3877 lines
113 KiB
C
3877 lines
113 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) 1996-2003, 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 1.141 2004/05/21 05:07:56 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <fcntl.h>
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#include <signal.h>
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#include <unistd.h>
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#include <sys/stat.h>
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#include "access/clog.h"
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#include "access/transam.h"
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#include "access/xact.h"
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#include "access/xlog.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 "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/sinval.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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#include "miscadmin.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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#define SYNC_METHOD_FSYNC 0
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#define SYNC_METHOD_FDATASYNC 1
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#define SYNC_METHOD_OPEN 2 /* used for both O_SYNC and
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* O_DSYNC */
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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(OPEN_SYNC_FLAG)
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#if defined(O_DSYNC) && (O_DSYNC != OPEN_SYNC_FLAG)
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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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#else
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#if 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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#else
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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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#endif
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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 *XLOG_sync_method = NULL;
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const char XLOG_sync_method_default[] = DEFAULT_SYNC_METHOD_STR;
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char XLOG_archive_dir[MAXPGPATH]; /* null string means
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* delete 'em */
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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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static 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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* ThisStartUpID will be same in all backends --- it identifies current
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* instance of the database system.
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*/
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StartUpID ThisStartUpID = 0;
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/* Are we doing recovery by reading XLOG? */
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bool InRecovery = false;
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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.
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*/
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NON_EXEC_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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/*
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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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StartUpID ThisStartUpID;
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/* This value is not protected by *any* lock... */
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/* see SetSavedRedoRecPtr/GetSavedRedoRecPtr */
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XLogRecPtr SavedRedoRecPtr;
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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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/* Increment an xlogid/segment pair */
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#define NextLogSeg(logId, logSeg) \
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do { \
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if ((logSeg) >= XLogSegsPerFile-1) \
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{ \
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(logId)++; \
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(logSeg) = 0; \
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} \
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else \
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(logSeg)++; \
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} while (0)
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/* Decrement an xlogid/segment pair (assume it's not 0,0) */
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#define PrevLogSeg(logId, logSeg) \
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do { \
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if (logSeg) \
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(logSeg)--; \
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else \
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{ \
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(logId)--; \
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(logSeg) = XLogSegsPerFile-1; \
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} \
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} while (0)
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/*
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* Compute ID and segment from an XLogRecPtr.
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*
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* For XLByteToSeg, do the computation at face value. For XLByteToPrevSeg,
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* a boundary byte is taken to be in the previous segment. This is suitable
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* for deciding which segment to write given a pointer to a record end,
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* for example. (We can assume xrecoff is not zero, since no valid recptr
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* can have that.)
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*/
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#define XLByteToSeg(xlrp, logId, logSeg) \
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( logId = (xlrp).xlogid, \
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logSeg = (xlrp).xrecoff / XLogSegSize \
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)
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#define XLByteToPrevSeg(xlrp, logId, logSeg) \
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( logId = (xlrp).xlogid, \
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logSeg = ((xlrp).xrecoff - 1) / XLogSegSize \
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)
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/*
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* Is an XLogRecPtr within a particular XLOG segment?
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*
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* For XLByteInSeg, do the computation at face value. For XLByteInPrevSeg,
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* a boundary byte is taken to be in the previous segment.
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*/
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#define XLByteInSeg(xlrp, logId, logSeg) \
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((xlrp).xlogid == (logId) && \
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(xlrp).xrecoff / XLogSegSize == (logSeg))
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#define XLByteInPrevSeg(xlrp, logId, logSeg) \
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((xlrp).xlogid == (logId) && \
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((xlrp).xrecoff - 1) / XLogSegSize == (logSeg))
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#define XLogFileName(path, log, seg) \
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snprintf(path, MAXPGPATH, "%s/%08X%08X", \
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XLogDir, log, seg)
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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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#define XRecOffIsValid(xrecoff) \
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((xrecoff) % BLCKSZ >= SizeOfXLogPHD && \
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(BLCKSZ - (xrecoff) % BLCKSZ) >= SizeOfXLogRecord)
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/*
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* _INTL_MAXLOGRECSZ: max space needed for a record including header and
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* any backup-block data.
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*/
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#define _INTL_MAXLOGRECSZ (SizeOfXLogRecord + MAXLOGRECSZ + \
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XLR_MAX_BKP_BLOCKS * (sizeof(BkpBlock) + BLCKSZ))
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/* File path names */
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static 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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NON_EXEC_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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/* State information for XLOG reading */
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static XLogRecPtr ReadRecPtr;
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static XLogRecPtr EndRecPtr;
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static XLogRecord *nextRecord = NULL;
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static StartUpID lastReadSUI;
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static bool InRedo = false;
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static bool AdvanceXLInsertBuffer(void);
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static bool WasteXLInsertBuffer(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, bool econt);
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static void PreallocXlogFiles(XLogRecPtr endptr);
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static void MoveOfflineLogs(uint32 log, uint32 seg, XLogRecPtr endptr);
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static XLogRecord *ReadRecord(XLogRecPtr *RecPtr, int emode, char *buffer);
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static bool ValidXLOGHeader(XLogPageHeader hdr, int emode, bool checkSUI);
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static XLogRecord *ReadCheckpointRecord(XLogRecPtr RecPtr,
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int whichChkpt,
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char *buffer);
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static void WriteControlFile(void);
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static void ReadControlFile(void);
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static char *str_time(time_t tnow);
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static void issue_xlog_fsync(void);
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#ifdef WAL_DEBUG
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static void xlog_outrec(char *buf, XLogRecord *record);
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#endif
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/*
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* Insert an XLOG record having the specified RMID and info bytes,
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* with the body of the record being the data chunk(s) described by
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* the rdata list (see xlog.h for notes about rdata).
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*
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* Returns XLOG pointer to end of record (beginning of next record).
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* This can be used as LSN for data pages affected by the logged action.
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* (LSN is the XLOG point up to which the XLOG must be flushed to disk
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* before the data page can be written out. This implements the basic
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* WAL rule "write the log before the data".)
