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-rw-r--r--libbtrfsutil/btrfsutil.h97
-rw-r--r--libbtrfsutil/python/btrfsutilpy.h1
-rw-r--r--libbtrfsutil/python/module.c8
-rw-r--r--libbtrfsutil/python/subvolume.c211
-rw-r--r--libbtrfsutil/python/tests/test_subvolume.py56
-rw-r--r--libbtrfsutil/subvolume.c319
6 files changed, 692 insertions, 0 deletions
diff --git a/libbtrfsutil/btrfsutil.h b/libbtrfsutil/btrfsutil.h
index 76ab06b..09a71c3 100644
--- a/libbtrfsutil/btrfsutil.h
+++ b/libbtrfsutil/btrfsutil.h
@@ -391,6 +391,103 @@ enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd,
uint64_t *async_transid,
struct btrfs_util_qgroup_inherit *qgroup_inherit);
+struct btrfs_util_subvolume_iterator;
+
+/**
+ * BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER - Iterate post-order. The default
+ * behavior is pre-order, e.g., foo will be yielded before foo/bar. If this flag
+ * is specified, foo/bar will be yielded before foo.
+ */
+#define BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER (1 << 0)
+#define BTRFS_UTIL_SUBVOLUME_ITERATOR_MASK ((1 << 1) - 1)
+
+/**
+ * btrfs_util_create_subvolume_iterator() - Create an iterator over subvolumes
+ * in a Btrfs filesystem.
+ * @path: Path in a Btrfs filesystem. This may be any path in the filesystem; it
+ * does not have to refer to a subvolume unless @top is zero.
+ * @top: List subvolumes beneath (but not including) the subvolume with this ID.
+ * If zero is given, the subvolume ID of @path is used. To list all subvolumes,
+ * pass %BTRFS_FS_TREE_OBJECTID (i.e., 5). The returned paths are relative to
+ * the subvolume with this ID.
+ * @flags: Bitmask of BTRFS_UTIL_SUBVOLUME_ITERATOR_* flags.
+ * @ret: Returned iterator.
+ *
+ * The returned iterator must be freed with
+ * btrfs_util_destroy_subvolume_iterator().
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_create_subvolume_iterator(const char *path,
+ uint64_t top,
+ int flags,
+ struct btrfs_util_subvolume_iterator **ret);
+
+/**
+ * btrfs_util_create_subvolume_iterator_fd() - See
+ * btrfs_util_create_subvolume_iterator().
+ */
+enum btrfs_util_error btrfs_util_create_subvolume_iterator_fd(int fd,
+ uint64_t top,
+ int flags,
+ struct btrfs_util_subvolume_iterator **ret);
+
+/**
+ * btrfs_util_destroy_subvolume_iterator() - Destroy a subvolume iterator
+ * previously created by btrfs_util_create_subvolume_iterator().
+ * @iter: Iterator to destroy.
+ */
+void btrfs_util_destroy_subvolume_iterator(struct btrfs_util_subvolume_iterator *iter);
+
+/**
+ * btrfs_util_subvolume_iterator_fd() - Get the file descriptor associated with
+ * a subvolume iterator.
+ * @iter: Iterator to get.
+ *
+ * This can be used to get the file descriptor opened by
+ * btrfs_util_create_subvolume_iterator() in order to use it for other
+ * functions.
+ *
+ * Return: File descriptor.
+ */
+int btrfs_util_subvolume_iterator_fd(const struct btrfs_util_subvolume_iterator *iter);
+
+/**
+ * btrfs_util_subvolume_iterator_next() - Get the next subvolume from a
+ * subvolume iterator.
+ * @iter: Subvolume iterator.
+ * @path_ret: Returned subvolume path, relative to the subvolume ID used to
+ * create the iterator. May be %NULL.
+ * Must be freed with free().
+ * @id_ret: Returned subvolume ID. May be %NULL.
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: %BTRFS_UTIL_OK on success, %BTRFS_UTIL_ERROR_STOP_ITERATION if there
+ * are no more subvolumes, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_util_subvolume_iterator *iter,
+ char **path_ret,
+ uint64_t *id_ret);
+
+/**
+ * btrfs_util_subvolume_iterator_next_info() - Get information about the next
+ * subvolume for a subvolume iterator.
