2882 implement libzfs_core
2883 changing "canmount" property to "on" should not always remount dataset
2900 "zfs snapshot" should be able to create multiple, arbitrary snapshots at once
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Chris Siden <christopher.siden@delphix.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Dan Kruchinin <dan.kruchinin@gmail.com>

*** 178,188 ****
   */
  #define MAX_TAG_PREFIX_LEN      17
  
  struct dsl_ds_holdarg {
          dsl_sync_task_group_t *dstg;
!         char *htag;
          char *snapname;
          boolean_t recursive;
          boolean_t gotone;
          boolean_t temphold;
          char failed[MAXPATHLEN];
--- 178,188 ----
   */
  #define MAX_TAG_PREFIX_LEN      17
  
  struct dsl_ds_holdarg {
          dsl_sync_task_group_t *dstg;
!         const char *htag;
          char *snapname;
          boolean_t recursive;
          boolean_t gotone;
          boolean_t temphold;
          char failed[MAXPATHLEN];
*** 213,228 ****
  uint64_t dsl_dataset_create_sync(dsl_dir_t *pds, const char *lastname,
      dsl_dataset_t *origin, uint64_t flags, cred_t *, dmu_tx_t *);
  uint64_t dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
      uint64_t flags, dmu_tx_t *tx);
  int dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer);
- int dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer);
  dsl_checkfunc_t dsl_dataset_destroy_check;
  dsl_syncfunc_t dsl_dataset_destroy_sync;
- dsl_checkfunc_t dsl_dataset_snapshot_check;
- dsl_syncfunc_t dsl_dataset_snapshot_sync;
  dsl_syncfunc_t dsl_dataset_user_hold_sync;
  int dsl_dataset_rename(char *name, const char *newname, boolean_t recursive);
  int dsl_dataset_promote(const char *name, char *conflsnap);
  int dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
      boolean_t force);
  int dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
--- 213,227 ----
  uint64_t dsl_dataset_create_sync(dsl_dir_t *pds, const char *lastname,
      dsl_dataset_t *origin, uint64_t flags, cred_t *, dmu_tx_t *);
  uint64_t dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
      uint64_t flags, dmu_tx_t *tx);
  int dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer);
  dsl_checkfunc_t dsl_dataset_destroy_check;
  dsl_syncfunc_t dsl_dataset_destroy_sync;
  dsl_syncfunc_t dsl_dataset_user_hold_sync;
+ int dsl_dataset_snapshot_check(dsl_dataset_t *ds, const char *, dmu_tx_t *tx);
+ void dsl_dataset_snapshot_sync(dsl_dataset_t *ds, const char *, dmu_tx_t *tx);
  int dsl_dataset_rename(char *name, const char *newname, boolean_t recursive);
  int dsl_dataset_promote(const char *name, char *conflsnap);
  int dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
      boolean_t force);
  int dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,