Index: sys/compat/linuxkpi/common/include/linux/fs.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/fs.h
+++ sys/compat/linuxkpi/common/include/linux/fs.h
@@ -254,6 +254,13 @@
 	return (f);
 }
 
+static inline bool
+get_file_rcu(struct linux_file *f)
+{
+	return (refcount_acquire_if_not_zero(
+	    f->_file == NULL ? &f->f_count : &f->_file->f_count));
+}
+
 static inline struct inode *
 igrab(struct inode *inode)
 {