Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760907AbYFYOpB (ORCPT ); Wed, 25 Jun 2008 10:45:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759818AbYFYOl1 (ORCPT ); Wed, 25 Jun 2008 10:41:27 -0400 Received: from fxip-0047f.externet.hu ([88.209.222.127]:43078 "EHLO pomaz-ex.szeredi.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754763AbYFYOlZ (ORCPT ); Wed, 25 Jun 2008 10:41:25 -0400 To: johnpol@2ka.mipt.ru CC: miklos@szeredi.hu, jens.axboe@oracle.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, hugh@veritas.com, nickpiggin@yahoo.com.au In-reply-to: <20080625141654.GA4803@2ka.mipt.ru> (message from Evgeniy Polyakov on Wed, 25 Jun 2008 18:16:55 +0400) Subject: Re: [patch 1/2] mm: dont clear PG_uptodate in invalidate_complete_page2() References: <20080625124038.103406301@szeredi.hu> <20080625124121.839734708@szeredi.hu> <20080625131117.GA28136@2ka.mipt.ru> <20080625141654.GA4803@2ka.mipt.ru> Message-Id: From: Miklos Szeredi Date: Wed, 25 Jun 2008 16:41:10 +0200 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1596 Lines: 43 > > > Like __block_prepare_write()? > > > > That's called with the page locked and page->mapping verified. > > Only when called via standard codepath. It would be a grave error to call it without the page lock. > > I want the page fully invalidated, and I also want splice and nfs > > exporting to work as for other filesystems. > > Fully invalidated page can not be uptodate, doesnt' it? :) That's just a question of how we interpret PG_uptodate. If it means: the page contains data that is valid, or was valid at some point in time, then an invalidated or truncated page can be uptodate. > You destroy existing functionality just because there are some obscure > places, where it is used, so instead of fixing that places, you treat > the symptom. After writing previous mail I found a way to workaround it > even with your changes, but the whole approach of changing > invalidate_complete_page2() is not correct imho. You rely on page being !PageUptodate() after being invalidated? Why can't you check page->mapping instead (as everything else does)? > Is this nfs/fuse problem you described: > http://marc.info/?l=linux-fsdevel&m=121396920822693&w=2 Yes. > Instead of returning error when reading from invalid page, now you > return old content of it? No, instead of returning a short count, it is now returning old content. Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/