dsl_dataset: rename dmu_objset_clone* to dsl_dataset_clone*

And make its check and sync functions visible, so I can hook them up to
zcp_synctask. Rename not strictly necessary, but it definitely looks
more like a dsl_dataset thing than a dmu_objset thing, to the extent
that those things even have a meaningful distinction.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/
Closes #17426

include/sys/dmu.h

@@ -360,7 +360,6 @@ void dmu_objset_evict_dbufs(objset_t *os);
 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags,
     struct dsl_crypto_params *dcp, dmu_objset_create_sync_func_t func,
     void *arg);
-int dmu_objset_clone(const char *name, const char *origin);
 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer,
     struct nvlist *errlist);
 int dmu_objset_snapshot_one(const char *fsname, const char *snapname);

include/sys/dsl_dataset.h

@@ -276,6 +276,12 @@ dsl_dataset_phys(dsl_dataset_t *ds)
 	return ((dsl_dataset_phys_t *)ds->ds_dbuf->db_data);
 }
 
+typedef struct dsl_dataset_clone_arg_t {
+	const char *ddca_clone;
+	const char *ddca_origin;
+	cred_t *ddca_cred;
+} dsl_dataset_clone_arg_t;
+
 typedef struct dsl_dataset_promote_arg {
 	const char *ddpa_clonename;
 	dsl_dataset_t *ddpa_clone;
@@ -364,6 +370,9 @@ uint64_t dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
 void dsl_dataset_snapshot_sync(void *arg, dmu_tx_t *tx);
 int dsl_dataset_snapshot_check(void *arg, dmu_tx_t *tx);
 int dsl_dataset_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t *errors);
+void dsl_dataset_clone_sync(void *arg, dmu_tx_t *tx);
+int dsl_dataset_clone_check(void *arg, dmu_tx_t *tx);
+int dsl_dataset_clone(const char *clone, const char *origin);
 void dsl_dataset_promote_sync(void *arg, dmu_tx_t *tx);
 int dsl_dataset_promote_check(void *arg, dmu_tx_t *tx);
 int dsl_dataset_promote(const char *name, char *conflsnap);