord *record)
|
|
{
|
|
uint8 info = record->xl_info & ~XLR_INFO_MASK;
|
|
|
|
/* Backup blocks are not used in xlog records */
|
|
Assert(!(record->xl_info & XLR_BKP_BLOCK_MASK));
|
|
|
|
if (info == XLOG_NEXTOID)
|
|
{
|
|
Oid nextOid;
|
|
|
|
memcpy(&nextOid, XLogRecGetData(record), sizeof(Oid));
|
|
if (ShmemVariableCache->nextOid < nextOid)
|
|
{
|
|
ShmemVariableCache->nextOid = nextOid;
|
|
ShmemVariableCache->oidCount = 0;
|
|
}
|
|
}
|
|
else if (info == XLOG_CHECKPOINT_SHUTDOWN)
|
|
{
|
|
CheckPoint checkPoint;
|
|
|
|
memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
|
|
/* In a SHUTDOWN checkpoint, believe the counters exactly */
|
|
ShmemVariableCache->nextXid = checkPoint.nextXid;
|
|
ShmemVariableCache->nextOid = checkPoint.nextOid;
|
|
ShmemVariableCache->oidCount = 0;
|
|
MultiXactSetNextMXact(checkPoint.nextMulti,
|
|
checkPoint.nextMultiOffset);
|
|
SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
|
|
|
|
/* Check to see if any changes to max_connections give problems */
|
|
if (standbyState != STANDBY_DISABLED)
|
|
CheckRequiredParameterValues(checkPoint);
|
|
|
|
if (standbyState >= STANDBY_INITIALIZED)
|
|
{
|
|
/*
|
|
* Remove stale transactions, if any.
|
|
*/
|
|
ExpireOldKnownAssignedTransactionIds(checkPoint.nextXid);
|
|
StandbyReleaseOldLocks(checkPoint.nextXid);
|
|
}
|
|
|
|
/* ControlFile->checkPointCopy always tracks the latest ckpt XID */
|
|
ControlFile->checkPointCopy.nextXidEpoch = checkPoint.nextXidEpoch;
|
|
ControlFile->checkPointCopy.nextXid = checkPoint.nextXid;
|
|
|
|
/*
|
|
* TLI may change in a shutdown checkpoint, but it shouldn't decrease
|
|
*/
|
|
if (checkPoint.ThisTimeLineID != ThisTimeLineID)
|
|
{
|
|
if (checkPoint.ThisTimeLineID < ThisTimeLineID ||
|
|
!list_member_int(expectedTLIs,
|
|
(int) checkPoint.ThisTimeLineID))
|
|
ereport(PANIC,
|
|
(errmsg("unexpected timeline ID %u (after %u) in checkpoint record",
|
|
checkPoint.ThisTimeLineID, ThisTimeLineID)));
|
|
/* Following WAL records should be run with new TLI */
|
|
ThisTimeLineID = checkPoint.ThisTimeLineID;
|
|
}
|
|
|
|
RecoveryRestartPoint(&checkPoint);
|
|
}
|
|
else if (info == XLOG_CHECKPOINT_ONLINE)
|
|
{
|
|
CheckPoint checkPoint;
|
|
|
|
memcpy(&checkPoint, XLogRecGetData(record), sizeof(CheckPoint));
|
|
/* In an ONLINE checkpoint, treat the counters like NEXTOID */
|
|
if (TransactionIdPrecedes(ShmemVariableCache->nextXid,
|
|
checkPoint.nextXid))
|
|
ShmemVariableCache->nextXid = checkPoint.nextXid;
|
|
if (ShmemVariableCache->nextOid < checkPoint.nextOid)
|
|
{
|
|
ShmemVariableCache->nextOid = checkPoint.nextOid;
|
|
ShmemVariableCache->oidCount = 0;
|
|
}
|
|
MultiXactAdvanceNextMXact(checkPoint.nextMulti,
|
|
checkPoint.nextMultiOffset);
|
|
if (TransactionIdPrecedes(ShmemVariableCache->oldestXid,
|
|
checkPoint.oldestXid))
|
|
SetTransactionIdLimit(checkPoint.oldestXid,
|
|
checkPoint.oldestXidDB);
|
|
|
|
/* ControlFile->checkPointCopy always tracks the latest ckpt XID */
|
|
ControlFile->checkPointCopy.nextXidEpoch = checkPoint.nextXidEpoch;
|
|
ControlFile->checkPointCopy.nextXid = checkPoint.nextXid;
|
|
|
|
/* TLI should not change in an on-line checkpoint */
|
|
if (checkPoint.ThisTimeLineID != ThisTimeLineID)
|
|
ereport(PANIC,
|
|
(errmsg("unexpected timeline ID %u (should be %u) in checkpoint record",
|
|
checkPoint.ThisTimeLineID, ThisTimeLineID)));
|
|
|
|
RecoveryRestartPoint(&checkPoint);
|
|
}
|
|
else if (info == XLOG_NOOP)
|
|
{
|
|
/* nothing to do here */
|
|
}
|
|
else if (info == XLOG_SWITCH)
|
|
{
|
|
/* nothing to do here */
|
|
}
|
|
else if (info == XLOG_BACKUP_END)
|
|
{
|
|
XLogRecPtr startpoint;
|
|
memcpy(&startpoint, XLogRecGetData(record), sizeof(startpoint));
|
|
|
|
if (XLByteEQ(ControlFile->backupStartPoint, startpoint))
|
|
{
|
|
/*
|
|
* We have reached the end of base backup, the point where
|
|
* pg_stop_backup() was done. The data on disk is now consistent.
|
|
* Reset backupStartPoint, and update minRecoveryPoint to make
|
|
* sure we don't allow starting up at an earlier point even if
|
|
* recovery is stopped and restarted soon after this.
