3752 want more verifiable dbuf user eviction
Submitted by:   Justin Gibbs <justing@spectralogic.com>
Submitted by:   Will Andrews <willa@spectralogic.com>

*** 215,228 ****
           */
          list_node_t db_link;
  
          /* Data which is unique to data (leaf) blocks: */
  
!         /* stuff we store for the user (see dmu_buf_set_user) */
!         void *db_user_ptr;
!         void **db_user_data_ptr_ptr;
!         dmu_buf_evict_func_t *db_evict_func;
  
          uint8_t db_immediate_evict;
          uint8_t db_freed_in_flight;
  
          uint8_t db_dirtycnt;
--- 215,226 ----
           */
          list_node_t db_link;
  
          /* Data which is unique to data (leaf) blocks: */
  
!         /* User callback information.  See dmu_buf_set_user(). */
!         dmu_buf_user_t *db_user;
  
          uint8_t db_immediate_evict;
          uint8_t db_freed_in_flight;
  
          uint8_t db_dirtycnt;
*** 271,282 ****
  void dmu_buf_fill_done(dmu_buf_t *db, dmu_tx_t *tx);
  void dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx);
  dbuf_dirty_record_t *dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
  arc_buf_t *dbuf_loan_arcbuf(dmu_buf_impl_t *db);
  
! void dbuf_clear(dmu_buf_impl_t *db);
! void dbuf_evict(dmu_buf_impl_t *db);
  
  void dbuf_setdirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
  void dbuf_unoverride(dbuf_dirty_record_t *dr);
  void dbuf_sync_list(list_t *list, dmu_tx_t *tx);
  void dbuf_release_bp(dmu_buf_impl_t *db);
--- 269,280 ----
  void dmu_buf_fill_done(dmu_buf_t *db, dmu_tx_t *tx);
  void dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx);
  dbuf_dirty_record_t *dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
  arc_buf_t *dbuf_loan_arcbuf(dmu_buf_impl_t *db);
  
! void dbuf_clear(dmu_buf_impl_t *db, list_t *evict_list_p);
! void dbuf_evict(dmu_buf_impl_t *db, list_t *evict_list_p);
  
  void dbuf_setdirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
  void dbuf_unoverride(dbuf_dirty_record_t *dr);
  void dbuf_sync_list(list_t *list, dmu_tx_t *tx);
  void dbuf_release_bp(dmu_buf_impl_t *db);