From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 28/33] nfs: teach the NFS client how to treat PG_swapcache pages Date: Wed, 31 Oct 2007 08:52:37 +0000 Message-ID: <20071031085237.GB4362@infradead.org> References: <20071030160401.296770000@chello.nl> <20071030160915.377778000@chello.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no To: Peter Zijlstra Return-path: Received: from pentafluge.infradead.org ([213.146.154.40]:37987 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753607AbXJaIwi (ORCPT ); Wed, 31 Oct 2007 04:52:38 -0400 Content-Disposition: inline In-Reply-To: <20071030160915.377778000@chello.nl> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, Oct 30, 2007 at 05:04:29PM +0100, Peter Zijlstra wrote: > Replace all relevant occurences of page->index and page->mapping in the NFS > client with the new page_file_index() and page_file_mapping() functions. As discussed personally and on the list a strong NACK for this. Swapcache pages have no business at all ever coming through ->writepage(s). If you really want to support swap over NFS that can only be done properly by adding separate methods to write out and read in pages separated from the pagecache. Incidentally that would also clean up the mess we have with swap files on "normal" filesystems using ->bmap and bypassing the filesystem later on.