|
|
*/
|
|
elog(DEBUG1, "end of backup reached");
|
|
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
|
|
if (XLByteLT(ControlFile->minRecoveryPoint, lsn))
|
|
ControlFile->minRecoveryPoint = lsn;
|
|
MemSet(&ControlFile->backupStartPoint, 0, sizeof(XLogRecPtr));
|
|
UpdateControlFile();
|
|
|
|
LWLockRelease(ControlFileLock);
|
|
}
|
|
}
|
|
else if (info == XLOG_UNLOGGED)
|
|
{
|
|
if (InArchiveRecovery)
|
|
{
|
|
/*
|
|
* Note: We don't print the reason string from the record,
|
|
* because that gets added as a line using xlog_desc()
|
|
*/
|
|
ereport(WARNING,
|
|
(errmsg("unlogged operation performed, data may be missing"),
|
|
errhint("This can happen if you temporarily disable archive_mode without taking a new base backup.")));
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
xlog_desc(StringInfo buf, uint8 xl_info, char *rec)
|
|
{
|
|
uint8 info = xl_info & ~XLR_INFO_MASK;
|
|
|
|
if (info == XLOG_CHECKPOINT_SHUTDOWN ||
|
|
info == XLOG_CHECKPOINT_ONLINE)
|
|
{
|
|
CheckPoint *checkpoint = (CheckPoint *) rec;
|
|
|
|
appendStringInfo(buf, "checkpoint: redo %X/%X; "
|
|
"tli %u; xid %u/%u; oid %u; multi %u; offset %u; "
|
|
"oldest xid %u in DB %u; oldest running xid %u; %s",
|
|
checkpoint->redo.xlogid, checkpoint->redo.xrecoff,
|
|
checkpoint->ThisTimeLineID,
|
|
checkpoint->nextXidEpoch, checkpoint->nextXid,
|
|
checkpoint->nextOid,
|
|
checkpoint->nextMulti,
|
|
checkpoint->nextMultiOffset,
|
|
checkpoint->oldestXid,
|
|
checkpoint->oldestXidDB,
|
|
checkpoint->oldestActiveXid,
|
|
(info == XLOG_CHECKPOINT_SHUTDOWN) ? "shutdown" : "online");
|
|
}
|
|
else if (info == XLOG_NOOP)
|
|
{
|
|
appendStringInfo(buf, "xlog no-op");
|
|
}
|
|
else if (info == XLOG_NEXTOID)
|
|
{
|
|
Oid nextOid;
|
|
|
|
memcpy(&nextOid, rec, sizeof(Oid));
|
|
appendStringInfo(buf, "nextOid: %u", nextOid);
|
|
}
|
|
else if (info == XLOG_SWITCH)
|
|
{
|
|
appendStringInfo(buf, "xlog switch");
|
|
}
|
|
else if (info == XLOG_BACKUP_END)
|
|
{
|
|
XLogRecPtr startpoint;
|
|
|
|
memcpy(&startpoint, rec, sizeof(XLogRecPtr));
|
|
appendStringInfo(buf, "backup end: %X/%X",
|
|
startpoint.xlogid, startpoint.xrecoff);
|
|
}
|
|
else if (info == XLOG_UNLOGGED)
|
|
{
|
|
char *reason = rec;
|
|
|
|
appendStringInfo(buf, "unlogged operation: %s", reason);
|
|
}
|
|
else
|
|
appendStringInfo(buf, "UNKNOWN");
|
|
}
|
|
|
|
#ifdef WAL_DEBUG
|
|
|
|
static void
|
|
xlog_outrec(StringInfo buf, XLogRecord *record)
|
|
{
|
|
int i;
|
|
|
|
appendStringInfo(buf, "prev %X/%X; xid %u",
|
|
record->xl_prev.xlogid, record->xl_prev.xrecoff,
|
|
record->xl_xid);
|
|
|
|
appendStringInfo(buf, "; len %u",
|
|
record->xl_len);
|
|
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (record->xl_info & XLR_SET_BKP_BLOCK(i))
|
|
appendStringInfo(buf, "; bkpb%d", i + 1);
|
|
}
|
|
|
|
appendStringInfo(buf, ": %s", RmgrTable[record->xl_rmid].rm_name);
|
|
}
|
|
#endif /* WAL_DEBUG */
|
|
|
|
|
|
/*
|
|
* Return the (possible) sync flag used for opening a file, depending on the
|
|
* value of the GUC wal_sync_method.
|
|
*/
|
|
static int
|
|
get_sync_bit(int method)
|
|
{
|
|
/* If fsync is disabled, never open in sync mode */
|
|
if (!enableFsync)
|
|
return 0;
|
|
|
|
switch (method)
|
|
{
|
|
/*
|
|
* enum values for all sync options are defined even if they are
|
|
* not supported on the current platform. But if not, they are
|
|
* not included in the enum option array, and therefore will never
|
|
* be seen here.
|
|
*/
|
|
case SYNC_METHOD_FSYNC:
|
|
case SYNC_METHOD_FSYNC_WRITETHROUGH:
|
|
case SYNC_METHOD_FDATASYNC:
|
|
return 0;
|
|
#ifdef OPEN_SYNC_FLAG
|
|
case SYNC_METHOD_OPEN:
|
|
return OPEN_SYNC_FLAG;
|
|
#endif
|
|
#ifdef OPEN_DATASYNC_FLAG
|
|
case SYNC_METHOD_OPEN_DSYNC:
|
|
return OPEN_DATASYNC_FLAG;
|
|
#endif
|
|
default:
|
|
/* can't happen (unless we are out of sync with option array) */
|
|
elog(ERROR, "unrecognized wal_sync_method: %d", method);
|
|
return 0; /* silence warning */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* GUC support
|
|
*/
|
|
bool
|
|
assign_xlog_sync_method(int new_sync_method, bool doit, GucSource source)
|
|
{
|
|
if (!doit)
|
|
return true;
|
|
|
|
if (sync_method != new_sync_method)
|
|
{
|
|
/*
|
|
* To ensure that no blocks escape unsynced, force an fsync on the
|
|
* currently open log segment (if any). Also, if the open flag is
|
|
* changing, close the log file so it will be reopened (with new flag
|
|
* bit) at next use.
|
|
*/
|
|
if (openLogFile >= 0)
|
|
{
|
|
if (pg_fsync(openLogFile) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
if (get_sync_bit(sync_method) != get_sync_bit(new_sync_method))
|
|
XLogFileClose();
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
/*
|
|
* Issue appropriate kind of fsync (if any) for an XLOG output file.
|
|
*
|
|
* 'fd' is a file descriptor for the XLOG file to be fsync'd.
|
|
* 'log' and 'seg' are for error reporting purposes.
|
|
*/
|
|
void
|
|
issue_xlog_fsync(int fd, uint32 log, uint32 seg)
|
|
{
|
|
switch (sync_method)
|
|
{
|
|
case SYNC_METHOD_FSYNC:
|
|
if (pg_fsync_no_writethrough(fd) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync log file %u, segment %u: %m",
|
|
log, seg)));
|
|
break;
|
|
#ifdef HAVE_FSYNC_WRITETHROUGH
|
|
case SYNC_METHOD_FSYNC_WRITETHROUGH:
|
|
if (pg_fsync_writethrough(fd) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync write-through log file %u, segment %u: %m",
|
|
log, seg)));
|
|
break;
|
|
#endif
|
|
#ifdef HAVE_FDATASYNC
|
|
case SYNC_METHOD_FDATASYNC:
|
|
if (pg_fdatasync(fd) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fdatasync log file %u, segment %u: %m",
|
|
log, seg)));
|
|
break;
|
|
#endif
|
|
case SYNC_METHOD_OPEN:
|
|
case SYNC_METHOD_OPEN_DSYNC:
|
|
/* write synced it already */
|
|
break;
|
|
default:
|
|
elog(PANIC, "unrecognized wal_sync_method: %d", sync_method);
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* pg_start_backup: set up for taking an on-line backup dump
|
|
*
|
|
* Essentially what this does is to create a backup label file in $PGDATA,
|
|
* where it will be archived as part of the backup dump. The label file
|
|
* contains the user-supplied label string (typically this would be used
|
|
* to tell where the backup dump will be stored) and the starting time and
|
|
* starting WAL location for the dump.
