From 3add974b54359e19dccfdbc3e94b49bc73f74393 Mon Sep 17 00:00:00 2001
From: Marius Kittler <mariuskittler@gmx.de>
Date: Wed, 13 Apr 2022 17:20:30 +0200
Subject: [PATCH] Print concrete error when creating mddev

Example from my testing:
```
mdadm: unexpected failure opening /dev/md127: No such device or address
```

Before it would just print:
```
mdadm: unexpected failure opening /dev/md127
```
---
 mdopen.c | 4 ++--
 util.c   | 5 +++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/mdopen.c b/mdopen.c
index 245be53..c8e5cb9 100644
--- a/mdopen.c
+++ b/mdopen.c
@@ -444,8 +444,8 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
 	}
 	mdfd = open_dev_excl(devnm);
 	if (mdfd < 0)
-		pr_err("unexpected failure opening %s\n",
-			devname);
+		pr_err("unexpected failure opening %s: %s\n",
+			devname, strerror(errno));
 	return mdfd;
 }
 
diff --git a/util.c b/util.c
index cc94f96..7c8c0bb 100644
--- a/util.c
+++ b/util.c
@@ -1088,8 +1088,9 @@ int open_dev_excl(char *devnm)
 	long delay = 1000;
 
 	sprintf(buf, "%d:%d", major(devid), minor(devid));
+	int fd = -1;
 	for (i = 0; i < 25; i++) {
-		int fd = dev_open(buf, flags|O_EXCL);
+		fd = dev_open(buf, flags|O_EXCL);
 		if (fd >= 0)
 			return fd;
 		if (errno == EACCES && flags == O_RDWR) {
@@ -1102,7 +1103,7 @@ int open_dev_excl(char *devnm)
 		if (delay < 200000)
 			delay *= 2;
 	}
-	return -1;
+	return fd;
 }
 
 int same_dev(char *one, char *two)