From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [patch 1/9] fs: libfs buffered write leak fix Date: Fri, 2 Feb 2007 17:58:01 -0800 Message-ID: <20070202175801.3f97f79b.akpm@linux-foundation.org> References: <20070129081905.23584.97878.sendpatchset@linux.site> <20070129081914.23584.23886.sendpatchset@linux.site> <20070202155236.dae54aa2.akpm@linux-foundation.org> <20070203013316.GB27300@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Linux Kernel , Linux Filesystems , Linux Memory Management To: Nick Piggin Return-path: Received: from smtp.osdl.org ([65.172.181.24]:50706 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946202AbXBCB6H (ORCPT ); Fri, 2 Feb 2007 20:58:07 -0500 In-Reply-To: <20070203013316.GB27300@wotan.suse.de> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sat, 3 Feb 2007 02:33:16 +0100 Nick Piggin wrote: > > > =================================================================== > > > --- linux-2.6.orig/fs/buffer.c > > > +++ linux-2.6/fs/buffer.c > > > @@ -2344,6 +2344,8 @@ int nobh_prepare_write(struct page *page > > > > > > if (is_mapped_to_disk) > > > SetPageMappedToDisk(page); > > > + > > > + /* XXX: information leak vs read(2) */ > > > SetPageUptodate(page); > > > > > > /* > > > > That comment is too terse to be useful. > > OK, similar problem here - we have brought all the buffers uptodate > that we are *not* going to write over, or partially write over, but > we can have an uninitialised hole over the region we want to write. > > I think just setting page uptodate in commit_write might do the > trick? (and getting rid of the set_page_dirty there). Yes, the page just isn't uptodate yet in prepare_write() - moving things to commti_write() sounds sane. But please, can we have sufficient changelogs and comments in the next version?