|
|
*/
|
|
Datum
|
|
pg_start_backup(PG_FUNCTION_ARGS)
|
|
{
|
|
text *backupid = PG_GETARG_TEXT_P(0);
|
|
bool fast = PG_GETARG_BOOL(1);
|
|
char *backupidstr;
|
|
XLogRecPtr checkpointloc;
|
|
XLogRecPtr startpoint;
|
|
pg_time_t stamp_time;
|
|
char strfbuf[128];
|
|
char xlogfilename[MAXFNAMELEN];
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
struct stat stat_buf;
|
|
FILE *fp;
|
|
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
errmsg("must be superuser to run a backup")));
|
|
|
|
if (RecoveryInProgress())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("recovery is in progress"),
|
|
errhint("WAL control functions cannot be executed during recovery.")));
|
|
|
|
if (!XLogArchivingActive())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("WAL archiving is not active"),
|
|
errhint("archive_mode must be enabled at server start.")));
|
|
|
|
if (!XLogArchiveCommandSet())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("WAL archiving is not active"),
|
|
errhint("archive_command must be defined before "
|
|
"online backups can be made safely.")));
|
|
|
|
backupidstr = text_to_cstring(backupid);
|
|
|
|
/*
|
|
* Mark backup active in shared memory. We must do full-page WAL writes
|
|
* during an on-line backup even if not doing so at other times, because
|
|
* it's quite possible for the backup dump to obtain a "torn" (partially
|
|
* written) copy of a database page if it reads the page concurrently with
|
|
* our write to the same page. This can be fixed as long as the first
|
|
* write to the page in the WAL sequence is a full-page write. Hence, we
|
|
* turn on forcePageWrites and then force a CHECKPOINT, to ensure there
|
|
* are no dirty pages in shared memory that might get dumped while the
|
|
* backup is in progress without having a corresponding WAL record. (Once
|
|
* the backup is complete, we need not force full-page writes anymore,
|
|
* since we expect that any pages not modified during the backup interval
|
|
* must have been correctly captured by the backup.)
|
|
*
|
|
* We must hold WALInsertLock to change the value of forcePageWrites, to
|
|
* ensure adequate interlocking against XLogInsert().
|
|
*/
|
|
LWLockAcquire(WALInsertLock, LW_EXCLUSIVE);
|
|
if (XLogCtl->Insert.forcePageWrites)
|
|
{
|
|
LWLockRelease(WALInsertLock);
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("a backup is already in progress"),
|
|
errhint("Run pg_stop_backup() and try again.")));
|
|
}
|
|
XLogCtl->Insert.forcePageWrites = true;
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
/*
|
|
* Force an XLOG file switch before the checkpoint, to ensure that the WAL
|
|
* segment the checkpoint is written to doesn't contain pages with old
|
|
* timeline IDs. That would otherwise happen if you called
|
|
* pg_start_backup() right after restoring from a PITR archive: the first
|
|
* WAL segment containing the startup checkpoint has pages in the
|
|
* beginning with the old timeline ID. That can cause trouble at recovery:
|
|
* we won't have a history file covering the old timeline if pg_xlog
|
|
* directory was not included in the base backup and the WAL archive was
|
|
* cleared too before starting the backup.
|
|
*/
|
|
RequestXLogSwitch();
|
|
|
|
/* Ensure we release forcePageWrites if fail below */
|
|
PG_ENSURE_ERROR_CLEANUP(pg_start_backup_callback, (Datum) 0);
|
|
{
|
|
/*
|
|
* Force a CHECKPOINT. Aside from being necessary to prevent torn
|
|
* page problems, this guarantees that two successive backup runs will
|
|
* have different checkpoint positions and hence different history
|
|
* file names, even if nothing happened in between.
|
|
*
|
|
* We use CHECKPOINT_IMMEDIATE only if requested by user (via passing
|
|
* fast = true). Otherwise this can take awhile.
|
|
*/
|
|
RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT |
|
|
(fast ? CHECKPOINT_IMMEDIATE : 0));
|
|
|
|
/*
|
|
* Now we need to fetch the checkpoint record location, and also its
|
|
* REDO pointer. The oldest point in WAL that would be needed to
|
|
* restore starting from the checkpoint is precisely the REDO pointer.
|
|
*/
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
checkpointloc = ControlFile->checkPoint;
|
|
startpoint = ControlFile->checkPointCopy.redo;
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
XLByteToSeg(startpoint, _logId, _logSeg);
|
|
XLogFileName(xlogfilename, ThisTimeLineID, _logId, _logSeg);
|
|
|
|
/* Use the log timezone here, not the session timezone */
|
|
stamp_time = (pg_time_t) time(NULL);
|
|
pg_strftime(strfbuf, sizeof(strfbuf),
|
|
"%Y-%m-%d %H:%M:%S %Z",
|
|
pg_localtime(&stamp_time, log_timezone));
|
|
|
|
/*
|
|
* Check for existing backup label --- implies a backup is already
|
|
* running. (XXX given that we checked forcePageWrites above, maybe
|
|
* it would be OK to just unlink any such label file?)
|
|
*/
|
|
if (stat(BACKUP_LABEL_FILE, &stat_buf) != 0)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not stat file \"%s\": %m",
|
|
BACKUP_LABEL_FILE)));
|
|
}
|
|
else
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("a backup is already in progress"),
|
|
errhint("If you're sure there is no backup in progress, remove file \"%s\" and try again.",
|
|
BACKUP_LABEL_FILE)));
|
|
|
|
/*
|
|
* Okay, write the file
|
|
*/
|
|
fp = AllocateFile(BACKUP_LABEL_FILE, "w");
|
|
if (!fp)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create file \"%s\": %m",
|
|
BACKUP_LABEL_FILE)));
|
|
fprintf(fp, "START WAL LOCATION: %X/%X (file %s)\n",
|
|
startpoint.xlogid, startpoint.xrecoff, xlogfilename);
|
|
fprintf(fp, "CHECKPOINT LOCATION: %X/%X\n",
|
|
checkpointloc.xlogid, checkpointloc.xrecoff);
|
|
fprintf(fp, "START TIME: %s\n", strfbuf);
|
|
fprintf(fp, "LABEL: %s\n", backupidstr);
|
|
if (fflush(fp) || ferror(fp) || FreeFile(fp))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write file \"%s\": %m",
|
|
BACKUP_LABEL_FILE)));
|
|
}
|
|
PG_END_ENSURE_ERROR_CLEANUP(pg_start_backup_callback, (Datum) 0);
|
|
|
|
/*
|
|
* We're done. As a convenience, return the starting WAL location.
|
|
*/
|
|
snprintf(xlogfilename, sizeof(xlogfilename), "%X/%X",
|
|
startpoint.xlogid, startpoint.xrecoff);
|
|
PG_RETURN_TEXT_P(cstring_to_text(xlogfilename));
|
|
}
|
|
|
|
/* Error cleanup callback for pg_start_backup */
|
|
static void
|
|
pg_start_backup_callback(int code, Datum arg)
|
|
{
|
|
/* Turn off forcePageWrites on failure */
|
|
LWLockAcquire(WALInsertLock, LW_EXCLUSIVE);
|
|
XLogCtl->Insert.forcePageWrites = false;
|
|
LWLockRelease(WALInsertLock);
|
|
}
|
|
|
|
/*
|
|
* pg_stop_backup: finish taking an on-line backup dump
|
|
*
|
|
* We write an end-of-backup WAL record, and remove the backup label file
|
|
* created by pg_start_backup, creating a backup history file in pg_xlog
|
|
* instead (whence it will immediately be archived). The backup history file
|
|
* contains the same info found in the label file, plus the backup-end time
|
|
* and WAL location. Before 8.5, the backup-end time was read from the backup
|
|
* history file at the beginning of archive recovery, but we now use the WAL
|
|
* record for that and the file is for informational and debug purposes only.
