From mboxrd@z Thu Jan 1 00:00:00 1970 From: hooanon05@yahoo.co.jp Subject: Re: [fuse-devel] delta filesystem prototype Date: Wed, 04 Mar 2009 01:19:12 +0900 Message-ID: <20279.1236097152@jrobl> References: <9884.1236069117@jrobl> <87r61ec1o7.fsf@frosties.localdomain> <7200.1236085884@jrobl> <1236094078.6988.3.camel@norville.austin.ibm.com> <19642.1236095410@jrobl> <1236095699.6988.6.camel@norville.austin.ibm.com> <19966.1236096162@jrobl> <1236096857.6988.28.camel@norville.austin.ibm.com> Cc: Goswin von Brederlow , Miklos Szeredi , linux-fsdevel@vger.kernel.org, fuse-devel@lists.sourceforge.net To: Dave Kleikamp Return-path: Received: from vsmtp01.dti.ne.jp ([202.216.231.136]:47014 "EHLO vsmtp01.dti.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750747AbZCCQT3 (ORCPT ); Tue, 3 Mar 2009 11:19:29 -0500 In-Reply-To: <1236096857.6988.28.camel@norville.austin.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Dave Kleikamp: > > - you have two mmap for a single file > > Explain what you mean by a single file. If there are two mmaps to the > upper file, they will see the same changes. If one is to the upper > file, and one is to the lower file, they will NOT be mmap'ed to the same > file. A regular file on the lower readonly layer. Not a single block/page is copied-up yet. > No. The first mapping is not even aware of the second mapping. It > continues to see the read-only data Should the first mapping see the latest (modified) content? J. R. Okajima