func (sr *streamRecver) prepare() error {
var buf [SchemeV1HeaderLength]byte
if _, err := io.ReadFull(sr.r, buf[:]); err != nil {
return err
}
if err := sr.header.UnmarshalBinary(buf[:]); err != nil {
return err
}
// check whether block size of pool match with the stream
root, err := vgcfg.Dump(sr.vgname)
if err != nil {
return err
}
pool, ok := root.FindThinPool(sr.poolname)
if !ok {
return errors.New("can not find thin pool " + sr.poolname)
}
if pool.ChunkSize != int64(sr.header.BlockSize) {
return errors.New("block size does not match with that of local pool")
}
// create new lv if needed
if sr.header.StreamType == StreamTypeFull {
if err := lvmutil.CreateThinLv(sr.vgname, sr.poolname, sr.lvname, int64(sr.header.VolumeSize)); err != nil {
return errors.New("can not create thin lv: " + err.Error())
}
}
if sr.header.StreamType == StreamTypeDelta {
expected := string(sr.header.DeltaSourceUUID[:])
if len(sr.prevUUID) > 0 && sr.prevUUID != expected {
return fmt.Errorf("incremental backup chain is broken; expects %s but prev is %s ", expected, sr.prevUUID)
}
// resize the volume if needed
lv, ok := root.FindThinLv(sr.lvname)
if !ok {
return errors.New("can not find thin lv " + sr.lvname)
}
size := int64(sr.header.VolumeSize)
if lv.ExtentCount*root.ExtentSize() != size {
if err := lvmutil.ResizeLv(sr.vgname, sr.lvname, size); err != nil {
return errors.New("can not resize thin lv: " + err.Error())
}
}
}
return nil
}
func (s *streamSender) prepare() error {
root, err := vgcfg.Dump(s.vgname)
if err != nil {
return err
}
var lv, srclv *vgcfg.ThinLvInfo
var ok bool
lv, ok = root.FindThinLv(s.lvname)
if !ok {
return errors.New("can not find thin lv " + s.lvname)
}
if len(s.srcname) > 0 {
srclv, ok = root.FindThinLv(s.srcname)
if !ok {
return errors.New("can not find thin lv " + s.srcname)
}
}
if srclv != nil && lv.Pool != srclv.Pool {
return errors.New("thin volumes must in same pool for delta backup")
}
pool, ok := root.FindThinPool(lv.Pool)
if !ok {
return errors.New("can not find thin pool " + lv.Pool)
}
// dump block mapping
tpoolDev := lvmutil.TPoolDevicePath(s.vgname, pool.Name)
tmetaDev := lvmutil.LvDevicePath(s.vgname, pool.MetaName)
superblk, err := thindump.Dump(tpoolDev, tmetaDev)
if err != nil {
return err
}
var dev, srcdev *thindump.Device
dev, ok = superblk.FindDevice(lv.DeviceId)
if !ok {
return errors.New("super block do not have device " + string(lv.DeviceId))
}
if srclv != nil {
srcdev, ok = superblk.FindDevice(srclv.DeviceId)
if !ok {
return errors.New("super block do not have device " + string(srclv.DeviceId))
}
}
// list all blocks for full backup, or find changed blocks by comparing block
// mappings for incremental backup.
deltas, err := thindump.CompareDeviceBlocks(srcdev, dev)
if err != nil {
return err
}
s.blocks = deltas
s.header.SchemeVersion = StreamSchemeV1
s.header.StreamType = StreamTypeFull
s.header.VolumeSize = uint64(lv.ExtentCount) * uint64(root.ExtentSize())
s.header.BlockSize = uint32(pool.ChunkSize)
s.header.BlockCount = uint64(len(s.blocks))
copy(s.header.VolumeUUID[:], []byte(lv.UUID))
if srclv != nil {
s.header.StreamType = StreamTypeDelta
copy(s.header.DeltaSourceUUID[:], []byte(srclv.UUID))
}
return nil
}