+ * @iter: Subvolume iterator.
+ * @path_ret: See btrfs_util_subvolume_iterator_next().
+ * @subvol: Returned subvolume information.
+ *
+ * This convenience function basically combines
+ * btrfs_util_subvolume_iterator_next() and btrfs_util_subvolume_info().
+ *
+ * This requires appropriate privilege (CAP_SYS_ADMIN).
+ *
+ * Return: See btrfs_util_subvolume_iterator_next().
+ */
+enum btrfs_util_error btrfs_util_subvolume_iterator_next_info(struct btrfs_util_subvolume_iterator *iter,
+ char **path_ret,
+ struct btrfs_util_subvolume_info *subvol);
+
/**
* btrfs_util_create_qgroup_inherit() - Create a qgroup inheritance specifier
* for btrfs_util_create_subvolume() or btrfs_util_create_snapshot().
diff --git a/libbtrfsutil/python/btrfsutilpy.h b/libbtrfsutil/python/btrfsutilpy.h
index a56e41f..79ac2ee 100644
--- a/libbtrfsutil/python/btrfsutilpy.h
+++ b/libbtrfsutil/python/btrfsutilpy.h
@@ -37,6 +37,7 @@ typedef struct {
extern PyTypeObject BtrfsUtilError_type;
extern PyStructSequence_Desc SubvolumeInfo_desc;
extern PyTypeObject SubvolumeInfo_type;
+extern PyTypeObject SubvolumeIterator_type;
extern PyTypeObject QgroupInherit_type;
/*
diff --git a/libbtrfsutil/python/module.c b/libbtrfsutil/python/module.c
index 91c4b9b..9a23714 100644
--- a/libbtrfsutil/python/module.c
+++ b/libbtrfsutil/python/module.c
@@ -239,6 +239,10 @@ PyInit_btrfsutil(void)
if (PyStructSequence_InitType2(&SubvolumeInfo_type, &SubvolumeInfo_desc) < 0)
return NULL;
+ SubvolumeIterator_type.tp_new = PyType_GenericNew;
+ if (PyType_Ready(&SubvolumeIterator_type) < 0)
+ return NULL;
+
QgroupInherit_type.tp_new = PyType_GenericNew;
if (PyType_Ready(&QgroupInherit_type) < 0)
return NULL;
@@ -254,6 +258,10 @@ PyInit_btrfsutil(void)
Py_INCREF(&SubvolumeInfo_type);
PyModule_AddObject(m, "SubvolumeInfo", (PyObject *)&SubvolumeInfo_type);
+ Py_INCREF(&SubvolumeIterator_type);
+ PyModule_AddObject(m, "SubvolumeIterator",
+ (PyObject *)&SubvolumeIterator_type);
+
Py_INCREF(&QgroupInherit_type);
PyModule_AddObject(m, "QgroupInherit",
(PyObject *)&QgroupInherit_type);
diff --git a/libbtrfsutil/python/subvolume.c b/libbtrfsutil/python/subvolume.c
index fa3ec4a..6c38458 100644
--- a/libbtrfsutil/python/subvolume.c
+++ b/libbtrfsutil/python/subvolume.c
@@ -348,3 +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 */
+};
diff --git a/libbtrfsutil/python/tests/test_subvolume.py b/libbtrfsutil/python/tests/test_subvolume.py
index 937a439..b43beca 100644
--- a/libbtrfsutil/python/tests/test_subvolume.py
+++ b/libbtrfsutil/python/tests/test_subvolume.py
@@ -214,3 +214,59 @@ class TestSubvolume(BtrfsTestCase):
wstatus = os.waitpid(pid, 0)[1]
self.assertTrue(os.WIFEXITED(wstatus))
self.assertEqual(os.WEXITSTATUS(wstatus), 0)
+
+ def test_subvolume_iterator(self):
+ pwd = os.getcwd()
+ try:
+ os.chdir(self.mountpoint)
+ btrfsutil.create_subvolume('foo')
+
+ path, subvol = next(btrfsutil.SubvolumeIterator('.', info=True))
+ self.assertEqual(path, 'foo')
+ self.assertIsInstance(subvol, btrfsutil.SubvolumeInfo)
+ self.assertEqual(subvol.id, 256)
+ self.assertEqual(subvol.parent_id, 5)
+
