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during it: When bgwriter is active, the startup process can't perform mdsync() correctly because it won't see the fsync requests accumulated in bgwriter's private pendingOpsTable. Therefore make bgwriter responsible for the end-of-recovery checkpoint as well, when it's active. When bgwriter is active (= archive recovery), the startup process must not accumulate fsync requests to its own pendingOpsTable, since bgwriter won't see them there when it performs restartpoints. Make startup process drop its pendingOpsTable when bgwriter is launched to avoid that. Update minimum recovery point one last time when leaving archive recovery. It won't be updated by the end-of-recovery checkpoint because XLogFlush() sees us as out of recovery already. This fixes bug #4879 reported by Fujii Masao.
7934 lines
233 KiB
C
7934 lines
233 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) 1996-2009, 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 1.344 2009/06/25 21:36:00 heikki 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_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 "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/flatfiles.h"
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#include "utils/guc.h"
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#include "utils/ps_status.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 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, even if the system is still
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* in recovery. Prior to 8.4, all activity during recovery were carried out
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* by Startup process. This local variable continues to be used in functions
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* that need to act differently when called from a redo function (e.g skip
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* WAL logging). To check whether the system is in recovery regardless of what
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* process you're running in, use RecoveryInProgress().
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*/
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bool InRecovery = false;
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/* Are we recovering using offline XLOG archives? */
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static bool InArchiveRecovery = false;
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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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/* 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 */
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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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/* 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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* 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)
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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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/*
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* SharedRecoveryInProgress indicates if we're still in crash or archive
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* recovery. It's checked by RecoveryInProgress().
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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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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.
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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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/* 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;
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/* State information for XLOG reading */
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static XLogRecPtr ReadRecPtr; /* start of last record read */
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static XLogRecPtr EndRecPtr; /* end+1 of last record read */
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static XLogRecord *nextRecord = NULL;
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static TimeLineID lastPageTLI = 0;
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static XLogRecPtr minRecoveryPoint; /* local copy of
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* ControlFile->minRecoveryPoint */
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static bool updateMinRecoveryPoint = true;
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static bool InRedo = false;
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/*
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* Flag set by interrupt handlers for later service in the redo loop.
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*/
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static volatile sig_atomic_t got_SIGHUP = false;
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static volatile sig_atomic_t shutdown_requested = false;
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/*
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* Flag set when executing a restore command, to tell SIGTERM signal handler
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* that it's safe to just proc_exit.
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*/
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static volatile sig_atomic_t in_restore_command = false;
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static void XLogArchiveNotify(const char *xlog);
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static void XLogArchiveNotifySeg(uint32 log, uint32 seg);
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static bool XLogArchiveCheckDone(const char *xlog);
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static bool XLogArchiveIsBusy(const char *xlog);
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static void XLogArchiveCleanup(const char *xlog);
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static void readRecoveryCommandFile(void);
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static void exitArchiveRecovery(TimeLineID endTLI,
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uint32 endLogId, uint32 endLogSeg);
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static bool recoveryStopsHere(XLogRecord *record, bool *includeThis);
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static void CheckPointGuts(XLogRecPtr checkPointRedo, int flags);
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static bool XLogCheckBuffer(XLogRecData *rdata, bool doPageWrites,
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XLogRecPtr *lsn, BkpBlock *bkpb);
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static bool AdvanceXLInsertBuffer(bool new_segment);
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static void XLogWrite(XLogwrtRqst WriteRqst, bool flexible, bool xlog_switch);
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static int XLogFileInit(uint32 log, uint32 seg,
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bool *use_existent, bool use_lock);
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static bool InstallXLogFileSegment(uint32 *log, uint32 *seg, char *tmppath,
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bool find_free, int *max_advance,
|
|
bool use_lock);
|
|
static int XLogFileOpen(uint32 log, uint32 seg);
|
|
static int XLogFileRead(uint32 log, uint32 seg, int emode);
|
|
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);
|
|
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);
|
|
|
|
#ifdef WAL_DEBUG
|
|
static void xlog_outrec(StringInfo buf, XLogRecord *record);
|
|
#endif
|
|
static void issue_xlog_fsync(void);
|
|
static void pg_start_backup_callback(int code, Datum arg);
|
|
static bool read_backup_label(XLogRecPtr *checkPointLoc,
|
|
XLogRecPtr *minRecoveryLoc);
|
|
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 (RecoveryInProgress())
|
|
elog(FATAL, "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();
|
|
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();
|
|
}
|
|
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 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,
|
|
* ie. crash recovery. Don't update the control file in that case.