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*
|
|
* 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_rdt[2 * XLR_MAX_BKP_BLOCKS];
|
|
crc64 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 = SizeOfXLogPHD; /* start of 1st checkpoint record */
|
|
return (RecPtr);
|
|
}
|
|
|
|
/*
|
|
* Here we scan the rdata list, 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 yet since we don't know the final
|
|
* length or info bits quite yet.
|
|
*
|
|
* 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 list 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 list 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
|
|
* list later.
|
|
*/
|
|
begin:;
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
dtbuf[i] = InvalidBuffer;
|
|
dtbuf_bkp[i] = false;
|
|
}
|
|
|
|
INIT_CRC64(rdata_crc);
|
|
len = 0;
|
|
for (rdt = rdata;;)
|
|
{
|
|
if (rdt->buffer == InvalidBuffer)
|
|
{
|
|
/* Simple data, just include it */
|
|
len += rdt->len;
|
|
COMP_CRC64(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 list item */
|
|
if (dtbuf_bkp[i])
|
|
rdt->data = NULL;
|
|
else if (rdt->data)
|
|
{
|
|
len += rdt->len;
|
|
COMP_CRC64(rdata_crc, rdt->data, rdt->len);
|
|
}
|
|
break;
|
|
}
|
|
if (dtbuf[i] == InvalidBuffer)
|
|
{
|
|
/* OK, put it in this slot */
|
|
dtbuf[i] = rdt->buffer;
|
|
|
|
/*
|
|
* XXX We assume page LSN is first data on page
|
|
*/
|
|
dtbuf_lsn[i] = *((XLogRecPtr *) BufferGetBlock(rdt->buffer));
|
|
if (XLByteLE(dtbuf_lsn[i], RedoRecPtr))
|
|
{
|
|
crc64 dtcrc;
|
|
|
|
dtbuf_bkp[i] = true;
|
|
rdt->data = NULL;
|
|
INIT_CRC64(dtcrc);
|
|
COMP_CRC64(dtcrc,
|
|
BufferGetBlock(dtbuf[i]),
|
|
BLCKSZ);
|
|
dtbuf_xlg[i].node = BufferGetFileNode(dtbuf[i]);
|
|
dtbuf_xlg[i].block = BufferGetBlockNumber(dtbuf[i]);
|
|
COMP_CRC64(dtcrc,
|
|
(char *) &(dtbuf_xlg[i]) + sizeof(crc64),
|
|
sizeof(BkpBlock) - sizeof(crc64));
|
|
FIN_CRC64(dtcrc);
|
|
dtbuf_xlg[i].crc = dtcrc;
|
|
}
|
|
else if (rdt->data)
|
|
{
|
|
len += rdt->len;
|
|
COMP_CRC64(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 list item */
|
|
if (rdt->next == NULL)
|
|
break;
|
|
rdt = rdt->next;
|
|
}
|
|
|
|
/*
|
|
* 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 || len > MAXLOGRECSZ)
|
|
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 list 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 list. 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 list.
|
|
*/
|
|
write_len = len;
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (dtbuf[i] == InvalidBuffer || !(dtbuf_bkp[i]))
|
|
continue;
|
|
|
|
info |= XLR_SET_BKP_BLOCK(i);
|
|
|
|
rdt->next = &(dtbuf_rdt[2 * i]);
|
|
|
|
dtbuf_rdt[2 * i].data = (char *) &(dtbuf_xlg[i]);
|
|
dtbuf_rdt[2 * i].len = sizeof(BkpBlock);
|
|
write_len += sizeof(BkpBlock);
|
|
|
|
rdt = dtbuf_rdt[2 * i].next = &(dtbuf_rdt[2 * i + 1]);
|
|
|
|
dtbuf_rdt[2 * i + 1].data = (char *) BufferGetBlock(dtbuf[i]);
|
|
dtbuf_rdt[2 * i + 1].len = BLCKSZ;
|
|
write_len += BLCKSZ;
|
|
dtbuf_rdt[2 * i + 1].next = NULL;
|
|
}
|
|
|
|
/*
|
|
* Determine exactly where we will place the new XLOG record. 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).
|
|
* If there isn't enough space in the current XLOG segment for the whole
|
|
* record, advance to the next segment (inserting wasted-space records).
|
|
* This avoids needing a continuation record at the start of a segment
|
|
* file, which would conflict with placing a FILE_HEADER record there.
|
|
* We assume that no XLOG record can be larger than a segment file...
|
|
*/
|
|
|
|
updrqst = false;
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
if (freespace < SizeOfXLogRecord)
|
|
{
|
|
updrqst = AdvanceXLInsertBuffer();
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
}
|
|
|
|
if (freespace < (uint32) (SizeOfXLogRecord + write_len))
|
|
{
|
|
/* Doesn't fit on this page, so check for overrunning the file */
|
|
uint32 avail;
|
|
|
|
/* First figure the space available in remaining pages of file */
|
|
avail = XLogSegSize - BLCKSZ -
|
|
(Insert->currpage->xlp_pageaddr.xrecoff % XLogSegSize);
|
|
avail /= BLCKSZ; /* convert to pages, then usable bytes */
|
|
avail *= (BLCKSZ - SizeOfXLogPHD - SizeOfXLogContRecord);
|
|
avail += freespace; /* add in the current page too */
|
|
if (avail < (uint32) (SizeOfXLogRecord + write_len))
|
|
{
|
|
/* It overruns the file, so waste the rest of the file... */
|
|
do {
|
|
updrqst = WasteXLInsertBuffer();
|
|
} while ((Insert->currpage->xlp_pageaddr.xrecoff % XLogSegSize) != 0);
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
}
|
|
}
|
|
|
|
curridx = Insert->curridx;
|
|
record = (XLogRecord *) Insert->currpos;
|
|
|
|
/* Insert record header */
|
|
|
|
record->xl_prev = Insert->PrevRecord;
|
|
if (no_tran)
|
|
{
|
|
record->xl_xact_prev.xlogid = 0;
|
|
record->xl_xact_prev.xrecoff = 0;
|
|
}
|
|
else
|
|
record->xl_xact_prev = MyLastRecPtr;
|
|
|
|
record->xl_xid = GetCurrentTransactionId();
|
|
record->xl_len = len; /* doesn't include backup blocks */
|
|
record->xl_info = info;
|
|
record->xl_rmid = rmid;
|
|
|
|
/* Now we can finish computing the main CRC */
|
|
COMP_CRC64(rdata_crc, (char *) record + sizeof(crc64),
|
|
SizeOfXLogRecord - sizeof(crc64));
|
|
FIN_CRC64(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 SInvalLock 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;
|
|
/* This assert checks we did not insert a file header record */
|
|
Assert(INSERT_FREESPACE(Insert) == BLCKSZ - SizeOfXLogPHD);
|
|
/* 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 = BLCKSZ - SizeOfXLogPHD - SizeOfXLogContRecord;
|
|
}
|
|
|
|
/* 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);
|
|
}
|
|
|
|
/*
|
|
* 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) + SizeOfXLogPHD;
|
|
|
|
/*
|
|
* 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_sui = ThisStartUpID;
|
|
NewPage->xlp_pageaddr.xlogid = NewPageEndPtr.xlogid;
|
|
NewPage->xlp_pageaddr.xrecoff = NewPageEndPtr.xrecoff - BLCKSZ;
|
|
|
|
/*
|
|
* If first page of an XLOG segment file, add a FILE_HEADER record.
