|
7 | 7 | * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group |
8 | 8 | * Portions Copyright (c) 1994, Regents of the University of California |
9 | 9 | * |
10 | | - * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.193 2005/05/20 14:53:25 momjian Exp $ |
| 10 | + * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.194 2005/05/31 19:10:28 tgl Exp $ |
11 | 11 | * |
12 | 12 | *------------------------------------------------------------------------- |
13 | 13 | */ |
@@ -417,8 +417,8 @@ static char *readRecordBuf = NULL; |
417 | 417 | staticuint32readRecordBufSize=0; |
418 | 418 |
|
419 | 419 | /* State information for XLOG reading */ |
420 | | -staticXLogRecPtrReadRecPtr; |
421 | | -staticXLogRecPtrEndRecPtr; |
| 420 | +staticXLogRecPtrReadRecPtr;/* start of last record read */ |
| 421 | +staticXLogRecPtrEndRecPtr;/* end+1 of last record read */ |
422 | 422 | staticXLogRecord*nextRecord=NULL; |
423 | 423 | staticTimeLineIDlastPageTLI=0; |
424 | 424 |
|
@@ -2525,6 +2525,37 @@ got_record:; |
2525 | 2525 | record->xl_rmid,RecPtr->xlogid,RecPtr->xrecoff))); |
2526 | 2526 | gotonext_record_is_invalid; |
2527 | 2527 | } |
| 2528 | +if (randAccess) |
| 2529 | +{ |
| 2530 | +/* |
| 2531 | + * We can't exactly verify the prev-link, but surely it should be |
| 2532 | + * less than the record's own address. |
| 2533 | + */ |
| 2534 | +if (!XLByteLT(record->xl_prev,*RecPtr)) |
| 2535 | +{ |
| 2536 | +ereport(emode, |
| 2537 | +(errmsg("record with incorrect prev-link %X/%X at %X/%X", |
| 2538 | +record->xl_prev.xlogid,record->xl_prev.xrecoff, |
| 2539 | +RecPtr->xlogid,RecPtr->xrecoff))); |
| 2540 | +gotonext_record_is_invalid; |
| 2541 | +} |
| 2542 | +} |
| 2543 | +else |
| 2544 | +{ |
| 2545 | +/* |
| 2546 | + * Record's prev-link should exactly match our previous location. |
| 2547 | + * This check guards against torn WAL pages where a stale but |
| 2548 | + * valid-looking WAL record starts on a sector boundary. |
| 2549 | + */ |
| 2550 | +if (!XLByteEQ(record->xl_prev,ReadRecPtr)) |
| 2551 | +{ |
| 2552 | +ereport(emode, |
| 2553 | +(errmsg("record with incorrect prev-link %X/%X at %X/%X", |
| 2554 | +record->xl_prev.xlogid,record->xl_prev.xrecoff, |
| 2555 | +RecPtr->xlogid,RecPtr->xrecoff))); |
| 2556 | +gotonext_record_is_invalid; |
| 2557 | +} |
| 2558 | +} |
2528 | 2559 |
|
2529 | 2560 | /* |
2530 | 2561 | * Compute total length of record including any appended backup |
|