File util-linux-fdisk-dm-partname.patch of Package util-linux

From 97c68d42041bb8761568f988b27cbfc470f6fb7d Mon Sep 17 00:00:00 2001
From: Stanislav Brabec <sbrabec@suse.cz>
Date: Tue, 26 May 2015 17:59:29 +0200
Subject: [PATCH] libfdisk: Use predictable /dev/mapper partition names for /dev/dm-N

It is impossible to predict /dev/dm-N partition names. Use predictable
and better readable /dev/mapper names instead.

[kzak@redhat.com: - remove if-before-free]

Signed-off-by: Stanislav Brabec <sbrabec@suse.cz>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 libfdisk/src/utils.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

Index: util-linux-2.25/libfdisk/src/utils.c
===================================================================
--- util-linux-2.25.orig/libfdisk/src/utils.c
+++ util-linux-2.25/libfdisk/src/utils.c
@@ -1,6 +1,7 @@
 
 #include "fdiskP.h"
 #include "pathnames.h"
+#include "canonicalize.h"
 
 #include <ctype.h>
 
@@ -68,6 +69,7 @@ char *fdisk_partname(const char *dev, si
 {
 	char *res = NULL;
 	const char *p = "";
+	char *dev_mapped = NULL;
 	int w = 0;
 
 	if (!dev || !*dev) {
@@ -76,6 +78,13 @@ char *fdisk_partname(const char *dev, si
 		return NULL;
 	}
 
+	/* It is impossible to predict /dev/dm-N partition names. */
+	if (strncmp(dev, "/dev/dm-", sizeof("/dev/dm-") - 1) == 0) {
+		dev_mapped = canonicalize_dm_name (dev + 5);
+		if (dev_mapped)
+			dev = dev_mapped;
+	}
+
 	w = strlen(dev);
 	if (isdigit(dev[w - 1]))
 		p = "p";
@@ -96,10 +105,11 @@ char *fdisk_partname(const char *dev, si
 	       p = "-part";
 	}
 
-	if (asprintf(&res, "%.*s%s%zu", w, dev, p, partno) > 0)
-		return res;
+	if (asprintf(&res, "%.*s%s%zu", w, dev, p, partno) <= 0)
+		res = NULL;
 
-	return NULL;
+	free(dev_mapped);
+	return res;
 }
 
 #ifdef TEST_PROGRAM