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5953 lines
170 KiB
C
5953 lines
170 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) 1996-2005, 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 1.200 2005/06/15 01:36:08 momjian 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 <fcntl.h>
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#include <signal.h>
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#include <time.h>
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#include <unistd.h>
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#include <sys/stat.h>
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#include <sys/time.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/xact.h"
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#include "access/xlog.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 "miscadmin.h"
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#include "postmaster/bgwriter.h"
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#include "storage/bufpage.h"
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#include "storage/fd.h"
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#include "storage/lwlock.h"
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#include "storage/pmsignal.h"
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#include "storage/proc.h"
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#include "storage/procarray.h"
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#include "storage/spin.h"
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#include "utils/builtins.h"
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#include "utils/guc.h"
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#include "utils/relcache.h"
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/*
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* This chunk of hackery attempts to determine which file sync methods
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* are available on the current platform, and to choose an appropriate
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* default method. We assume that fsync() is always available, and that
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* configure determined whether fdatasync() is.
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*/
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#if defined(O_SYNC)
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#define OPEN_SYNC_FLAG O_SYNC
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#else
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#if defined(O_FSYNC)
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#define OPEN_SYNC_FLAG O_FSYNC
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#endif
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#endif
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#if defined(O_DSYNC)
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#if defined(OPEN_SYNC_FLAG)
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#if O_DSYNC != OPEN_SYNC_FLAG
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#define OPEN_DATASYNC_FLAG O_DSYNC
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#endif
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#else /* !defined(OPEN_SYNC_FLAG) */
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/* Win32 only has O_DSYNC */
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#define OPEN_DATASYNC_FLAG O_DSYNC
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#endif
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#endif
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#if defined(OPEN_DATASYNC_FLAG)
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#define DEFAULT_SYNC_METHOD_STR "open_datasync"
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#define DEFAULT_SYNC_METHOD SYNC_METHOD_OPEN
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#define DEFAULT_SYNC_FLAGBIT OPEN_DATASYNC_FLAG
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#elif defined(HAVE_FDATASYNC)
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#define DEFAULT_SYNC_METHOD_STR "fdatasync"
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#define DEFAULT_SYNC_METHOD SYNC_METHOD_FDATASYNC
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#define DEFAULT_SYNC_FLAGBIT 0
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#elif !defined(HAVE_FSYNC_WRITETHROUGH_ONLY)
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#define DEFAULT_SYNC_METHOD_STR "fsync"
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#define DEFAULT_SYNC_METHOD SYNC_METHOD_FSYNC
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#define DEFAULT_SYNC_FLAGBIT 0
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#else
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#define DEFAULT_SYNC_METHOD_STR "fsync_writethrough"
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#define DEFAULT_SYNC_METHOD SYNC_METHOD_FSYNC_WRITETHROUGH
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#define DEFAULT_SYNC_FLAGBIT 0
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#endif
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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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char *XLogArchiveCommand = NULL;
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char *XLOG_sync_method = NULL;
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const char XLOG_sync_method_default[] = DEFAULT_SYNC_METHOD_STR;
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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 used in the code as the allowed "fuzz" in the number of
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* preallocated XLOG segments --- we try to have at least XLOGfiles advance
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* segments but no more than XLOGfileslop segments. This could
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* be made a separate GUC variable, but at present I think it's sufficient
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* to hardwire it as 2*CheckPointSegments+1. Under normal conditions, a
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* checkpoint will free no more than 2*CheckPointSegments log segments, and
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* we want to recycle all of them; the +1 allows boundary cases to happen
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* without wasting a delete/create-segment cycle.
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*/
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#define XLOGfileslop (2*CheckPointSegments + 1)
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/* these are derived from XLOG_sync_method by assign_xlog_sync_method */
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int sync_method = DEFAULT_SYNC_METHOD;
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static int open_sync_bit = DEFAULT_SYNC_FLAGBIT;
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#define XLOG_SYNC_BIT (enableFsync ? open_sync_bit : 0)
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#define MinXLOGbuffers 4
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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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/* Are we doing recovery from XLOG? */
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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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/* 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 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 time_t recoveryTargetTime;
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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 time_t recoveryStopTime;
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static bool recoveryStopAfter;
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/* constraint set by read_backup_label */
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static XLogRecPtr recoveryMinXlogOffset = {0, 0};
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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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* MyLastRecPtr points to the start of the last XLOG record inserted by the
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* current transaction. If MyLastRecPtr.xrecoff == 0, then the current
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* xact hasn't yet inserted any transaction-controlled XLOG records.
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*
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* Note that XLOG records inserted outside transaction control are not
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* reflected into MyLastRecPtr. They do, however, cause MyXactMadeXLogEntry
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* to be set true. The latter can be used to test whether the current xact
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* made any loggable changes (including out-of-xact changes, such as
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* sequence updates).
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*
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* When we insert/update/delete a tuple in a temporary relation, we do not
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* make any XLOG record, since we don't care about recovering the state of
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* the temp rel after a crash. However, we will still need to remember
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* whether our transaction committed or aborted in that case. So, we must
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* set MyXactMadeTempRelUpdate true to indicate that the XID will be of
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* interest later.
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*/
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XLogRecPtr MyLastRecPtr = {0, 0};
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bool MyXactMadeXLogEntry = false;
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bool MyXactMadeTempRelUpdate = false;
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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, transaction-controlled
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* or not. ProcLastRecEnd is similar but points to end+1 of last record.
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*/
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static XLogRecPtr ProcLastRecPtr = {0, 0};
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XLogRecPtr ProcLastRecEnd = {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 (ensures only one
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* checkpointer at a time; even though the postmaster won't launch
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* parallel checkpoint processes, we need this because manual checkpoints
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* could be launched simultaneously).
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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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uint16 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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} 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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uint16 curridx; /* cache index of next block to write */
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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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/* 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
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* pages and xlblocks values certainly do. Permission to read/write
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* the pages and xlblocks values depends on WALInsertLock and
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* 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 + BLCKSZ */
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uint32 XLogCacheByte; /* # bytes in xlog buffers */
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uint32 XLogCacheBlck; /* highest allocated xlog buffer index */
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TimeLineID ThisTimeLineID;
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slock_t info_lck; /* locks shared LogwrtRqst/LogwrtResult */
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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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(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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/* File path names */
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char XLogDir[MAXPGPATH];
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static char ControlFilePath[MAXPGPATH];
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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 (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 bool InRedo = 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 XLogArchiveIsDone(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 bool XLogCheckBuffer(XLogRecData *rdata,
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XLogRecPtr *lsn, BkpBlock *bkpb);
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static bool AdvanceXLInsertBuffer(void);
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static void XLogWrite(XLogwrtRqst WriteRqst);
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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,
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bool use_lock);
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static int XLogFileOpen(uint32 log, uint32 seg);
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static int XLogFileRead(uint32 log, uint32 seg, int emode);
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static bool RestoreArchivedFile(char *path, const char *xlogfname,
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const char *recovername, off_t expectedSize);
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static int PreallocXlogFiles(XLogRecPtr endptr);
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static void MoveOfflineLogs(uint32 log, uint32 seg, XLogRecPtr endptr,
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int *nsegsremoved, int *nsegsrecycled);
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static void RemoveOldBackupHistory(void);
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static XLogRecord *ReadRecord(XLogRecPtr *RecPtr, int emode);
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static bool ValidXLOGHeader(XLogPageHeader hdr, int emode);
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static XLogRecord *ReadCheckpointRecord(XLogRecPtr RecPtr, int whichChkpt);
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static List *readTimeLineHistory(TimeLineID targetTLI);
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static bool existsTimeLineHistory(TimeLineID probeTLI);
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static TimeLineID findNewestTimeLine(TimeLineID startTLI);
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static void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
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TimeLineID endTLI,
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uint32 endLogId, uint32 endLogSeg);
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static void WriteControlFile(void);
|
|
static void ReadControlFile(void);
|
|
static char *str_time(time_t tnow);
|
|
static void issue_xlog_fsync(void);
|
|
|
|
#ifdef WAL_DEBUG
|
|
static void xlog_outrec(char *buf, XLogRecord *record);
|
|
#endif
|
|
static bool read_backup_label(XLogRecPtr *checkPointLoc);
|
|
static void remove_backup_label(void);
|
|
|
|
|
|
/*
|
|
* 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;
|
|
uint16 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;
|
|
XLogwrtRqst LogwrtRqst;
|
|
bool updrqst;
|
|
bool no_tran = (rmid == RM_XLOG_ID) ? true : false;
|
|
|
|
if (info & XLR_INFO_MASK)
|
|
{
|
|
if ((info & XLR_INFO_MASK) != XLOG_NO_TRAN)
|
|
elog(PANIC, "invalid xlog info mask %02X", (info & XLR_INFO_MASK));
|
|
no_tran = true;
|
|
info &= ~XLR_INFO_MASK;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
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, &(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: the test for len == 0 here is somewhat fishy, since in theory
|
|
* all of the rmgr data might have been suppressed in favor of backup
|
|
* blocks. Currently, all callers of XLogInsert provide at least some
|
|
* not-in-a-buffer data and so len == 0 should never happen, but that
|
|
* may not be true forever. If you need to remove the len == 0 check,
|
|
* also remove the check for xl_len == 0 in ReadRecord, below.
