Add HINT for restartpoint race with KeepFileRestoredFromArchive().

nmisch · nmisch · commit 2ffcb7dce806 · 2022-08-05T08:31:02.000-07:00
The five commits ending at cc2c7d6 closed this race condition for v15+. For v14 through v10, add a HINT to discourage studying the cosmetic problem. Reviewed by Kyotaro Horiguchi and David Steele. Discussion: https://postgr.es/m/20220731061747.GA3692882@rfd.leadboat.com
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
@@ -3354,7 +3354,10 @@ XLogFileInit(XLogSegNo logsegno, bool *use_existent, bool use_lock)
 	if (fd < 0)
 		ereport(ERROR,
 				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m", path)));
+				 errmsg("could not open file \"%s\": %m", path),
+				 (AmCheckpointerProcess() ?
+				  errhint("This is known to fail occasionally during archive recovery, where it is harmless.") :
+				  0)));
 
 	elog(DEBUG2, "done creating and filling new WAL file");
 
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
@@ -744,7 +744,10 @@ durable_link_or_rename(const char *oldfile, const char *newfile, int elevel)
 		ereport(elevel,
 				(errcode_for_file_access(),
 				 errmsg("could not link file \"%s\" to \"%s\": %m",
-						oldfile, newfile)));
+						oldfile, newfile),
+				 (AmCheckpointerProcess() ?
+				  errhint("This is known to fail occasionally during archive recovery, where it is harmless.") :
+				  0)));
 		return -1;
 	}
 	unlink(oldfile);
@@ -755,7 +758,10 @@ durable_link_or_rename(const char *oldfile, const char *newfile, int elevel)
 		ereport(elevel,
 				(errcode_for_file_access(),
 				 errmsg("could not rename file \"%s\" to \"%s\": %m",
-						oldfile, newfile)));
+						oldfile, newfile),
+				 (AmCheckpointerProcess() ?
+				  errhint("This is known to fail occasionally during archive recovery, where it is harmless.") :
+				  0)));
 		return -1;
 	}
 #endif
