Assemble: --update=metadata converts v0.90 to v1.0

This allows the smooth conversion of legacy 0.90 arrays
to 1.0 metadata.
Old metadata is likely to remain but will be ignored.
It can be removed with
  mdadm --zero-superblock --metadata=0.90 /dev/whatever

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 54 insertions, 0 deletions

diff --git a/super1.c b/super1.c
index b7fc8347..a4677b9b 100644
--- a/super1.c
+++ b/super1.c
@@ -2275,6 +2275,60 @@ static int validate_geometry1(struct supertype *st, int level,
 }
 #endif /* MDASSEMBLE */
 
+void *super1_make_v0(struct supertype *st, struct mdinfo *info, mdp_super_t *sb0)
+{
+	/* Create a v1.0 superblock based on 'info'*/
+	void *ret;
+	struct mdp_superblock_1 *sb;
+	int i;
+	int rfd;
+	unsigned long long offset;
+
+	if (posix_memalign(&ret, 4096, 1024) != 0)
+		return NULL;
+	sb = ret;
+	memset(ret, 0, 1024);
+	sb->magic = __cpu_to_le32(MD_SB_MAGIC);
+	sb->major_version = __cpu_to_le32(1);
+
+	copy_uuid(sb->set_uuid, info->uuid, super1.swapuuid);
+	sprintf(sb->set_name, "%d", sb0->md_minor);
+	sb->ctime = __cpu_to_le32(info->array.ctime+1);
+	sb->level = __cpu_to_le32(info->array.level);
+	sb->layout = __cpu_to_le32(info->array.layout);
+	sb->size = __cpu_to_le64(info->component_size);
+	sb->chunksize = __cpu_to_le32(info->array.chunk_size/512);
+	sb->raid_disks = __cpu_to_le32(info->array.raid_disks);
+	sb->data_size = sb->size;
+	sb->resync_offset = MaxSector;
+	sb->max_dev = __cpu_to_le32(MD_SB_DISKS);
+	sb->dev_number = __cpu_to_le32(info->disk.number);
+	sb->utime = __cpu_to_le64(info->array.utime);
+
+	offset = st->devsize/512 - 8*2;
+	offset &= ~(4*2-1);
+	sb->super_offset = __cpu_to_le64(offset);
+	//*(__u64*)(st->other + 128 + 8 + 8) = __cpu_to_le64(offset);
+
+	if ((rfd = open("/dev/urandom", O_RDONLY)) < 0 ||
+	    read(rfd, sb->device_uuid, 16) != 16) {
+		__u32 r[4] = {random(), random(), random(), random()};
+		memcpy(sb->device_uuid, r, 16);
+	}
+	if (rfd >= 0)
+		close(rfd);
+
+	for (i = 0; i < MD_SB_DISKS; i++) {
+		int state = sb0->disks[i].state;
+		sb->dev_roles[i] = 0xFFFF;
+		if ((state & (1<<MD_DISK_SYNC)) &&
+		    !(state & (1<<MD_DISK_FAULTY)))
+			sb->dev_roles[i] = __cpu_to_le16(sb0->disks[i].raid_disk);
+	}
+	sb->sb_csum = calc_sb_1_csum(sb);
+	return ret;
+}
+
 struct superswitch super1 = {
 #ifndef MDASSEMBLE
 	.examine_super = examine_super1,