|
|
*/
|
|
if (len == 0)
|
|
elog(PANIC, "invalid xlog record length %u", len);
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/* update LogwrtResult before doing cache fill check */
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire_NoHoldoff(&xlogctl->info_lck);
|
|
LogwrtRqst = xlogctl->LogwrtRqst;
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
SpinLockRelease_NoHoldoff(&xlogctl->info_lck);
|
|
}
|
|
|
|
/*
|
|
* If cache is half filled then try to acquire write lock and do
|
|
* XLogWrite. Ignore any fractional blocks in performing this check.
|
|
*/
|
|
LogwrtRqst.Write.xrecoff -= LogwrtRqst.Write.xrecoff % BLCKSZ;
|
|
if (LogwrtRqst.Write.xlogid != LogwrtResult.Write.xlogid ||
|
|
(LogwrtRqst.Write.xrecoff >= LogwrtResult.Write.xrecoff +
|
|
XLogCtl->XLogCacheByte / 2))
|
|
{
|
|
if (LWLockConditionalAcquire(WALWriteLock, LW_EXCLUSIVE))
|
|
{
|
|
LogwrtResult = XLogCtl->Write.LogwrtResult;
|
|
if (XLByteLT(LogwrtResult.Write, LogwrtRqst.Write))
|
|
XLogWrite(LogwrtRqst);
|
|
LWLockRelease(WALWriteLock);
|
|
}
|
|
}
|
|
|
|
/* 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 (!XLByteEQ(RedoRecPtr, Insert->RedoRecPtr))
|
|
{
|
|
Assert(XLByteLT(RedoRecPtr, Insert->RedoRecPtr));
|
|
RedoRecPtr = Insert->RedoRecPtr;
|
|
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 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();
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
}
|
|
|
|
curridx = Insert->curridx;
|
|
record = (XLogRecord *) Insert->currpos;
|
|
|
|
/* Insert record header */
|
|
|
|
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;
|
|
|
|
/* Compute record's XLOG location */
|
|
INSERT_RECPTR(RecPtr, Insert, curridx);
|
|
|
|
/* If first XLOG record of transaction, save it in PGPROC array */
|
|
if (MyLastRecPtr.xrecoff == 0 && !no_tran)
|
|
{
|
|
/*
|
|
* We do not acquire ProcArrayLock here because of possible deadlock.
|
|
* Anyone who wants to inspect other procs' logRec must acquire
|
|
* WALInsertLock, instead. A better solution would be a per-PROC
|
|
* spinlock, but no time for that before 7.2 --- tgl 12/19/01.
|
|
*/
|
|
MyProc->logRec = RecPtr;
|
|
}
|
|
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG)
|
|
{
|
|
char buf[8192];
|
|
|
|
sprintf(buf, "INSERT @ %X/%X: ", RecPtr.xlogid, RecPtr.xrecoff);
|
|
xlog_outrec(buf, record);
|
|
if (rdata->data != NULL)
|
|
{
|
|
strcat(buf, " - ");
|
|
RmgrTable[record->xl_rmid].rm_desc(buf, record->xl_info, rdata->data);
|
|
}
|
|
elog(LOG, "%s", buf);
|
|
}
|
|
#endif
|
|
|
|
/* Record begin of record in appropriate places */
|
|
if (!no_tran)
|
|
MyLastRecPtr = RecPtr;
|
|
ProcLastRecPtr = RecPtr;
|
|
Insert->PrevRecord = RecPtr;
|
|
MyXactMadeXLogEntry = true;
|
|
|
|
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();
|
|
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);
|
|
|
|
/* Need to update shared LogwrtRqst if some block was filled up */
|
|
if (freespace < SizeOfXLogRecord)
|
|
updrqst = true; /* curridx is filled and available for
|
|
* writing out */
|
|
else
|
|
curridx = PrevBufIdx(curridx);
|
|
WriteRqst = XLogCtl->xlblocks[curridx];
|
|
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
if (updrqst)
|
|
{
|
|
/* use volatile pointer to prevent code rearrangement */
|
|
volatile XLogCtlData *xlogctl = XLogCtl;
|
|
|
|
SpinLockAcquire_NoHoldoff(&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_NoHoldoff(&xlogctl->info_lck);
|
|
}
|
|
|
|
ProcLastRecEnd = 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,
|
|
XLogRecPtr *lsn, BkpBlock *bkpb)
|
|
{
|
|
PageHeader page;
|
|
|
|
page = (PageHeader) BufferGetBlock(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 = page->pd_lsn;
|
|
|
|
if (XLByteLE(page->pd_lsn, RedoRecPtr))
|
|
{
|
|
/*
|
|
* The page needs to be backed up, so set up *bkpb
|
|
*/
|
|
bkpb->node = BufferGetFileNode(rdata->buffer);
|
|
bkpb->block = BufferGetBlockNumber(rdata->buffer);
|
|
|
|
if (rdata->buffer_std)
|
|
{
|
|
/* Assume we can omit data between pd_lower and pd_upper */
|
|
uint16 lower = page->pd_lower;
|
|
uint16 upper = 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);
|
|
}
|
|
|
|
/*
|
|
* XLogArchiveIsDone
|
|
*
|
|
* Checks for a ".done" archive notification file. This is called when we
|
|
* are ready to delete or recycle an old XLOG segment file. If it is okay
|
|
* to delete it then return true.
|
|
*
|
|
* If <XLOG>.done exists, then return true; else if <XLOG>.ready exists,
|
|
* then return false; else create <XLOG>.ready and return false. The
|
|
* last case covers the possibility that the original attempt to create
|
|
* <XLOG>.ready failed.
|
|
*/
|
|
static bool
|
|
XLogArchiveIsDone(const char *xlog)
|
|
{
|
|
char archiveStatusPath[MAXPGPATH];
|
|
struct stat stat_buf;
|
|
|
|
/* First check for .done --- this is the expected case */
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* 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(void)
|
|
{
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
XLogCtlWrite *Write = &XLogCtl->Write;
|
|
uint16 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_NoHoldoff(&xlogctl->info_lck);
|
|
if (XLByteLT(xlogctl->LogwrtRqst.Write, FinishedPageRqstPtr))
|
|
xlogctl->LogwrtRqst.Write = FinishedPageRqstPtr;
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
SpinLockRelease_NoHoldoff(&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.
|
|
*/
|
|
WriteRqst.Write = OldPageRqstPtr;
|
|
WriteRqst.Flush.xlogid = 0;
|
|
WriteRqst.Flush.xrecoff = 0;
|
|
XLogWrite(WriteRqst);
|
|
LWLockRelease(WALWriteLock);
|
|
Insert->LogwrtResult = LogwrtResult;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 (NewPageEndPtr.xrecoff >= XLogFileSize)
|
|
{
|
|
/* crossing a logid boundary */
|
|
NewPageEndPtr.xlogid += 1;
|
|
NewPageEndPtr.xrecoff = BLCKSZ;
|
|
}
|
|
else
|
|
NewPageEndPtr.xrecoff += BLCKSZ;
|
|
XLogCtl->xlblocks[nextidx] = NewPageEndPtr;
|
|
NewPage = (XLogPageHeader) (XLogCtl->pages + nextidx * 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, 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 - 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;
|
|
NewPage->xlp_info |= XLP_LONG_HEADER;
|
|
Insert->currpos = ((char *) NewPage) + SizeOfXLogLongPHD;
|
|
}
|
|
|
|
return update_needed;
|
|
}
|
|
|
|
/*
|
|
* Write and/or fsync the log at least as far as WriteRqst indicates.
|
|
*
|
|
* Must be called with WALWriteLock held.
|
|
*/
|
|
static void
|
|
XLogWrite(XLogwrtRqst WriteRqst)
|
|
{
|
|
XLogCtlWrite *Write = &XLogCtl->Write;
|
|
char *from;
|
|
bool ispartialpage;
|
|
bool use_existent;
|
|
|
|
/* We should always be inside a critical section here */
|
|
Assert(CritSectionCount > 0);
|
|
|
|
/*
|
|
* Update local LogwrtResult (caller probably did this already,
|
|
* but...)
|
|
*/
|
|
LogwrtResult = Write->LogwrtResult;
|
|
|
|
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[Write->curridx]))
|
|
elog(PANIC, "xlog write request %X/%X is past end of log %X/%X",
|
|
LogwrtResult.Write.xlogid, LogwrtResult.Write.xrecoff,
|
|
XLogCtl->xlblocks[Write->curridx].xlogid,
|
|
XLogCtl->xlblocks[Write->curridx].xrecoff);
|
|
|
|
/* Advance LogwrtResult.Write to end of current buffer page */
|
|
LogwrtResult.Write = XLogCtl->xlblocks[Write->curridx];
|
|
ispartialpage = XLByteLT(WriteRqst.Write, LogwrtResult.Write);
|
|
|
|
if (!XLByteInPrevSeg(LogwrtResult.Write, openLogId, openLogSeg))
|
|
{
|
|
/*
|
|
* Switch to new logfile segment.
