From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264401AbUEIWRP (ORCPT ); Sun, 9 May 2004 18:17:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264402AbUEIWRP (ORCPT ); Sun, 9 May 2004 18:17:15 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:19870 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S264401AbUEIWRO (ORCPT ); Sun, 9 May 2004 18:17:14 -0400 Date: Sun, 9 May 2004 23:17:12 +0100 From: viro@parcelfarce.linux.theplanet.co.uk To: Dipankar Sarma Cc: Manfred Spraul , Linus Torvalds , Andrew Morton , davej@redhat.com, wli@holomorphy.com, Kernel Mailing List , Maneesh Soni Subject: Re: dentry bloat. Message-ID: <20040509221712.GA17014@parcelfarce.linux.theplanet.co.uk> References: <20040508012357.3559fb6e.akpm@osdl.org> <20040508022304.17779635.akpm@osdl.org> <20040508031159.782d6a46.akpm@osdl.org> <20040508120148.1be96d66.akpm@osdl.org> <20040508204239.GB6383@in.ibm.com> <409DDDAE.3090700@colorfullife.com> <20040509153316.GE4007@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040509153316.GE4007@in.ibm.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 09, 2004 at 09:03:16PM +0530, Dipankar Sarma wrote: > Actually, what may happen is that since the dentries are added > in the front, a double move like that would result in hash chain > traversal looping. Timing dependent and unlikely, but d_move_count > avoided that theoritical possibility. It is not about skipping > dentries which is safe because a miss would result in a real_lookup() Not really. A miss could result in getting another dentry allocated for the same e.g. directory, which is *NOT* harmless at all.