+ btrfsutil.create_subvolume('foo/bar')
+ btrfsutil.create_subvolume('foo/bar/baz')
+
+ subvols = [
+ ('foo', 256),
+ ('foo/bar', 257),
+ ('foo/bar/baz', 258),
+ ]
+
+ for arg in self.path_or_fd('.'):
+ with self.subTest(type=type(arg)):
+ self.assertEqual(list(btrfsutil.SubvolumeIterator(arg)), subvols)
+ self.assertEqual(list(btrfsutil.SubvolumeIterator('.', top=0)), subvols)
+
+ self.assertEqual(list(btrfsutil.SubvolumeIterator('.', post_order=True)),
+ [('foo/bar/baz', 258),
+ ('foo/bar', 257),
+ ('foo', 256)])
+
+ subvols = [
+ ('bar', 257),
+ ('bar/baz', 258),
+ ]
+
+ self.assertEqual(list(btrfsutil.SubvolumeIterator('.', top=256)), subvols)
+ self.assertEqual(list(btrfsutil.SubvolumeIterator('foo', top=0)), subvols)
+
+ os.rename('foo/bar/baz', 'baz')
+ self.assertEqual(sorted(btrfsutil.SubvolumeIterator('.')),
+ [('baz', 258),
+ ('foo', 256),
+ ('foo/bar', 257)])
+
+ with btrfsutil.SubvolumeIterator('.') as it:
+ self.assertGreaterEqual(it.fileno(), 0)
+ it.close()
+ with self.assertRaises(ValueError):
+ next(iter(it))
+ with self.assertRaises(ValueError):
+ it.fileno()
+ it.close()
+ finally:
+ os.chdir(pwd)
diff --git a/libbtrfsutil/subvolume.c b/libbtrfsutil/subvolume.c
index b9bb99f..4f71cb0 100644
--- a/libbtrfsutil/subvolume.c
+++ b/libbtrfsutil/subvolume.c
@@ -691,3 +691,322 @@ PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd,
return BTRFS_UTIL_OK;
}
+
+#define BTRFS_UTIL_SUBVOLUME_ITERATOR_CLOSE_FD (1 << 30)
+
+struct search_stack_entry {
+ struct btrfs_ioctl_search_args search;
+ size_t items_pos, buf_off;
+ size_t path_len;
+};
+
+struct btrfs_util_subvolume_iterator {
+ int fd;
+ int flags;
+
+ struct search_stack_entry *search_stack;
+ size_t search_stack_len;
+ size_t search_stack_capacity;
+
+ char *cur_path;
+ size_t cur_path_capacity;
+};
+
+static enum btrfs_util_error append_to_search_stack(struct btrfs_util_subvolume_iterator *iter,
+ uint64_t tree_id,
+ size_t path_len)
+{
+ struct search_stack_entry *entry;
+
+ if (iter->search_stack_len >= iter->search_stack_capacity) {
+ size_t new_capacity = iter->search_stack_capacity * 2;
+ struct search_stack_entry *new_search_stack;
+
+ new_search_stack = reallocarray(iter->search_stack,
+ new_capacity,
+ sizeof(*iter->search_stack));
+ if (!new_search_stack)
+ return BTRFS_UTIL_ERROR_NO_MEMORY;
+
+ iter->search_stack_capacity = new_capacity;
+ iter->search_stack = new_search_stack;
+ }
+
+ entry = &iter->search_stack[iter->search_stack_len++];
+
+ memset(&entry->search, 0, sizeof(entry->search));
+ entry->search.key.tree_id = BTRFS_ROOT_TREE_OBJECTID;
+ entry->search.key.min_objectid = tree_id;
+ entry->search.key.max_objectid = tree_id;
+ entry->search.key.min_type = BTRFS_ROOT_REF_KEY;
+ entry->search.key.max_type = BTRFS_ROOT_REF_KEY;
+ entry->search.key.min_offset = 0;
+ entry->search.key.max_offset = UINT64_MAX;
+ entry->search.key.min_transid = 0;
+ entry->search.key.max_transid = UINT64_MAX;
+ entry->search.key.nr_items = 0;
+
+ entry->items_pos = 0;
+ entry->buf_off = 0;
+
+ entry->path_len = path_len;
+
+ return BTRFS_UTIL_OK;
+}
+
+PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_iterator(const char *path,