|
|
*/
|
|
if (openLogFile >= 0)
|
|
{
|
|
if (close(openLogFile))
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
openLogFile = -1;
|
|
}
|
|
XLByteToPrevSeg(LogwrtResult.Write, openLogId, openLogSeg);
|
|
|
|
/* create/use new log file */
|
|
use_existent = true;
|
|
openLogFile = XLogFileInit(openLogId, openLogSeg,
|
|
&use_existent, true);
|
|
openLogOff = 0;
|
|
|
|
/* update pg_control, unless someone else already did */
|
|
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
|
|
if (ControlFile->logId < openLogId ||
|
|
(ControlFile->logId == openLogId &&
|
|
ControlFile->logSeg < openLogSeg + 1))
|
|
{
|
|
ControlFile->logId = openLogId;
|
|
ControlFile->logSeg = openLogSeg + 1;
|
|
ControlFile->time = time(NULL);
|
|
UpdateControlFile();
|
|
|
|
/*
|
|
* Signal bgwriter to start a checkpoint if it's been
|
|
* too long since the last one. (We look at local copy of
|
|
* RedoRecPtr which might be a little out of date, but
|
|
* should be close enough for this purpose.)
|
|
*
|
|
* 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.
|
|
*/
|
|
if (IsUnderPostmaster)
|
|
{
|
|
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)
|
|
{
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG)
|
|
elog(LOG, "time for a checkpoint, signaling bgwriter");
|
|
#endif
|
|
RequestCheckpoint(false);
|
|
}
|
|
}
|
|
}
|
|
LWLockRelease(ControlFileLock);
|
|
}
|
|
|
|
if (openLogFile < 0)
|
|
{
|
|
XLByteToPrevSeg(LogwrtResult.Write, openLogId, openLogSeg);
|
|
openLogFile = XLogFileOpen(openLogId, openLogSeg);
|
|
openLogOff = 0;
|
|
}
|
|
|
|
/* Need to seek in the file? */
|
|
if (openLogOff != (LogwrtResult.Write.xrecoff - BLCKSZ) % XLogSegSize)
|
|
{
|
|
openLogOff = (LogwrtResult.Write.xrecoff - BLCKSZ) % XLogSegSize;
|
|
if (lseek(openLogFile, (off_t) openLogOff, 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, openLogOff)));
|
|
}
|
|
|
|
/* OK to write the page */
|
|
from = XLogCtl->pages + Write->curridx * BLCKSZ;
|
|
errno = 0;
|
|
if (write(openLogFile, from, BLCKSZ) != 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 to log file %u, segment %u at offset %u: %m",
|
|
openLogId, openLogSeg, openLogOff)));
|
|
}
|
|
openLogOff += BLCKSZ;
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* This is also the right place to notify the Archiver that the
|
|
* segment is ready to copy to archival storage.
|
|
*/
|
|
if (openLogOff >= XLogSegSize && !ispartialpage)
|
|
{
|
|
issue_xlog_fsync();
|
|
LogwrtResult.Flush = LogwrtResult.Write; /* end of current page */
|
|
|
|
if (XLogArchivingActive())
|
|
XLogArchiveNotifySeg(openLogId, openLogSeg);
|
|
}
|
|
|
|
if (ispartialpage)
|
|
{
|
|
/* Only asked to write a partial page */
|
|
LogwrtResult.Write = WriteRqst.Write;
|
|
break;
|
|
}
|
|
Write->curridx = NextBufIdx(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)
|
|
{
|
|
if (openLogFile >= 0 &&
|
|
!XLByteInPrevSeg(LogwrtResult.Write, openLogId, openLogSeg))
|
|
{
|
|
if (close(openLogFile))
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
openLogFile = -1;
|
|
}
|
|
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_NoHoldoff(&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_NoHoldoff(&xlogctl->info_lck);
|
|
}
|
|
|
|
Write->LogwrtResult = LogwrtResult;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
/* Disabled during REDO */
|
|
if (InRedo)
|
|
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_NoHoldoff(&xlogctl->info_lck);
|
|
if (XLByteLT(WriteRqstPtr, xlogctl->LogwrtRqst.Write))
|
|
WriteRqstPtr = xlogctl->LogwrtRqst.Write;
|
|
LogwrtResult = xlogctl->LogwrtResult;
|
|
SpinLockRelease_NoHoldoff(&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);
|
|
}
|
|
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 InRedo is true, but if
|
|
* the bad page is brought in and marked dirty during recovery then
|
|
* CreateCheckPoint will try to flush it at the end of recovery.)
|
|
*
|
|
* 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);
|
|
}
|
|
|
|
/*
|
|
* 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[BLCKSZ];
|
|
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 | XLOG_SYNC_BIT,
|
|
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.
|
|
*/
|
|
snprintf(tmppath, MAXPGPATH, "%s/xlogtemp.%d", XLogDir, (int)getpid());
|
|
|
|
unlink(tmppath);
|
|
|
|
/* do not use XLOG_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.
|
|
*/
|
|
MemSet(zbuffer, 0, sizeof(zbuffer));
|
|
for (nbytes = 0; nbytes < XLogSegSize; nbytes += sizeof(zbuffer))
|
|
{
|
|
errno = 0;
|
|
if ((int) write(fd, zbuffer, sizeof(zbuffer)) != (int) sizeof(zbuffer))
|
|
{
|
|
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 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);
|
|
}
|
|
|
|
/* 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 | XLOG_SYNC_BIT,
|
|
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[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, "%s/xlogtemp.%d", XLogDir, (int)getpid());
|
|
|
|
unlink(tmppath);
|
|
|
|
/* do not use XLOG_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. (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)
|
|
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 | XLOG_SYNC_BIT,
|
|
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];
|
|
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 */
|
|
|
|
if (InArchiveRecovery)
|
|
{
|
|
XLogFileName(xlogfname, tli, log, seg);
|
|
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;
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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 *dp;
|
|
char *endp;
|
|
const char *sp;
|
|
int rc;
|
|
struct stat stat_buf;
|
|
|
|
/*
|
|
* 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, "%s/%s", XLogDir, 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)));
|
|
}
|
|
|
|
/*
|
|
* 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: full 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 '%':
|
|
/* 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)));
|
|
|
|
/*
|
|
* Copy xlog from archival storage to XLogDir
|
|
*/
|
|
rc = system(xlogRestoreCmd);
|
|
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.
|
|
*/
|
|
ereport(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, "%s/%s", XLogDir, xlogfname);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Preallocate log files beyond the specified log endpoint, according to
|
|
* the XLOGfile user parameter.
|
|
*/
|
|
static int
|
|
PreallocXlogFiles(XLogRecPtr endptr)
|
|
{
|
|
int nsegsadded = 0;
|
|
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)
|
|
nsegsadded++;
|
|
}
|
|
return nsegsadded;
|
|
}
|
|
|
|
/*
|
|
* Remove or move offline 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
|
|
MoveOfflineLogs(uint32 log, uint32 seg, XLogRecPtr endptr,
|
|
int *nsegsremoved, int *nsegsrecycled)
|
|
{
|
|
uint32 endlogId;
|
|
uint32 endlogSeg;
|
|
int max_advance;
|
|
DIR *xldir;
|
|
struct dirent *xlde;
|
|
char lastoff[MAXFNAMELEN];
|
|
char path[MAXPGPATH];
|
|
|
|
*nsegsremoved = 0;
|
|
*nsegsrecycled = 0;
|
|
|
|
/*
|
|
* 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);
|
|
|
|
errno = 0;
|
|
while ((xlde = readdir(xldir)) != 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)
|
|
{
|
|
bool recycle;
|
|
|
|
if (XLogArchivingActive())
|
|
recycle = XLogArchiveIsDone(xlde->d_name);
|
|
else
|
|
recycle = true;
|
|
|
|
if (recycle)
|
|
{
|
|
snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
|
|
|
|
/*
|
|
* Before deleting the file, see if it can be recycled as
|
|
* a future log segment.
|
|
*/
|
|
if (InstallXLogFileSegment(&endlogId, &endlogSeg, path,
|
|
true, &max_advance,
|
|
true))
|
|
{
|
|
ereport(DEBUG2,
|
|
(errmsg("recycled transaction log file \"%s\"",
|
|
xlde->d_name)));
|
|
(*nsegsrecycled)++;
|
|
/* 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);
|
|
(*nsegsremoved)++;
|
|
}
|
|
|
|
XLogArchiveCleanup(xlde->d_name);
|
|
}
|
|
}
|
|
errno = 0;
|
|
}
|
|
#ifdef WIN32
|
|
|
|
/*
|
|
* This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but
|
|
* not in released version
|
|
*/
|
|
if (GetLastError() == ERROR_NO_MORE_FILES)
|
|
errno = 0;
|
|
#endif
|
|
if (errno)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read transaction log directory \"%s\": %m",
|
|
XLogDir)));
|
|
FreeDir(xldir);
|
|
}
|
|
|
|
/*
|
|
* Remove previous backup history files
|
|
*/
|
|
static void
|
|
RemoveOldBackupHistory(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)));
|
|
|
|
errno = 0;
|
|
while ((xlde = readdir(xldir)) != 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)
|
|
{
|
|
/* Remove any *.backup files that have been archived. */
|
|
if (!XLogArchivingActive() || XLogArchiveIsDone(xlde->d_name))
|
|
{
|
|
ereport(DEBUG2,
|
|
(errmsg("removing transaction log backup history file \"%s\"",
|
|
xlde->d_name)));
|
|
snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
|
|
unlink(path);
|
|
XLogArchiveCleanup(xlde->d_name);
|
|
}
|
|
}
|
|
errno = 0;
|
|
}
|
|
#ifdef WIN32
|
|
|
|
/*
|
|
* This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but
|
|
* not in released version
|
|
*/
|
|
if (GetLastError() == ERROR_NO_MORE_FILES)
|
|
errno = 0;
|
|
#endif
|
|
if (errno)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read transaction log directory \"%s\": %m",
|
|
XLogDir)));
|
|
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.