|
|
*/
|
|
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.
|
|
*/
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
newMinRecoveryPoint = xlogctl->replayEndRecPtr;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
/* 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 don't try to flush the WAL, but update minRecoveryPoint
|
|
* instead.
|
|
*/
|
|
if (RecoveryInProgress())
|
|
{
|
|
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 has actually
|
|
* happened in the field several times with 7.1 releases. Note that we
|
|
* cannot get here while RecoveryInProgress(), but if the bad page is
|
|
* brought in and marked dirty during recovery then if a checkpoint were
|
|
* performed at the end of recovery it will try to flush it.
|
|
*
|
|
* The current approach is to ERROR under normal conditions, but only
|
|
* WARNING during recovery, so that the system can be brought up even if
|
|
* there's a corrupt 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(InRecovery ? WARNING : 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();
|
|
}
|
|
|
|
/*
|
|
* Flush any previous asynchronously-committed transactions' commit records.
|
|
*
|
|
* NOTE: it is unwise to assume that this provides any strong guarantees.
|
|
* In particular, because of the inexact LSN bookkeeping used by clog.c,
|
|
* we cannot assume that hint bits will be settable for these transactions.
|
|
*/
|
|
void
|
|
XLogAsyncCommitFlush(void)
|
|
{
|
|
XLogRecPtr WriteRqstPtr;
|
|
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
/* There's no asynchronously committed transactions during recovery */
|
|
if (RecoveryInProgress())
|
|
return;
|
|
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
WriteRqstPtr = xlogctl->asyncCommitLSN;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
XLogFlush(WriteRqstPtr);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
/* XLOG doesn't need flushing during recovery */
|
|
if (RecoveryInProgress())
|
|
return false;
|
|
|
|
/* 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.
|
|
*/
|
|
static 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... */
|
|
unlink(tmppath);
|
|
}
|
|
|
|
elog(DEBUG2, "done creating and filling new WAL file");
|
|
|
|
/* 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)));
|
|
|
|
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 file installed, FALSE if not installed because of
|
|
* exceeding max_advance limit. On Windows, we also return FALSE if we
|
|
* can't rename the file into place because someone's got it open.
|
|
* (Any other kind of failure causes ereport().)
|
|
*/
|
|
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)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not link file \"%s\" to \"%s\" (initialization of log file %u, segment %u): %m",
|
|
tmppath, path, *log, *seg)));
|
|
unlink(tmppath);
|
|
#else
|
|
if (rename(tmppath, path) < 0)
|
|
{
|
|
#ifdef WIN32
|
|
#if !defined(__CYGWIN__)
|
|
if (GetLastError() == ERROR_ACCESS_DENIED)
|
|
#else
|
|
if (errno == EACCES)
|
|
#endif
|
|
{
|
|
if (use_lock)
|
|
LWLockRelease(ControlFileLock);
|
|
return false;
|
|
}
|
|
#endif /* WIN32 */
|
|
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename file \"%s\" to \"%s\" (initialization of log file %u, segment %u): %m",
|
|
tmppath, path, *log, *seg)));
|
|
}
|
|
#endif
|
|
|
|
if (use_lock)
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Open a pre-existing logfile segment for writing.
|
|
*/
|
|
static 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).
|
|
*/
|
|
static int
|
|
XLogFileRead(uint32 log, uint32 seg, int emode)
|
|
{
|
|
char path[MAXPGPATH];
|
|
char xlogfname[MAXFNAMELEN];
|
|
char activitymsg[MAXFNAMELEN + 16];
|
|
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 */
|
|
|
|
XLogFileName(xlogfname, tli, log, seg);
|
|
|
|
if (InArchiveRecovery)
|
|
{
|
|
/* 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);
|
|
}
|
|
else
|
|
XLogFilePath(path, tli, log, seg);
|
|
|
|
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) /* unexpected failure? */
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
}
|
|
|
|
/* 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
|
|
* is active, because archiver 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 (!XLogArchivingActive() &&
|
|
(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;
|
|
|
|
/*
|
|
* 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 in 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.
