code: func (lbs *linkedBlobStore) newBlobUpload(ctx context.Context, uuid, path string, startedAt time.Time, append bool) (distribution.BlobWriter, error) {
  	fw, err := lbs.driver.Writer(ctx, path, append)
  	if err != nil {
  		return nil, err
  	}
  
  	bw := &blobWriter{
  		ctx:                    ctx,
  		blobStore:              lbs,
  		id:                     uuid,
  		startedAt:              startedAt,
  		digester:               digest.Canonical.Digester(),
  		fileWriter:             fw,
  		driver:                 lbs.driver,
  		path:                   path,
  		resumableDigestEnabled: lbs.resumableDigestEnabled,
  	}
  
  	return bw, nil
  }
docs: // newBlobUpload allocates a new upload controller with the given state.