Make homehost information appear in superblock.

[thirdparty/mdadm.git] / super0.c

diff --git a/super0.c b/super0.c
index 0bf38ed8560773f960994ed1050509f8db7b8c6c..7fe2336666f8aed2307f831d157c74e51c0e3b49 100644 (file)
--- a/super0.c
+++ b/super0.c
@@ -28,7 +28,7 @@
  */
 
 #include "mdadm.h"
-
+#include <openssl/sha.h> /* for SHA1 */
 /*
  * All handling for the 0.90.0 version superblock is in
  * this file.
@@ -449,9 +449,17 @@ static __u64 event_super0(void *sbv)
        return md_event(sb);
 }
 
+/*
+ * For verion-0 superblock, the homehost is 'stored' in the
+ * uuid.  8 bytes for a hash of the host leaving 8 bytes
+ * of random material.
+ * We use the first 8 bytes (64bits) of the sha1 of the
+ * host name
+ */
 
 
-static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info, unsigned long long size, char *ignored_name)
+static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
+                      unsigned long long size, char *ignored_name, char *homehost)
 {
        mdp_super_t *sb = malloc(MD_SB_BYTES + sizeof(bitmap_super_t));
        int spares;
@@ -460,6 +468,7 @@ static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
 
        if (info->major_version == -1) {
                /* zeroing the superblock */
+               *sbp = sb;
                return 0;
        }
 
@@ -494,6 +503,12 @@ static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
        }
        if (rfd >= 0)
                close(rfd);
+       if (homehost) {
+               unsigned char *hash = SHA1((unsigned char*)homehost,
+                                          strlen(homehost),
+                                          NULL);
+               memcpy(&sb->set_uuid2, hash, 8);
+       }
 
        sb->utime = sb->ctime;
        sb->state = info->state;