Make some xlogreader messages more accurate

petere · petere · commit 4ac30ba4f29d · 2023-03-02T07:46:12.000+01:00
When you have some invalid WAL, you often get a message like "wanted 24, got 0". This is a bit incorrect, since it really wanted *at least* 24, not exactly 24. This updates the messages to that effect, and also adds that detail to one message where it was available but not printed. Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: Jeevan Ladhe <jeevanladhe.os@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/726d782b-5e45-0c3e-d775-6686afe9aa83%40enterprisedb.com
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
@@ -623,8 +623,9 @@ XLogDecodeNextRecord(XLogReaderState *state, bool nonblocking)
 	}
 	else if (targetRecOff < pageHeaderSize)
 	{
-		report_invalid_record(state, "invalid record offset at %X/%X",
-							  LSN_FORMAT_ARGS(RecPtr));
+		report_invalid_record(state, "invalid record offset at %X/%X: expected at least %u, got %u",
+							  LSN_FORMAT_ARGS(RecPtr),
+							  pageHeaderSize, targetRecOff);
 		goto err;
 	}
 
@@ -672,7 +673,7 @@ XLogDecodeNextRecord(XLogReaderState *state, bool nonblocking)
 		if (total_len < SizeOfXLogRecord)
 		{
 			report_invalid_record(state,
-								  "invalid record length at %X/%X: wanted %u, got %u",
+								  "invalid record length at %X/%X: expected at least %u, got %u",
 								  LSN_FORMAT_ARGS(RecPtr),
 								  (uint32) SizeOfXLogRecord, total_len);
 			goto err;
@@ -1119,7 +1120,7 @@ ValidXLogRecordHeader(XLogReaderState *state, XLogRecPtr RecPtr,
 	if (record->xl_tot_len < SizeOfXLogRecord)
 	{
 		report_invalid_record(state,
-							  "invalid record length at %X/%X: wanted %u, got %u",
+							  "invalid record length at %X/%X: expected at least %u, got %u",
 							  LSN_FORMAT_ARGS(RecPtr),
 							  (uint32) SizeOfXLogRecord, record->xl_tot_len);
 		return false;

Original file line number	Diff line number	Diff line change
`@@ -623,8 +623,9 @@ XLogDecodeNextRecord(XLogReaderState *state, bool nonblocking)`
`623`	`623`	`}`
`624`	`624`	`else if (targetRecOff < pageHeaderSize)`
`625`	`625`	`{`
`626`		`- report_invalid_record(state, "invalid record offset at %X/%X",`
`627`		`- LSN_FORMAT_ARGS(RecPtr));`
	`626`	`+ report_invalid_record(state, "invalid record offset at %X/%X: expected at least %u, got %u",`
	`627`	`+ LSN_FORMAT_ARGS(RecPtr),`
	`628`	`+ pageHeaderSize, targetRecOff);`
`628`	`629`	`goto err;`
`629`	`630`	`}`
`630`	`631`
`@@ -672,7 +673,7 @@ XLogDecodeNextRecord(XLogReaderState *state, bool nonblocking)`
`672`	`673`	`if (total_len < SizeOfXLogRecord)`
`673`	`674`	`{`
`674`	`675`	`report_invalid_record(state,`
`675`		`- "invalid record length at %X/%X: wanted %u, got %u",`
	`676`	`+ "invalid record length at %X/%X: expected at least %u, got %u",`
`676`	`677`	`LSN_FORMAT_ARGS(RecPtr),`
`677`	`678`	`(uint32) SizeOfXLogRecord, total_len);`
`678`	`679`	`goto err;`
`@@ -1119,7 +1120,7 @@ ValidXLogRecordHeader(XLogReaderState *state, XLogRecPtr RecPtr,`
`1119`	`1120`	`if (record->xl_tot_len < SizeOfXLogRecord)`
`1120`	`1121`	`{`
`1121`	`1122`	`report_invalid_record(state,`
`1122`		`- "invalid record length at %X/%X: wanted %u, got %u",`
	`1123`	`+ "invalid record length at %X/%X: expected at least %u, got %u",`
`1123`	`1124`	`LSN_FORMAT_ARGS(RecPtr),`
`1124`	`1125`	`(uint32) SizeOfXLogRecord, record->xl_tot_len);`
`1125`	`1126`	`return false;`