|
|
*/
|
|
static void
|
|
RestoreBkpBlocks(XLogRecord *record, XLogRecPtr lsn)
|
|
{
|
|
Relation reln;
|
|
Buffer buffer;
|
|
Page page;
|
|
BkpBlock bkpb;
|
|
char *blk;
|
|
int i;
|
|
|
|
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);
|
|
|
|
reln = XLogOpenRelation(bkpb.node);
|
|
|
|
if (reln)
|
|
{
|
|
buffer = XLogReadBuffer(true, reln, bkpb.block);
|
|
if (BufferIsValid(buffer))
|
|
{
|
|
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);
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
WriteBuffer(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(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 % BLCKSZ != 0)
|
|
tmpRecPtr.xrecoff += (BLCKSZ - tmpRecPtr.xrecoff % 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;
|
|
readOff = (uint32) (-1); /* force read to occur below */
|
|
}
|
|
|
|
targetPageOff = ((RecPtr->xrecoff % XLogSegSize) / BLCKSZ) * 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, BLCKSZ) != BLCKSZ)
|
|
{
|
|
ereport(emode,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read from log file %u, segment %u at 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 % 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 % BLCKSZ);
|
|
|
|
got_record:;
|
|
|
|
/*
|
|
* Currently, xl_len == 0 must be bad data, but that might not be true
|
|
* forever. See note in XLogInsert.
|
|
*/
|
|
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 BLCKSZ, and make
|
|
* sure it's at least 4*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 += BLCKSZ - (newSize % BLCKSZ);
|
|
newSize = Max(newSize, 4 * 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 = BLCKSZ - RecPtr->xrecoff % 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 += 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, BLCKSZ) != 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 = 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 (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;
|
|
return record;
|
|
}
|
|
|
|
/* Record does not cross a page boundary */
|
|
if (!RecordIsValid(record, *RecPtr, emode))
|
|
goto next_record_is_invalid;
|
|
if (BLCKSZ - SizeOfXLogRecord >= RecPtr->xrecoff % 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);
|
|
return (XLogRecord *) buffer;
|
|
|
|
next_record_is_invalid:;
|
|
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;
|
|
}
|
|
}
|
|
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, MAXPGPATH, 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, "%s/xlogtemp.%d", XLogDir, (int)getpid());
|
|
|
|
unlink(tmppath);
|
|
|
|
/* do not use XLOG_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,
|
|
str_time(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.
|
|
*/
|
|
|
|
void
|
|
XLOGPathInit(void)
|
|
{
|
|
/* Init XLOG file paths */
|
|
snprintf(XLogDir, MAXPGPATH, "%s/pg_xlog", DataDir);
|
|
snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
|
|
}
|
|
|
|
static void
|
|
WriteControlFile(void)
|
|
{
|
|
int fd;
|
|
char buffer[BLCKSZ]; /* need not be aligned */
|
|
char *localeptr;
|
|
|
|
/*
|
|
* Initialize version and compatibility-check fields
|
|
*/
|
|
ControlFile->pg_control_version = PG_CONTROL_VERSION;
|
|
ControlFile->catalog_version_no = CATALOG_VERSION_NO;
|
|
ControlFile->blcksz = BLCKSZ;
|
|
ControlFile->relseg_size = RELSEG_SIZE;
|
|
ControlFile->xlog_seg_size = XLOG_SEG_SIZE;
|
|
|
|
ControlFile->nameDataLen = NAMEDATALEN;
|
|
ControlFile->indexMaxKeys = INDEX_MAX_KEYS;
|
|
|
|
#ifdef HAVE_INT64_TIMESTAMP
|
|
ControlFile->enableIntTimes = TRUE;
|
|
#else
|
|
ControlFile->enableIntTimes = FALSE;
|
|
#endif
|
|
|
|
ControlFile->localeBuflen = LOCALE_NAME_BUFLEN;
|
|
localeptr = setlocale(LC_COLLATE, NULL);
|
|
if (!localeptr)
|
|
ereport(PANIC,
|
|
(errmsg("invalid LC_COLLATE setting")));
|
|
StrNCpy(ControlFile->lc_collate, localeptr, LOCALE_NAME_BUFLEN);
|
|
localeptr = setlocale(LC_CTYPE, NULL);
|
|
if (!localeptr)
|
|
ereport(PANIC,
|
|
(errmsg("invalid LC_CTYPE setting")));
|
|
StrNCpy(ControlFile->lc_ctype, localeptr, LOCALE_NAME_BUFLEN);
|
|
|
|
/* 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 BLCKSZ 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) > BLCKSZ)
|
|
ereport(PANIC,
|
|
(errmsg("sizeof(ControlFileData) is larger than BLCKSZ; fix either one")));
|
|
|
|
memset(buffer, 0, BLCKSZ);
|
|
memcpy(buffer, ControlFile, sizeof(ControlFileData));
|
|
|
|
fd = BasicOpenFile(ControlFilePath, 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",
|
|
ControlFilePath)));
|
|
|
|
errno = 0;
|
|
if (write(fd, buffer, BLCKSZ) != 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 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(ControlFilePath, 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",
|
|
ControlFilePath)));
|
|
|
|
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)
|
|
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. We do this here for 2
|
|
* reasons:
|
|
*
|
|
* (1) if the database isn't compatible with the backend executable, we
|
|
* want to abort before we can possibly do any damage;
|
|
*
|
|
* (2) this code is executed in the postmaster, so the setlocale() will
|
|
* propagate to forked backends, which aren't going to read this file
|
|
* for themselves. (These locale settings are considered critical
|
|
* compatibility items because they can affect sort order of indexes.)
|
|
*/
|
|
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->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_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.")));
|
|
|
|
#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
|
|
|
|
if (ControlFile->localeBuflen != LOCALE_NAME_BUFLEN)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with LOCALE_NAME_BUFLEN %d,"
|
|
" but the server was compiled with LOCALE_NAME_BUFLEN %d.",
|
|
ControlFile->localeBuflen, LOCALE_NAME_BUFLEN),
|
|
errhint("It looks like you need to recompile or initdb.")));
|
|
if (setlocale(LC_COLLATE, ControlFile->lc_collate) == NULL)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with operating system"),
|
|
errdetail("The database cluster was initialized with LC_COLLATE \"%s\","
|
|
" which is not recognized by setlocale().",
|
|
ControlFile->lc_collate),
|
|
errhint("It looks like you need to initdb or install locale support.")));
|
|
if (setlocale(LC_CTYPE, ControlFile->lc_ctype) == NULL)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with operating system"),
|
|
errdetail("The database cluster was initialized with LC_CTYPE \"%s\","
|
|
" which is not recognized by setlocale().",
|
|
ControlFile->lc_ctype),
|
|
errhint("It looks like you need to initdb or install locale support.")));
|
|
|
|
/* Make the fixed locale settings visible as GUC variables, too */
|
|
SetConfigOption("lc_collate", ControlFile->lc_collate,
|
|
PGC_INTERNAL, PGC_S_OVERRIDE);
|
|
SetConfigOption("lc_ctype", ControlFile->lc_ctype,
|
|
PGC_INTERNAL, PGC_S_OVERRIDE);
|
|
}
|
|
|
|
void
|
|
UpdateControlFile(void)
|
|
{
|
|
int fd;
|
|
|
|
INIT_CRC32(ControlFile->crc);
|
|
COMP_CRC32(ControlFile->crc,
|
|
(char *) ControlFile,
|
|
offsetof(ControlFileData, crc));
|
|
FIN_CRC32(ControlFile->crc);
|
|
|
|
fd = BasicOpenFile(ControlFilePath, 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",
|
|
ControlFilePath)));
|
|
|
|
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
|
|
*/
|
|
|
|
int
|
|
XLOGShmemSize(void)
|
|
{
|
|
if (XLOGbuffers < MinXLOGbuffers)
|
|
XLOGbuffers = MinXLOGbuffers;
|
|
|
|
return MAXALIGN(sizeof(XLogCtlData) + sizeof(XLogRecPtr) * XLOGbuffers)
|
|
+ BLCKSZ * XLOGbuffers +
|
|
MAXALIGN(sizeof(ControlFileData));
|
|
}
|
|
|
|
void
|
|
XLOGShmemInit(void)
|
|
{
|
|
bool foundXLog,
|
|
foundCFile;
|
|
|
|
/* this must agree with space requested by XLOGShmemSize() */
|
|
if (XLOGbuffers < MinXLOGbuffers)
|
|
XLOGbuffers = MinXLOGbuffers;
|
|
|
|
XLogCtl = (XLogCtlData *)
|
|
ShmemInitStruct("XLOG Ctl",
|
|
MAXALIGN(sizeof(XLogCtlData) +
|
|
sizeof(XLogRecPtr) * XLOGbuffers)
|
|
+ BLCKSZ * XLOGbuffers,
|
|
&foundXLog);
|
|
ControlFile = (ControlFileData *)
|
|
ShmemInitStruct("Control File", sizeof(ControlFileData), &foundCFile);
|
|
|
|
if (foundXLog || foundCFile)
|
|
{
|
|
/* both should be present or neither */
|
|
Assert(foundXLog && foundCFile);
|
|
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.
