libbtrfsutil: add qgroup inheritance helpers

We want to hide struct btrfs_qgroup_inherit from the user because that
comes from the Btrfs UAPI headers. Instead, wrap it in a struct
btrfs_util_qgroup_inherit and provide helpers to manipulate it. This
will be used for subvolume and snapshot creation.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 154 insertions, 0 deletions

diff --git a/libbtrfsutil/python/qgroup.c b/libbtrfsutil/python/qgroup.c
new file mode 100644
index 00000000..69716d92
--- /dev/null
+++ b/libbtrfsutil/python/qgroup.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2018 Facebook
+ *
+ * This file is part of libbtrfsutil.
+ *
+ * libbtrfsutil is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libbtrfsutil is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libbtrfsutil.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "btrfsutilpy.h"
+
+static void QgroupInherit_dealloc(QgroupInherit *self)
+{
+	btrfs_util_destroy_qgroup_inherit(self->inherit);
+	Py_TYPE(self)->tp_free((PyObject *)self);
+}
+
+static int QgroupInherit_init(QgroupInherit *self, PyObject *args,
+			      PyObject *kwds)
+{
+	static char *keywords[] = {NULL};
+	enum btrfs_util_error err;
+
+	if (!PyArg_ParseTupleAndKeywords(args, kwds, ":QgroupInherit",
+					 keywords))
+		return -1;
+
+	err = btrfs_util_create_qgroup_inherit(0, &self->inherit);
+	if (err) {
+		SetFromBtrfsUtilError(err);
+		return -1;
+	}
+
+	return 0;
+}
+
+static PyObject *QgroupInherit_getattro(QgroupInherit *self, PyObject *nameobj)
+{
+    const char *name = "";
+
+    if (PyUnicode_Check(nameobj)) {
+	    name = PyUnicode_AsUTF8(nameobj);
+	    if (!name)
+		    return NULL;
+    }
+
+    if (strcmp(name, "groups") == 0) {
+	    PyObject *ret, *tmp;
+	    const uint64_t *arr;
+	    size_t n, i;
+
+	    btrfs_util_qgroup_inherit_get_groups(self->inherit, &arr, &n);
+	    ret = PyList_New(n);
+	    if (!ret)
+		    return NULL;
+
+	    for (i = 0; i < n; i++) {
+		    tmp = PyLong_FromUnsignedLongLong(arr[i]);
+		    if (!tmp) {
+			    Py_DECREF(ret);
+			    return NULL;
+		    }
+		    PyList_SET_ITEM(ret, i, tmp);
+	    }
+
+	    return ret;
+    } else {
+	    return PyObject_GenericGetAttr((PyObject *)self, nameobj);
+    }
+}
+
+static PyObject *QgroupInherit_add_group(QgroupInherit *self, PyObject *args,
+					 PyObject *kwds)
+{
+	static char *keywords[] = {"qgroupid", NULL};
+	enum btrfs_util_error err;
+	uint64_t qgroupid;
+
+	if (!PyArg_ParseTupleAndKeywords(args, kwds, "K:add_group", keywords,
+					 &qgroupid))
+		return NULL;
+
+	err = btrfs_util_qgroup_inherit_add_group(&self->inherit, qgroupid);
+	if (err) {
+		SetFromBtrfsUtilError(err);
+		return NULL;
+	}
+
+	Py_RETURN_NONE;
+}
+
+static PyMethodDef QgroupInherit_methods[] = {
+	{"add_group", (PyCFunction)QgroupInherit_add_group,
+	 METH_VARARGS | METH_KEYWORDS,
+	 "add_group(qgroupid)\n\n"
+	 "Add a qgroup to inherit from.\n\n"
+	 "Arguments:\n"
+	 "qgroupid -- ID of qgroup to add"},
+	{},
+};
+
+#define QgroupInherit_DOC	\
+	"QgroupInherit() -> new qgroup inheritance specifier\n\n"	\
+	"Create a new object which specifies what qgroups to inherit\n"	\
+	"from for create_subvolume() and create_snapshot()"
+
+PyTypeObject QgroupInherit_type = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	"btrfsutil.QgroupInherit",		/* tp_name */
+	sizeof(QgroupInherit),			/* tp_basicsize */
+	0,					/* tp_itemsize */
+	(destructor)QgroupInherit_dealloc,	/* tp_dealloc */
+	NULL,					/* tp_print */
+	NULL,					/* tp_getattr */
+	NULL,					/* tp_setattr */
+	NULL,					/* tp_as_async */
+	NULL,					/* tp_repr */
+	NULL,					/* tp_as_number */
+	NULL,					/* tp_as_sequence */
+	NULL,					/* tp_as_mapping */
+	NULL,					/* tp_hash  */
+	NULL,					/* tp_call */
+	NULL,					/* tp_str */
+	(getattrofunc)QgroupInherit_getattro,	/* tp_getattro */
+	NULL,					/* tp_setattro */
+	NULL,					/* tp_as_buffer */
+	Py_TPFLAGS_DEFAULT,			/* tp_flags */
+	QgroupInherit_DOC,			/* tp_doc */
+	NULL,					/* tp_traverse */
+	NULL,					/* tp_clear */
+	NULL,					/* tp_richcompare */
+	0,					/* tp_weaklistoffset */
+	NULL,					/* tp_iter */
+	NULL,					/* tp_iternext */
+	QgroupInherit_methods,			/* tp_methods */
+	NULL,					/* tp_members */
+	NULL,					/* tp_getset */
+	NULL,					/* tp_base */
+	NULL,					/* tp_dict */
+	NULL,					/* tp_descr_get */
+	NULL,					/* tp_descr_set */
+	0,					/* tp_dictoffset */
+	(initproc)QgroupInherit_init,		/* tp_init */
+};