+ uint64_t top,
+ int flags,
+ struct btrfs_util_subvolume_iterator **ret)
+{
+ enum btrfs_util_error err;
+ int fd;
+
+ fd = open(path, O_RDONLY);
+ if (fd == -1)
+ return BTRFS_UTIL_ERROR_OPEN_FAILED;
+
+ err = btrfs_util_create_subvolume_iterator_fd(fd, top, flags, ret);
+ if (err)
+ SAVE_ERRNO_AND_CLOSE(fd);
+ else
+ (*ret)->flags |= BTRFS_UTIL_SUBVOLUME_ITERATOR_CLOSE_FD;
+
+ return err;
+}
+
+PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_iterator_fd(int fd,
+ uint64_t top,
+ int flags,
+ struct btrfs_util_subvolume_iterator **ret)
+{
+ struct btrfs_util_subvolume_iterator *iter;
+ enum btrfs_util_error err;
+
+ if (flags & ~BTRFS_UTIL_SUBVOLUME_ITERATOR_MASK) {
+ errno = EINVAL;
+ return BTRFS_UTIL_ERROR_INVALID_ARGUMENT;
+ }
+
+ if (top == 0) {
+ err = btrfs_util_is_subvolume_fd(fd);
+ if (err)
+ return err;
+
+ err = btrfs_util_subvolume_id_fd(fd, &top);
+ if (err)
+ return err;
+ }
+
+ iter = malloc(sizeof(*iter));
+ if (!iter)
+ return BTRFS_UTIL_ERROR_NO_MEMORY;
+
+ iter->fd = fd;
+ iter->flags = flags;
+
+ iter->search_stack_len = 0;
+ iter->search_stack_capacity = 4;
+ iter->search_stack = malloc(sizeof(*iter->search_stack) *
+ iter->search_stack_capacity);
+ if (!iter->search_stack) {
+ err = BTRFS_UTIL_ERROR_NO_MEMORY;
+ goto out_iter;
+ }
+
+ iter->cur_path_capacity = 256;
+ iter->cur_path = malloc(iter->cur_path_capacity);
+ if (!iter->cur_path) {
+ err = BTRFS_UTIL_ERROR_NO_MEMORY;
+ goto out_search_stack;
+ }
+
+ err = append_to_search_stack(iter, top, 0);
+ if (err)
+ goto out_cur_path;
+
+ *ret = iter;
+
+ return BTRFS_UTIL_OK;
+
+out_cur_path:
+ free(iter->cur_path);
+out_search_stack:
+ free(iter->search_stack);
+out_iter:
+ free(iter);
+ return err;
+}
+
+PUBLIC void btrfs_util_destroy_subvolume_iterator(struct btrfs_util_subvolume_iterator *iter)
+{
+ if (iter) {
+ free(iter->cur_path);
+ free(iter->search_stack);
+ if (iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_CLOSE_FD)
+ SAVE_ERRNO_AND_CLOSE(iter->fd);
+ free(iter);
+ }
+}
+
+PUBLIC int btrfs_util_subvolume_iterator_fd(const struct btrfs_util_subvolume_iterator *iter)
+{
+ return iter->fd;
+}
+
+static struct search_stack_entry *top_search_stack_entry(struct btrfs_util_subvolume_iterator *iter)
+{
+ return &iter->search_stack[iter->search_stack_len - 1];
+}
+
+static enum btrfs_util_error build_subvol_path(struct btrfs_util_subvolume_iterator *iter,
+ const struct btrfs_ioctl_search_header *header,
+ const struct btrfs_root_ref *ref,
+ const char *name,
+ size_t *path_len_ret)
+{
+ struct btrfs_ioctl_ino_lookup_args lookup = {
+ .treeid = header->objectid,
+ .objectid = le64_to_cpu(ref->dirid),
+ };
+ struct search_stack_entry *top = top_search_stack_entry(iter);
+ size_t dir_len, name_len, path_len;
+ char *p;
+ int ret;
+
+ ret = ioctl(iter->fd, BTRFS_IOC_INO_LOOKUP, &lookup);
+ if (ret == -1)
+ return BTRFS_UTIL_ERROR_INO_LOOKUP_FAILED;
+
+ dir_len = strlen(lookup.name);
+ name_len = le16_to_cpu(ref->name_len);
+
+ path_len = top->path_len;
+ /*
+ * We need a joining slash if we have a current path and a subdirectory.