|
|
*
|
|
* Note: different from CancelBackup which just cancels online backup mode.
|
|
*/
|
|
Datum
|
|
pg_stop_backup(PG_FUNCTION_ARGS)
|
|
{
|
|
XLogRecPtr startpoint;
|
|
XLogRecPtr stoppoint;
|
|
XLogRecData rdata;
|
|
pg_time_t stamp_time;
|
|
char strfbuf[128];
|
|
char histfilepath[MAXPGPATH];
|
|
char startxlogfilename[MAXFNAMELEN];
|
|
char stopxlogfilename[MAXFNAMELEN];
|
|
char lastxlogfilename[MAXFNAMELEN];
|
|
char histfilename[MAXFNAMELEN];
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
FILE *lfp;
|
|
FILE *fp;
|
|
char ch;
|
|
int ich;
|
|
int seconds_before_warning;
|
|
int waits = 0;
|
|
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to run a backup"))));
|
|
|
|
if (RecoveryInProgress())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("recovery is in progress"),
|
|
errhint("WAL control functions cannot be executed during recovery.")));
|
|
|
|
if (!XLogArchivingActive())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("WAL archiving is not active"),
|
|
errhint("archive_mode must be enabled at server start.")));
|
|
|
|
/*
|
|
* OK to clear forcePageWrites
|
|
*/
|
|
LWLockAcquire(WALInsertLock, LW_EXCLUSIVE);
|
|
XLogCtl->Insert.forcePageWrites = false;
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
/*
|
|
* Open the existing label file
|
|
*/
|
|
lfp = AllocateFile(BACKUP_LABEL_FILE, "r");
|
|
if (!lfp)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
BACKUP_LABEL_FILE)));
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("a backup is not in progress")));
|
|
}
|
|
|
|
/*
|
|
* Read and parse the START WAL LOCATION line (this code is pretty crude,
|
|
* but we are not expecting any variability in the file format).
|
|
*/
|
|
if (fscanf(lfp, "START WAL LOCATION: %X/%X (file %24s)%c",
|
|
&startpoint.xlogid, &startpoint.xrecoff, startxlogfilename,
|
|
&ch) != 4 || ch != '\n')
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("invalid data in file \"%s\"", BACKUP_LABEL_FILE)));
|
|
|
|
/*
|
|
* Write the backup-end xlog record
|
|
*/
|
|
rdata.data = (char *) (&startpoint);
|
|
rdata.len = sizeof(startpoint);
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.next = NULL;
|
|
stoppoint = XLogInsert(RM_XLOG_ID, XLOG_BACKUP_END, &rdata);
|
|
|
|
/*
|
|
* Force a switch to a new xlog segment file, so that the backup is valid
|
|
* as soon as archiver moves out the current segment file.
|
|
*/
|
|
RequestXLogSwitch();
|
|
|
|
XLByteToSeg(stoppoint, _logId, _logSeg);
|
|
XLogFileName(stopxlogfilename, ThisTimeLineID, _logId, _logSeg);
|
|
|
|
/* Use the log timezone here, not the session timezone */
|
|
stamp_time = (pg_time_t) time(NULL);
|
|
pg_strftime(strfbuf, sizeof(strfbuf),
|
|
"%Y-%m-%d %H:%M:%S %Z",
|
|
pg_localtime(&stamp_time, log_timezone));
|
|
|
|
/*
|
|
* Write the backup history file
|
|
*/
|
|
XLByteToSeg(startpoint, _logId, _logSeg);
|
|
BackupHistoryFilePath(histfilepath, ThisTimeLineID, _logId, _logSeg,
|
|
startpoint.xrecoff % XLogSegSize);
|
|
fp = AllocateFile(histfilepath, "w");
|
|
if (!fp)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create file \"%s\": %m",
|
|
histfilepath)));
|
|
fprintf(fp, "START WAL LOCATION: %X/%X (file %s)\n",
|
|
startpoint.xlogid, startpoint.xrecoff, startxlogfilename);
|
|
fprintf(fp, "STOP WAL LOCATION: %X/%X (file %s)\n",
|
|
stoppoint.xlogid, stoppoint.xrecoff, stopxlogfilename);
|
|
/* transfer remaining lines from label to history file */
|
|
while ((ich = fgetc(lfp)) != EOF)
|
|
fputc(ich, fp);
|
|
fprintf(fp, "STOP TIME: %s\n", strfbuf);
|
|
if (fflush(fp) || ferror(fp) || FreeFile(fp))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write file \"%s\": %m",
|
|
histfilepath)));
|
|
|
|
/*
|
|
* Close and remove the backup label file
|
|
*/
|
|
if (ferror(lfp) || FreeFile(lfp))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
BACKUP_LABEL_FILE)));
|
|
if (unlink(BACKUP_LABEL_FILE) != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not remove file \"%s\": %m",
|
|
BACKUP_LABEL_FILE)));
|
|
|
|
/*
|
|
* Clean out any no-longer-needed history files. As a side effect, this
|
|
* will post a .ready file for the newly created history file, notifying
|
|
* the archiver that history file may be archived immediately.
|
|
*/
|
|
CleanupBackupHistory();
|
|
|
|
/*
|
|
* Wait until both the last WAL file filled during backup and the history
|
|
* file have been archived. We assume that the alphabetic sorting
|
|
* property of the WAL files ensures any earlier WAL files are safely
|
|
* archived as well.
|
|
*
|
|
* We wait forever, since archive_command is supposed to work and we
|
|
* assume the admin wanted his backup to work completely. If you don't
|
|
* wish to wait, you can set statement_timeout.
|
|
*/
|
|
XLByteToPrevSeg(stoppoint, _logId, _logSeg);
|
|
XLogFileName(lastxlogfilename, ThisTimeLineID, _logId, _logSeg);
|
|
|
|
XLByteToSeg(startpoint, _logId, _logSeg);
|
|
BackupHistoryFileName(histfilename, ThisTimeLineID, _logId, _logSeg,
|
|
startpoint.xrecoff % XLogSegSize);
|
|
|
|
seconds_before_warning = 60;
|
|
waits = 0;
|
|
|
|
while (XLogArchiveIsBusy(lastxlogfilename) ||
|
|
XLogArchiveIsBusy(histfilename))
|
|
{
|
|
CHECK_FOR_INTERRUPTS();
|
|
|
|
pg_usleep(1000000L);
|
|
|
|
if (++waits >= seconds_before_warning)
|
|
{
|
|
seconds_before_warning *= 2; /* This wraps in >10 years... */
|
|
ereport(WARNING,
|
|
(errmsg("pg_stop_backup still waiting for archive to complete (%d seconds elapsed)",
|
|
waits)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We're done. As a convenience, return the ending WAL location.
