From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Charles P. Wright" Subject: Re: filesystem transactions API Date: Tue, 26 Apr 2005 13:22:44 -0400 Message-ID: <1114536164.1932.1.camel@polarbear.fsl.cs.sunysb.edu> References: <20050424211942.GN13052@parcelfarce.linux.theplanet.co.uk> <20050426134629.GU16169@viasys.com> <20050426141426.GC10833@mail.shareable.org> <426E4EBD.6070104@oktetlabs.ru> <1114530002.29907.21.camel@polarbear.fsl.cs.sunysb.edu> <426E6731.5000703@oktetlabs.ru> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Jamie Lokier , Ville Herva , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from filer.fsl.cs.sunysb.edu ([130.245.126.2]:8122 "EHLO filer.fsl.cs.sunysb.edu") by vger.kernel.org with ESMTP id S261690AbVDZRWx (ORCPT ); Tue, 26 Apr 2005 13:22:53 -0400 To: "Artem B. Bityuckiy" In-Reply-To: <426E6731.5000703@oktetlabs.ru> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tue, 2005-04-26 at 20:07 +0400, Artem B. Bityuckiy wrote: > Charles P. Wright wrote: > > Atomicity is difficult, because you have lots of caches each with their > > own bits of state (e.g., the inode/dentry caches). Assuming your > > transaction is committed that isn't so much of a problem, but once you > > have on rollback you need to undo any changes to those caches. > I guess if you do synchronization before unlocking all is OK. Roll-back > means deleting partially written things and restore old things, then run > fsyncs. Whys this may be not enough? That would be fine for the on-disk image of the file system, but the in- memory image also needs to be handled. Keeping track of all of these objects and their changes is not a simple task. Charles