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

[thirdparty/mdadm.git] / super1.c

diff --git a/super1.c b/super1.c
index 88f1502455d2dab9f06f2a39b0eb467a26973b43..eb6499e912e400980115b29d615abc01123d37d6 100644 (file)
--- a/super1.c
+++ b/super1.c
@@ -600,7 +600,7 @@ static int update_super1(struct mdinfo *info, void *sbv, char *update,
 }
 
 static int init_super1(struct supertype *st, void **sbp, mdu_array_info_t *info,
-                      unsigned long long size, char *name, char *homehost)
+                      unsigned long long size, char *name, char *homehost, int *uuid)
 {
        struct mdp_superblock_1 *sb = malloc(1024 + sizeof(bitmap_super_t) +
                                             sizeof(struct misc_dev_info));
@@ -627,14 +627,29 @@ static int init_super1(struct supertype *st, void **sbp, mdu_array_info_t *info,
        sb->feature_map = 0;
        sb->pad0 = 0;
 
-       if ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
-           read(rfd, sb->set_uuid, 16) != 16) {
-               *(__u32*)(sb->set_uuid) = random();
-               *(__u32*)(sb->set_uuid+4) = random();
-               *(__u32*)(sb->set_uuid+8) = random();
-               *(__u32*)(sb->set_uuid+12) = random();
+       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 ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
+                   read(rfd, sb->set_uuid, 16) != 16) {
+                       *(__u32*)(sb->set_uuid) = random();
+                       *(__u32*)(sb->set_uuid+4) = random();
+                       *(__u32*)(sb->set_uuid+8) = random();
+                       *(__u32*)(sb->set_uuid+12) = random();
+               }
+               if (rfd >= 0) close(rfd);
        }
-       if (rfd >= 0) close(rfd);
 
        if (name == NULL || *name == 0) {
                sprintf(defname, "%d", info->md_minor);