Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754352AbYHKBaj (ORCPT ); Sun, 10 Aug 2008 21:30:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752833AbYHKBab (ORCPT ); Sun, 10 Aug 2008 21:30:31 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:45211 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752524AbYHKBab (ORCPT ); Sun, 10 Aug 2008 21:30:31 -0400 Date: Sun, 10 Aug 2008 21:30:24 -0400 From: Christoph Hellwig To: Hugh Dickins Cc: Keith Packard , Nick Piggin , Christoph Hellwig , Eric Anholt , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Export shmem_file_setup and shmem_getpage for DRM-GEM Message-ID: <20080811013024.GA28884@infradead.org> References: <1217573919-7496-1-git-send-email-eric@anholt.net> <200808041902.23970.nickpiggin@yahoo.com.au> <1217845590.24714.45.camel@koto.keithp.com> <200808042043.46710.nickpiggin@yahoo.com.au> <1217850352.24714.66.camel@koto.keithp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1104 Lines: 20 On Mon, Aug 04, 2008 at 06:09:24PM +0100, Hugh Dickins wrote: > Whether such usage conforms to VFS API I'm not so sure: as I understand > it, it's really for internal use by a filesystem - if it's going to be > used beyond that, we ought to add a check that the filesystem it's used > upon really has a ->readpage method (and I'd rather we add such a check > than you do it at your end, in case we change the implementation later > to use something other than a ->readpage method - Nick, you'll be > nauseated to hear I was looking to see if ->fault with a pseudo-vma > could do it). But if the layering police are happy with this, I am. Using read_mapping_page is fine on any pagecache backed file. What is much more difficult is actually writing into pagecache on a sub-page level where we don't have proper APIs for anything but the filesystem itself. -- 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/