|
|
*
|
|
* XXX I made wrong-size a fatal error 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 (stat(xlogpath, &stat_buf) == 0)
|
|
{
|
|
if (expectedSize > 0 && stat_buf.st_size != expectedSize)
|
|
ereport(FATAL,
|
|
(errmsg("archive file \"%s\" has wrong size: %lu instead of %lu",
|
|
xlogfname,
|
|
(unsigned long) stat_buf.st_size,
|
|
(unsigned long) expectedSize)));
|
|
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 (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)));
|
|
|
|
/*
|
|
* 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];
|
|
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)
|
|
{
|
|
if (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... */
|
|
ereport(DEBUG2,
|
|
(errmsg("removing transaction log file \"%s\"",
|
|
xlde->d_name)));
|
|
unlink(path);
|
|
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. At the moment, that's just
|
|
* pro forma, because there can't be any regular backends in the system
|
|
* during recovery. 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 or 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)
|
|
{
|
|
XLogRecord *record;
|
|
char *buffer;
|
|
XLogRecPtr tmpRecPtr = EndRecPtr;
|
|
bool randAccess = false;
|
|
uint32 len,
|
|
total_len;
|
|
uint32 targetPageOff;
|
|
uint32 targetRecOff;
|
|
uint32 pageHeaderSize;
|
|
|
|
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;
|
|
/* fast case if next record is on same page */
|
|
if (nextRecord != NULL)
|
|
{
|
|
record = nextRecord;
|
|
goto got_record;
|
|
}
|
|
/* align old recptr to next page */
|
|
if (tmpRecPtr.xrecoff % XLOG_BLCKSZ != 0)
|
|
tmpRecPtr.xrecoff += (XLOG_BLCKSZ - tmpRecPtr.xrecoff % XLOG_BLCKSZ);
|
|
if (tmpRecPtr.xrecoff >= XLogFileSize)
|
|
{
|
|
(tmpRecPtr.xlogid)++;
|
|
tmpRecPtr.xrecoff = 0;
|
|
}
|
|
/* We will account for page header size below */
|
|
}
|
|
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 */
|
|
}
|
|
|
|
if (readFile >= 0 && !XLByteInSeg(*RecPtr, readId, readSeg))
|
|
{
|
|
close(readFile);
|
|
readFile = -1;
|
|
}
|
|
XLByteToSeg(*RecPtr, readId, readSeg);
|
|
if (readFile < 0)
|
|
{
|
|
/* Now it's okay to reset curFileTLI if random fetch */
|
|
if (randAccess)
|
|
curFileTLI = 0;
|
|
|
|
readFile = XLogFileRead(readId, readSeg, emode);
|
|
if (readFile < 0)
|
|
goto next_record_is_invalid;
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
targetPageOff = ((RecPtr->xrecoff % XLogSegSize) / XLOG_BLCKSZ) * XLOG_BLCKSZ;
|
|
if (readOff != targetPageOff)
|
|
{
|
|
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;
|
|
}
|
|
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);
|
|
|
|
got_record:;
|
|
|
|
/*
|
|
* 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;
|
|
nextRecord = NULL;
|
|
len = XLOG_BLCKSZ - RecPtr->xrecoff % XLOG_BLCKSZ;
|
|
if (total_len > len)
|
|
{
|
|
/* Need to reassemble record */
|
|
XLogContRecord *contrecord;
|
|
uint32 gotlen = len;
|
|
|
|
memcpy(buffer, record, len);
|
|
record = (XLogRecord *) buffer;
|
|
buffer += len;
|
|
for (;;)
|
|
{
|
|
readOff += XLOG_BLCKSZ;
|
|
if (readOff >= XLogSegSize)
|
|
{
|
|
close(readFile);
|
|
readFile = -1;
|
|
NextLogSeg(readId, readSeg);
|
|
readFile = XLogFileRead(readId, readSeg, emode);
|
|
if (readFile < 0)
|
|
goto next_record_is_invalid;
|
|
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;
|
|
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);
|
|
if (XLOG_BLCKSZ - SizeOfXLogRecord >= pageHeaderSize +
|
|
MAXALIGN(SizeOfXLogContRecord + contrecord->xl_rem_len))
|
|
{
|
|
nextRecord = (XLogRecord *) ((char *) contrecord +
|
|
MAXALIGN(SizeOfXLogContRecord + contrecord->xl_rem_len));
|
|
}
|
|
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;
|
|
if (XLOG_BLCKSZ - SizeOfXLogRecord >= RecPtr->xrecoff % XLOG_BLCKSZ +
|
|
MAXALIGN(total_len))
|
|
nextRecord = (XLogRecord *) ((char *) record + MAXALIGN(total_len));
|
|
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;
|
|
nextRecord = NULL; /* definitely not on same page */
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
nextRecord = NULL;
|
|
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;
|
|
|
|
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;
|
|
|
|
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")));
|
|
}
|
|
|
|
/*
|
|
* 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->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.time = (pg_time_t) time(NULL);
|
|
|
|
ShmemVariableCache->nextXid = checkPoint.nextXid;
|
|
ShmemVariableCache->nextOid = checkPoint.nextOid;
|
|
ShmemVariableCache->oidCount = 0;
|
|
MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
|
|
|
|
/* 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.