|
|
*/
|
|
if ((NewPage->xlp_pageaddr.xrecoff % XLogSegSize) == 0)
|
|
{
|
|
XLogRecPtr RecPtr;
|
|
XLogRecord *record;
|
|
XLogFileHeaderData *fhdr;
|
|
crc64 crc;
|
|
|
|
record = (XLogRecord *) Insert->currpos;
|
|
record->xl_prev = Insert->PrevRecord;
|
|
record->xl_xact_prev.xlogid = 0;
|
|
record->xl_xact_prev.xrecoff = 0;
|
|
record->xl_xid = InvalidTransactionId;
|
|
record->xl_len = SizeOfXLogFHD;
|
|
record->xl_info = XLOG_FILE_HEADER;
|
|
record->xl_rmid = RM_XLOG_ID;
|
|
fhdr = (XLogFileHeaderData *) XLogRecGetData(record);
|
|
fhdr->xlfhd_sysid = ControlFile->system_identifier;
|
|
fhdr->xlfhd_xlogid = NewPage->xlp_pageaddr.xlogid;
|
|
fhdr->xlfhd_segno = NewPage->xlp_pageaddr.xrecoff / XLogSegSize;
|
|
fhdr->xlfhd_seg_size = XLogSegSize;
|
|
|
|
INIT_CRC64(crc);
|
|
COMP_CRC64(crc, fhdr, SizeOfXLogFHD);
|
|
COMP_CRC64(crc, (char *) record + sizeof(crc64),
|
|
SizeOfXLogRecord - sizeof(crc64));
|
|
FIN_CRC64(crc);
|
|
record->xl_crc = crc;
|
|
|
|
/* Compute record's XLOG location */
|
|
INSERT_RECPTR(RecPtr, Insert, nextidx);
|
|
|
|
/* Record begin of record in appropriate places */
|
|
Insert->PrevRecord = RecPtr;
|
|
|
|
Insert->currpos += SizeOfXLogRecord + SizeOfXLogFHD;
|
|
}
|
|
|
|
return update_needed;
|
|
}
|
|
|
|
/*
|
|
* Fill the remainder of the current XLOG page with an XLOG_WASTED_SPACE
|
|
* record, and advance to the next page. This has the same calling and
|
|
* result conditions as AdvanceXLInsertBuffer, except that
|
|
* AdvanceXLInsertBuffer expects the current page to be already filled.
|
|
*/
|
|
static bool
|
|
WasteXLInsertBuffer(void)
|
|
{
|
|
XLogCtlInsert *Insert = &XLogCtl->Insert;
|
|
XLogRecord *record;
|
|
XLogRecPtr RecPtr;
|
|
uint32 freespace;
|
|
uint16 curridx;
|
|
crc64 rdata_crc;
|
|
|
|
freespace = INSERT_FREESPACE(Insert);
|
|
Assert(freespace >= SizeOfXLogRecord);
|
|
freespace -= SizeOfXLogRecord;
|
|
|
|
curridx = Insert->curridx;
|
|
record = (XLogRecord *) Insert->currpos;
|
|
|
|
record->xl_prev = Insert->PrevRecord;
|
|
record->xl_xact_prev.xlogid = 0;
|
|
record->xl_xact_prev.xrecoff = 0;
|
|
|
|
record->xl_xid = InvalidTransactionId;
|
|
record->xl_len = freespace;
|
|
record->xl_info = XLOG_WASTED_SPACE;
|
|
record->xl_rmid = RM_XLOG_ID;
|
|
|
|
INIT_CRC64(rdata_crc);
|
|
COMP_CRC64(rdata_crc, XLogRecGetData(record), freespace);
|
|
COMP_CRC64(rdata_crc, (char *) record + sizeof(crc64),
|
|
SizeOfXLogRecord - sizeof(crc64));
|
|
FIN_CRC64(rdata_crc);
|
|
record->xl_crc = rdata_crc;
|
|
|
|
/* Compute record's XLOG location */
|
|
INSERT_RECPTR(RecPtr, Insert, curridx);
|
|
|
|
/* Record begin of record in appropriate places */
|
|
Insert->PrevRecord = RecPtr;
|
|
|
|
/* We needn't bother to advance Insert->currpos */
|
|
|
|
return AdvanceXLInsertBuffer();
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
/*
|
|
* 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 postmaster 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.)
|
|
*/
|
|
if (IsUnderPostmaster &&
|
|
(openLogId != RedoRecPtr.xlogid ||
|
|
openLogSeg >= (RedoRecPtr.xrecoff / XLogSegSize) +
|
|
(uint32) CheckPointSegments))
|
|
{
|
|
#ifdef WAL_DEBUG
|
|
if (XLOG_DEBUG)
|
|
elog(LOG, "time for a checkpoint, signaling postmaster");
|
|
#endif
|
|
SendPostmasterSignal(PMSIGNAL_DO_CHECKPOINT);
|
|
}
|
|
}
|
|
LWLockRelease(ControlFileLock);
|
|
}
|
|
|
|
if (openLogFile < 0)
|
|
{
|
|
XLByteToPrevSeg(LogwrtResult.Write, openLogId, openLogSeg);
|
|
openLogFile = XLogFileOpen(openLogId, openLogSeg, false);
|
|
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.
|
|
*/
|
|
if (openLogOff >= XLogSegSize && !ispartialpage)
|
|
{
|
|
issue_xlog_fsync();
|
|
LogwrtResult.Flush = LogwrtResult.Write; /* end of current page */
|
|
}
|
|
|
|
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, false);
|
|
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.
|
|
*/
|
|
static int
|
|
XLogFileInit(uint32 log, uint32 seg,
|
|
bool *use_existent, bool use_lock)
|
|
{
|
|
char path[MAXPGPATH];
|
|
char tmppath[MAXPGPATH];
|
|
char zbuffer[BLCKSZ];
|
|
int fd;
|
|
int nbytes;
|
|
|
|
XLogFileName(path, 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(PANIC,
|
|
(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(PANIC,
|
|
(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(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write to file \"%s\": %m", tmppath)));
|
|
}
|
|
}
|
|
|
|
if (pg_fsync(fd) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync file \"%s\": %m", tmppath)));
|
|
|
|
if (close(fd))
|
|
ereport(PANIC,
|
|
(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.
|
|
*/
|
|
if (!InstallXLogFileSegment(log, seg, tmppath,
|
|
*use_existent, XLOGfileslop,
|
|
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(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
|
|
return (fd);
|
|
}
|
|
|
|
/*
|
|
* 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).
|
|
*
|
|
* 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. (Irrelevant if
|
|
* 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;
|
|
|
|
XLogFileName(path, 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);
|
|
XLogFileName(path, 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(PANIC,
|
|
(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(PANIC,
|
|
(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.