|
|
*/
|
|
snprintf(stopxlogfilename, sizeof(stopxlogfilename), "%X/%X",
|
|
stoppoint.xlogid, stoppoint.xrecoff);
|
|
PG_RETURN_TEXT_P(cstring_to_text(stopxlogfilename));
|
|
}
|
|
|
|
/*
|
|
* pg_switch_xlog: switch to next xlog file
|
|
*/
|
|
Datum
|
|
pg_switch_xlog(PG_FUNCTION_ARGS)
|
|
{
|
|
XLogRecPtr switchpoint;
|
|
char location[MAXFNAMELEN];
|
|
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to switch transaction log files"))));
|
|
|
|
if (RecoveryInProgress())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("recovery is in progress"),
|
|
errhint("WAL control functions cannot be executed during recovery.")));
|
|
|
|
switchpoint = RequestXLogSwitch();
|
|
|
|
/*
|
|
* As a convenience, return the WAL location of the switch record
|
|
*/
|
|
snprintf(location, sizeof(location), "%X/%X",
|
|
switchpoint.xlogid, switchpoint.xrecoff);
|
|
PG_RETURN_TEXT_P(cstring_to_text(location));
|
|
}
|
|
|
|
/*
|
|
* Report the current WAL write location (same format as pg_start_backup etc)
|
|
*
|
|
* This is useful for determining how much of WAL is visible to an external
|
|
* archiving process. Note that the data before this point is written out
|
|
* to the kernel, but is not necessarily synced to disk.
|
|
*/
|
|
Datum
|
|
pg_current_xlog_location(PG_FUNCTION_ARGS)
|
|
{
|
|
char location[MAXFNAMELEN];
|
|
|
|
if (RecoveryInProgress())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("recovery is in progress"),
|
|
errhint("WAL control functions cannot be executed during recovery.")));
|
|
|
|
/* Make sure we have an up-to-date local LogwrtResult */
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
}
|
|
|
|
snprintf(location, sizeof(location), "%X/%X",
|
|
LogwrtResult.Write.xlogid, LogwrtResult.Write.xrecoff);
|
|
PG_RETURN_TEXT_P(cstring_to_text(location));
|
|
}
|
|
|
|
/*
|
|
* Report the current WAL insert location (same format as pg_start_backup etc)
|
|
*
|
|
* This function is mostly for debugging purposes.
|
|
*/
|
|
Datum
|
|
pg_current_xlog_insert_location(PG_FUNCTION_ARGS)
|
|
{
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
XLogRecPtr current_recptr;
|
|
char location[MAXFNAMELEN];
|
|
|
|
if (RecoveryInProgress())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("recovery is in progress"),
|
|
errhint("WAL control functions cannot be executed during recovery.")));
|
|
|
|
/*
|
|
* Get the current end-of-WAL position ... shared lock is sufficient
|
|
*/
|
|
LWLockAcquire(WALInsertLock, LW_SHARED);
|
|
INSERT_RECPTR(current_recptr, Insert, Insert->curridx);
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
snprintf(location, sizeof(location), "%X/%X",
|
|
current_recptr.xlogid, current_recptr.xrecoff);
|
|
PG_RETURN_TEXT_P(cstring_to_text(location));
|
|
}
|
|
|
|
/*
|
|
* Report the last WAL receive location (same format as pg_start_backup etc)
|
|
*
|
|
* This is useful for determining how much of WAL is guaranteed to be received
|
|
* and synced to disk by walreceiver.
|
|
*/
|
|
Datum
|
|
pg_last_xlog_receive_location(PG_FUNCTION_ARGS)
|
|
{
|
|
XLogRecPtr recptr;
|
|
char location[MAXFNAMELEN];
|
|
|
|
recptr = GetWalRcvWriteRecPtr();
|
|
|
|
snprintf(location, sizeof(location), "%X/%X",
|
|
recptr.xlogid, recptr.xrecoff);
|
|
PG_RETURN_TEXT_P(cstring_to_text(location));
|
|
}
|
|
|
|
/*
|
|
* Report the last WAL replay location (same format as pg_start_backup etc)
|
|
*
|
|
* This is useful for determining how much of WAL is visible to read-only
|
|
* connections during recovery.
|
|
*/
|
|
Datum
|
|
pg_last_xlog_replay_location(PG_FUNCTION_ARGS)
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
XLogRecPtr recptr;
|
|
char location[MAXFNAMELEN];
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
recptr = xlogctl->recoveryLastRecPtr;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
snprintf(location, sizeof(location), "%X/%X",
|
|
recptr.xlogid, recptr.xrecoff);
|
|
PG_RETURN_TEXT_P(cstring_to_text(location));
|
|
}
|
|
|
|
/*
|
|
* Compute an xlog file name and decimal byte offset given a WAL location,
|
|
* such as is returned by pg_stop_backup() or pg_xlog_switch().
|
|
*
|
|
* Note that a location exactly at a segment boundary is taken to be in
|
|
* the previous segment. This is usually the right thing, since the
|
|
* expected usage is to determine which xlog file(s) are ready to archive.
|
|
*/
|
|
Datum
|
|
pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
|
|
{
|
|
text *location = PG_GETARG_TEXT_P(0);
|
|
char *locationstr;
|
|
unsigned int uxlogid;
|
|
unsigned int uxrecoff;
|
|
uint32 xlogid;
|
|
uint32 xlogseg;
|
|
uint32 xrecoff;
|
|
XLogRecPtr locationpoint;
|
|
char xlogfilename[MAXFNAMELEN];
|
|
Datum values[2];
|
|
bool isnull[2];
|
|
TupleDesc resultTupleDesc;
|
|
HeapTuple resultHeapTuple;
|
|
Datum result;
|
|
|
|
/*
|
|
* Read input and parse
|
|
*/
|
|
locationstr = text_to_cstring(location);
|
|
|
|
if (sscanf(locationstr, "%X/%X", &uxlogid, &uxrecoff) != 2)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("could not parse transaction log location \"%s\"",
|
|
locationstr)));
|
|
|
|
locationpoint.xlogid = uxlogid;
|
|
locationpoint.xrecoff = uxrecoff;
|
|
|
|
/*
|
|
* Construct a tuple descriptor for the result row. This must match this
|
|
* function's pg_proc entry!
