From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evgeniy Polyakov Subject: Re: [Btrfs-devel] transaction ioctls Date: Wed, 23 Apr 2008 16:57:54 +0400 Message-ID: <20080423125754.GA31257@2ka.mipt.ru> References: <200804221655.38102.chris.mason@oracle.com> <20080422210515.GA31827@2ka.mipt.ru> <200804230850.55074.chris.mason@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Sage Weil , btrfs-devel@oss.oracle.com, Zach Brown , linux-btrfs@vger.kernel.org To: Chris Mason Return-path: In-Reply-To: <200804230850.55074.chris.mason@oracle.com> List-ID: Hi Chris. On Wed, Apr 23, 2008 at 08:50:54AM -0400, Chris Mason (chris.mason@oracle.com) wrote: > Transaction rollback from a filesystem point of view is a reboot. Real > database style transactions with rollback and isolation from other procs etc > etc are outside the scope of Btrfs. Why rollback is a reboot? With copy-on-write it could be possible to just commit tree state, which was before transaction start, as a current one and thus rollback all changes. Having that possibility from userspace could be a great benefit, since in case of application error it is relly simple to undo all changes. -- Evgeniy Polyakov