3748 zfs headers should be C++ compatible
Submitted by:   Justin Gibbs <justing@spectralogic.com>
Submitted by:   Will Andrews <willa@spectralogic.com>
Reviewed by:    Matthew Ahrens <mahrens@delphix.com>

*** 2753,2790 ****
   * space freed                         [---------------------]
   * snapshots                       ---O-------O--------O-------O------
   *                                         oldsnap            new
   */
  int
! dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
      uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
  {
          int err = 0;
          uint64_t snapobj;
!         dsl_pool_t *dp = new->ds_dir->dd_pool;
  
          ASSERT(dsl_pool_config_held(dp));
  
          *usedp = 0;
!         *usedp += new->ds_phys->ds_referenced_bytes;
          *usedp -= oldsnap->ds_phys->ds_referenced_bytes;
  
          *compp = 0;
!         *compp += new->ds_phys->ds_compressed_bytes;
          *compp -= oldsnap->ds_phys->ds_compressed_bytes;
  
          *uncompp = 0;
!         *uncompp += new->ds_phys->ds_uncompressed_bytes;
          *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
  
!         snapobj = new->ds_object;
          while (snapobj != oldsnap->ds_object) {
                  dsl_dataset_t *snap;
                  uint64_t used, comp, uncomp;
  
!                 if (snapobj == new->ds_object) {
!                         snap = new;
                  } else {
                          err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
                          if (err != 0)
                                  break;
                  }
--- 2753,2790 ----
   * space freed                         [---------------------]
   * snapshots                       ---O-------O--------O-------O------
   *                                         oldsnap            new
   */
  int
! dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *newds,
      uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
  {
          int err = 0;
          uint64_t snapobj;
!         dsl_pool_t *dp = newds->ds_dir->dd_pool;
  
          ASSERT(dsl_pool_config_held(dp));
  
          *usedp = 0;
!         *usedp += newds->ds_phys->ds_referenced_bytes;
          *usedp -= oldsnap->ds_phys->ds_referenced_bytes;
  
          *compp = 0;
!         *compp += newds->ds_phys->ds_compressed_bytes;
          *compp -= oldsnap->ds_phys->ds_compressed_bytes;
  
          *uncompp = 0;
!         *uncompp += newds->ds_phys->ds_uncompressed_bytes;
          *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
  
!         snapobj = newds->ds_object;
          while (snapobj != oldsnap->ds_object) {
                  dsl_dataset_t *snap;
                  uint64_t used, comp, uncomp;
  
!                 if (snapobj == newds->ds_object) {
!                         snap = newds;
                  } else {
                          err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
                          if (err != 0)
                                  break;
                  }
*** 2811,2824 ****
                  *uncompp += uncomp;
  
                  /*
                   * If we get to the beginning of the chain of snapshots
                   * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
!                  * was not a snapshot of/before new.
                   */
                  snapobj = snap->ds_phys->ds_prev_snap_obj;
!                 if (snap != new)
                          dsl_dataset_rele(snap, FTAG);
                  if (snapobj == 0) {
                          err = SET_ERROR(EINVAL);
                          break;
                  }
--- 2811,2824 ----
                  *uncompp += uncomp;
  
                  /*
                   * If we get to the beginning of the chain of snapshots
                   * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
!                  * was not a snapshot of/before newds.
                   */
                  snapobj = snap->ds_phys->ds_prev_snap_obj;
!                 if (snap != newds)
                          dsl_dataset_rele(snap, FTAG);
                  if (snapobj == 0) {
                          err = SET_ERROR(EINVAL);
                          break;
                  }