|
|
*/
|
|
resultTupleDesc = CreateTemplateTupleDesc(2, false);
|
|
TupleDescInitEntry(resultTupleDesc, (AttrNumber) 1, "file_name",
|
|
TEXTOID, -1, 0);
|
|
TupleDescInitEntry(resultTupleDesc, (AttrNumber) 2, "file_offset",
|
|
INT4OID, -1, 0);
|
|
|
|
resultTupleDesc = BlessTupleDesc(resultTupleDesc);
|
|
|
|
/*
|
|
* xlogfilename
|
|
*/
|
|
XLByteToPrevSeg(locationpoint, xlogid, xlogseg);
|
|
XLogFileName(xlogfilename, ThisTimeLineID, xlogid, xlogseg);
|
|
|
|
values[0] = CStringGetTextDatum(xlogfilename);
|
|
isnull[0] = false;
|
|
|
|
/*
|
|
* offset
|
|
*/
|
|
xrecoff = locationpoint.xrecoff - xlogseg * XLogSegSize;
|
|
|
|
values[1] = UInt32GetDatum(xrecoff);
|
|
isnull[1] = false;
|
|
|
|
/*
|
|
* Tuple jam: Having first prepared your Datums, then squash together
|
|
*/
|
|
resultHeapTuple = heap_form_tuple(resultTupleDesc, values, isnull);
|
|
|
|
result = HeapTupleGetDatum(resultHeapTuple);
|
|
|
|
PG_RETURN_DATUM(result);
|
|
}
|
|
|
|
/*
|
|
* Compute an xlog file name given a WAL location,
|
|
* such as is returned by pg_stop_backup() or pg_xlog_switch().
|
|
*/
|
|
Datum
|
|
pg_xlogfile_name(PG_FUNCTION_ARGS)
|
|
{
|
|
text *location = PG_GETARG_TEXT_P(0);
|
|
char *locationstr;
|
|
unsigned int uxlogid;
|
|
unsigned int uxrecoff;
|
|
uint32 xlogid;
|
|
uint32 xlogseg;
|
|
XLogRecPtr locationpoint;
|
|
char xlogfilename[MAXFNAMELEN];
|
|
|
|
locationstr = text_to_cstring(location);
|
|
|
|
if (sscanf(locationstr, "%X/%X", &uxlogid, &uxrecoff) != 2)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("could not parse transaction log location \"%s\"",
|
|
locationstr)));
|
|
|
|
locationpoint.xlogid = uxlogid;
|
|
locationpoint.xrecoff = uxrecoff;
|
|
|
|
XLByteToPrevSeg(locationpoint, xlogid, xlogseg);
|
|
XLogFileName(xlogfilename, ThisTimeLineID, xlogid, xlogseg);
|
|
|
|
PG_RETURN_TEXT_P(cstring_to_text(xlogfilename));
|
|
}
|
|
|
|
/*
|
|
* read_backup_label: check to see if a backup_label file is present
|
|
*
|
|
* If we see a backup_label during recovery, we assume that we are recovering
|
|
* from a backup dump file, and we therefore roll forward from the checkpoint
|
|
* identified by the label file, NOT what pg_control says. This avoids the
|
|
* problem that pg_control might have been archived one or more checkpoints
|
|
* later than the start of the dump, and so if we rely on it as the start
|
|
* point, we will fail to restore a consistent database state.
|
|
*
|
|
* Returns TRUE if a backup_label was found (and fills the checkpoint
|
|
* location and its REDO location into *checkPointLoc and RedoStartLSN,
|
|
* respectively); returns FALSE if not.
|
|
*/
|
|
static bool
|
|
read_backup_label(XLogRecPtr *checkPointLoc)
|
|
{
|
|
char startxlogfilename[MAXFNAMELEN];
|
|
TimeLineID tli;
|
|
FILE *lfp;
|
|
char ch;
|
|
|
|
/*
|
|
* See if label file is present
|
|
*/
|
|
lfp = AllocateFile(BACKUP_LABEL_FILE, "r");
|
|
if (!lfp)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
BACKUP_LABEL_FILE)));
|
|
return false; /* it's not there, all is fine */
|
|
}
|
|
|
|
/*
|
|
* Read and parse the START WAL LOCATION and CHECKPOINT lines (this code
|
|
* is pretty crude, but we are not expecting any variability in the file
|
|
* format).
|
|
*/
|
|
if (fscanf(lfp, "START WAL LOCATION: %X/%X (file %08X%16s)%c",
|
|
&RedoStartLSN.xlogid, &RedoStartLSN.xrecoff, &tli,
|
|
startxlogfilename, &ch) != 5 || ch != '\n')
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("invalid data in file \"%s\"", BACKUP_LABEL_FILE)));
|
|
if (fscanf(lfp, "CHECKPOINT LOCATION: %X/%X%c",
|
|
&checkPointLoc->xlogid, &checkPointLoc->xrecoff,
|
|
&ch) != 3 || ch != '\n')
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("invalid data in file \"%s\"", BACKUP_LABEL_FILE)));
|
|
if (ferror(lfp) || FreeFile(lfp))
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
BACKUP_LABEL_FILE)));
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Error context callback for errors occurring during rm_redo().
|
|
*/
|
|
static void
|
|
rm_redo_error_callback(void *arg)
|
|
{
|
|
XLogRecord *record = (XLogRecord *) arg;
|
|
StringInfoData buf;
|
|
|
|
initStringInfo(&buf);
|
|
RmgrTable[record->xl_rmid].rm_desc(&buf,
|
|
record->xl_info,
|
|
XLogRecGetData(record));
|
|
|
|
/* don't bother emitting empty description */
|
|
if (buf.len > 0)
|
|
errcontext("xlog redo %s", buf.data);
|
|
|
|
pfree(buf.data);
|
|
}
|
|
|
|
/*
|
|
* BackupInProgress: check if online backup mode is active
|
|
*
|
|
* This is done by checking for existence of the "backup_label" file.
|
|
*/
|
|
bool
|
|
BackupInProgress(void)
|
|
{
|
|
struct stat stat_buf;
|
|
|
|
return (stat(BACKUP_LABEL_FILE, &stat_buf) == 0);
|
|
}
|
|
|
|
/*
|
|
* CancelBackup: rename the "backup_label" file to cancel backup mode
|
|
*
|
|
* If the "backup_label" file exists, it will be renamed to "backup_label.old".
|
|
* Note that this will render an online backup in progress useless.
|
|
* To correctly finish an online backup, pg_stop_backup must be called.
|
|
*/
|
|
void
|
|
CancelBackup(void)
|
|
{
|
|
struct stat stat_buf;
|
|
|
|
/* if the file is not there, return */
|
|
if (stat(BACKUP_LABEL_FILE, &stat_buf) < 0)
|
|
return;
|
|
|
|
/* remove leftover file from previously cancelled backup if it exists */
|
|
unlink(BACKUP_LABEL_OLD);
|
|
|
|
if (rename(BACKUP_LABEL_FILE, BACKUP_LABEL_OLD) == 0)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("online backup mode cancelled"),
|
|
errdetail("\"%s\" was renamed to \"%s\".",
|
|
BACKUP_LABEL_FILE, BACKUP_LABEL_OLD)));
|
|
}
|
|
else
|
|
{
|
|
ereport(WARNING,
|
|
(errcode_for_file_access(),
|
|
errmsg("online backup mode was not cancelled"),
|
|
errdetail("Could not rename \"%s\" to \"%s\": %m.",
|
|
BACKUP_LABEL_FILE, BACKUP_LABEL_OLD)));
|
|
}
|
|
}
|
|
|
|
/* ------------------------------------------------------
|
|
* Startup Process main entry point and signal handlers
|
|
* ------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* startupproc_quickdie() occurs when signalled SIGQUIT by the postmaster.