|
|
*
|
|
* 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)));
|
|
}
|
|
|
|
ereport(LOG,
|
|
(errmsg("starting archive recovery")));
|
|
|
|
/*
|
|
* 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(LOG,
|
|
(errmsg("restore_command = '%s'",
|
|
recoveryRestoreCommand)));
|
|
}
|
|
else if (strcmp(tok1, "recovery_end_command") == 0)
|
|
{
|
|
recoveryEndCommand = pstrdup(tok2);
|
|
ereport(LOG,
|
|
(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(LOG,
|
|
(errmsg("recovery_target_timeline = %u", rtli)));
|
|
else
|
|
ereport(LOG,
|
|
(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(LOG,
|
|
(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(LOG,
|
|
(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(LOG,
|
|
(errmsg("recovery_target_inclusive = %s", tok2)));
|
|
}
|
|
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'.")));
|
|
|
|
/* Check that required parameters were supplied */
|
|
if (recoveryRestoreCommand == NULL)
|
|
ereport(FATAL,
|
|
(errmsg("recovery command file \"%s\" did not specify restore_command",
|
|
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);
|
|
|
|
/*
|
|
* We should have the ending log segment currently open. Verify, and then
|
|
* close it (to avoid problems on Windows with trying to rename or delete
|
|
* an open file).
|
|
*/
|
|
Assert(readFile >= 0);
|
|
Assert(readId == endLogId);
|
|
Assert(readSeg == endLogSeg);
|
|
|
|
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)
|
|
return false;
|
|
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;
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/*
|
|
* 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,
|
|
LastRec,
|
|
checkPointLoc,
|
|
backupStopLoc,
|
|
EndOfLog;
|
|
uint32 endLogId;
|
|
uint32 endLogSeg;
|
|
XLogRecord *record;
|
|
uint32 freespace;
|
|
TransactionId oldestActiveXID;
|
|
bool bgwriterLaunched = false;
|
|
|
|
XLogCtl->SharedRecoveryInProgress = true;
|
|
|
|
/*
|
|
* 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();
|
|
|
|
/*
|
|
* 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)));
|
|
|
|
if (read_backup_label(&checkPointLoc, &backupStopLoc))
|
|
{
|
|
/*
|
|
* 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;
|
|
record = ReadCheckpointRecord(checkPointLoc, 1);
|
|
if (record != NULL)
|
|
{
|
|
ereport(DEBUG1,
|
|
(errmsg("checkpoint record is at %X/%X",
|
|
checkPointLoc.xlogid, checkPointLoc.xrecoff)));
|
|
}
|
|
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)));
|
|
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);
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("automatic recovery in progress")));
|
|
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 (backupStopLoc.xlogid != 0 || backupStopLoc.xrecoff != 0)
|
|
{
|
|
if (XLByteLT(ControlFile->minRecoveryPoint, backupStopLoc))
|
|
ControlFile->minRecoveryPoint = backupStopLoc;
|
|
}
|
|
ControlFile->time = (pg_time_t) time(NULL);
|
|
/* No need to hold ControlFileLock yet, we aren't up far enough */
|
|
UpdateControlFile();
|
|
|
|
/* update 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 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);
|
|
}
|
|
else
|
|
{
|
|
/* just have to read next record after CheckPoint */
|
|
record = ReadRecord(NULL, LOG);
|
|
}
|
|
|
|
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;
|
|
|
|
/* Update shared replayEndRecPtr */
|
|
SpinLockAcquire(&xlogctl->info_lck);
|
|
xlogctl->replayEndRecPtr = ReadRecPtr;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
InRedo = true;
|
|
|
|
if (minRecoveryPoint.xlogid == 0 && minRecoveryPoint.xrecoff == 0)
|
|
ereport(LOG,
|
|
(errmsg("redo starts at %X/%X",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff)));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("redo starts at %X/%X, consistency will be reached at %X/%X",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff,
|
|
minRecoveryPoint.xlogid, minRecoveryPoint.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!
