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7 | 7 | * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group |
8 | 8 | * Portions Copyright (c) 1994, Regents of the University of California |
9 | 9 | * |
10 | | - * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.85 2001/12/28 18:16:41 tgl Exp $ |
| 10 | + * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.86 2002/01/14 17:55:57 tgl Exp $ |
11 | 11 | * |
12 | 12 | *------------------------------------------------------------------------- |
13 | 13 | */ |
@@ -1262,15 +1262,40 @@ XLogFlush(XLogRecPtr record) |
1262 | 1262 | WriteRqst.Write=WriteRqstPtr; |
1263 | 1263 | WriteRqst.Flush=record; |
1264 | 1264 | XLogWrite(WriteRqst); |
1265 | | -if (XLByteLT(LogwrtResult.Flush,record)) |
1266 | | -elog(STOP,"XLogFlush: request %X/%X is not satisfied --- flushed only to %X/%X", |
1267 | | -record.xlogid,record.xrecoff, |
1268 | | -LogwrtResult.Flush.xlogid,LogwrtResult.Flush.xrecoff); |
1269 | 1265 | } |
1270 | 1266 | LWLockRelease(WALWriteLock); |
1271 | 1267 | } |
1272 | 1268 |
|
1273 | 1269 | END_CRIT_SECTION(); |
| 1270 | + |
| 1271 | +/* |
| 1272 | + * If we still haven't flushed to the request point then we have a |
| 1273 | + * problem; most likely, the requested flush point is past end of XLOG. |
| 1274 | + * This has been seen to occur when a disk page has a corrupted LSN. |
| 1275 | + * |
| 1276 | + * Formerly we treated this as a STOP condition, but that hurts the |
| 1277 | + * system's robustness rather than helping it: we do not want to take |
| 1278 | + * down the whole system due to corruption on one data page. In |
| 1279 | + * particular, if the bad page is encountered again during recovery then |
| 1280 | + * we would be unable to restart the database at all! (This scenario |
| 1281 | + * has actually happened in the field several times with 7.1 releases. |
| 1282 | + * Note that we cannot get here while InRedo is true, but if the bad |
| 1283 | + * page is brought in and marked dirty during recovery then |
| 1284 | + * CreateCheckpoint will try to flush it at the end of recovery.) |
| 1285 | + * |
| 1286 | + * The current approach is to ERROR under normal conditions, but only |
| 1287 | + * NOTICE during recovery, so that the system can be brought up even if |
| 1288 | + * there's a corrupt LSN. Note that for calls from xact.c, the ERROR |
| 1289 | + * will be promoted to STOP since xact.c calls this routine inside a |
| 1290 | + * critical section. However, calls from bufmgr.c are not within |
| 1291 | + * critical sections and so we will not force a restart for a bad LSN |
| 1292 | + * on a data page. |
| 1293 | + */ |
| 1294 | +if (XLByteLT(LogwrtResult.Flush,record)) |
| 1295 | +elog(InRecovery ?NOTICE :ERROR, |
| 1296 | +"XLogFlush: request %X/%X is not satisfied --- flushed only to %X/%X", |
| 1297 | +record.xlogid,record.xrecoff, |
| 1298 | +LogwrtResult.Flush.xlogid,LogwrtResult.Flush.xrecoff); |
1274 | 1299 | } |
1275 | 1300 |
|
1276 | 1301 | /* |
|