|
|
*
|
|
* Some backend has bought the farm,
|
|
* so we need to stop what we're doing and exit.
|
|
*/
|
|
static void
|
|
startupproc_quickdie(SIGNAL_ARGS)
|
|
{
|
|
PG_SETMASK(&BlockSig);
|
|
|
|
/*
|
|
* We DO NOT want to run proc_exit() callbacks -- we're here because
|
|
* shared memory may be corrupted, so we don't want to try to clean up our
|
|
* transaction. Just nail the windows shut and get out of town. Now that
|
|
* there's an atexit callback to prevent third-party code from breaking
|
|
* things by calling exit() directly, we have to reset the callbacks
|
|
* explicitly to make this work as intended.
|
|
*/
|
|
on_exit_reset();
|
|
|
|
/*
|
|
* Note we do exit(2) not exit(0). This is to force the postmaster into a
|
|
* system reset cycle if some idiot DBA sends a manual SIGQUIT to a random
|
|
* backend. This is necessary precisely because we don't clean up our
|
|
* shared memory state. (The "dead man switch" mechanism in pmsignal.c
|
|
* should ensure the postmaster sees this as a crash, too, but no harm in
|
|
* being doubly sure.)
|
|
*/
|
|
exit(2);
|
|
}
|
|
|
|
|
|
/* SIGHUP: set flag to re-read config file at next convenient time */
|
|
static void
|
|
StartupProcSigHupHandler(SIGNAL_ARGS)
|
|
{
|
|
got_SIGHUP = true;
|
|
}
|
|
|
|
/* SIGTERM: set flag to abort redo and exit */
|
|
static void
|
|
StartupProcShutdownHandler(SIGNAL_ARGS)
|
|
{
|
|
if (in_restore_command)
|
|
proc_exit(1);
|
|
else
|
|
shutdown_requested = true;
|
|
}
|
|
|
|
/* Handle SIGHUP and SIGTERM signals of startup process */
|
|
void
|
|
HandleStartupProcInterrupts(void)
|
|
{
|
|
/*
|
|
* Check if we were requested to re-read config file.
|
|
*/
|
|
if (got_SIGHUP)
|
|
{
|
|
got_SIGHUP = false;
|
|
ProcessConfigFile(PGC_SIGHUP);
|
|
}
|
|
/*
|
|
* Check if we were requested to exit without finishing recovery.
|
|
*/
|
|
if (shutdown_requested)
|
|
proc_exit(1);
|
|
|
|
/*
|
|
* Emergency bailout if postmaster has died. This is to avoid the
|
|
* necessity for manual cleanup of all postmaster children.
|
|
*/
|
|
if (IsUnderPostmaster && !PostmasterIsAlive(true))
|
|
exit(1);
|
|
}
|
|
|
|
/* Main entry point for startup process */
|
|
void
|
|
StartupProcessMain(void)
|
|
{
|
|
/*
|
|
* If possible, make this process a group leader, so that the postmaster
|
|
* can signal any child processes too.
|
|
*/
|
|
#ifdef HAVE_SETSID
|
|
if (setsid() < 0)
|
|
elog(FATAL, "setsid() failed: %m");
|
|
#endif
|
|
|
|
/*
|
|
* Properly accept or ignore signals the postmaster might send us
|
|
*/
|
|
pqsignal(SIGHUP, StartupProcSigHupHandler); /* reload config file */
|
|
pqsignal(SIGINT, SIG_IGN); /* ignore query cancel */
|
|
pqsignal(SIGTERM, StartupProcShutdownHandler); /* request shutdown */
|
|
pqsignal(SIGQUIT, startupproc_quickdie); /* hard crash time */
|
|
if (XLogRequestRecoveryConnections)
|
|
pqsignal(SIGALRM, handle_standby_sig_alarm); /* ignored unless InHotStandby */
|
|
else
|
|
pqsignal(SIGALRM, SIG_IGN);
|
|
pqsignal(SIGPIPE, SIG_IGN);
|
|
pqsignal(SIGUSR1, SIG_IGN);
|
|
pqsignal(SIGUSR2, SIG_IGN);
|
|
|
|
/*
|
|
* Reset some signals that are accepted by postmaster but not here
|
|
*/
|
|
pqsignal(SIGCHLD, SIG_DFL);
|
|
pqsignal(SIGTTIN, SIG_DFL);
|
|
pqsignal(SIGTTOU, SIG_DFL);
|
|
pqsignal(SIGCONT, SIG_DFL);
|
|
pqsignal(SIGWINCH, SIG_DFL);
|
|
|
|
/*
|
|
* Unblock signals (they were blocked when the postmaster forked us)
|
|
*/
|
|
PG_SETMASK(&UnBlockSig);
|
|
|
|
StartupXLOG();
|
|
|
|
/*
|
|
* Exit normally. Exit code 0 tells postmaster that we completed recovery
|
|
* successfully.
|
|
*/
|
|
proc_exit(0);
|
|
}
|
|
|
|
/*
|
|
* Read the XLOG page containing RecPtr into readBuf (if not read already).
|
|
* Returns true if successful, false otherwise or fails if emode is PANIC.
|
|
*
|
|
* This is responsible for restoring files from archive as needed, as well
|
|
* as for waiting for the requested WAL record to arrive in standby mode.
|
|
*/
|
|
static bool
|
|
XLogPageRead(XLogRecPtr *RecPtr, int emode, bool fetching_ckpt,
|
|
bool randAccess)
|
|
{
|
|
static XLogRecPtr receivedUpto = {0, 0};
|
|
bool switched_segment = false;
|
|
uint32 targetPageOff;
|
|
uint32 targetRecOff;
|
|
uint32 targetId;
|
|
uint32 targetSeg;
|
|
|
|
XLByteToSeg(*RecPtr, targetId, targetSeg);
|
|
targetPageOff = ((RecPtr->xrecoff % XLogSegSize) / XLOG_BLCKSZ) * XLOG_BLCKSZ;
|
|
targetRecOff = RecPtr->xrecoff % XLOG_BLCKSZ;
|
|
|
|
/* Fast exit if we have read the record in the current buffer already */
|
|
if (targetId == readId && targetSeg == readSeg &&
|
|
targetPageOff == readOff && targetRecOff < readLen)
|
|
return true;
|
|
|
|
/*
|
|
* See if we need to switch to a new segment because the requested record
|
|
* is not in the currently open one.
|
|
*/
|
|
if (readFile >= 0 && !XLByteInSeg(*RecPtr, readId, readSeg))
|
|
{
|
|
close(readFile);
|
|
readFile = -1;
|
|
}
|
|
|
|
XLByteToSeg(*RecPtr, readId, readSeg);
|
|
|
|
/* See if we need to retrieve more data */
|
|
if (readFile < 0 ||
|
|
(readStreamed && !XLByteLT(*RecPtr, receivedUpto)))
|
|
{
|
|
if (StandbyMode)
|
|
{
|
|
bool last_restore_failed = false;
|
|
|
|
/*
|
|
* In standby mode, wait for the requested record to become
|
|
* available, either via restore_command succeeding to restore
|
|
* the segment, or via walreceiver having streamed the record.
