- Set and get user property

zfs.c

@@ -82,6 +82,47 @@ int read_dataset_property(zfs_handle_t *zh, property_list_t *list, int prop) {
 	return r;
 }
 
+int read_user_property(zfs_handle_t *zh, property_list_t *list, const char *prop) {
+	nvlist_t *user_props = zfs_get_user_props(zh);
+	nvlist_t *propval;
+	zprop_source_t sourcetype;
+	char *strval;
+	char *sourceval;
+	// char source[ZFS_MAX_DATASET_NAME_LEN];
+	
+	if (nvlist_lookup_nvlist(user_props,
+		prop, &propval) != 0) {
+		sourcetype = ZPROP_SRC_NONE;
+		(void) strncpy(list->source,
+				"none", sizeof (list->source));
+		strval = "-";
+	} else {
+		verify(nvlist_lookup_string(propval,
+			ZPROP_VALUE, &strval) == 0);
+		verify(nvlist_lookup_string(propval,
+			ZPROP_SOURCE, &sourceval) == 0);
+
+		if (strcmp(sourceval,
+			zfs_get_name(zh)) == 0) {
+			sourcetype = ZPROP_SRC_LOCAL;
+			(void) strncpy(list->source,
+				"local", sizeof (list->source));
+		} else if (strcmp(sourceval,
+			ZPROP_SOURCE_VAL_RECVD) == 0) {
+			sourcetype = ZPROP_SRC_RECEIVED;
+			(void) strncpy(list->source,
+				"received", sizeof (list->source));
+		} else {
+			sourcetype = ZPROP_SRC_INHERITED;
+			(void) strncpy(list->source,
+				sourceval, sizeof (list->source));
+		}
+	}
+	(void) strncpy(list->value,
+				strval, sizeof (list->value));
+	return 0;
+}
+
 int clear_last_error(libzfs_handle_t *hdl) {
 	zfs_standard_error(hdl, EZFS_SUCCESS, "success");
 	return 0;

zfs.go

@@ -278,6 +278,26 @@ func (d *Dataset) GetProperty(p Prop) (prop Property, err error) {
 	return
 }
 
+func (d *Dataset) GetUserProperty(p string) (prop Property, err error) {
+	if d.list == nil {
+		err = errors.New(msgDatasetIsNil)
+		return
+	}
+	var plist *C.property_list_t
+	plist = C.new_property_list()
+	defer C.free_properties(plist)
+	csp := C.CString(p)
+	defer C.free(unsafe.Pointer(csp))
+	errcode := C.read_user_property(d.list.zh, plist, csp)
+	if errcode != 0 {
+		err = LastError()
+		return
+	}
+	prop = Property{Value: C.GoString(&(*plist).value[0]),
+		Source: C.GoString(&(*plist).source[0])}
+	return
+}
+
 // SetProperty set ZFS dataset property to value. Not all properties can be set,
 // some can be set only at creation time and some are read only.
 // Always check if returned error and its description.
@@ -300,6 +320,22 @@ func (d *Dataset) SetProperty(p Prop, value string) (err error) {
 	return
 }
 
+func (d *Dataset) SetUserProperty(prop, value string) (err error) {
+	if d.list == nil {
+		err = errors.New(msgDatasetIsNil)
+		return
+	}
+	csValue := C.CString(value)
+	csProp := C.CString(prop)
+	errcode := C.zfs_prop_set(d.list.zh, csProp, csValue)
+	C.free(unsafe.Pointer(csValue))
+	C.free(unsafe.Pointer(csProp))
+	if errcode != 0 {
+		err = LastError()
+	}
+	return
+}
+
 // Clone - clones the dataset.  The target must be of the same type as
 // the source.
 func (d *Dataset) Clone(target string, props map[Prop]Property) (rd Dataset, err error) {

zfs.h

@@ -21,6 +21,7 @@ int dataset_list_children(zfs_handle_t *zfs, dataset_list_t **first);
 dataset_list_t *dataset_next(dataset_list_t *dataset);
 
 int read_dataset_property(zfs_handle_t *zh, property_list_t *list, int prop);
+int read_user_property(zfs_handle_t *zh, property_list_t *list, const char* prop);
 
 int clear_last_error(libzfs_handle_t *libzfs);
 

zfs_test.go

@@ -74,7 +74,22 @@ func zfsTestDatasetOpen(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	d.Close()
+	defer d.Close()
+	print("PASS\n\n")
+
+	println("TEST Set/GetUserProperty(prop, value string) ... ")
+	var p zfs.Property
+	// Test set/get user property
+	if err = d.SetUserProperty("go-libzfs:test", "yes"); err != nil {
+		t.Error(err)
+		return
+	}
+	if p, err = d.GetUserProperty("go-libzfs:test"); err != nil {
+		t.Error(err)
+		return
+	}
+	println("go-libzfs:test", " = ",
+		p.Value)
 	print("PASS\n\n")
 }
 

zpool.h

@@ -7,6 +7,8 @@
 
 #define INT_MAX_NAME 256
 #define INT_MAX_VALUE 1024
+#define	ZAP_OLDMAXVALUELEN 1024
+#define	ZFS_MAX_DATASET_NAME_LEN 256
 
 struct zpool_list {
 	zpool_handle_t *zph;
@@ -15,7 +17,7 @@ struct zpool_list {
 
 typedef struct property_list {
 	char value[INT_MAX_VALUE];
-	char source[INT_MAX_NAME];
+	char source[ZFS_MAX_DATASET_NAME_LEN];
 	int property;
 	void *pnext;
 } property_list_t;