|
|
*/
|
|
static int
|
|
XLogFileOpen(uint32 log, uint32 seg, bool econt)
|
|
{
|
|
char path[MAXPGPATH];
|
|
int fd;
|
|
|
|
XLogFileName(path, log, seg);
|
|
|
|
fd = BasicOpenFile(path, O_RDWR | PG_BINARY | XLOG_SYNC_BIT,
|
|
S_IRUSR | S_IWUSR);
|
|
if (fd < 0)
|
|
{
|
|
if (econt && errno == ENOENT)
|
|
{
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
return (fd);
|
|
}
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open file \"%s\" (log file %u, segment %u): %m",
|
|
path, log, seg)));
|
|
}
|
|
|
|
return (fd);
|
|
}
|
|
|
|
/*
|
|
* Preallocate log files beyond the specified log endpoint, according to
|
|
* the XLOGfile user parameter.
|
|
*/
|
|
static void
|
|
PreallocXlogFiles(XLogRecPtr endptr)
|
|
{
|
|
uint32 _logId;
|
|
uint32 _logSeg;
|
|
int lf;
|
|
bool use_existent;
|
|
|
|
XLByteToPrevSeg(endptr, _logId, _logSeg);
|
|
if ((endptr.xrecoff - 1) % XLogSegSize >=
|
|
(uint32) (0.75 * XLogSegSize))
|
|
{
|
|
NextLogSeg(_logId, _logSeg);
|
|
use_existent = true;
|
|
lf = XLogFileInit(_logId, _logSeg, &use_existent, true);
|
|
close(lf);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
uint32 endlogId;
|
|
uint32 endlogSeg;
|
|
DIR *xldir;
|
|
struct dirent *xlde;
|
|
char lastoff[32];
|
|
char path[MAXPGPATH];
|
|
|
|
XLByteToPrevSeg(endptr, endlogId, endlogSeg);
|
|
|
|
xldir = AllocateDir(XLogDir);
|
|
if (xldir == NULL)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open transaction log directory \"%s\": %m",
|
|
XLogDir)));
|
|
|
|
sprintf(lastoff, "%08X%08X", log, seg);
|
|
|
|
errno = 0;
|
|
while ((xlde = readdir(xldir)) != NULL)
|
|
{
|
|
if (strlen(xlde->d_name) == 16 &&
|
|
strspn(xlde->d_name, "0123456789ABCDEF") == 16 &&
|
|
strcmp(xlde->d_name, lastoff) <= 0)
|
|
{
|
|
snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
|
|
if (XLOG_archive_dir[0])
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("archiving transaction log file \"%s\"",
|
|
xlde->d_name)));
|
|
elog(WARNING, "archiving log files is not implemented");
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Before deleting the file, see if it can be recycled as
|
|
* a future log segment. We allow recycling segments up
|
|
* to XLOGfileslop segments beyond the current XLOG
|
|
* location.
|
|
*/
|
|
if (InstallXLogFileSegment(endlogId, endlogSeg, path,
|
|
true, XLOGfileslop,
|
|
true))
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("recycled transaction log file \"%s\"",
|
|
xlde->d_name)));
|
|
}
|
|
else
|
|
{
|
|
/* No need for any more future segments... */
|
|
ereport(LOG,
|
|
(errmsg("removing transaction log file \"%s\"",
|
|
xlde->d_name)));
|
|
unlink(path);
|
|
}
|
|
}
|
|
}
|
|
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.
|
|
*/
|
|
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((char *) &bkpb, blk, sizeof(BkpBlock));
|
|
blk += sizeof(BkpBlock);
|
|
|
|
reln = XLogOpenRelation(true, record->xl_rmid, bkpb.node);
|
|
|
|
if (reln)
|
|
{
|
|
buffer = XLogReadBuffer(true, reln, bkpb.block);
|
|
if (BufferIsValid(buffer))
|
|
{
|
|
page = (Page) BufferGetPage(buffer);
|
|
memcpy((char *) page, blk, BLCKSZ);
|
|
PageSetLSN(page, lsn);
|
|
PageSetSUI(page, ThisStartUpID);
|
|
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
|
|
WriteBuffer(buffer);
|
|
}
|
|
}
|
|
|
|
blk += BLCKSZ;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
crc64 crc;
|
|
crc64 cbuf;
|
|
int i;
|
|
uint32 len = record->xl_len;
|
|
char *blk;
|
|
|
|
/* Check CRC of rmgr data and record header */
|
|
INIT_CRC64(crc);
|
|
COMP_CRC64(crc, XLogRecGetData(record), len);
|
|
COMP_CRC64(crc, (char *) record + sizeof(crc64),
|
|
SizeOfXLogRecord - sizeof(crc64));
|
|
FIN_CRC64(crc);
|
|
|
|
if (!EQ_CRC64(record->xl_crc, crc))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("incorrect resource manager data checksum in record at %X/%X",
|
|
recptr.xlogid, recptr.xrecoff)));
|
|
return (false);
|
|
}
|
|
|
|
/* Check CRCs of backup blocks, if any */
|
|
blk = (char *) XLogRecGetData(record) + len;
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (!(record->xl_info & XLR_SET_BKP_BLOCK(i)))
|
|
continue;
|
|
|
|
INIT_CRC64(crc);
|
|
COMP_CRC64(crc, blk + sizeof(BkpBlock), BLCKSZ);
|
|
COMP_CRC64(crc, blk + sizeof(crc64),
|
|
sizeof(BkpBlock) - sizeof(crc64));
|
|
FIN_CRC64(crc);
|
|
memcpy((char *) &cbuf, blk, sizeof(crc64)); /* don't assume
|
|
* alignment */
|
|
|
|
if (!EQ_CRC64(cbuf, crc))
|
|
{
|
|
ereport(emode,
|
|
(errmsg("incorrect checksum of backup block %d in record at %X/%X",
|
|
i + 1, recptr.xlogid, recptr.xrecoff)));
|
|
return (false);
|
|
}
|
|
blk += sizeof(BkpBlock) + BLCKSZ;
|
|
}
|
|
|
|
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.)
|
|
*
|
|
* buffer is a workspace at least _INTL_MAXLOGRECSZ bytes long. It is needed
|
|
* to reassemble a record that crosses block boundaries. Note that on
|
|
* successful return, the returned record pointer always points at buffer.