|
|
*/
|
|
XLogCtl->xlblocks = (XLogRecPtr *)
|
|
(((char *) XLogCtl) + sizeof(XLogCtlData));
|
|
memset(XLogCtl->xlblocks, 0, sizeof(XLogRecPtr) * XLOGbuffers);
|
|
|
|
/*
|
|
* Here, on the other hand, we must MAXALIGN to ensure the page
|
|
* buffers have worst-case alignment.
|
|
*/
|
|
XLogCtl->pages =
|
|
((char *) XLogCtl) + MAXALIGN(sizeof(XLogCtlData) +
|
|
sizeof(XLogRecPtr) * XLOGbuffers);
|
|
memset(XLogCtl->pages, 0, BLCKSZ * XLOGbuffers);
|
|
|
|
/*
|
|
* Do basic initialization of XLogCtl shared data. (StartupXLOG will
|
|
* fill in additional info.)
|
|
*/
|
|
XLogCtl->XLogCacheByte = BLCKSZ * XLOGbuffers;
|
|
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;
|
|
|
|
/* Use malloc() to ensure buffer is MAXALIGNED */
|
|
buffer = (char *) malloc(BLCKSZ);
|
|
page = (XLogPageHeader) buffer;
|
|
memset(buffer, 0, BLCKSZ);
|
|
|
|
/* Set up information for the initial checkpoint record */
|
|
checkPoint.redo.xlogid = 0;
|
|
checkPoint.redo.xrecoff = SizeOfXLogLongPHD;
|
|
checkPoint.undo = checkPoint.redo;
|
|
checkPoint.ThisTimeLineID = ThisTimeLineID;
|
|
checkPoint.nextXid = FirstNormalTransactionId;
|
|
checkPoint.nextOid = FirstBootstrapObjectId;
|
|
checkPoint.nextMulti = FirstMultiXactId;
|
|
checkPoint.nextMultiOffset = 0;
|
|
checkPoint.time = 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;
|
|
|
|
/* 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, buffer, BLCKSZ) != 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->logId = 0;
|
|
ControlFile->logSeg = 1;
|
|
ControlFile->checkPoint = checkPoint.redo;
|
|
ControlFile->checkPointCopy = checkPoint;
|
|
/* some additional ControlFile fields are set in WriteControlFile() */
|
|
|
|
WriteControlFile();
|
|
|
|
/* Bootstrap the commit log, too */
|
|
BootStrapCLOG();
|
|
BootStrapSUBTRANS();
|
|
BootStrapMultiXact();
|
|
free(buffer);
|
|
}
|
|
|
|
static char *
|
|
str_time(time_t tnow)
|
|
{
|
|
static char buf[128];
|
|
|
|
strftime(buf, sizeof(buf),
|
|
"%Y-%m-%d %H:%M:%S %Z",
|
|
localtime(&tnow));
|
|
|
|
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)
|
|
{
|
|
char recoveryCommandFile[MAXPGPATH];
|
|
FILE *fd;
|
|
char cmdline[MAXPGPATH];
|
|
TimeLineID rtli = 0;
|
|
bool rtliGiven = false;
|
|
bool syntaxError = false;
|
|
|
|
snprintf(recoveryCommandFile, MAXPGPATH, "%s/recovery.conf", DataDir);
|
|
fd = AllocateFile(recoveryCommandFile, "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",
|
|
recoveryCommandFile)));
|
|
}
|
|
|
|
ereport(LOG,
|
|
(errmsg("starting archive recovery")));
|
|
|
|
/*
|
|
* Parse the file...
|
|
*/
|
|
while (fgets(cmdline, MAXPGPATH, 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_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 the time_t
|
|
* format. We use type abstime's input converter because we
|
|
* know abstime has the same representation as time_t.
|
|
*/
|
|
recoveryTargetTime = (time_t)
|
|
DatumGetAbsoluteTime(DirectFunctionCall1(abstimein,
|
|
CStringGetDatum(tok2)));
|
|
ereport(LOG,
|
|
(errmsg("recovery_target_time = %s",
|
|
DatumGetCString(DirectFunctionCall1(abstimeout,
|
|
AbsoluteTimeGetDatum((AbsoluteTime) recoveryTargetTime))))));
|
|
}
|
|
else if (strcmp(tok1, "recovery_target_inclusive") == 0)
|
|
{
|
|
/*
|
|
* does nothing if a recovery_target is not also set
|
|
*/
|
|
if (strcmp(tok2, "true") == 0)
|
|
recoveryTargetInclusive = true;
|
|
else
|
|
{
|
|
recoveryTargetInclusive = false;
|
|
tok2 = "false";
|
|
}
|
|
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",
|
|
recoveryCommandFile)));
|
|
|
|
/* 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];
|
|
char recoveryCommandFile[MAXPGPATH];
|
|
char recoveryCommandDone[MAXPGPATH];
|
|
|
|
/*
|
|
* We are no longer in archive recovery state.
|
|
*/
|
|
InArchiveRecovery = false;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
snprintf(recoveryPath, MAXPGPATH, "%s/RECOVERYXLOG", XLogDir);
|
|
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.
|
|
*/
|
|
if (endTLI != ThisTimeLineID)
|
|
XLogFileCopy(endLogId, endLogSeg,
|
|
endTLI, endLogId, endLogSeg);
|
|
}
|
|
|
|
/*
|
|
* 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, "%s/RECOVERYHISTORY", XLogDir);
|
|
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.
|
|
*/
|
|
snprintf(recoveryCommandFile, MAXPGPATH, "%s/recovery.conf", DataDir);
|
|
snprintf(recoveryCommandDone, MAXPGPATH, "%s/recovery.done", DataDir);
|
|
unlink(recoveryCommandDone);
|
|
if (rename(recoveryCommandFile, recoveryCommandDone) != 0)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename file \"%s\" to \"%s\": %m",
|
|
recoveryCommandFile, recoveryCommandDone)));
|
|
|
|
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.
|
|
* 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;
|
|
time_t recordXtime;
|
|
|
|
/* Do we have a PITR target at all? */
|
|
if (!recoveryTarget)
|
|
return false;
|
|
|
|
/* 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->xtime;
|
|
}
|
|
else if (record_info == XLOG_XACT_ABORT)
|
|
{
|
|
xl_xact_abort *recordXactAbortData;
|
|
|
|
recordXactAbortData = (xl_xact_abort *) XLogRecGetData(record);
|
|
recordXtime = recordXactAbortData->xtime;
|
|
}
|
|
else
|
|
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, str_time(recoveryStopTime))));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("recovery stopping before commit of transaction %u, time %s",
|
|
recoveryStopXid, str_time(recoveryStopTime))));
|
|
}
|
|
else
|
|
{
|
|
if (recoveryStopAfter)
|
|
ereport(LOG,
|
|
(errmsg("recovery stopping after abort of transaction %u, time %s",
|
|
recoveryStopXid, str_time(recoveryStopTime))));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("recovery stopping before abort of transaction %u, time %s",
|
|
recoveryStopXid, str_time(recoveryStopTime))));
|
|
}
|
|
}
|
|
|
|
return stopsHere;
|
|
}
|
|
|
|
/*
|
|
* This must be called ONCE during postmaster or standalone-backend startup
|
|
*/
|
|
void
|
|
StartupXLOG(void)
|
|
{
|
|
XLogCtlInsert *Insert;
|
|
CheckPoint checkPoint;
|
|
bool wasShutdown;
|
|
bool needNewTimeLine = false;
|
|
XLogRecPtr RecPtr,
|
|
LastRec,
|
|
checkPointLoc,
|
|
EndOfLog;
|
|
uint32 endLogId;
|
|
uint32 endLogSeg;
|
|
XLogRecord *record;
|
|
uint32 freespace;
|
|
|
|
CritSectionCount++;
|
|
|
|
/*
|
|
* 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->logSeg == 0 ||
|
|
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 at %s",
|
|
str_time(ControlFile->time))));
|
|
else if (ControlFile->state == DB_IN_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_PRODUCTION)
|
|
ereport(LOG,
|
|
(errmsg("database system was interrupted 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
|
|
|
|
/*
|
|
* 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))
|
|
{
|
|
/*
|
|
* 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(LOG,
|
|
(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)));
|
|
}
|
|
}
|
|
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(LOG,
|
|
(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(LOG,
|
|
(errmsg("redo record is at %X/%X; undo record is at %X/%X; shutdown %s",
|
|
checkPoint.redo.xlogid, checkPoint.redo.xrecoff,
|
|
checkPoint.undo.xlogid, checkPoint.undo.xrecoff,
|
|
wasShutdown ? "TRUE" : "FALSE")));
|
|
ereport(LOG,
|
|
(errmsg("next transaction ID: %u; next OID: %u",
|
|
checkPoint.nextXid, checkPoint.nextOid)));
|
|
ereport(LOG,
|
|
(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")));
|
|
if (checkPoint.undo.xrecoff == 0)
|
|
checkPoint.undo = RecPtr;
|
|
|
|
/*
|
|
* 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.undo, RecPtr) ||
|
|
XLByteLT(checkPoint.redo, RecPtr))
|
|
{
|
|
if (wasShutdown)
|
|
ereport(PANIC,
|
|
(errmsg("invalid redo/undo 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;
|
|
|
|
if (InArchiveRecovery)
|
|
ereport(LOG,
|
|
(errmsg("automatic recovery in progress")));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("database system was not properly shut down; "
|
|
"automatic recovery in progress")));
|
|
ControlFile->state = DB_IN_RECOVERY;
|
|
ControlFile->time = time(NULL);
|
|
UpdateControlFile();
|
|
|
|
/* Start up the recovery environment */
|
|
XLogInitRelationCache();
|
|
|
|
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;
|
|
|
|
InRedo = true;
|
|
ereport(LOG,
|
|
(errmsg("redo starts at %X/%X",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff)));
|
|
|
|
/*
|
|
* main redo apply loop
|
|
*/
|
|
do
|
|
{
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG)
|
|
{
|
|
char buf[8192];
|
|
|
|
sprintf(buf, "REDO @ %X/%X; LSN %X/%X: ",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff,
|
|
EndRecPtr.xlogid, EndRecPtr.xrecoff);
|
|
xlog_outrec(buf, record);
|
|
strcat(buf, " - ");
|
|
RmgrTable[record->xl_rmid].rm_desc(buf,
|
|
record->xl_info, XLogRecGetData(record));
|
|
elog(LOG, "%s", buf);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Have we reached our recovery target?
