From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Slaby Subject: Re: Broken link in /sys/class/net/ [was: [GIT] Networking] Date: Sun, 30 Oct 2011 21:49:40 +0100 Message-ID: <4EADB864.3060702@suse.cz> References: <20111025.063206.2273357152859701628.davem@davemloft.net> <20111025131315.GA1899@suse.de> <4EAC8642.3050309@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Jiri Slaby , Greg KH , Linus Torvalds , David Miller , Mikulas Patocka , akpm@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: "Eric W. Biederman" Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:37153 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752100Ab1J3Utp (ORCPT ); Sun, 30 Oct 2011 16:49:45 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 10/30/2011 05:49 AM, Eric W. Biederman wrote: > Jiri Slaby writes: > >> On 10/25/2011 03:13 PM, Greg KH wrote: >>> On Tue, Oct 25, 2011 at 01:46:11PM +0200, Linus Torvalds wrote: >>>> Anyway, after that rant about really bad practices, let me say that I >>>> did fix up the conflict and I think it's right. But I won't guarantee >>>> it, so please check the changes to fs/sysfs/dir.c. >>> >>> I think it looks ok, I've booted the merge result, and am typing and >>> sending this from the new kernel, and it hasn't crashed yet :) >> >> Hi, maybe this was not caused by the merge, but the patch[1] causes this >> mess in /sys/class/net/ for me: >> l????????? ? ? ? ? ? eth1 >> >> This happens after one renames a net device -- the new name is eth1 here. >> >> [1] 4f72c0cab40 (sysfs: use rb-tree for name lookups) > > This looks pretty fixable but today sysfs_rename does not do anything > with the to move a renamed entry to a different position in the rbtree. > > If the directory itself changes sysfs_rename should be fine, and it > looks like a trivial patch to always apply the directory rename logic > in sysfs_rename. > > I think all we need is something like the untested patch below to fix > the network device rename problem. Looks like it works. Thanks. > diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c > index 48ffbdf..a294068 100644 > --- a/fs/sysfs/dir.c > +++ b/fs/sysfs/dir.c > @@ -865,14 +865,13 @@ int sysfs_rename(struct sysfs_dirent *sd, > sd->s_name = new_name; > } > > - /* Remove from old parent's list and insert into new parent's list. */ > - if (sd->s_parent != new_parent_sd) { > - sysfs_unlink_sibling(sd); > - sysfs_get(new_parent_sd); > - sysfs_put(sd->s_parent); > - sd->s_parent = new_parent_sd; > - sysfs_link_sibling(sd); > - } > + /* Move to the appropriate place in the appropriate directories rbtree. */ > + sysfs_unlink_sibling(sd); > + sysfs_get(new_parent_sd); > + sysfs_put(sd->s_parent); > + sd->s_parent = new_parent_sd; > + sysfs_link_sibling(sd); > + > sd->s_ns = new_ns; > > error = 0; > -- js suse labs