From: Jan Blunck Subject: Re: [PATCH 13/35] fallthru: ext2 fallthru support Date: Mon, 19 Apr 2010 15:23:44 +0200 Message-ID: <20100419132344.GI10776@bolzano.suse.de> References: <1271372682-21225-7-git-send-email-vaurora@redhat.com> <1271372682-21225-8-git-send-email-vaurora@redhat.com> <1271372682-21225-9-git-send-email-vaurora@redhat.com> <1271372682-21225-10-git-send-email-vaurora@redhat.com> <1271372682-21225-11-git-send-email-vaurora@redhat.com> <1271372682-21225-12-git-send-email-vaurora@redhat.com> <1271372682-21225-13-git-send-email-vaurora@redhat.com> <1271372682-21225-14-git-send-email-vaurora@redhat.com> <20100419124025.GG10776@bolzano.suse.de> <1271682168.14748.718.camel@macbook.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Valerie Aurora , Alexander Viro , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Theodore Tso , linux-ext4@vger.kernel.org To: David Woodhouse Return-path: Received: from cantor2.suse.de ([195.135.220.15]:50356 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754798Ab0DSNXr (ORCPT ); Mon, 19 Apr 2010 09:23:47 -0400 Content-Disposition: inline In-Reply-To: <1271682168.14748.718.camel@macbook.infradead.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Apr 19, David Woodhouse wrote: > On Mon, 2010-04-19 at 14:40 +0200, Jan Blunck wrote: > > On Thu, Apr 15, Valerie Aurora wrote: > > > > > Add support for fallthru directory entries to ext2. > > > > > > XXX - Makes up inode number for fallthru entry > > > XXX - Might be better implemented as special symlinks > > > > Better not. David Woodhouse actually convinced me of moving away from the > > special symlink approach. The whiteouts have been implemented as special > > symlinks before. > > I certainly asked whether you really need a real 'struct inode' for > whiteouts, and suggested that they should be represented _purely_ as a > dentry with type DT_WHT. > > I don't much like the manifestation of that in this patch though, > especially with the made-up inode number. (ISTR I had other > jffs2-specific objections too, which I'll dig out and forward). Yes, this patches still have issues that Val and me are aware off. I can't remember anything jffs2-specific though. We return that inode number because we don't want to lookup the name on the other filesystem during readdir. Therefore returning DT_UNKNOWN to let the userspace decide if it needs to stat the file was the easiest workaround. I know that POSIX requires d_ino and d_name but on the other hand it does not require anything more on how long d_ino is valid. If somebody has an idea how to make this cleaner please speak up. Regards, Jan -- Jan Blunck