Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756801Ab1FPPP7 (ORCPT ); Thu, 16 Jun 2011 11:15:59 -0400 Received: from mail04-md.ns.itscom.net ([175.177.155.114]:39895 "EHLO mail04-md.ns.itscom.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755448Ab1FPPPz (ORCPT ); Thu, 16 Jun 2011 11:15:55 -0400 From: "J. R. Okajima" Subject: Re: [PATCH 0/7] overlay filesystem: request for inclusion To: Michal Suchanek Cc: Miklos Szeredi , Alan Cox , Valerie Aurora , Andrew Morton , NeilBrown , viro@zeniv.linux.org.uk, torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, apw@canonical.com, nbd@openwrt.org, jordipujolp@gmail.com, ezk@fsl.cs.sunysb.edu In-Reply-To: References: <20110609125114.8dff08da.akpm@linux-foundation.org> <20110610100143.28037551@lxorguk.ukuu.org.uk> <8739jbjqa7.fsf@tucsk.pomaz.szeredi.hu> <11186.1308148376@jrobl> <87vcw7hz7y.fsf@tucsk.pomaz.szeredi.hu> <15402.1308154495@jrobl> <18273.1308192226@jrobl> Date: Fri, 17 Jun 2011 00:15:53 +0900 Message-ID: <12737.1308237353@jrobl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1863 Lines: 48 Michal Suchanek: > Probably swap the two above, you can't make a whiteout in presence of > the directory, right? > Anyway, you could just mark dirA as whiteout and remove any whiteouts > contained in it asynchronously, and only jump through these hoops when > trying to create a new entry in place of non-empty whiteout, or sync > on emptying the old whiteout before making a new entry. Unfortunately I cannot understand what you wrote. First, the order of > - create whiteout for dirA > - rename dirA to .wh..wh.XXXXXXXX is correct and I think it should be, in order to make a little help for fsck/auchk. And what is "non-empty whiteout" and "emptying the old whiteout"? The whiteout is a size zero-ed and hardlinked regular file in aufs. > Yes, it can only cause pollution with whiteouts unrelated to any files > that ever existed which is not too much of an issue unless people want > to add random stuff to the lower layer and see it in the union when > they reconstruct it again. ?? Do you think that the .wh..wh.XXXXXXXX hides something on the lower layer? If so, it is wrong. Such doubly whiteout hides nothing except itself. > It is only valid when in the upper layer of a union. However, so is > whiteout, and so are files that were visible in the union but are not > visible in the top layer if examined separately, outside of the union. Do you mean that your special symlink has totally different file-type from a symlink? Anyway what I want to say is, what such symlink refers may differ from what users originally expect. But I may misunderstand what you call "fallthru symlink". J. R. Okajima -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/