|
|
*/
|
|
static XLogRecord *
|
|
ReadRecord(XLogRecPtr *RecPtr, int emode, char *buffer)
|
|
{
|
|
XLogRecord *record;
|
|
XLogRecPtr tmpRecPtr = EndRecPtr;
|
|
uint32 len,
|
|
total_len;
|
|
uint32 targetPageOff;
|
|
unsigned i;
|
|
bool nextmode = false;
|
|
|
|
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;
|
|
nextmode = true;
|
|
/* 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;
|
|
}
|
|
tmpRecPtr.xrecoff += SizeOfXLogPHD;
|
|
}
|
|
else if (!XRecOffIsValid(RecPtr->xrecoff))
|
|
ereport(PANIC,
|
|
(errmsg("invalid record offset at %X/%X",
|
|
RecPtr->xlogid, RecPtr->xrecoff)));
|
|
|
|
if (readFile >= 0 && !XLByteInSeg(*RecPtr, readId, readSeg))
|
|
{
|
|
close(readFile);
|
|
readFile = -1;
|
|
}
|
|
XLByteToSeg(*RecPtr, readId, readSeg);
|
|
if (readFile < 0)
|
|
{
|
|
readFile = XLogFileOpen(readId, readSeg, (emode == LOG));
|
|
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, nextmode))
|
|
goto next_record_is_invalid;
|
|
}
|
|
if ((((XLogPageHeader) readBuf)->xlp_info & XLP_FIRST_IS_CONTRECORD) &&
|
|
RecPtr->xrecoff % BLCKSZ == SizeOfXLogPHD)
|
|
{
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Compute total length of record including any appended backup
|
|
* blocks.
|
|
*/
|
|
total_len = SizeOfXLogRecord + record->xl_len;
|
|
for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
|
|
{
|
|
if (!(record->xl_info & XLR_SET_BKP_BLOCK(i)))
|
|
continue;
|
|
total_len += sizeof(BkpBlock) + BLCKSZ;
|
|
}
|
|
|
|
/*
|
|
* Make sure it will fit in buffer (currently, it is mechanically
|
|
* impossible for this test to fail, but it seems like a good idea
|
|
* anyway).
|
|
*/
|
|
if (total_len > _INTL_MAXLOGRECSZ)
|
|
{
|
|
ereport(emode,
|
|
(errmsg("record length %u at %X/%X too long",
|
|
total_len, 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;
|
|
}
|
|
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 = XLogFileOpen(readId, readSeg, (emode == LOG));
|
|
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, true))
|
|
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;
|
|
}
|
|
contrecord = (XLogContRecord *) ((char *) readBuf + SizeOfXLogPHD);
|
|
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 - SizeOfXLogPHD - 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;
|
|
if (BLCKSZ - SizeOfXLogRecord >= SizeOfXLogPHD +
|
|
SizeOfXLogContRecord + MAXALIGN(contrecord->xl_rem_len))
|
|
{
|
|
nextRecord = (XLogRecord *) ((char *) contrecord +
|
|
SizeOfXLogContRecord + MAXALIGN(contrecord->xl_rem_len));
|
|
}
|
|
EndRecPtr.xlogid = readId;
|
|
EndRecPtr.xrecoff = readSeg * XLogSegSize + readOff +
|
|
SizeOfXLogPHD + SizeOfXLogContRecord +
|
|
MAXALIGN(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, bool checkSUI)
|
|
{
|
|
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;
|
|
}
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* We disbelieve a SUI less than the previous page's SUI, or more than
|
|
* a few counts greater. In theory as many as 512 shutdown checkpoint
|
|
* records could appear on a 32K-sized xlog page, so that's the most
|
|
* differential there could legitimately be.
|
|
*
|
|
* Note this check can only be applied when we are reading the next page
|
|
* in sequence, so ReadRecord passes a flag indicating whether to
|
|
* check.
|
|
*/
|
|
if (checkSUI)
|
|
{
|
|
if (hdr->xlp_sui < lastReadSUI ||
|
|
hdr->xlp_sui > lastReadSUI + 512)
|
|
{
|
|
ereport(emode,
|
|
/* translator: SUI = startup id */
|
|
(errmsg("out-of-sequence SUI %u (after %u) in log file %u, segment %u, offset %u",
|
|
hdr->xlp_sui, lastReadSUI,
|
|
readId, readSeg, readOff)));
|
|
return false;
|
|
}
|
|
}
|
|
lastReadSUI = hdr->xlp_sui;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* 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->funcMaxArgs = FUNC_MAX_ARGS;
|
|
|
|
#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_CRC64(ControlFile->crc);
|
|
COMP_CRC64(ControlFile->crc,
|
|
(char *) ControlFile + sizeof(crc64),
|
|
sizeof(ControlFileData) - sizeof(crc64));
|
|
FIN_CRC64(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)
|
|
{
|
|
crc64 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_CRC64(crc);
|
|
COMP_CRC64(crc,
|
|
(char *) ControlFile + sizeof(crc64),
|
|
sizeof(ControlFileData) - sizeof(crc64));
|
|
FIN_CRC64(crc);
|
|
|
|
if (!EQ_CRC64(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->funcMaxArgs != FUNC_MAX_ARGS)
|
|
ereport(FATAL,
|
|
(errmsg("database files are incompatible with server"),
|
|
errdetail("The database cluster was initialized with FUNC_MAX_ARGS %d,"
|
|
" but the server was compiled with FUNC_MAX_ARGS %d.",
|
|
ControlFile->funcMaxArgs, FUNC_MAX_ARGS),
|
|
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_CRC64(ControlFile->crc);
|
|
COMP_CRC64(ControlFile->crc,
|
|
(char *) ControlFile + sizeof(crc64),
|
|
sizeof(ControlFileData) - sizeof(crc64));
|
|
FIN_CRC64(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;
|
|
XLogRecord *record;
|
|
XLogFileHeaderData *fhdr;
|
|
bool use_existent;
|
|
uint64 sysidentifier;
|
|
struct timeval tv;
|
|
crc64 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);
|
|
|
|
/* 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 = SizeOfXLogPHD + SizeOfXLogRecord + SizeOfXLogFHD;
|
|
checkPoint.undo = checkPoint.redo;
|
|
checkPoint.ThisStartUpID = 0;
|
|
checkPoint.nextXid = FirstNormalTransactionId;
|
|
checkPoint.nextOid = BootstrapObjectIdData;
|
|
checkPoint.time = time(NULL);
|
|
|
|
ShmemVariableCache->nextXid = checkPoint.nextXid;
|
|
ShmemVariableCache->nextOid = checkPoint.nextOid;
|
|
ShmemVariableCache->oidCount = 0;
|
|
|
|
/* Set up the XLOG page header */
|
|
page->xlp_magic = XLOG_PAGE_MAGIC;
|
|
page->xlp_info = 0;
|
|