+ */
+ if (top->path_len && dir_len)
+ path_len++;
+ path_len += dir_len;
+ /*
+ * We need another joining slash if we have a current path and a name,
+ * but not if we have a subdirectory, because the lookup ioctl includes
+ * a trailing slash.
+ */
+ if (top->path_len && !dir_len && name_len)
+ path_len++;
+ path_len += name_len;
+
+ if (path_len > iter->cur_path_capacity) {
+ char *tmp = realloc(iter->cur_path, path_len);
+
+ if (!tmp)
+ return BTRFS_UTIL_ERROR_NO_MEMORY;
+ iter->cur_path = tmp;
+ iter->cur_path_capacity = path_len;
+ }
+
+ p = iter->cur_path + top->path_len;
+ if (top->path_len && dir_len)
+ *p++ = '/';
+ memcpy(p, lookup.name, dir_len);
+ p += dir_len;
+ if (top->path_len && !dir_len && name_len)
+ *p++ = '/';
+ memcpy(p, name, name_len);
+ p += name_len;
+
+ *path_len_ret = path_len;
+
+ return BTRFS_UTIL_OK;
+}
+
+PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_util_subvolume_iterator *iter,
+ char **path_ret,
+ uint64_t *id_ret)
+{
+ struct search_stack_entry *top;
+ const struct btrfs_ioctl_search_header *header;
+ const struct btrfs_root_ref *ref;
+ const char *name;
+ enum btrfs_util_error err;
+ size_t path_len;
+ int ret;
+
+ for (;;) {
+ for (;;) {
+ if (iter->search_stack_len == 0)
+ return BTRFS_UTIL_ERROR_STOP_ITERATION;
+
+ top = top_search_stack_entry(iter);
+ if (top->items_pos < top->search.key.nr_items) {
+ break;
+ } else {
+ top->search.key.nr_items = 4096;
+ ret = ioctl(iter->fd, BTRFS_IOC_TREE_SEARCH, &top->search);
+ if (ret == -1)
+ return BTRFS_UTIL_ERROR_SEARCH_FAILED;
+ top->items_pos = 0;
+ top->buf_off = 0;
+
+ if (top->search.key.nr_items == 0) {
+ iter->search_stack_len--;
+ if ((iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER) &&
+ iter->search_stack_len)
+ goto out;
+ }
+ }
+ }
+
+ header = (struct btrfs_ioctl_search_header *)(top->search.buf + top->buf_off);
+
+ top->items_pos++;
+ top->buf_off += sizeof(*header) + header->len;
+ top->search.key.min_offset = header->offset + 1;
+
+ /* This shouldn't happen, but handle it just in case. */
+ if (header->type != BTRFS_ROOT_REF_KEY)
+ continue;
+
+ ref = (struct btrfs_root_ref *)(header + 1);
+ name = (const char *)(ref + 1);
+ err = build_subvol_path(iter, header, ref, name, &path_len);
+ if (err)
+ return err;
+
+ err = append_to_search_stack(iter, header->offset, path_len);
+ if (err)
+ return err;
+
+ if (!(iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER)) {
+ top = top_search_stack_entry(iter);
+ goto out;
+ }
+ }
+
+out:
+ if (path_ret) {
+ *path_ret = malloc(top->path_len + 1);
+ if (!*path_ret)
+ return BTRFS_UTIL_ERROR_NO_MEMORY;
+ memcpy(*path_ret, iter->cur_path, top->path_len);
+ (*path_ret)[top->path_len] = '\0';
+ }
+ if (id_ret)
+ *id_ret = top->search.key.min_objectid;
+ return BTRFS_UTIL_OK;
+}
+
+PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next_info(struct btrfs_util_subvolume_iterator *iter,
+ char **path_ret,
+ struct btrfs_util_subvolume_info *subvol)
+{
+ enum btrfs_util_error err;
+ uint64_t id;
+
+ err = btrfs_util_subvolume_iterator_next(iter, path_ret, &id);
+ if (err)
+ return err;
+
+ return btrfs_util_subvolume_info_fd(iter->fd, id, subvol);
+}