From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755412Ab0I2T3j (ORCPT ); Wed, 29 Sep 2010 15:29:39 -0400 Received: from moutng.kundenserver.de ([212.227.17.9]:58384 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754970Ab0I2T3i (ORCPT ); Wed, 29 Sep 2010 15:29:38 -0400 From: Arnd Bergmann To: Roland Dreier Subject: Re: [PATCH] RDMA/cxgb4: Add default_llseek to debugfs files. Date: Wed, 29 Sep 2010 21:29:31 +0200 User-Agent: KMail/1.13.5 (Linux/2.6.36-rc5+; KDE/4.5.1; x86_64; ; ) Cc: Steve Wise , linux-rdma@vger.kernel.org, linux-next@vger.kernel.org, linux-kernel@vger.kernel.org References: <20100929141112.26944.21931.stgit@build.ogc.int> <201009292117.54828.arnd@arndb.de> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201009292129.31415.arnd@arndb.de> X-Provags-ID: V02:K0:Dby9X+JnLhx1G/zSu8umJOlJ8RUL+VqY21MOPnBp2NE JSAeUbiV/FdhR9aAHO1vb5mmPkR/o/R1j2Yt8xBaUhB1ik14pi pPVGpWhKRcwVA+6y1zoqujCFFMlIVPLZRtd0768Io0ojrHy0R1 C7xMsbLgd/dvE6ZbCYaxvK/NljSUfygejqvD2hyPLAAZP71zjL mSjY+LDxIp9IKB5aj9Lgg== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 29 September 2010 21:21:14 Roland Dreier wrote: > > > The main difference between default_llseek and generic_file_llseek > > is that default_llseek doesn't care about the maximum file size > > of the underlying file system, which is ULONG_MAX on debugfs, > > so they are equivalent. > > I thought default_llseek also takes the BKL still? Not any more in linux-next. > > In general, the preferred one is no_llseek for those files where > > you know you do not need to seek. If you do, I'd use default_llseek > > for character devices and generic_file_llseek for file systems > > that set the s_maxbytes. > > The case in question is for debugfs files, so we should use > generic_file_llseek, right? Yes, but it's a very weak "should". My automatic conversion script uses default_llseek. Arnd