|
|
*/
|
|
if (recoveryStopsHere(record, &recoveryApply))
|
|
{
|
|
needNewTimeLine = true; /* see below */
|
|
recoveryContinue = false;
|
|
if (!recoveryApply)
|
|
break;
|
|
}
|
|
|
|
/* nextXid must be beyond record's xid */
|
|
if (TransactionIdFollowsOrEquals(record->xl_xid,
|
|
ShmemVariableCache->nextXid))
|
|
{
|
|
ShmemVariableCache->nextXid = record->xl_xid;
|
|
TransactionIdAdvance(ShmemVariableCache->nextXid);
|
|
}
|
|
|
|
if (record->xl_info & XLR_BKP_BLOCK_MASK)
|
|
RestoreBkpBlocks(record, EndRecPtr);
|
|
|
|
RmgrTable[record->xl_rmid].rm_redo(EndRecPtr, record);
|
|
|
|
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)));
|
|
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 (XLByteLT(EndOfLog, recoveryMinXlogOffset))
|
|
{
|
|
if (needNewTimeLine) /* stopped because of stop request */
|
|
ereport(FATAL,
|
|
(errmsg("requested recovery stop point is before end time of backup dump")));
|
|
else
|
|
/* ran off end of WAL */
|
|
ereport(FATAL,
|
|
(errmsg("WAL ends before end time of backup dump")));
|
|
}
|
|
|
|
/*
|
|
* Consider whether we need to assign a new timeline ID.
|
|
*
|
|
* If we stopped short of the end of WAL during recovery, then we are
|
|
* generating a new timeline and must assign it a unique new ID.
|
|
* Otherwise, we can just extend the timeline we were in when we ran
|
|
* out of WAL.
|
|
*/
|
|
if (needNewTimeLine)
|
|
{
|
|
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;
|
|
ControlFile->logId = openLogId;
|
|
ControlFile->logSeg = openLogSeg + 1;
|
|
Insert = &XLogCtl->Insert;
|
|
Insert->PrevRecord = LastRec;
|
|
XLogCtl->xlblocks[0].xlogid = openLogId;
|
|
XLogCtl->xlblocks[0].xrecoff =
|
|
((EndOfLog.xrecoff - 1) / BLCKSZ + 1) * 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 - BLCKSZ) % XLogSegSize);
|
|
memcpy((char *) Insert->currpage, readBuf, BLCKSZ);
|
|
Insert->currpos = (char *) Insert->currpage +
|
|
(EndOfLog.xrecoff + 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);
|
|
}
|
|
|
|
#ifdef NOT_USED
|
|
/* UNDO */
|
|
if (InRecovery)
|
|
{
|
|
RecPtr = ReadRecPtr;
|
|
if (XLByteLT(checkPoint.undo, RecPtr))
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("undo starts at %X/%X",
|
|
RecPtr.xlogid, RecPtr.xrecoff)));
|
|
do
|
|
{
|
|
record = ReadRecord(&RecPtr, PANIC);
|
|
if (TransactionIdIsValid(record->xl_xid) &&
|
|
!TransactionIdDidCommit(record->xl_xid))
|
|
RmgrTable[record->xl_rmid].rm_undo(EndRecPtr, record);
|
|
RecPtr = record->xl_prev;
|
|
} while (XLByteLE(checkPoint.undo, RecPtr));
|
|
ereport(LOG,
|
|
(errmsg("undo done at %X/%X",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff)));
|
|
}
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("undo is not required")));
|
|
}
|
|
#endif
|
|
|
|
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();
|
|
}
|
|
|
|
/*
|
|
* Perform a new checkpoint to update 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.
|
|
*
|
|
* In case we had to use the secondary checkpoint, make sure that it
|
|
* will still be shown as the secondary checkpoint after this
|
|
* CreateCheckPoint operation; we don't want the broken primary
|
|
* checkpoint to become prevCheckPoint...
|
|
*/
|
|
if (XLByteEQ(checkPointLoc, ControlFile->prevCheckPoint))
|
|
ControlFile->checkPoint = checkPointLoc;
|
|
|
|
CreateCheckPoint(true, true);
|
|
|
|
/*
|
|
* Close down recovery environment
|
|
*/
|
|
XLogCloseRelationCache();
|
|
|
|
/*
|
|
* Now that we've checkpointed the recovery, it's safe to flush
|
|
* old backup_label, if present.
|
|
*/
|
|
remove_backup_label();
|
|
}
|
|
|
|
/*
|
|
* Preallocate additional log files, if wanted.
|
|
*/
|
|
(void) PreallocXlogFiles(EndOfLog);
|
|
|
|
/*
|
|
* Okay, we're officially UP.
|
|
*/
|
|
InRecovery = false;
|
|
|
|
ControlFile->state = DB_IN_PRODUCTION;
|
|
ControlFile->time = time(NULL);
|
|
UpdateControlFile();
|
|
|
|
/* Start up the commit log and related stuff, too */
|
|
StartupCLOG();
|
|
StartupSUBTRANS();
|
|
StartupMultiXact();
|
|
|
|
ereport(LOG,
|
|
(errmsg("database system is ready")));
|
|
CritSectionCount--;
|
|
|
|
/* 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;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
/* 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_NoHoldoff(&xlogctl->info_lck);
|
|
Assert(XLByteLE(RedoRecPtr, xlogctl->Insert.RedoRecPtr));
|
|
RedoRecPtr = xlogctl->Insert.RedoRecPtr;
|
|
SpinLockRelease_NoHoldoff(&xlogctl->info_lck);
|
|
|
|
return RedoRecPtr;
|
|
}
|
|
|
|
/*
|
|
* This must be called ONCE during postmaster or standalone-backend shutdown
|
|
*/
|
|
void
|
|
ShutdownXLOG(int code, Datum arg)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("shutting down")));
|
|
|
|
CritSectionCount++;
|
|
CreateCheckPoint(true, true);
|
|
ShutdownCLOG();
|
|
ShutdownSUBTRANS();
|
|
ShutdownMultiXact();
|
|
CritSectionCount--;
|
|
|
|
ereport(LOG,
|
|
(errmsg("database system is shut down")));
|
|
}
|
|
|
|
/*
|
|
* Perform a checkpoint --- either during shutdown, or on-the-fly
|
|
*
|
|
* If force is true, we force a checkpoint regardless of whether any XLOG
|
|
* activity has occurred since the last one.
|
|
*/
|
|
void
|
|
CreateCheckPoint(bool shutdown, bool force)
|
|
{
|
|
CheckPoint checkPoint;
|
|
XLogRecPtr recptr;
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
XLogRecData rdata;
|
|
uint32 freespace;
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
int nsegsadded = 0;
|
|
int nsegsremoved = 0;
|
|
int nsegsrecycled = 0;
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* Use a critical section to force system panic if we have trouble.