|
|
*/
|
|
for (;;)
|
|
{
|
|
if (WalRcvInProgress())
|
|
{
|
|
/*
|
|
* While walreceiver is active, wait for new WAL to
|
|
* arrive from primary.
|
|
*/
|
|
receivedUpto = GetWalRcvWriteRecPtr();
|
|
if (XLByteLT(*RecPtr, receivedUpto))
|
|
{
|
|
/*
|
|
* Great, streamed far enough. Open the file if it's
|
|
* not open already.
|
|
*/
|
|
if (readFile < 0)
|
|
{
|
|
readFile =
|
|
XLogFileRead(readId, readSeg, PANIC,
|
|
recoveryTargetTLI, false, false);
|
|
switched_segment = true;
|
|
readStreamed = true;
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (CheckForStandbyTrigger())
|
|
goto next_record_is_invalid;
|
|
|
|
/*
|
|
* When streaming is active, we want to react quickly when
|
|
* the next WAL record arrives, so sleep only a bit.
|
|
*/
|
|
pg_usleep(100000L); /* 100ms */
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Until walreceiver manages to reconnect, poll the
|
|
* archive.
|
|
*/
|
|
if (readFile >= 0)
|
|
{
|
|
close(readFile);
|
|
readFile = -1;
|
|
}
|
|
/* Reset curFileTLI if random fetch. */
|
|
if (randAccess)
|
|
curFileTLI = 0;
|
|
readFile = XLogFileReadAnyTLI(readId, readSeg, DEBUG2, true);
|
|
switched_segment = true;
|
|
readStreamed = false;
|
|
if (readFile != -1)
|
|
{
|
|
elog(DEBUG1, "got WAL segment from archive");
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If we succeeded restoring some segments from archive
|
|
* since the last connection attempt (or we haven't
|
|
* tried streaming yet, retry immediately. But if we
|
|
* haven't, assume the problem is persistent, so be
|
|
* less aggressive.
|
|
*/
|
|
if (last_restore_failed)
|
|
{
|
|
/*
|
|
* Check to see if the trigger file exists. Note that
|
|
* we do this only after failure, so when you create
|
|
* the trigger file, we still finish replaying as much
|
|
* as we can before failover.
|
|
*/
|
|
if (CheckForStandbyTrigger())
|
|
goto next_record_is_invalid;
|
|
pg_usleep(5000000L); /* 5 seconds */
|
|
}
|
|
last_restore_failed = true;
|
|
|
|
/*
|
|
* Nope, not found in archive. Try to stream it.
|
|
*
|
|
* If fetching_ckpt is TRUE, RecPtr points to the initial
|
|
* checkpoint location. In that case, we use RedoStartLSN
|
|
* as the streaming start position instead of RecPtr, so
|
|
* that when we later jump backwards to start redo at
|
|
* RedoStartLSN, we will have the logs streamed already.
|
|
*/
|
|
if (PrimaryConnInfo)
|
|
RequestXLogStreaming(fetching_ckpt ? RedoStartLSN : *RecPtr,
|
|
PrimaryConnInfo);
|
|
}
|
|
|
|
/*
|
|
* This possibly-long loop needs to handle interrupts of startup
|
|
* process.
|
|
*/
|
|
HandleStartupProcInterrupts();
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* In archive or crash recovery. */
|
|
if (readFile < 0)
|
|
{
|
|
/* Reset curFileTLI if random fetch. */
|
|
if (randAccess)
|
|
curFileTLI = 0;
|
|
readFile = XLogFileReadAnyTLI(readId, readSeg, emode,
|
|
InArchiveRecovery);
|
|
switched_segment = true;
|
|
readStreamed = false;
|
|
if (readFile < 0)
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* At this point, we have the right segment open and we know the
|
|
* requested record is in it.
|
|
*/
|
|
Assert(readFile != -1);
|
|
|
|
/*
|
|
* If the current segment is being streamed from master, calculate
|
|
* how much of the current page we have received already. We know the
|
|
* requested record has been received, but this is for the benefit
|
|
* of future calls, to allow quick exit at the top of this function.
|
|
*/
|
|
if (readStreamed)
|
|
{
|
|
if (RecPtr->xlogid != receivedUpto.xlogid ||
|
|
(RecPtr->xrecoff / XLOG_BLCKSZ) != (receivedUpto.xrecoff / XLOG_BLCKSZ))
|
|
{
|
|
readLen = XLOG_BLCKSZ;
|
|
}
|
|
else
|
|
readLen = receivedUpto.xrecoff % XLogSegSize - targetPageOff;
|
|
}
|
|
else
|
|
readLen = XLOG_BLCKSZ;
|
|
|
|
if (switched_segment && targetPageOff != 0)
|
|
{
|
|
/*
|
|
* Whenever switching to a new WAL segment, we read the first page of
|
|
* the file and validate its header, even if that's not where the
|
|
* target record is. This is so that we can check the additional
|
|
* identification info that is present in the first page's "long"
|
|
* header.
|
|
*/
|
|
readOff = 0;
|
|
if (read(readFile, readBuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
|
|
{
|
|
ereport(emode,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from log file %u, segment %u, offset %u: %m",
|
|
readId, readSeg, readOff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
if (!ValidXLOGHeader((XLogPageHeader) readBuf, emode))
|
|
goto next_record_is_invalid;
|
|
}
|
|
|
|
/* Read the requested page */
|
|
readOff = targetPageOff;
|
|
if (lseek(readFile, (off_t) readOff, SEEK_SET) < 0)
|
|
{
|
|
ereport(emode,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not seek in log file %u, segment %u to offset %u: %m",
|
|
readId, readSeg, readOff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
if (read(readFile, readBuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
|
|
{
|
|
ereport(emode,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from log file %u, segment %u, offset %u: %m",
|
|
readId, readSeg, readOff)));
|
|
goto next_record_is_invalid;
|
|
}
|
|
if (!ValidXLOGHeader((XLogPageHeader) readBuf, emode))
|
|
goto next_record_is_invalid;
|
|
|
|
Assert(targetId == readId);
|
|
Assert(targetSeg == readSeg);
|
|
Assert(targetPageOff == readOff);
|
|
Assert(targetRecOff < readLen);
|
|
|
|
return true;
|
|
|
|
next_record_is_invalid:
|
|
if (readFile >= 0)
|
|
close(readFile);
|
|
readFile = -1;
|
|
readStreamed = false;
|
|
readLen = 0;
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check to see if the trigger file exists. If it does, request postmaster
|
|
* to shut down walreceiver, wait for it to exit, remove the trigger
|
|
* file, and return true.
|
|
*/
|
|
static bool
|
|
CheckForStandbyTrigger(void)
|
|
{
|
|
struct stat stat_buf;
|
|
|
|
if (TriggerFile == NULL)
|
|
return false;
|
|
|
|
if (stat(TriggerFile, &stat_buf) == 0)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("trigger file found: %s", TriggerFile)));
|
|
ShutdownWalRcv();
|
|
unlink(TriggerFile);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|