1 files changed, 28 insertions, 0 deletions
diff --git a/fs/xfs/scrub/bitmap.c b/fs/xfs/scrub/bitmap.c
index f707434b1c86..c98f4c45414a 100644
--- a/fs/xfs/scrub/bitmap.c
+++ b/fs/xfs/scrub/bitmap.c
@@ -379,3 +379,31 @@ xbitmap_test(
 	*len = bn->bn_start - start;
 	return false;
 }
+
+/*
+ * Find the first set bit in this bitmap, clear it, and return the index of
+ * that bit in @valp.  Returns -ENODATA if no bits were set, or the usual
+ * negative errno.
+ */
+int
+xbitmap_take_first_set(
+	struct xbitmap		*bitmap,
+	uint64_t		start,
+	uint64_t		last,
+	uint64_t		*valp)
+{
+	struct xbitmap_node	*bn;
+	uint64_t		val;
+	int			error;
+
+	bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
+	if (!bn)
+		return -ENODATA;
+
+	val = bn->bn_start;
+	error = xbitmap_clear(bitmap, bn->bn_start, 1);
+	if (error)
+		return error;
+	*valp = val;
+	return 0;
+}