4101 metaslab_debug should allow for fine-grained control
4102 space_maps should store more information about themselves
4103 space map object blocksize should be increased
4104 ::spa_space no longer works
4105 removing a mirrored log device results in a leaked object
4106 asynchronously load metaslab
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Sebastien Roy <seb@delphix.com>

*** 18,28 ****
   *
   * CDDL HEADER END
   */
  
  /*
!  * Copyright (c) 2012 by Delphix. All rights reserved.
   */
  
  #ifndef _SYS_ZFEATURE_H
  #define _SYS_ZFEATURE_H
  
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  
  /*
!  * Copyright (c) 2013 by Delphix. All rights reserved.
   */
  
  #ifndef _SYS_ZFEATURE_H
  #define _SYS_ZFEATURE_H
  
*** 45,54 ****
--- 45,55 ----
      struct dmu_tx *);
  extern void spa_feature_incr(struct spa *, zfeature_info_t *, struct dmu_tx *);
  extern void spa_feature_decr(struct spa *, zfeature_info_t *, struct dmu_tx *);
  extern boolean_t spa_feature_is_enabled(struct spa *, zfeature_info_t *);
  extern boolean_t spa_feature_is_active(struct spa *, zfeature_info_t *);
+ extern int spa_feature_get_refcount(struct spa *, zfeature_info_t *);
  
  #ifdef  __cplusplus
  }
  #endif