page->xlp_sui = checkPoint.ThisStartUpID;
|
|
page->xlp_pageaddr.xlogid = 0;
|
|
page->xlp_pageaddr.xrecoff = 0;
|
|
|
|
/* Insert the file header record */
|
|
record = (XLogRecord *) ((char *) page + SizeOfXLogPHD);
|
|
record->xl_prev.xlogid = 0;
|
|
record->xl_prev.xrecoff = 0;
|
|
record->xl_xact_prev.xlogid = 0;
|
|
record->xl_xact_prev.xrecoff = 0;
|
|
record->xl_xid = InvalidTransactionId;
|
|
record->xl_len = SizeOfXLogFHD;
|
|
record->xl_info = XLOG_FILE_HEADER;
|
|
record->xl_rmid = RM_XLOG_ID;
|
|
fhdr = (XLogFileHeaderData *) XLogRecGetData(record);
|
|
fhdr->xlfhd_sysid = sysidentifier;
|
|
fhdr->xlfhd_xlogid = 0;
|
|
fhdr->xlfhd_segno = 0;
|
|
fhdr->xlfhd_seg_size = XLogSegSize;
|
|
|
|
INIT_CRC64(crc);
|
|
COMP_CRC64(crc, fhdr, SizeOfXLogFHD);
|
|
COMP_CRC64(crc, (char *) record + sizeof(crc64),
|
|
SizeOfXLogRecord - sizeof(crc64));
|
|
FIN_CRC64(crc);
|
|
record->xl_crc = crc;
|
|
|
|
/* Insert the initial checkpoint record */
|
|
record = (XLogRecord *) ((char *) page + SizeOfXLogPHD + SizeOfXLogRecord + SizeOfXLogFHD);
|
|
record->xl_prev.xlogid = 0;
|
|
record->xl_prev.xrecoff = SizeOfXLogPHD;
|
|
record->xl_xact_prev.xlogid = 0;
|
|
record->xl_xact_prev.xrecoff = 0;
|
|
record->xl_xid = InvalidTransactionId;
|
|
record->xl_len = sizeof(checkPoint);
|
|
record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
|
|
record->xl_rmid = RM_XLOG_ID;
|
|
memcpy(XLogRecGetData(record), &checkPoint, sizeof(checkPoint));
|
|
|
|
INIT_CRC64(crc);
|
|
COMP_CRC64(crc, &checkPoint, sizeof(checkPoint));
|
|
COMP_CRC64(crc, (char *) record + sizeof(crc64),
|
|
SizeOfXLogRecord - sizeof(crc64));
|
|
FIN_CRC64(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 records */
|
|
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();
|
|
}
|
|
|
|
static char *
|
|
str_time(time_t tnow)
|
|
{
|
|
static char buf[128];
|
|
|
|
pg_strftime(buf, sizeof(buf),
|
|
"%Y-%m-%d %H:%M:%S %Z",
|
|
pg_localtime(&tnow));
|
|
|
|
return buf;
|
|
}
|
|
|
|
/*
|
|
* This must be called ONCE during postmaster or standalone-backend startup
|
|
*/
|
|
void
|
|
StartupXLOG(void)
|
|
{
|
|
XLogCtlInsert *Insert;
|
|
CheckPoint checkPoint;
|
|
bool wasShutdown;
|
|
XLogRecPtr RecPtr,
|
|
LastRec,
|
|
checkPointLoc,
|
|
EndOfLog;
|
|
XLogRecord *record;
|
|
char *buffer;
|
|
uint32 freespace;
|
|
|
|
/* Use malloc() to ensure record buffer is MAXALIGNED */
|
|
buffer = (char *) malloc(_INTL_MAXLOGRECSZ);
|
|
|
|
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
|
|
|
|
/*
|
|
* Get the last valid checkpoint record. If the latest one according
|
|
* to pg_control is broken, try the next-to-last one.
|
|
*/
|
|
record = ReadCheckpointRecord(ControlFile->checkPoint, 1, buffer);
|
|
if (record != NULL)
|
|
{
|
|
checkPointLoc = ControlFile->checkPoint;
|
|
ereport(LOG,
|
|
(errmsg("checkpoint record is at %X/%X",
|
|
checkPointLoc.xlogid, checkPointLoc.xrecoff)));
|
|
}
|
|
else
|
|
{
|
|
record = ReadCheckpointRecord(ControlFile->prevCheckPoint, 2, buffer);
|
|
if (record != NULL)
|
|
{
|
|
checkPointLoc = ControlFile->prevCheckPoint;
|
|
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)));
|
|
if (!TransactionIdIsNormal(checkPoint.nextXid))
|
|
ereport(PANIC,
|
|
(errmsg("invalid next transaction ID")));
|
|
|
|
ShmemVariableCache->nextXid = checkPoint.nextXid;
|
|
ShmemVariableCache->nextOid = checkPoint.nextOid;
|
|
ShmemVariableCache->oidCount = 0;
|
|
|
|
/*
|
|
* If it was a shutdown checkpoint, then any following WAL entries
|
|
* were created under the next StartUpID; if it was a regular
|
|
* checkpoint then any following WAL entries were created under the
|
|
* same StartUpID. We must replay WAL entries using the same StartUpID
|
|
* they were created under, so temporarily adopt that SUI (see also
|
|
* xlog_redo()).
|
|
*/
|
|
if (wasShutdown)
|
|
ThisStartUpID = checkPoint.ThisStartUpID + 1;
|
|
else
|
|
ThisStartUpID = checkPoint.ThisStartUpID;
|
|
|
|
RedoRecPtr = XLogCtl->Insert.RedoRecPtr =
|
|
XLogCtl->SavedRedoRecPtr = checkPoint.redo;
|
|
|
|
if (XLByteLT(RecPtr, checkPoint.redo))
|
|
ereport(PANIC,
|
|
(errmsg("invalid redo in checkpoint record")));
|
|
if (checkPoint.undo.xrecoff == 0)
|
|
checkPoint.undo = RecPtr;
|
|
|
|
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;
|
|
|
|
/* REDO */
|
|
if (InRecovery)
|
|
{
|
|
int rmid;
|
|
|
|
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();
|
|
}
|
|
|
|
/* Is REDO required ? */
|
|
if (XLByteLT(checkPoint.redo, RecPtr))
|
|
record = ReadRecord(&(checkPoint.redo), PANIC, buffer);
|
|
else
|
|
{
|
|
/* read past CheckPoint record */
|
|
record = ReadRecord(NULL, LOG, buffer);
|
|
}
|
|
|
|
if (record != NULL)
|
|
{
|
|
InRedo = true;
|
|
ereport(LOG,
|
|
(errmsg("redo starts at %X/%X",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff)));
|
|
do
|
|
{
|
|
/* nextXid must be beyond record's xid */
|
|
if (TransactionIdFollowsOrEquals(record->xl_xid,
|
|
ShmemVariableCache->nextXid))
|
|
{
|
|
ShmemVariableCache->nextXid = record->xl_xid;
|
|
TransactionIdAdvance(ShmemVariableCache->nextXid);
|
|
}
|
|
|
|
#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
|
|
|
|
if (record->xl_info & XLR_BKP_BLOCK_MASK)
|
|
RestoreBkpBlocks(record, EndRecPtr);
|
|
|
|
RmgrTable[record->xl_rmid].rm_redo(EndRecPtr, record);
|
|
record = ReadRecord(NULL, LOG, buffer);
|
|
} while (record != NULL);
|
|
ereport(LOG,
|
|
(errmsg("redo done at %X/%X",
|
|
ReadRecPtr.xlogid, ReadRecPtr.xrecoff)));
|
|
LastRec = ReadRecPtr;
|
|
InRedo = false;
|
|
}
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("redo is not required")));
|
|
}
|
|
|
|
/*
|
|
* Init xlog buffer cache using the block containing the last valid
|
|
* record from the previous incarnation.
