From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Artem B. Bityuckiy" Subject: Re: filesystem transactions API Date: Tue, 26 Apr 2005 18:46:00 +0400 Message-ID: <426E5428.2090306@oktetlabs.ru> References: <20050424211942.GN13052@parcelfarce.linux.theplanet.co.uk> <20050426134629.GU16169@viasys.com> <20050426141426.GC10833@mail.shareable.org> <426E4EBD.6070104@oktetlabs.ru> <20050426143247.GF10833@mail.shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Ville Herva , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from [213.170.72.194] ([213.170.72.194]:59276 "EHLO shelob.oktetlabs.ru") by vger.kernel.org with ESMTP id S261394AbVDZOqB (ORCPT ); Tue, 26 Apr 2005 10:46:01 -0400 To: Jamie Lokier In-Reply-To: <20050426143247.GF10833@mail.shareable.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Jamie Lokier wrote: > Artem B. Bityuckiy wrote: > > No. A transaction means that _all_ processes will see the whole > transaction or not. > > It does _not_ mean that only a subset of programs, which happen to > link with a particular user-space library, will see it or not. > > For example, you can use transactions for distro package management: a > whole update of a package would be a single transaction, so that at no > time does any program see an inconsistent set of files. See why > _every_ process in the system must have the same view? > > [ If you meant that you can implement it with a user-space library > that every process in the system links to, that's true. But it would > rather misses the point of having filesystems in the kernel at all :) ] > Hmm, so the whole point to implement transactions in the kernel space is to do the transactions in a way that nobody can see any intermediate inconsistent state ? -- Best regards, Artem B. Bityuckiy Oktet Labs (St. Petersburg), Software Engineer. +78124286709 (office) +79112449030 (mobile) E-mail: dedekind@oktetlabs.ru, web: http://www.oktetlabs.ru