Return-Path: linux-nfs-owner@vger.kernel.org Received: from bombadil.infradead.org ([198.137.202.9]:60576 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032Ab3IIHpo (ORCPT ); Mon, 9 Sep 2013 03:45:44 -0400 Date: Mon, 9 Sep 2013 00:45:40 -0700 From: Christoph Hellwig To: Al Viro Cc: "J. Bruce Fields" , linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH 4/4] dcache: don't clear DCACHE_DISCONNECTED too early Message-ID: <20130909074540.GA21076@infradead.org> References: <1378579561-26868-1-git-send-email-bfields@redhat.com> <1378579561-26868-5-git-send-email-bfields@redhat.com> <20130909004647.GK13318@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20130909004647.GK13318@ZenIV.linux.org.uk> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Sep 09, 2013 at 01:46:47AM +0100, Al Viro wrote: > On Sat, Sep 07, 2013 at 02:46:01PM -0400, J. Bruce Fields wrote: > > From: "J. Bruce Fields" > > > > DCACHE_DISCONNECTED should not be cleared until we're sure the dentry is > > connected all the way up to the root of the filesystem. It *shouldn't* > > be cleared as soon as the dentry is connected to a parent. That will > > cause bugs at least on exportable filesystems. > > Then you probably want this > if (!IS_ROOT(pd)) { > /* must have found a connected parent - great */ > spin_lock(&pd->d_lock); > pd->d_flags &= ~DCACHE_DISCONNECTED; > spin_unlock(&pd->d_lock); > noprogress = 0; > to go through all intermediates, clearing DCACHE_DISCONNECTED on all of > them; O(depth^2) can suck when we have a long chain of directories... Aka call reconnect_path() from fs/exportfs/expfs.c on it.