|
|
*/
|
|
record = ReadRecord(&LastRec, PANIC, buffer);
|
|
EndOfLog = EndRecPtr;
|
|
XLByteToPrevSeg(EndOfLog, openLogId, openLogSeg);
|
|
openLogFile = XLogFileOpen(openLogId, openLogSeg, false);
|
|
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
|
|
* we can't since we haven't yet determined the correct StartUpID
|
|
* to put into the new page's header. 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, buffer);
|
|
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();
|
|
}
|
|
|
|
/* suppress in-transaction check in CreateCheckPoint */
|
|
MyLastRecPtr.xrecoff = 0;
|
|
MyXactMadeXLogEntry = false;
|
|
MyXactMadeTempRelUpdate = false;
|
|
|
|
/*
|
|
* At this point, ThisStartUpID is the largest SUI that we could
|
|
* find evidence for in the WAL entries. But check it against
|
|
* pg_control's latest checkpoint, to make sure that we can't
|
|
* accidentally re-use an already-used SUI.
|
|
*/
|
|
if (ThisStartUpID < ControlFile->checkPointCopy.ThisStartUpID)
|
|
ThisStartUpID = ControlFile->checkPointCopy.ThisStartUpID;
|
|
|
|
/*
|
|
* Perform a new checkpoint to update our recovery activity to
|
|
* disk.
|
|
*
|
|
* Note that we write a shutdown checkpoint. This is correct since
|
|
* the records following it will use SUI one more than what is
|
|
* shown in the checkpoint's ThisStartUpID.
|
|
*
|
|
* 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...
|
|
*/
|
|
ControlFile->checkPoint = checkPointLoc;
|
|
CreateCheckPoint(true, true);
|
|
|
|
/*
|
|
* Close down recovery environment
|
|
*/
|
|
XLogCloseRelationCache();
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If we are not doing recovery, then we saw a checkpoint with
|
|
* nothing after it, and we can safely use StartUpID equal to one
|
|
* more than the checkpoint's SUI. But just for paranoia's sake,
|
|
* check against pg_control too.
|
|
*/
|
|
ThisStartUpID = checkPoint.ThisStartUpID;
|
|
if (ThisStartUpID < ControlFile->checkPointCopy.ThisStartUpID)
|
|
ThisStartUpID = ControlFile->checkPointCopy.ThisStartUpID;
|
|
}
|
|
|
|
/*
|
|
* Preallocate additional log files, if wanted.
|
|
*/
|
|
PreallocXlogFiles(EndOfLog);
|
|
|
|
/*
|
|
* Advance StartUpID to one more than the highest value used
|
|
* previously.
|
|
*/
|
|
ThisStartUpID++;
|
|
XLogCtl->ThisStartUpID = ThisStartUpID;
|
|
|
|
/*
|
|
* Okay, we're officially UP.
|
|
*/
|
|
InRecovery = false;
|
|
|
|
ControlFile->state = DB_IN_PRODUCTION;
|
|
ControlFile->time = time(NULL);
|
|
UpdateControlFile();
|
|
|
|
/* Start up the commit log, too */
|
|
StartupCLOG();
|
|
|
|
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;
|
|
}
|
|
|
|
free(buffer);
|
|
}
|
|
|
|
/*
|
|
* Subroutine to try to fetch and validate a prior checkpoint record.
|
|
* whichChkpt = 1 for "primary", 2 for "secondary", merely informative
|
|
*/
|
|
static XLogRecord *
|
|
ReadCheckpointRecord(XLogRecPtr RecPtr,
|
|
int whichChkpt,
|
|
char *buffer)
|
|
{
|
|
XLogRecord *record;
|
|
|
|
if (!XRecOffIsValid(RecPtr.xrecoff))
|
|
{
|
|
if (whichChkpt == 1)
|
|
ereport(LOG,
|
|
(errmsg("invalid primary checkpoint link in control file")));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("invalid secondary checkpoint link in control file")));
|
|
return NULL;
|
|
}
|
|
|
|
record = ReadRecord(&RecPtr, LOG, buffer);
|
|
|
|
if (record == NULL)
|
|
{
|
|
if (whichChkpt == 1)
|
|
ereport(LOG,
|
|
(errmsg("invalid primary checkpoint record")));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("invalid secondary checkpoint record")));
|
|
return NULL;
|
|
}
|
|
if (record->xl_rmid != RM_XLOG_ID)
|
|
{
|
|
if (whichChkpt == 1)
|
|
ereport(LOG,
|
|
(errmsg("invalid resource manager ID in primary checkpoint record")));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("invalid resource manager ID in secondary checkpoint record")));
|
|
return NULL;
|
|
}
|
|
if (record->xl_info != XLOG_CHECKPOINT_SHUTDOWN &&
|
|
record->xl_info != XLOG_CHECKPOINT_ONLINE)
|
|
{
|
|
if (whichChkpt == 1)
|
|
ereport(LOG,
|
|
(errmsg("invalid xl_info in primary checkpoint record")));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("invalid xl_info in secondary checkpoint record")));
|
|
return NULL;
|
|
}
|
|
if (record->xl_len != sizeof(CheckPoint))
|
|
{
|
|
if (whichChkpt == 1)
|
|
ereport(LOG,
|
|
(errmsg("invalid length of primary checkpoint record")));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("invalid length of secondary checkpoint record")));
|
|
return NULL;
|
|
}
|
|
return record;
|
|
}
|
|
|
|
/*
|
|
* Postmaster uses this to initialize ThisStartUpID & RedoRecPtr from
|
|
* XLogCtlData located in shmem after successful startup.
|
|
*/
|
|
void
|
|
SetThisStartUpID(void)
|
|
{
|
|
ThisStartUpID = XLogCtl->ThisStartUpID;
|
|
RedoRecPtr = XLogCtl->SavedRedoRecPtr;
|
|
}
|
|
|
|
/*
|
|
* CheckPoint process called by postmaster saves copy of new RedoRecPtr
|
|
* in shmem (using SetSavedRedoRecPtr). When checkpointer completes,
|
|
* postmaster calls GetSavedRedoRecPtr to update its own copy of RedoRecPtr,
|
|
* so that subsequently-spawned backends will start out with a reasonably
|
|
* up-to-date local RedoRecPtr. Since these operations are not protected by
|
|
* any lock and copying an XLogRecPtr isn't atomic, it's unsafe to use either
|
|
* of these routines at other times!
