libbtrfsutil: add subvolume iterator helpers
[platform/upstream/btrfs-progs.git] / libbtrfsutil / python / subvolume.c
index 7648786..6c38458 100644 (file)
@@ -270,6 +270,56 @@ PyObject *set_subvolume_read_only(PyObject *self, PyObject *args, PyObject *kwds
        Py_RETURN_NONE;
 }
 
+PyObject *get_default_subvolume(PyObject *self, PyObject *args, PyObject *kwds)
+{
+       static char *keywords[] = {"path", NULL};
+       struct path_arg path = {.allow_fd = true};
+       enum btrfs_util_error err;
+       uint64_t id;
+
+       if (!PyArg_ParseTupleAndKeywords(args, kwds, "O&:get_default_subvolume",
+                                        keywords, &path_converter, &path))
+               return NULL;
+
+       if (path.path)
+               err = btrfs_util_get_default_subvolume(path.path, &id);
+       else
+               err = btrfs_util_get_default_subvolume_fd(path.fd, &id);
+       if (err) {
+               SetFromBtrfsUtilErrorWithPath(err, &path);
+               path_cleanup(&path);
+               return NULL;
+       }
+
+       path_cleanup(&path);
+       return PyLong_FromUnsignedLongLong(id);
+}
+
+PyObject *set_default_subvolume(PyObject *self, PyObject *args, PyObject *kwds)
+{
+       static char *keywords[] = {"path", "id", NULL};
+       struct path_arg path = {.allow_fd = true};
+       enum btrfs_util_error err;
+       uint64_t id = 0;
+
+       if (!PyArg_ParseTupleAndKeywords(args, kwds, "O&|K:set_default_subvolume",
+                                        keywords, &path_converter, &path, &id))
+               return NULL;
+
+       if (path.path)
+               err = btrfs_util_set_default_subvolume(path.path, id);
+       else
+               err = btrfs_util_set_default_subvolume_fd(path.fd, id);
+       if (err) {
+               SetFromBtrfsUtilErrorWithPath(err, &path);
+               path_cleanup(&path);
+               return NULL;
+       }
+
+       path_cleanup(&path);
+       Py_RETURN_NONE;
+}
+
 PyObject *create_subvolume(PyObject *self, PyObject *args, PyObject *kwds)
 {
        static char *keywords[] = {"path", "async", "qgroup_inherit", NULL};
@@ -298,3 +348,214 @@ PyObject *create_subvolume(PyObject *self, PyObject *args, PyObject *kwds)
        else
                Py_RETURN_NONE;
 }
+
+typedef struct {
+       PyObject_HEAD
+       struct btrfs_util_subvolume_iterator *iter;
+       bool info;
+} SubvolumeIterator;
+
+static void SubvolumeIterator_dealloc(SubvolumeIterator *self)
+{
+       btrfs_util_destroy_subvolume_iterator(self->iter);
+       Py_TYPE(self)->tp_free((PyObject *)self);
+}
+
+static PyObject *SubvolumeIterator_next(SubvolumeIterator *self)
+{
+       enum btrfs_util_error err;
+       PyObject *ret, *tmp;
+       char *path;
+
+       if (!self->iter) {
+               PyErr_SetString(PyExc_ValueError,
+                               "operation on closed iterator");
+               return NULL;
+       }
+
+       if (self->info) {
+               struct btrfs_util_subvolume_info subvol;
+
+               err = btrfs_util_subvolume_iterator_next_info(self->iter, &path,
+                                                             &subvol);
+               if (err == BTRFS_UTIL_ERROR_STOP_ITERATION) {
+                       PyErr_SetNone(PyExc_StopIteration);
+                       return NULL;
+               } else if (err) {
+                       SetFromBtrfsUtilError(err);
+                       return NULL;
+               }
+
+               tmp = subvolume_info_to_object(&subvol);
+       } else {
+               uint64_t id;
+
+               err = btrfs_util_subvolume_iterator_next(self->iter, &path, &id);
+               if (err == BTRFS_UTIL_ERROR_STOP_ITERATION) {
+                       PyErr_SetNone(PyExc_StopIteration);
+                       return NULL;
+               } else if (err) {
+                       SetFromBtrfsUtilError(err);
+                       return NULL;
+               }
+
+               tmp = PyLong_FromUnsignedLongLong(id);
+
+       }
+       if (tmp) {
+               ret = Py_BuildValue("O&O", PyUnicode_DecodeFSDefault, path,
+                                   tmp);
+               Py_DECREF(tmp);
+               free(path);
+       } else {
+               ret = NULL;
+       }
+       return ret;
+}
+
+static int SubvolumeIterator_init(SubvolumeIterator *self, PyObject *args,
+                                 PyObject *kwds)
+{
+       static char *keywords[] = {"path", "top", "info", "post_order", NULL};
+       struct path_arg path = {.allow_fd = true};
+       enum btrfs_util_error err;
+       unsigned long long top = 5;
+       int info = 0;
+       int post_order = 0;
+       int flags = 0;
+
+       if (!PyArg_ParseTupleAndKeywords(args, kwds, "O&|Kpp:SubvolumeIterator",
+                                        keywords, &path_converter, &path, &top,
+                                        &info, &post_order))
+               return -1;
+
+       if (post_order)
