From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: [PATCH 25/20] sysfs: Only support removing emtpy sysfs directories. Date: Mon, 25 May 2009 00:53:21 -0700 Message-ID: References: <1243109591-21611-5-git-send-email-ebiederm@xmission.com> <1243169978.3502.7.camel@poy> <1243178448.4035.12.camel@poy> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Tejun Heo , Cornelia Huck , linux-fsdevel@vger.kernel.org, "Eric W. Biederman" , stern To: Kay Sievers Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]:36553 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754107AbZEYHxX (ORCPT ); Mon, 25 May 2009 03:53:23 -0400 In-Reply-To: (Eric W. Biederman's message of "Mon\, 25 May 2009 00\:44\:26 -0700") Sender: linux-fsdevel-owner@vger.kernel.org List-ID: ebiederm@xmission.com (Eric W. Biederman) writes: > Kay Sievers writes: > >>> Let's make the plan to investigate these, and see how hard it would be >>> to actually remove these with the current device/sysfs infrastructure. >>> >>> Fixing the users and adding back auto-deletion are the only two real options. >> >> Seems, we should remove non-directory files, which in most cases belong >> to the kobject itself, but the user's cleanup logic does not cover the >> removal of the created files. >> >> But I think, we should still warn, if we find a sub-directory inside a >> directory we are going to remove. > > So far complaining about deleting non-empty directories is finding > real bugs. It does not appear that too many users that delete > non-empty directories. > > My plan moving forward is to see what has goofed and how hard it is to > change the callers to clean up after themselves. If it is not a pain > to fix the callers who forget to delete their attributes that looks > like the right way forward. > > It is certainly the principle of least surprise. Currently I expect that those attributes that are not deleted may actually be bugs as well. If a driver manually adds sysfs files after device_create/device_register the uevent will have already been sent and you can not safely use those attributes in when processing a hotplug event. Eric