diff --git a/include/crucible/fs.h b/include/crucible/fs.h
index df7b936..6d1780b 100644
--- a/include/crucible/fs.h
+++ b/include/crucible/fs.h
@@ -69,9 +69,11 @@ namespace crucible {
 
 		uint64_t get_flags() const;
 		void set_flags(uint64_t new_flags);
+		void set_logical(uint64_t new_logical);
+		void set_size(uint64_t new_size);
 
-		virtual void do_ioctl(int fd);
-		virtual bool do_ioctl_nothrow(int fd);
+		void do_ioctl(int fd);
+		bool do_ioctl_nothrow(int fd);
 
 		struct BtrfsInodeOffsetRootSpan {
 			using iterator = BtrfsInodeOffsetRoot*;
diff --git a/lib/fs.cc b/lib/fs.cc
index 002c7a7..4327c28 100644
--- a/lib/fs.cc
+++ b/lib/fs.cc
@@ -315,6 +315,18 @@ namespace crucible {
 		return m_flags;
 	}
 
+	void
+	BtrfsIoctlLogicalInoArgs::set_logical(uint64_t new_logical)
+	{
+		m_logical = new_logical;
+	}
+
+	void
+	BtrfsIoctlLogicalInoArgs::set_size(uint64_t new_size)
+	{
+		m_container_size = new_size;
+	}
+
 	bool
 	BtrfsIoctlLogicalInoArgs::do_ioctl_nothrow(int fd)
 	{