|
|
*/
|
|
START_CRIT_SECTION();
|
|
|
|
if (shutdown)
|
|
{
|
|
ControlFile->state = DB_SHUTDOWNING;
|
|
ControlFile->time = time(NULL);
|
|
UpdateControlFile();
|
|
}
|
|
|
|
MemSet(&checkPoint, 0, sizeof(checkPoint));
|
|
checkPoint.ThisTimeLineID = ThisTimeLineID;
|
|
checkPoint.time = time(NULL);
|
|
|
|
/*
|
|
* We must hold CheckpointStartLock while determining the checkpoint
|
|
* REDO pointer. This ensures that any concurrent transaction commits
|
|
* will be either not yet logged, or logged and recorded in pg_clog.
|
|
* See notes in RecordTransactionCommit().
|
|
*/
|
|
LWLockAcquire(CheckpointStartLock, LW_EXCLUSIVE);
|
|
|
|
/* And we need WALInsertLock too */
|
|
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 (!shutdown && !force)
|
|
{
|
|
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(CheckpointStartLock);
|
|
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();
|
|
/* 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_NoHoldoff(&xlogctl->info_lck);
|
|
RedoRecPtr = xlogctl->Insert.RedoRecPtr = checkPoint.redo;
|
|
SpinLockRelease_NoHoldoff(&xlogctl->info_lck);
|
|
}
|
|
|
|
/*
|
|
* Get UNDO record ptr - this is oldest of PGPROC->logRec values. We
|
|
* do this while holding insert lock to ensure that we won't miss any
|
|
* about-to-commit transactions (UNDO must include all xacts that have
|
|
* commits after REDO point).
|
|
*
|
|
* XXX temporarily ifdef'd out to avoid three-way deadlock condition:
|
|
* GetUndoRecPtr needs to grab ProcArrayLock to ensure that it is looking
|
|
* at a stable set of proc records, but grabbing ProcArrayLock while
|
|
* holding WALInsertLock is no good. GetNewTransactionId may cause a
|
|
* WAL record to be written while holding XidGenLock, and
|
|
* GetSnapshotData needs to get XidGenLock while holding ProcArrayLock,
|
|
* so there's a risk of deadlock. Need to find a better solution. See
|
|
* pgsql-hackers discussion of 17-Dec-01.
|
|
*
|
|
* XXX actually, the whole UNDO code is dead code and unlikely to ever be
|
|
* revived, so the lack of a good solution here is not troubling.
|
|
*/
|
|
#ifdef NOT_USED
|
|
checkPoint.undo = GetUndoRecPtr();
|
|
|
|
if (shutdown && checkPoint.undo.xrecoff != 0)
|
|
elog(PANIC, "active transaction while database system is shutting down");
|
|
#endif
|
|
|
|
/*
|
|
* Now we can release insert lock and checkpoint start lock, allowing
|
|
* other xacts to proceed even while we are flushing disk buffers.
|
|
*/
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
LWLockRelease(CheckpointStartLock);
|
|
|
|
/*
|
|
* Get the other info we need for the checkpoint record.
|
|
*/
|
|
LWLockAcquire(XidGenLock, LW_SHARED);
|
|
checkPoint.nextXid = ShmemVariableCache->nextXid;
|
|
LWLockRelease(XidGenLock);
|
|
|
|
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. (If
|
|
* we are doing a shutdown checkpoint, we probably *should* panic ---
|
|
* but that will happen anyway because we'll still be inside the
|
|
* critical section established by ShutdownXLOG.)
|
|
*/
|
|
END_CRIT_SECTION();
|
|
|
|
if (!shutdown)
|
|
ereport(DEBUG2,
|
|
(errmsg("checkpoint starting")));
|
|
|
|
CheckPointCLOG();
|
|
CheckPointSUBTRANS();
|
|
CheckPointMultiXact();
|
|
FlushBufferPool();
|
|
|
|
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.
|
|
*
|
|
* With UNDO support: oldest item is redo or undo, whichever is older;
|
|
* but watch out for case that undo = 0.
|
|
*
|
|
* Without UNDO support: just use the redo pointer. This allows xlog
|
|
* space to be freed much faster when there are long-running
|
|
* transactions.
|
|
*/
|
|
#ifdef NOT_USED
|
|
if (ControlFile->checkPointCopy.undo.xrecoff != 0 &&
|
|
XLByteLT(ControlFile->checkPointCopy.undo,
|
|
ControlFile->checkPointCopy.redo))
|
|
XLByteToSeg(ControlFile->checkPointCopy.undo, _logId, _logSeg);
|
|
else
|
|
#endif
|
|
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 = time(NULL);
|
|
UpdateControlFile();
|
|
LWLockRelease(ControlFileLock);
|
|
|
|
/*
|
|
* We are now done with critical updates; no need for system panic if
|
|
* we have trouble while fooling with offline log segments.
|
|
*/
|
|
END_CRIT_SECTION();
|
|
|
|
/*
|
|
* Delete offline log files (those no longer needed even for previous
|
|
* checkpoint).
|
|
*/
|
|
if (_logId || _logSeg)
|
|
{
|
|
PrevLogSeg(_logId, _logSeg);
|
|
MoveOfflineLogs(_logId, _logSeg, recptr,
|
|
&nsegsremoved, &nsegsrecycled);
|
|
}
|
|
|
|
/*
|
|
* Make more log segments if needed. (Do this after deleting offline
|
|
* log segments, to avoid having peak disk space usage higher than
|
|
* necessary.)
|
|
*/
|
|
if (!shutdown)
|
|
nsegsadded = 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));
|
|
|
|
if (!shutdown)
|
|
ereport(DEBUG2,
|
|
(errmsg("checkpoint complete; %d transaction log file(s) added, %d removed, %d recycled",
|
|
nsegsadded, nsegsremoved, nsegsrecycled)));
|
|
|
|
LWLockRelease(CheckpointLock);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
}
|
|
|
|
/*
|
|
* XLOG resource manager's routines
|
|
*/
|
|
void
|
|
xlog_redo(XLogRecPtr lsn, XLogRecord *record)
|
|
{
|
|
uint8 info = record->xl_info & ~XLR_INFO_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);
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
}
|
|
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);
|
|
/* 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)));
|
|
}
|
|
}
|
|
|
|
void
|
|
xlog_desc(char *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;
|
|
|
|
sprintf(buf + strlen(buf), "checkpoint: redo %X/%X; undo %X/%X; "
|
|
"tli %u; xid %u; oid %u; multi %u; offset %u; %s",
|
|
checkpoint->redo.xlogid, checkpoint->redo.xrecoff,
|
|
checkpoint->undo.xlogid, checkpoint->undo.xrecoff,
|
|
checkpoint->ThisTimeLineID, checkpoint->nextXid,
|
|
checkpoint->nextOid,
|
|
checkpoint->nextMulti,
|
|
checkpoint->nextMultiOffset,
|
|
(info == XLOG_CHECKPOINT_SHUTDOWN) ? "shutdown" : "online");
|
|
}
|
|
else if (info == XLOG_NEXTOID)
|
|
{
|
|
Oid nextOid;
|
|
|
|
memcpy(&nextOid, rec, sizeof(Oid));
|
|
sprintf(buf + strlen(buf), "nextOid: %u", nextOid);
|
|
}
|
|
else
|
|
strcat(buf, "UNKNOWN");
|
|
}
|
|
|
|
#ifdef WAL_DEBUG
|
|
|
|
static void
|
|
xlog_outrec(char *buf, XLogRecord *record)
|
|
{
|
|
int bkpb;
|
|
int i;
|
|
|
|
sprintf(buf + strlen(buf), "prev %X/%X; xid %u",
|
|
record->xl_prev.xlogid, record->xl_prev.xrecoff,
|
|
record->xl_xid);
|
|
|
|
for (i = 0, bkpb = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (!(record->xl_info & (XLR_SET_BKP_BLOCK(i))))
|
|
continue;
|
|
bkpb++;
|
|
}
|
|
|
|
if (bkpb)
|
|
sprintf(buf + strlen(buf), "; bkpb %d", bkpb);
|
|
|
|
sprintf(buf + strlen(buf), ": %s",
|
|
RmgrTable[record->xl_rmid].rm_name);
|
|
}
|
|
#endif /* WAL_DEBUG */
|
|
|
|
|
|
/*
|
|
* GUC support
|
|
*/
|
|
const char *
|
|
assign_xlog_sync_method(const char *method, bool doit, GucSource source)
|
|
{
|
|
int new_sync_method;
|
|
int new_sync_bit;
|
|
|
|
if (pg_strcasecmp(method, "fsync") == 0)
|
|
{
|
|
new_sync_method = SYNC_METHOD_FSYNC;
|
|
new_sync_bit = 0;
|
|
}
|
|
#ifdef HAVE_FSYNC_WRITETHROUGH
|
|
else if (pg_strcasecmp(method, "fsync_writethrough") == 0)
|
|
{
|
|
new_sync_method = SYNC_METHOD_FSYNC_WRITETHROUGH;
|
|
new_sync_bit = 0;
|
|
}
|
|
#endif
|
|
#ifdef HAVE_FDATASYNC
|
|
else if (pg_strcasecmp(method, "fdatasync") == 0)
|
|
{
|
|
new_sync_method = SYNC_METHOD_FDATASYNC;
|
|
new_sync_bit = 0;
|
|
}
|
|
#endif
|
|
#ifdef OPEN_SYNC_FLAG
|
|
else if (pg_strcasecmp(method, "open_sync") == 0)
|
|
{
|
|
new_sync_method = SYNC_METHOD_OPEN;
|
|
new_sync_bit = OPEN_SYNC_FLAG;
|
|
}
|
|
#endif
|
|
#ifdef OPEN_DATASYNC_FLAG
|
|
else if (pg_strcasecmp(method, "open_datasync") == 0)
|
|
{
|
|
new_sync_method = SYNC_METHOD_OPEN;
|
|
new_sync_bit = OPEN_DATASYNC_FLAG;
|
|
}
|
|
#endif
|
|
else
|
|
return NULL;
|
|
|
|
if (!doit)
|
|
return method;
|
|
|
|
if (sync_method != new_sync_method || open_sync_bit != new_sync_bit)
|
|
{
|
|
/*
|
|
* 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 (open_sync_bit != new_sync_bit)
|
|
{
|
|
if (close(openLogFile))
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
openLogFile = -1;
|
|
}
|
|
}
|
|
sync_method = new_sync_method;
|
|
open_sync_bit = new_sync_bit;
|
|
}
|
|
|
|
return method;
|
|
}
|
|
|
|
|
|
/*
|
|
* 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:
|
|
/* 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 offset for the dump.