|
|
*/
|
|
void
|
|
SetSavedRedoRecPtr(void)
|
|
{
|
|
XLogCtl->SavedRedoRecPtr = RedoRecPtr;
|
|
}
|
|
|
|
void
|
|
GetSavedRedoRecPtr(void)
|
|
{
|
|
RedoRecPtr = XLogCtl->SavedRedoRecPtr;
|
|
}
|
|
|
|
/*
|
|
* 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")));
|
|
|
|
/* suppress in-transaction check in CreateCheckPoint */
|
|
MyLastRecPtr.xrecoff = 0;
|
|
MyXactMadeXLogEntry = false;
|
|
MyXactMadeTempRelUpdate = false;
|
|
|
|
CritSectionCount++;
|
|
CreateCheckPoint(true, true);
|
|
ShutdownCLOG();
|
|
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;
|
|
|
|
if (MyXactMadeXLogEntry)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
|
|
errmsg("checkpoint cannot be made inside transaction block")));
|
|
|
|
/*
|
|
* Acquire CheckpointLock to ensure only one checkpoint happens at a
|
|
* time.
|
|
*
|
|
* The CheckpointLock can be held for quite a while, which is not good
|
|
* because we won't respond to a cancel/die request while waiting for
|
|
* an LWLock. (But the alternative of using a regular lock won't work
|
|
* for background checkpoint processes, which are not regular
|
|
* backends.) So, rather than use a plain LWLockAcquire, use this
|
|
* kluge to allow an interrupt to be accepted while we are waiting:
|
|
*/
|
|
while (!LWLockConditionalAcquire(CheckpointLock, LW_EXCLUSIVE))
|
|
{
|
|
CHECK_FOR_INTERRUPTS();
|
|
pg_usleep(1000000L);
|
|
}
|
|
|
|
/*
|
|
* 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.ThisStartUpID = ThisStartUpID;
|
|
checkPoint.time = time(NULL);
|
|
|
|
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(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 SInvalLock to ensure that it is looking
|
|
* at a stable set of proc records, but grabbing SInvalLock 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 SInvalLock,
|
|
* so there's a risk of deadlock. Need to find a better solution. See
|
|
* pgsql-hackers discussion of 17-Dec-01.
|
|
*/
|
|
#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, allowing other xacts to proceed
|
|
* even while we are flushing disk buffers.
|
|
*/
|
|
LWLockRelease(WALInsertLock);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* Having constructed the checkpoint record, ensure all shmem disk
|
|
* buffers and commit-log buffers are flushed to disk.
|
|
*
|
|
* This I/O could fail for various reasons. If so, we will fail to
|
|
* complete the checkpoint, but there is no reason to force a system
|
|
* panic. Accordingly, exit critical section while doing it.
|
|
*/
|
|
END_CRIT_SECTION();
|
|
|
|
CheckPointCLOG();
|
|
FlushBufferPool();
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
/*
|
|
* Now insert the checkpoint record into XLOG.
|
|
*/
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.data = (char *) (&checkPoint);
|
|
rdata.len = sizeof(checkPoint);
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
PreallocXlogFiles(recptr);
|
|
|
|
LWLockRelease(CheckpointLock);
|
|
}
|
|
|
|
/*
|
|
* Write a NEXTOID log record
|
|
*/
|
|
void
|
|
XLogPutNextOid(Oid nextOid)
|
|
{
|
|
XLogRecData rdata;
|
|
|
|
rdata.buffer = InvalidBuffer;
|
|
rdata.data = (char *) (&nextOid);
|
|
rdata.len = sizeof(Oid);
|
|
rdata.next = NULL;
|
|
(void) XLogInsert(RM_XLOG_ID, XLOG_NEXTOID, &rdata);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
/* Any later WAL records should be run with shutdown SUI plus 1 */
|
|
ThisStartUpID = checkPoint.ThisStartUpID + 1;
|
|
}
|
|
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;
|
|
}
|
|
/* Any later WAL records should be run with the then-active SUI */
|
|
ThisStartUpID = checkPoint.ThisStartUpID;
|
|
}
|
|
else if (info == XLOG_FILE_HEADER)
|
|
{
|
|
XLogFileHeaderData fhdr;
|
|
|
|
memcpy(&fhdr, XLogRecGetData(record), sizeof(XLogFileHeaderData));
|
|
if (fhdr.xlfhd_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,
|
|
fhdr.xlfhd_sysid);
|
|
snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
|
|
ControlFile->system_identifier);
|
|
ereport(PANIC,
|
|
(errmsg("WAL file is from different system"),
|
|
errdetail("WAL file SYSID is %s, pg_control SYSID is %s",
|
|
fhdrident_str, sysident_str)));
|
|
}
|
|
if (fhdr.xlfhd_seg_size != XLogSegSize)
|
|
ereport(PANIC,
|
|
(errmsg("WAL file is from different system"),
|
|
errdetail("Incorrect XLOG_SEG_SIZE in file header.")));
|
|
}
|
|
else if (info == XLOG_WASTED_SPACE)
|
|
{
|
|
/* ignore */
|
|
}
|
|
}
|
|
|
|
void
|
|
xlog_undo(XLogRecPtr lsn, XLogRecord *record)
|
|
{
|
|
}
|
|
|
|
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; "
|
|
"sui %u; xid %u; oid %u; %s",
|
|
checkpoint->redo.xlogid, checkpoint->redo.xrecoff,
|
|
checkpoint->undo.xlogid, checkpoint->undo.xrecoff,
|
|
checkpoint->ThisStartUpID, checkpoint->nextXid,
|
|
checkpoint->nextOid,
|
|
(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 if (info == XLOG_FILE_HEADER)
|
|
{
|
|
XLogFileHeaderData *fhdr = (XLogFileHeaderData *) rec;
|
|
|
|
sprintf(buf + strlen(buf),
|
|
"file header: sysid " UINT64_FORMAT "; "
|
|
"xlogid %X segno %X; seg_size %X",
|
|
fhdr->xlfhd_sysid,
|
|
fhdr->xlfhd_xlogid,
|
|
fhdr->xlfhd_segno,
|
|
fhdr->xlfhd_seg_size);
|
|
}
|
|
else if (info == XLOG_WASTED_SPACE)
|
|
{
|
|
strcat(buf, "wasted space");
|
|
}
|
|
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; xprev %X/%X; xid %u",
|
|
record->xl_prev.xlogid, record->xl_prev.xrecoff,
|
|
record->xl_xact_prev.xlogid, record->xl_xact_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_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(openLogFile) != 0)
|
|
ereport(PANIC,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not fsync log file %u, segment %u: %m",
|
|
openLogId, openLogSeg)));
|
|
break;
|
|
#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;
|
|
}
|
|
}
|