From 350f29f90d1f6bb3ddfafea368327911f9e8b27c Mon Sep 17 00:00:00 2001
From: Neil Brown <neilb@suse.de>
Date: Thu, 14 Dec 2006 17:33:14 +1100
Subject: [PATCH] Centralise code for copying uuid

Rather than opencoding the byteswap all the time.
---
 bitmap.c | 13 +------------
 mdadm.h  |  1 +
 super1.c | 30 ++++--------------------------
 util.c   | 19 +++++++++++++++++++
 4 files changed, 25 insertions(+), 38 deletions(-)

diff --git a/bitmap.c b/bitmap.c
index c905b4d3..dcea2633 100644
--- a/bitmap.c
+++ b/bitmap.c
@@ -420,18 +420,7 @@ int bitmap_update_uuid(int fd, int *uuid, int swap)
 		return 1;
 	if (bm.magic != __cpu_to_le32(BITMAP_MAGIC))
 		return 1;
-	if (swap) {
-		unsigned char *ac = (unsigned char *)bm.uuid;
-		unsigned char *bc = (unsigned char *)uuid;
-		int i;
-		for (i=0; i<16; i+= 4) {
-			ac[i+0] = bc[i+3];
-			ac[i+1] = bc[i+2];
-			ac[i+2] = bc[i+1];
-			ac[i+3] = bc[i+0];
-		}
-	} else
-		memcpy(bm.uuid, uuid, 16);
+	copy_uuid(bm.uuid, uuid, swap);
 	if (lseek(fd, 0, 0) != 0)
 		return 2;
 	if (write(fd, &bm, sizeof(bm)) != sizeof(bm)) {
diff --git a/mdadm.h b/mdadm.h
index b4bf3435..d40d1873 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -460,6 +460,7 @@ extern void free_line(char *line);
 extern int match_oneof(char *devices, char *devname);
 extern void uuid_from_super(int uuid[4], mdp_super_t *super);
 extern int same_uuid(int a[4], int b[4], int swapuuid);
+extern void copy_uuid(void *a, int b[4], int swapuuid);
 /* extern int compare_super(mdp_super_t *first, mdp_super_t *second);*/
 extern unsigned long calc_csum(void *super, int bytes);
 extern int enough(int level, int raid_disks, int layout, int clean,
diff --git a/super1.c b/super1.c
index eb6499e9..a480f21c 100644
--- a/super1.c
+++ b/super1.c
@@ -538,18 +538,7 @@ static int update_super1(struct mdinfo *info, void *sbv, char *update,
 		sb->resync_offset = 0ULL;
 	}
 	if (strcmp(update, "uuid") == 0) {
-		if (super1.swapuuid) {
-			unsigned char *ac = (unsigned char *)sb->set_uuid;
-			unsigned char *bc = (unsigned char *)info->uuid;
-			int i;
-			for (i=0; i<16; i+= 4) {
-				ac[i+0] = bc[i+3];
-				ac[i+1] = bc[i+2];
-				ac[i+2] = bc[i+1];
-				ac[i+3] = bc[i+0];
-			}
-		} else
-			memcpy(sb->set_uuid, info->uuid, 16);
+		copy_uuid(sb->set_uuid, info->uuid, super1.swapuuid);
 
 		if (__le32_to_cpu(sb->feature_map)&MD_FEATURE_BITMAP_OFFSET) {
 			struct bitmap_super_s *bm;
@@ -627,20 +616,9 @@ static int init_super1(struct supertype *st, void **sbp, mdu_array_info_t *info,
 	sb->feature_map = 0;
 	sb->pad0 = 0;
 
-	if (uuid) {
-		if (super1.swapuuid) {
-			unsigned char *ac = (unsigned char *)sb->set_uuid;
-			unsigned char *bc = (unsigned char *)uuid;
-			int i;
-			for (i=0; i<16; i+= 4) {
-				ac[i+0] = bc[i+3];
-				ac[i+1] = bc[i+2];
-				ac[i+2] = bc[i+1];
-				ac[i+3] = bc[i+0];
-			}
-		} else
-			memcpy(sb->set_uuid, uuid, 16);
-	} else {
+	if (uuid)
+		copy_uuid(sb->set_uuid, uuid, super1.swapuuid);
+	else {
 		if ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
 		    read(rfd, sb->set_uuid, 16) != 16) {
 			*(__u32*)(sb->set_uuid) = random();
diff --git a/util.c b/util.c
index ffb113c3..c21bf514 100644
--- a/util.c
+++ b/util.c
@@ -246,6 +246,25 @@ int same_uuid(int a[4], int b[4], int swapuuid)
 		return 0;
 	}
 }
+void copy_uuid(void *a, int b[4], int swapuuid)
+{
+	if (swapuuid) {
+		/* parse uuids are hostendian.
+		 * uuid's from some superblocks are big-ending
+		 * if there is a difference, we need to swap..
+		 */
+		unsigned char *ac = (unsigned char *)a;
+		unsigned char *bc = (unsigned char *)b;
+		int i;
+		for (i=0; i<16; i+= 4) {
+			ac[i+0] = bc[i+3];
+			ac[i+1] = bc[i+2];
+			ac[i+2] = bc[i+1];
+			ac[i+3] = bc[i+0];
+		}
+	} else
+		memcpy(a, b, 16);
+}
 
 #ifndef MDASSEMBLE
 int check_ext2(int fd, char *name)
-- 
2.39.2