new helper: inode_unhashed()

note: for race-free uses you inode_lock held

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/fs.h

@@ -786,6 +786,11 @@ struct inode {
 	void			*i_private; /* fs or device private pointer */
 };
 
+static inline int inode_unhashed(struct inode *inode)
+{
+	return hlist_unhashed(&inode->i_hash);
+}
+
 /*
  * inode->i_mutex nesting subclasses for the lock validator:
  *