1 files changed, 87 insertions, 0 deletions
diff --git a/fs/bcachefs/darray.h b/fs/bcachefs/darray.h
new file mode 100644
index 000000000000..114f86b45fd5
--- /dev/null
+++ b/fs/bcachefs/darray.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_DARRAY_H
+#define _BCACHEFS_DARRAY_H
+
+/*
+ * Dynamic arrays:
+ *
+ * Inspired by CCAN's darray
+ */
+
+#include "util.h"
+#include <linux/slab.h>
+
+#define DARRAY(type)							\
+struct {								\
+	size_t nr, size;						\
+	type *data;							\
+}
+
+typedef DARRAY(void) darray_void;
+
+static inline int __darray_make_room(darray_void *d, size_t t_size, size_t more, gfp_t gfp)
+{
+	if (d->nr + more > d->size) {
+		size_t new_size = roundup_pow_of_two(d->nr + more);
+		void *data = krealloc_array(d->data, new_size, t_size, gfp);
+
+		if (!data)
+			return -ENOMEM;
+
+		d->data	= data;
+		d->size = new_size;
+	}
+
+	return 0;
+}
+
+#define darray_make_room_gfp(_d, _more, _gfp)				\
+	__darray_make_room((darray_void *) (_d), sizeof((_d)->data[0]), (_more), _gfp)
+
+#define darray_make_room(_d, _more)					\
+	darray_make_room_gfp(_d, _more, GFP_KERNEL)
+
+#define darray_top(_d)		((_d).data[(_d).nr])
+
+#define darray_push_gfp(_d, _item, _gfp)				\
+({									\
+	int _ret = darray_make_room_gfp((_d), 1, _gfp);			\
+									\
+	if (!_ret)							\
+		(_d)->data[(_d)->nr++] = (_item);			\
+	_ret;								\
+})
+
+#define darray_push(_d, _item)	darray_push_gfp(_d, _item, GFP_KERNEL)
+
+#define darray_pop(_d)		((_d)->data[--(_d)->nr])
+
+#define darray_first(_d)	((_d).data[0])
+#define darray_last(_d)		((_d).data[(_d).nr - 1])
+
+#define darray_insert_item(_d, pos, _item)				\
+({									\
+	size_t _pos = (pos);						\
+	int _ret = darray_make_room((_d), 1);				\
+									\
+	if (!_ret)							\
+		array_insert_item((_d)->data, (_d)->nr, _pos, (_item));	\
+	_ret;								\
+})
+
+#define darray_for_each(_d, _i)						\
+	for (_i = (_d).data; _i < (_d).data + (_d).nr; _i++)
+
+#define darray_init(_d)							\
+do {									\
+	(_d)->data = NULL;						\
+	(_d)->nr = (_d)->size = 0;					\
+} while (0)
+
+#define darray_exit(_d)							\
+do {									\
+	kfree((_d)->data);						\
+	darray_init(_d);						\
+} while (0)
+
+#endif /* _BCACHEFS_DARRAY_H */