1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bbf812ce89a8..06cbefd76de7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2724,6 +2724,20 @@ static inline struct user_namespace *file_mnt_user_ns(struct file *file)
 {
 	return mnt_user_ns(file->f_path.mnt);
 }
+
+/**
+ * is_idmapped_mnt - check whether a mount is mapped
+ * @mnt: the mount to check
+ *
+ * If @mnt has an idmapping attached to it @mnt is mapped.
+ *
+ * Return: true if mount is mapped, false if not.
+ */
+static inline bool is_idmapped_mnt(const struct vfsmount *mnt)
+{
+	return mnt_user_ns(mnt) != &init_user_ns;
+}
+
 extern long vfs_truncate(const struct path *, loff_t);
 int do_truncate(struct user_namespace *, struct dentry *, loff_t start,
 		unsigned int time_attrs, struct file *filp);