|
|
*/
|
|
Datum
|
|
pg_start_backup(PG_FUNCTION_ARGS)
|
|
{
|
|
text *backupid = PG_GETARG_TEXT_P(0);
|
|
text *result;
|
|
char *backupidstr;
|
|
XLogRecPtr checkpointloc;
|
|
XLogRecPtr startpoint;
|
|
time_t stamp_time;
|
|
char strfbuf[128];
|
|
char labelfilepath[MAXPGPATH];
|
|
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_command must be defined before "
|
|
"online backups can be made safely.")))));
|
|
|
|
backupidstr = DatumGetCString(DirectFunctionCall1(textout,
|
|
PointerGetDatum(backupid)));
|
|
|
|
/*
|
|
* Force a CHECKPOINT. This is not strictly necessary, but it seems
|
|
* like a good idea to minimize the amount of past WAL needed to use
|
|
* the backup. Also, this guarantees that two successive backup runs
|
|
* will have different checkpoint positions and hence different
|
|
* history file names, even if nothing happened in between.
|
|
*/
|
|
RequestCheckpoint(true);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* We deliberately use strftime/localtime not the src/timezone
|
|
* functions, so that backup labels will consistently be recorded in
|
|
* the same timezone regardless of TimeZone setting. This matches
|
|
* elog.c's practice.
|
|
*/
|
|
stamp_time = time(NULL);
|
|
strftime(strfbuf, sizeof(strfbuf),
|
|
"%Y-%m-%d %H:%M:%S %Z",
|
|
localtime(&stamp_time));
|
|
|
|
/*
|
|
* Check for existing backup label --- implies a backup is already
|
|
* running
|
|
*/
|
|
snprintf(labelfilepath, MAXPGPATH, "%s/backup_label", DataDir);
|
|
if (stat(labelfilepath, &stat_buf) != 0)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not stat file \"%s\": %m",
|
|
labelfilepath)));
|
|
}
|
|
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.",
|
|
labelfilepath)));
|
|
|
|
/*
|
|
* Okay, write the file
|
|
*/
|
|
fp = AllocateFile(labelfilepath, "w");
|
|
if (!fp)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create file \"%s\": %m",
|
|
labelfilepath)));
|
|
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",
|
|
labelfilepath)));
|
|
|
|
/*
|
|
* We're done. As a convenience, return the starting WAL offset.
|
|
*/
|
|
snprintf(xlogfilename, sizeof(xlogfilename), "%X/%X",
|
|
startpoint.xlogid, startpoint.xrecoff);
|
|
result = DatumGetTextP(DirectFunctionCall1(textin,
|
|
CStringGetDatum(xlogfilename)));
|
|
PG_RETURN_TEXT_P(result);
|
|
}
|
|
|
|
/*
|
|
* 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 offset.
|
|
*/
|
|
Datum
|
|
pg_stop_backup(PG_FUNCTION_ARGS)
|
|
{
|
|
text *result;
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
XLogRecPtr startpoint;
|
|
XLogRecPtr stoppoint;
|
|
time_t stamp_time;
|
|
char strfbuf[128];
|
|
char labelfilepath[MAXPGPATH];
|
|
char histfilepath[MAXPGPATH];
|
|
char startxlogfilename[MAXFNAMELEN];
|
|
char stopxlogfilename[MAXFNAMELEN];
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
FILE *lfp;
|
|
FILE *fp;
|
|
char ch;
|
|
int ich;
|
|
|
|
if (!superuser())
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
(errmsg("must be superuser to run a backup"))));
|
|
|
|
/*
|
|
* Get the current end-of-WAL position; it will be unsafe to use this
|
|
* dump to restore to a point in advance of this time.
|
|
*/
|
|
LWLockAcquire(WALInsertLock, LW_EXCLUSIVE);
|
|
INSERT_RECPTR(stoppoint, Insert, Insert->curridx);
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
XLByteToSeg(stoppoint, _logId, _logSeg);
|
|
XLogFileName(stopxlogfilename, ThisTimeLineID, _logId, _logSeg);
|
|
|
|
/*
|
|
* We deliberately use strftime/localtime not the src/timezone
|
|
* functions, so that backup labels will consistently be recorded in
|
|
* the same timezone regardless of TimeZone setting. This matches
|
|
* elog.c's practice.
|
|
*/
|
|
stamp_time = time(NULL);
|
|
strftime(strfbuf, sizeof(strfbuf),
|
|
"%Y-%m-%d %H:%M:%S %Z",
|
|
localtime(&stamp_time));
|
|
|
|
/*
|
|
* Open the existing label file
|
|
*/
|
|
snprintf(labelfilepath, MAXPGPATH, "%s/backup_label", DataDir);
|
|
lfp = AllocateFile(labelfilepath, "r");
|
|
if (!lfp)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
labelfilepath)));
|
|
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\"", labelfilepath)));
|
|
|
|
/*
|
|
* 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",
|
|
labelfilepath)));
|
|
if (unlink(labelfilepath) != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not remove file \"%s\": %m",
|
|
labelfilepath)));
|
|
|
|
RemoveOldBackupHistory();
|
|
|
|
/*
|
|
* Notify archiver that history file may be archived immediately
|
|
*/
|
|
if (XLogArchivingActive())
|
|
{
|
|
BackupHistoryFileName(histfilepath, ThisTimeLineID, _logId, _logSeg,
|
|
startpoint.xrecoff % XLogSegSize);
|
|
XLogArchiveNotify(histfilepath);
|
|
}
|
|
|
|
/*
|
|
* We're done. As a convenience, return the ending WAL offset.
|
|
*/
|
|
snprintf(stopxlogfilename, sizeof(stopxlogfilename), "%X/%X",
|
|
stoppoint.xlogid, stoppoint.xrecoff);
|
|
result = DatumGetTextP(DirectFunctionCall1(textin,
|
|
CStringGetDatum(stopxlogfilename)));
|
|
PG_RETURN_TEXT_P(result);
|
|
}
|
|
|
|
/*
|
|
* 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 recoveryMinXlogOffset 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 startpoint;
|
|
XLogRecPtr stoppoint;
|
|
char labelfilepath[MAXPGPATH];
|
|
char histfilename[MAXFNAMELEN];
|
|
char histfilepath[MAXPGPATH];
|
|
char startxlogfilename[MAXFNAMELEN];
|
|
char stopxlogfilename[MAXFNAMELEN];
|
|
TimeLineID tli;
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
FILE *lfp;
|
|
FILE *fp;
|
|
char ch;
|
|
|
|
/*
|
|
* See if label file is present
|
|
*/
|
|
snprintf(labelfilepath, MAXPGPATH, "%s/backup_label", DataDir);
|
|
lfp = AllocateFile(labelfilepath, "r");
|
|
if (!lfp)
|
|
{
|
|
if (errno != ENOENT)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
labelfilepath)));
|
|
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\"", labelfilepath)));
|
|
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\"", labelfilepath)));
|
|
if (ferror(lfp) || FreeFile(lfp))
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
labelfilepath)));
|
|
|
|
/*
|
|
* 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)));
|
|
recoveryMinXlogOffset = stoppoint;
|
|
if (ferror(fp) || FreeFile(fp))
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read file \"%s\": %m",
|
|
histfilepath)));
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* remove_backup_label: remove any extant backup_label after successful
|
|
* recovery. Once we have completed the end-of-recovery checkpoint there
|
|
* is no reason to have to replay from the start point indicated by the
|
|
* label (and indeed we'll probably have removed/recycled the needed WAL
|
|
* segments), so remove the label to prevent trouble in later crash recoveries.
|
|
*/
|
|
static void
|
|
remove_backup_label(void)
|
|
{
|
|
char labelfilepath[MAXPGPATH];
|
|
|
|
snprintf(labelfilepath, MAXPGPATH, "%s/backup_label", DataDir);
|
|
if (unlink(labelfilepath) != 0)
|
|
if (errno != ENOENT)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not remove file \"%s\": %m",
|
|
labelfilepath)));
|
|
}
|