Add LSN location in some error messages related to WAL pages

The error messages reported during any failures while reading or
validating the header of a WAL currently includes only the offset of the
page but not the compiled LSN referring to the page, requiring an extra
step to compile it if looking at the surroundings with pg_waldump or
similar.  Adding this information costs a bit in translation, but also
eases debugging.

Author: Bharath Rupireddy
Reviewed-by:  Álvaro Herrera, Kyotaro Horiguchi, Maxim Orlov, Michael
Paquier
Discussion: https://postgr.es/m/CALj2ACWV=FCddsxcGbVOA=cvPyMr75YCFbSQT6g4KDj=gcJK4g@mail.gmail.com

src/backend/access/transam/xlogreader.c

@@ -1226,9 +1226,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
 		XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
 
 		report_invalid_record(state,
-							  "invalid magic number %04X in WAL segment %s, offset %u",
+							  "invalid magic number %04X in WAL segment %s, LSN %X/%X, offset %u",
 							  hdr->xlp_magic,
 							  fname,
+							  LSN_FORMAT_ARGS(recptr),
 							  offset);
 		return false;
 	}
@@ -1240,9 +1241,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
 		XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
 
 		report_invalid_record(state,
-							  "invalid info bits %04X in WAL segment %s, offset %u",
+							  "invalid info bits %04X in WAL segment %s, LSN %X/%X, offset %u",
 							  hdr->xlp_info,
 							  fname,
+							  LSN_FORMAT_ARGS(recptr),
 							  offset);
 		return false;
 	}
@@ -1281,9 +1283,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
 
 		/* hmm, first page of file doesn't have a long header? */
 		report_invalid_record(state,
-							  "invalid info bits %04X in WAL segment %s, offset %u",
+							  "invalid info bits %04X in WAL segment %s, LSN %X/%X, offset %u",
 							  hdr->xlp_info,
 							  fname,
+							  LSN_FORMAT_ARGS(recptr),
 							  offset);
 		return false;
 	}
@@ -1300,9 +1303,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
 		XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
 
 		report_invalid_record(state,
-							  "unexpected pageaddr %X/%X in WAL segment %s, offset %u",
+							  "unexpected pageaddr %X/%X in WAL segment %s, LSN %X/%X, offset %u",
 							  LSN_FORMAT_ARGS(hdr->xlp_pageaddr),
 							  fname,
+							  LSN_FORMAT_ARGS(recptr),
 							  offset);
 		return false;
 	}
@@ -1325,10 +1329,11 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
 			XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
 
 			report_invalid_record(state,
-								  "out-of-sequence timeline ID %u (after %u) in WAL segment %s, offset %u",
+								  "out-of-sequence timeline ID %u (after %u) in WAL segment %s, LSN %X/%X, offset %u",
 								  hdr->xlp_tli,
 								  state->latestPageTLI,
 								  fname,
+								  LSN_FORMAT_ARGS(recptr),
 								  offset);
 			return false;
 		}

src/backend/access/transam/xlogrecovery.c

@@ -3075,9 +3075,10 @@ ReadRecord(XLogPrefetcher *xlogprefetcher, int emode,
 			XLogFileName(fname, xlogreader->seg.ws_tli, segno,
 						 wal_segment_size);
 			ereport(emode_for_corrupt_record(emode, xlogreader->EndRecPtr),
-					(errmsg("unexpected timeline ID %u in WAL segment %s, offset %u",
+					(errmsg("unexpected timeline ID %u in WAL segment %s, LSN %X/%X, offset %u",
 							xlogreader->latestPageTLI,
 							fname,
+							LSN_FORMAT_ARGS(xlogreader->latestPagePtr),
 							offset)));
 			record = NULL;
 		}
@@ -3280,14 +3281,16 @@ retry:
 			errno = save_errno;
 			ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen),
 					(errcode_for_file_access(),
-					 errmsg("could not read from WAL segment %s, offset %u: %m",
-							fname, readOff)));
+					 errmsg("could not read from WAL segment %s, LSN %X/%X, offset %u: %m",
+							fname, LSN_FORMAT_ARGS(targetPagePtr),
+							readOff)));
 		}
 		else
 			ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen),
 					(errcode(ERRCODE_DATA_CORRUPTED),
-					 errmsg("could not read from WAL segment %s, offset %u: read %d of %zu",
-							fname, readOff, r, (Size) XLOG_BLCKSZ)));
+					 errmsg("could not read from WAL segment %s, LSN %X/%X, offset %u: read %d of %zu",
+							fname, LSN_FORMAT_ARGS(targetPagePtr),
+							readOff, r, (Size) XLOG_BLCKSZ)));
 		goto next_record_is_invalid;
 	}
 	pgstat_report_wait_end();