From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266894AbUHVNba (ORCPT ); Sun, 22 Aug 2004 09:31:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267184AbUHVNba (ORCPT ); Sun, 22 Aug 2004 09:31:30 -0400 Received: from mx-00.sil.at ([62.116.68.196]:3090 "EHLO mx-00.sil.at") by vger.kernel.org with ESMTP id S266894AbUHVNb1 (ORCPT ); Sun, 22 Aug 2004 09:31:27 -0400 Subject: Re: Nonotify 0.3.2 (A simple dnotify replacement) From: nf Reply-To: nf2@scheinwelt.at To: Pascal Schmidt Cc: kernel mailing list In-Reply-To: References: <2vRn8-1D3-9@gated-at.bofh.it> Content-Type: text/plain Message-Id: <1093181664.4542.47.camel@lilota.lamp.priv> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6-2mdk Date: Sun, 22 Aug 2004 15:34:24 +0200 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2004-08-22 at 14:29, Pascal Schmidt wrote: > On Sun, 22 Aug 2004 05:40:06 +0200, you wrote in linux.kernel: > > > 2) The /dev/nonotify device: > > > > /dev/nonotify has the only purpose to offer a special stat() call via > > ioctl to read the contents_mtime field of directories (together with > > atime, mtime, ctime). The client has to set the 'filename' field of the > > 'nonotify_stat' structure and receives the four timespec fields updated > > via ioctl. > > A lot of people here (Linus, for instance) frown on ioctl() interfaces. > They're hard to do right in 32/64bit compat layers, for example. How > about using a syscall interface instead? Nonotify uses ioctl mainly for 'pragmatical' reasons. A syscall would be technically better - that's for sure, actually it was my initial idea to use one (or to change the stat-call). But i didn't want to bother people with asking to assign me a syscall-number before even knowing if they like my idea. And changing it to use a syscall lateron would be no problem at all from the concept of nonotify. Also - as a kernel newbie - i didn't find any good documentation how to add my own syscall into the kernel. I just wanted to get nonotify working as an 'optional patch', without changing tons of files. But you could help me if you have a look at my ioctl function. I'm using a structure which contains a char* pointer and four timespec fields. Do you know if this causes problems with 32/64bit compatibility. Thanks, Norbert