3740 Poor ZFS send / receive performance due to snapshot hold / release processing
Submitted by: Steven Hartland <steven.hartland@multiplay.co.uk>

*** 41,52 ****
  
  int dsl_dataset_user_hold(nvlist_t *holds, minor_t cleanup_minor,
      nvlist_t *errlist);
  int dsl_dataset_user_release(nvlist_t *holds, nvlist_t *errlist);
  int dsl_dataset_get_holds(const char *dsname, nvlist_t *nvl);
! void dsl_dataset_user_release_tmp(struct dsl_pool *dp, uint64_t dsobj,
!     const char *htag);
  int dsl_dataset_user_hold_check_one(struct dsl_dataset *ds, const char *htag,
      boolean_t temphold, struct dmu_tx *tx);
  void dsl_dataset_user_hold_sync_one(struct dsl_dataset *ds, const char *htag,
      minor_t minor, uint64_t now, struct dmu_tx *tx);
  
--- 41,51 ----
  
  int dsl_dataset_user_hold(nvlist_t *holds, minor_t cleanup_minor,
      nvlist_t *errlist);
  int dsl_dataset_user_release(nvlist_t *holds, nvlist_t *errlist);
  int dsl_dataset_get_holds(const char *dsname, nvlist_t *nvl);
! void dsl_dataset_user_release_tmp(struct dsl_pool *dp, nvlist_t *holds);
  int dsl_dataset_user_hold_check_one(struct dsl_dataset *ds, const char *htag,
      boolean_t temphold, struct dmu_tx *tx);
  void dsl_dataset_user_hold_sync_one(struct dsl_dataset *ds, const char *htag,
      minor_t minor, uint64_t now, struct dmu_tx *tx);