From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [BUG -next] sysfs change breaks userspace Date: Thu, 31 Oct 2013 13:25:06 -0400 Message-ID: <20131031172506.GE11698@mtj.dyndns.org> References: <20131031114358.GA5551@osiris> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-yh0-f49.google.com ([209.85.213.49]:62944 "EHLO mail-yh0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752769Ab3JaRbE (ORCPT ); Thu, 31 Oct 2013 13:31:04 -0400 Received: by mail-yh0-f49.google.com with SMTP id a41so1350877yho.36 for ; Thu, 31 Oct 2013 10:31:03 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20131031114358.GA5551@osiris> Sender: linux-next-owner@vger.kernel.org List-ID: To: Heiko Carstens Cc: Greg Kroah-Hartman , Kay Sievers , linux-next@vger.kernel.org Hello, Heiko. On Thu, Oct 31, 2013 at 12:43:58PM +0100, Heiko Carstens wrote: > Hi Tejun, > > I just tried out linux-next and my network doesn't come up anymore. > Userspace fails like this: > > network[2211]: Bringing up interface eth0: sysfs read broadcast value: Invalid argument > > I bisected that down to: > > commit 13c589d5b0ac654d9da7e490a2dd548e6b86b4a5 > Author: Tejun Heo > Date: Tue Oct 1 17:42:02 2013 -0400 > > sysfs: use seq_file when reading regular files Heh, intereting. The content doesn't change over multiple show invocations, so the behavior shouldn't change at all for the attribute and seq_file handles seeking and partial reads correctly. No idea what could go wrong there. It probably was reading /sys/devices/BLAHBLAH/net/NETIF/broadcast file. Can you please locate the file and do "ls -l" and "cat" on it? If that looks normal, can you please strace the network interface config program / script / whatever? BTW, what are you running on the system? Thanks. -- tejun