Support --uuid= with --create to choose your own UUID.

1 files changed, 18 insertions, 11 deletions

diff --git a/super0.c b/super0.c
index 770d96e..757d905 100644
--- a/super0.c
+++ b/super0.c
@@ -505,11 +505,11 @@ static int update_super0(struct mdinfo *info, void *sbv, char *update,
 
 
 static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
-		       unsigned long long size, char *ignored_name, char *homehost)
+		       unsigned long long size, char *ignored_name, char *homehost,
+		       int *uuid)
 {
 	mdp_super_t *sb = malloc(MD_SB_BYTES + sizeof(bitmap_super_t));
 	int spares;
-	int rfd;
 	memset(sb, 0, MD_SB_BYTES + sizeof(bitmap_super_t));
 
 	if (info->major_version == -1) {
@@ -525,14 +525,11 @@ static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
 		return 0;
 	}
 
-	rfd = open("/dev/urandom", O_RDONLY);
 	sb->md_magic = MD_SB_MAGIC;
 	sb->major_version = 0;
 	sb->minor_version = 90;
 	sb->patch_version = 0;
 	sb->gvalid_words = 0; /* ignored */
-	if (rfd < 0 || read(rfd, &sb->set_uuid0, 4) != 4)
-		sb->set_uuid0 = random();
 	sb->ctime = time(0);
 	sb->level = info->level;
 	if (size != info->size)
@@ -542,13 +539,23 @@ static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
 	sb->raid_disks = info->raid_disks;
 	sb->md_minor = info->md_minor;
 	sb->not_persistent = 0;
-	if (rfd < 0 || read(rfd, &sb->set_uuid1, 12) != 12) {
-		sb->set_uuid1 = random();
-		sb->set_uuid2 = random();
-		sb->set_uuid3 = random();
+	if (uuid) {
+		sb->set_uuid0 = uuid[0];
+		sb->set_uuid1 = uuid[1];
+		sb->set_uuid2 = uuid[2];
+		sb->set_uuid3 = uuid[3];
+	} else {
+		int rfd = open("/dev/urandom", O_RDONLY);
+		if (rfd < 0 || read(rfd, &sb->set_uuid0, 4) != 4)
+			sb->set_uuid0 = random();
+		if (rfd < 0 || read(rfd, &sb->set_uuid1, 12) != 12) {
+			sb->set_uuid1 = random();
+			sb->set_uuid2 = random();
+			sb->set_uuid3 = random();
+		}
+		if (rfd >= 0)
+			close(rfd);
 	}
-	if (rfd >= 0)
-		close(rfd);
 	if (homehost) {
 		char buf[20];
 		char *hash = sha1_buffer(homehost,