  We present an effective theory to describe the quantization of spherically
symmetric vacuum in loop quantum gravity. We include anomaly-free holonomy
corrections through a canonical transformation of the Hamiltonian of general
relativity, such that the modified constraint algebra closes. The system is
then provided with a fully covariant and unambigous geometric description,
independent of the gauge choice on the phase space. The resulting spacetime
corresponds to a singularity-free (black-hole/white-hole) interior and two
asymptotically flat exterior regions of equal mass. The interior region
contains a minimal smooth spacelike surface that replaces the Schwarzschild
singularity. We find the global causal structure and the maximal analytical
extension. Both Minkowski and Schwarzschild spacetimes are directly recovered
as particular limits of the model.