|
|
*/
|
|
if (InArchiveRecovery && IsUnderPostmaster)
|
|
{
|
|
SetForwardFsyncRequests();
|
|
SendPostmasterSignal(PMSIGNAL_RECOVERY_STARTED);
|
|
bgwriterLaunched = true;
|
|
}
|
|
|
|
/*
|
|
* main redo apply loop
|
|
*/
|
|
do
|
|
{
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG)
|
|
{
|
|
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
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* Have we reached our safe starting point? If so, we can tell
|
|
* postmaster that the database is consistent now.
|
|
*/
|
|
if (!reachedMinRecoveryPoint &&
|
|
XLByteLE(minRecoveryPoint, EndRecPtr))
|
|
{
|
|
reachedMinRecoveryPoint = true;
|
|
if (InArchiveRecovery)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("consistent recovery state reached")));
|
|
if (IsUnderPostmaster)
|
|
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;
|
|
SpinLockRelease(&xlogctl->info_lck);
|
|
|
|
RmgrTable[record->xl_rmid].rm_redo(EndRecPtr, record);
|
|
|
|
/* Pop the error context stack */
|
|
error_context_stack = errcontext.previous;
|
|
|
|
LastRec = ReadRecPtr;
|
|
|
|
record = ReadRecord(NULL, LOG);
|
|
} 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")));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
EndOfLog = EndRecPtr;
|
|
XLByteToPrevSeg(EndOfLog, endLogId, endLogSeg);
|
|
|
|
/*
|
|
* Complain if we did not roll forward far enough to render the backup
|
|
* dump consistent.
|
|
*/
|
|
if (InRecovery && XLByteLT(EndOfLog, minRecoveryPoint))
|
|
{
|
|
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();
|
|
|
|
if (InRecovery)
|
|
{
|
|
int rmid;
|
|
|
|
/*
|
|
* 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();
|
|
}
|
|
|
|
/*
|
|
* 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 */
|
|
StartupCLOG();
|
|
StartupSUBTRANS(oldestActiveXID);
|
|
StartupMultiXact();
|
|
|
|
/* Reload shared-memory state for prepared transactions */
|
|
RecoverPreparedTransactions();
|
|
|
|
/* 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.
|
|
*/
|
|
XLogCtl->SharedRecoveryInProgress = false;
|
|
}
|
|
|
|
/*
|
|
* Is the system still in recovery?
|
|
*
|
|
* 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 we rely on the local state variable after
|
|
* that.
|
|
*/
|
|
if (!LocalRecoveryInProgress)
|
|
return false;
|
|
else
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
LocalRecoveryInProgress = xlogctl->SharedRecoveryInProgress;
|
|
|
|
/*
|
|
* Initialize TimeLineID and RedoRecPtr the first time we see that
|
|
* recovery is finished.
|
|
*/
|
|
if (!LocalRecoveryInProgress)
|
|
InitXLOGAccess();
|
|
|
|
return LocalRecoveryInProgress;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
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);
|
|
|
|
/* 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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
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 and
|
|
* 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;
|
|
bool OldInRecovery = InRecovery;
|
|
|
|
/*
|
|
* 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) != 0))
|
|
shutdown = true;
|
|
else
|
|
shutdown = false;
|
|
|
|
/*
|
|
* A startup checkpoint is created before anyone else is allowed to
|
|
* write WAL. To allow us to write the checkpoint record, set
|
|
* LocalRecoveryInProgress to false. This lets us write WAL, but others
|
|
* are still not allowed to do so.
