func RestoreSnapshot(root, srcSnapshotID, srcVolumeID, dstVolumeID, objectstoreID string, sDriver drivers.Driver) error {
b, bsDriver, err := getObjectStoreCfgAndDriver(root, objectstoreID)
if err != nil {
return err
}
if _, err := loadVolumeConfig(srcVolumeID, bsDriver); err != nil {
return generateError(logrus.Fields{
LOG_FIELD_VOLUME: srcVolumeID,
LOG_FIELD_OBJECTSTORE: objectstoreID,
}, "Volume doesn't exist in objectstore: %v", err)
}
volDevName, err := sDriver.GetVolumeDevice(dstVolumeID)
if err != nil {
return err
}
volDev, err := os.Create(volDevName)
if err != nil {
return err
}
defer volDev.Close()
snapshotMap, err := loadSnapshotMap(srcSnapshotID, srcVolumeID, bsDriver)
if err != nil {
return err
}
log.WithFields(logrus.Fields{
LOG_FIELD_REASON: LOG_REASON_START,
LOG_FIELD_EVENT: LOG_EVENT_RESTORE,
LOG_FIELD_OBJECT: LOG_FIELD_SNAPSHOT,
LOG_FIELD_SNAPSHOT: srcSnapshotID,
LOG_FIELD_ORIN_VOLUME: srcVolumeID,
LOG_FIELD_VOLUME: dstVolumeID,
LOG_FIELD_OBJECTSTORE: objectstoreID,
}).Debug()
for _, block := range snapshotMap.Blocks {
blkFile := getBlockFilePath(srcVolumeID, block.BlockChecksum)
rc, err := bsDriver.Read(blkFile)
if err != nil {
return err
}
if _, err := volDev.Seek(block.Offset, 0); err != nil {
rc.Close()
return err
}
if _, err := io.CopyN(volDev, rc, b.BlockSize); err != nil {
rc.Close()
return err
}
rc.Close()
}
return nil
}