+               flags |= BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER;
+
+       if (path.path) {
+               err = btrfs_util_create_subvolume_iterator(path.path, top,
+                                                          flags, &self->iter);
+       } else {
+               err = btrfs_util_create_subvolume_iterator_fd(path.fd, top,
+                                                             flags,
+                                                             &self->iter);
+       }
+       if (err) {
+               SetFromBtrfsUtilErrorWithPath(err, &path);
+               path_cleanup(&path);
+               return -1;
+       }
+
+       self->info = info;
+
+       return 0;
+}
+
+static PyObject *SubvolumeIterator_close(SubvolumeIterator *self)
+{
+       if (self->iter) {
+               btrfs_util_destroy_subvolume_iterator(self->iter);
+               self->iter = NULL;
+       }
+       Py_RETURN_NONE;
+}
+
+static PyObject *SubvolumeIterator_fileno(SubvolumeIterator *self)
+{
+       if (!self->iter) {
+               PyErr_SetString(PyExc_ValueError,
+                               "operation on closed iterator");
+               return NULL;
+       }
+       return PyLong_FromLong(btrfs_util_subvolume_iterator_fd(self->iter));
+}
+
+static PyObject *SubvolumeIterator_enter(SubvolumeIterator *self)
+{
+       Py_INCREF((PyObject *)self);
+       return (PyObject *)self;
+}
+
+static PyObject *SubvolumeIterator_exit(SubvolumeIterator *self, PyObject *args,
+                                      PyObject *kwds)
+{
+       static char *keywords[] = {"exc_type", "exc_value", "traceback", NULL};
+       PyObject *exc_type, *exc_value, *traceback;
+
+       if (!PyArg_ParseTupleAndKeywords(args, kwds, "OOO:__exit__", keywords,
+                                        &exc_type, &exc_value, &traceback))
+               return NULL;
+
+       return SubvolumeIterator_close(self);
+}
+
+#define SubvolumeIterator_DOC  \
+        "SubvolumeIterator(path, top=0, info=False, post_order=False) -> new subvolume iterator\n\n"   \
+        "Create a new iterator that produces tuples of (path, ID) representing\n"      \
+        "subvolumes on a filesystem.\n\n"                                              \
+        "Arguments:\n"                                                                 \
+        "path -- string, bytes, path-like object, or open file descriptor in\n"        \
+        "filesystem to list\n"                                                         \
+        "top -- if not zero, instead of only listing subvolumes beneath the\n"         \
+        "given path, list subvolumes beneath the subvolume with this ID; passing\n"    \
+        "BTRFS_FS_TREE_OBJECTID (5) here lists all subvolumes. The subvolumes\n"       \
+        "are listed relative to the subvolume with this ID.\n"                         \
+        "info -- bool indicating the iterator should yield SubvolumeInfo instead of\n" \
+        "the subvolume ID\n"                                                           \
+        "post_order -- bool indicating whether to yield parent subvolumes before\n"    \
+        "child subvolumes (e.g., 'foo/bar' before 'foo')"
+
+static PyMethodDef SubvolumeIterator_methods[] = {
+       {"close", (PyCFunction)SubvolumeIterator_close,
+        METH_NOARGS,
+        "close()\n\n"
+        "Close this iterator."},
+       {"fileno", (PyCFunction)SubvolumeIterator_fileno,
+        METH_NOARGS,
+        "fileno() -> int\n\n"
+        "Get the file descriptor associated with this iterator."},
+       {"__enter__", (PyCFunction)SubvolumeIterator_enter,
+        METH_NOARGS, ""},
+       {"__exit__", (PyCFunction)SubvolumeIterator_exit,
+        METH_VARARGS | METH_KEYWORDS, ""},
+       {},
+};
+
+PyTypeObject SubvolumeIterator_type = {
+       PyVarObject_HEAD_INIT(NULL, 0)
+       "btrfsutil.SubvolumeIterator",          /* tp_name */
+       sizeof(SubvolumeIterator),              /* tp_basicsize */
+       0,                                      /* tp_itemsize */
+       (destructor)SubvolumeIterator_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 */
+       NULL,                                   /* tp_getattro */
+       NULL,                                   /* tp_setattro */
+       NULL,                                   /* tp_as_buffer */
+       Py_TPFLAGS_DEFAULT,                     /* tp_flags */
+       SubvolumeIterator_DOC,                  /* tp_doc */
+       NULL,                                   /* tp_traverse */
+       NULL,                                   /* tp_clear */
+       NULL,                                   /* tp_richcompare */
+       0,                                      /* tp_weaklistoffset */
+       PyObject_SelfIter,                      /* tp_iter */
+       (iternextfunc)SubvolumeIterator_next,   /* tp_iternext */
+       SubvolumeIterator_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)SubvolumeIterator_init,       /* tp_init */
+};