|
|
*/
|
|
if (flags & CHECKPOINT_END_OF_RECOVERY)
|
|
{
|
|
Assert(RecoveryInProgress());
|
|
LocalRecoveryInProgress = false;
|
|
InitXLOGAccess();
|
|
|
|
/*
|
|
* Before 8.4, end-of-recovery checkpoints were always performed by
|
|
* the startup process, and InRecovery was set true. InRecovery is not
|
|
* normally set in bgwriter, but we set it here temporarily to avoid
|
|
* confusing old code in the end-of-recovery checkpoint code path that
|
|
* rely on it.
|
|
*/
|
|
InRecovery = true;
|
|
}
|
|
else
|
|
{
|
|
/* shouldn't happen */
|
|
if (RecoveryInProgress())
|
|
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.ThisTimeLineID = ThisTimeLineID;
|
|
checkPoint.time = (pg_time_t) time(NULL);
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
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);
|
|
|
|
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 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);
|
|
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();
|
|
|
|
/*
|
|
* Delete old log files (those no longer needed even for previous
|
|
* checkpoint).
|
|
*/
|
|
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 (!InRecovery)
|
|
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);
|
|
|
|
/* Restore old value */
|
|
InRecovery = OldInRecovery;
|
|
}
|
|
|
|
/*
|
|
* 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();
|
|
CheckPointBuffers(flags); /* performs all required fsyncs */
|
|
/* We deliberately delay 2PC checkpointing as long as possible */
|
|
CheckPointTwoPhase(checkPointRedo);
|
|
}
|
|
|
|
/*
|
|
* This is used during WAL recovery to establish a point from which recovery
|
|
* can roll forward without replaying the entire recovery log. This function
|
|
* is called each time a checkpoint record is read from XLOG. It is stored
|
|
* in shared memory, so that it can be used as a restartpoint later on.
|
|
*/
|
|
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(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);
|
|
}
|
|
|
|
/*
|
|
* 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 checkpoint record since last
|
|
* restartpoint.
|
|
*/
|
|
bool
|
|
CreateRestartPoint(int flags)
|
|
{
|
|
XLogRecPtr lastCheckPointRecPtr;
|
|
CheckPoint lastCheckPoint;
|
|
|
|
/* 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 the a local copy of the last 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);
|
|
|
|
/*
|
|
* Update pg_control, using current time
|
|
*/
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
ControlFile->prevCheckPoint = ControlFile->checkPoint;
|
|
ControlFile->checkPoint = lastCheckPointRecPtr;
|
|
ControlFile->checkPointCopy = lastCheckPoint;
|
|
ControlFile->time = (pg_time_t) time(NULL);
|
|
UpdateControlFile();
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
/*
|
|
* 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",
|
|
lastCheckPoint.redo.xlogid, lastCheckPoint.redo.xrecoff)));
|
|
|
|
if (recoveryLastXTime)
|
|
ereport((log_checkpoints ? LOG : DEBUG2),
|
|
(errmsg("last completed transaction was at log time %s",
|
|
timestamptz_to_str(recoveryLastXTime))));
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* XLOG resource manager's routines
|
|
*
|
|
* Definitions of info values are in include/catalog/pg_control.h, though
|
|
* not all records types are related to control file processing.
|
|
*/
|
|
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);
|
|
|
|
/* 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);
|
|
|
|
/* 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 */
|
|
}
|
|
}
|
|
|
|
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; %s",
|
|
checkpoint->redo.xlogid, checkpoint->redo.xrecoff,
|
|
checkpoint->ThisTimeLineID,
|
|
checkpoint->nextXidEpoch, checkpoint->nextXid,
|
|
checkpoint->nextOid,
|
|
checkpoint->nextMulti,
|
|
checkpoint->nextMultiOffset,
|
|
(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
|
|
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);
|
|
|
|
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) on the current XLOG output file
|
|
*/
|
|
static void
|
|
issue_xlog_fsync(void)
|
|
{
|
|
switch (sync_method)
|
|
{
|
|
case SYNC_METHOD_FSYNC:
|
|
if (pg_fsync_no_writethrough(openLogFile) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
break;
|
|
#ifdef HAVE_FSYNC_WRITETHROUGH
|
|
case SYNC_METHOD_FSYNC_WRITETHROUGH:
|
|
if (pg_fsync_writethrough(openLogFile) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync write-through log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
break;
|
|
#endif
|
|
#ifdef HAVE_FDATASYNC
|
|
case SYNC_METHOD_FDATASYNC:
|
|
if (pg_fdatasync(openLogFile) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fdatasync log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
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 (!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 remove the backup label file created by pg_start_backup, and instead
|
|
* create a backup history file in pg_xlog (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.
