Further fix to the mode where we enter archive recovery after crash recovery.

hlinnaka · hlinnaka · commit d009f9036d62 · 2013-03-07T12:12:33.000+02:00
I missed to returns in the middle of ReadRecord function in my previous fix.
If a WAL file was not found at all during crash recovery, XLogPageRead would
return 'false', and ReadRecord would return without entering archive recovery.

9.2 only. In master, the code is structured differently and does not have this
problem.

Kyotaro HORIGUCHI, Mitsumasa KONDO and me.
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
@@ -4010,7 +4010,16 @@ ReadRecord(XLogRecPtr *RecPtr, int emode, bool fetching_ckpt)
 retry:
 	/* Read the page containing the record */
 	if (!XLogPageRead(RecPtr, emode, fetching_ckpt, randAccess))
-		return NULL;
+	{
+		/*
+		 * In standby-mode, XLogPageRead returning false means that promotion
+		 * has been triggered.
+		 */
+		if (StandbyMode)
+			return NULL;
+		else
+			goto next_record_is_invalid;
+	}
 
 	pageHeaderSize = XLogPageHeaderSize((XLogPageHeader) readBuf);
 	targetRecOff = RecPtr->xrecoff % XLOG_BLCKSZ;
@@ -4168,7 +4177,16 @@ ReadRecord(XLogRecPtr *RecPtr, int emode, bool fetching_ckpt)
 			}
 			/* Wait for the next page to become available */
 			if (!XLogPageRead(&pagelsn, emode, false, false))
-				return NULL;
+			{
+				/*
+				 * In standby-mode, XLogPageRead returning false means that
+				 * promotion has been triggered.
+				 */
+				if (StandbyMode)
+					return NULL;
+				else
+					goto next_record_is_invalid;
+			}
 
 			/* Check that the continuation record looks valid */
 			if (!(((XLogPageHeader) readBuf)->xlp_info & XLP_FIRST_IS_CONTRECORD))
@@ -10326,6 +10344,9 @@ CancelBackup(void)
  * and call XLogPageRead() again with the same arguments. This lets
  * XLogPageRead() to try fetching the record from another source, or to
  * sleep and retry.
+ *
+ * In standby mode, this only returns false if promotion has been triggered.
+ * Otherwise it keeps sleeping and retrying indefinitely.
  */
 static bool
 XLogPageRead(XLogRecPtr *RecPtr, int emode, bool fetching_ckpt,
