From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754674AbYFXTSU (ORCPT ); Tue, 24 Jun 2008 15:18:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751965AbYFXTSL (ORCPT ); Tue, 24 Jun 2008 15:18:11 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:41649 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751680AbYFXTSK (ORCPT ); Tue, 24 Jun 2008 15:18:10 -0400 Date: Tue, 24 Jun 2008 12:17:44 -0700 (PDT) From: Linus Torvalds To: Miklos Szeredi cc: jens.axboe@oracle.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [rfc patch 3/4] splice: remove confirm from pipe_buf_operations In-Reply-To: Message-ID: References: <20080621154607.154640724@szeredi.hu> <20080621154726.494538562@szeredi.hu> <20080624080440.GJ20851@kernel.dk> <20080624111913.GP20851@kernel.dk> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 24 Jun 2008, Miklos Szeredi wrote: > > Let's start with page_cache_pipe_buf_confirm(). How should we deal > with finding an invalidated page (!PageUptodate(page) && > !page->mapping)? I suspect we just have to use it. After all, it was valid when the read was done. The fact that it got invalidated later is kind of immaterial. splice() is an optimized read+write. The read reads it into a temporary buffer. The fact that it's a zero-copy buffer and basically just re-uses the source doesn't really change that. Linus