Handle fsync failures in pg_receivewal and pg_recvlogical

It is not safe to simply report an fsync error and continue.  We must
exit the program instead.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Sehrope Sarkuni <sehrope@jackdb.com>
Discussion: https://www.postgresql.org/message-id/flat/9b49fe44-8f3e-eca9-5914-29e9e99030bf@2ndquadrant.com

src/bin/pg_basebackup/pg_recvlogical.c

@@ -192,8 +192,8 @@ OutputFsync(TimestampTz now)
 
 	if (fsync(outfd) != 0)
 	{
-		pg_log_error("could not fsync file \"%s\": %m", outfile);
-		return false;
+		pg_log_fatal("could not fsync file \"%s\": %m", outfile);
+		exit(1);
 	}
 
 	return true;

src/bin/pg_basebackup/receivelog.c

@@ -134,10 +134,10 @@ open_walfile(StreamCtl *stream, XLogRecPtr startpoint)
 			/* fsync file in case of a previous crash */
 			if (stream->walmethod->sync(f) != 0)
 			{
-				pg_log_error("could not fsync existing write-ahead log file \"%s\": %s",
+				pg_log_fatal("could not fsync existing write-ahead log file \"%s\": %s",
 							 fn, stream->walmethod->getlasterror());
 				stream->walmethod->close(f, CLOSE_UNLINK);
-				return false;
+				exit(1);
 			}
 
 			walfile = f;
@@ -763,9 +763,9 @@ HandleCopyStream(PGconn *conn, StreamCtl *stream,
 		{
 			if (stream->walmethod->sync(walfile) != 0)
 			{
-				pg_log_error("could not fsync file \"%s\": %s",
+				pg_log_fatal("could not fsync file \"%s\": %s",
 							 current_walfile_name, stream->walmethod->getlasterror());
-				goto error;
+				exit(1);
 			}
 			lastFlushPosition = blockpos;
 
@@ -1015,9 +1015,9 @@ ProcessKeepaliveMsg(PGconn *conn, StreamCtl *stream, char *copybuf, int len,
 			 */
 			if (stream->walmethod->sync(walfile) != 0)
 			{
-				pg_log_error("could not fsync file \"%s\": %s",
+				pg_log_fatal("could not fsync file \"%s\": %s",
 							 current_walfile_name, stream->walmethod->getlasterror());
-				return false;
+				exit(1);
 			}
 			lastFlushPosition = blockpos;
 		}

src/bin/pg_basebackup/walmethods.c

@@ -864,7 +864,7 @@ tar_close(Walfile f, WalCloseMethod method)
 
 	/* Always fsync on close, so the padding gets fsynced */
 	if (tar_sync(f) < 0)
-		return -1;
+		exit(1);
 
 	/* Clean up and done */
 	pg_free(tf->pathname);