|
|
* Note: different from CancelBackup which just cancels online backup mode.
|
|
*/
|
|
Datum
|
|
pg_stop_backup(PG_FUNCTION_ARGS)
|
|
{
|
|
XLogRecPtr startpoint;
|
|
XLogRecPtr stoppoint;
|
|
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 (!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);
|
|
|
|
/*
|
|
* 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. We'll report
|
|
* the end address of the XLOG SWITCH record as the backup stopping point.
|
|
*/
|
|
stoppoint = 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));
|
|
|
|
/*
|
|
* 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 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"))));
|
|
|
|
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];
|
|
|
|
/* 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];
|
|
|
|
/*
|
|
* 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));
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* We also attempt to retrieve the corresponding backup history file.
|
|
* If successful, set *minRecoveryLoc to constrain valid PITR stopping
|
|
* points.
|
|
*
|
|
* Returns TRUE if a backup_label was found (and fills the checkpoint
|
|
* location into *checkPointLoc); returns FALSE if not.
|
|
*/
|
|
static bool
|
|
read_backup_label(XLogRecPtr *checkPointLoc, XLogRecPtr *minRecoveryLoc)
|
|
{
|
|
XLogRecPtr startpoint;
|
|
XLogRecPtr stoppoint;
|
|
char histfilename[MAXFNAMELEN];
|
|
char histfilepath[MAXPGPATH];
|
|
char startxlogfilename[MAXFNAMELEN];
|
|
char stopxlogfilename[MAXFNAMELEN];
|
|
TimeLineID tli;
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
FILE *lfp;
|
|
FILE *fp;
|
|
char ch;
|
|
|
|
/* Default is to not constrain recovery stop point */
|
|
minRecoveryLoc->xlogid = 0;
|
|
minRecoveryLoc->xrecoff = 0;
|
|
|
|
/*
|
|
* 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",
|
|
&startpoint.xlogid, &startpoint.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)));
|
|
|
|
/*
|
|
* Try to retrieve the backup history file (no error if we can't)
|
|
*/
|
|
XLByteToSeg(startpoint, _logId, _logSeg);
|
|
BackupHistoryFileName(histfilename, tli, _logId, _logSeg,
|
|
startpoint.xrecoff % XLogSegSize);
|
|
|
|
if (InArchiveRecovery)
|
|
RestoreArchivedFile(histfilepath, histfilename, "RECOVERYHISTORY", 0);
|
|
else
|
|
BackupHistoryFilePath(histfilepath, tli, _logId, _logSeg,
|
|
startpoint.xrecoff % XLogSegSize);
|
|
|
|
fp = AllocateFile(histfilepath, "r");
|
|
if (fp)
|
|
{
|
|
/*
|
|
* Parse history file to identify stop point.
|
|
*/
|
|
if (fscanf(fp, "START WAL LOCATION: %X/%X (file %24s)%c",
|
|
&startpoint.xlogid, &startpoint.xrecoff, startxlogfilename,
|
|
&ch) != 4 || ch != '\n')
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("invalid data in file \"%s\"", histfilename)));
|
|
if (fscanf(fp, "STOP WAL LOCATION: %X/%X (file %24s)%c",
|
|
&stoppoint.xlogid, &stoppoint.xrecoff, stopxlogfilename,
|
|
&ch) != 4 || ch != '\n')
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("invalid data in file \"%s\"", histfilename)));
|
|
*minRecoveryLoc = stoppoint;
|
|
if (ferror(fp) || FreeFile(fp))
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
histfilepath)));
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/* 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 */
|
|
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();
|
|
|
|
BuildFlatFiles(false);
|
|
|
|
/*
|
|
* Exit normally. Exit code 0 tells postmaster that we completed recovery
|
|
* successfully.
|
|
*/
|
|
proc_exit(0);
|
|
}
|