From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [RFC] fsblock Date: Sat, 30 Jun 2007 11:42:44 +0100 Message-ID: <20070630104244.GC24123@infradead.org> References: <20070624014528.GA17609@wotan.suse.de> <467DE00A.9080700@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Nick Piggin , Linux Kernel Mailing List , Linux Memory Management List , linux-fsdevel@vger.kernel.org To: Jeff Garzik Return-path: Received: from pentafluge.infradead.org ([213.146.154.40]:44091 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754540AbXF3Kmv (ORCPT ); Sat, 30 Jun 2007 06:42:51 -0400 Content-Disposition: inline In-Reply-To: <467DE00A.9080700@garzik.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sat, Jun 23, 2007 at 11:07:54PM -0400, Jeff Garzik wrote: > >- In line with the above item, filesystem block allocation is performed > > before a page is dirtied. In the buffer layer, mmap writes can dirty a > > page with no backing blocks which is a problem if the filesystem is > > ENOSPC (patches exist for buffer.c for this). > > This raises an eyebrow... The handling of ENOSPC prior to mmap write is > more an ABI behavior, so I don't see how this can be fixed with internal > changes, yet without changing behavior currently exported to userland > (and thus affecting code based on such assumptions). Not really, the current behaviour is a bug. And it's not actually buffer layer specific - XFS now has a fix for that bug and it's generic enough that everyone could use it.