From e869d3777e7fed09f29d9736e5584cd67777744e Mon Sep 17 00:00:00 2001
From: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Sun, 25 Jul 2004 08:17:23 +0000
Subject: [PATCH] Give better diagnostic for problems with backing files.

---
 sbin/mdconfig/mdconfig.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sbin/mdconfig/mdconfig.c b/sbin/mdconfig/mdconfig.c
index b23e903831ab..d83148dc1d70 100644
--- a/sbin/mdconfig/mdconfig.c
+++ b/sbin/mdconfig/mdconfig.c
@@ -113,6 +113,10 @@ main(int argc, char **argv)
 				cmdline = 2;
 			}
 			mdio.md_file = optarg;
+			fd = open(optarg, O_RDONLY);
+			if (fd < 0)
+				err(1, "could not open %s", optarg);
+			close(fd);
 			break;
 		case 'o':
 			if (cmdline != 2)