Message-ID: <20080603211045.z5e6w0z88c8kssgo@intran0x.frec.bull.fr>
Date: Tue, 03 Jun 2008 21:10:45 +0200
From: "Benjamin Thery " <Benjamin.Thery@bull.net>
To: Greg KH <gregkh@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
       Eric Biederman <ebiederm@xmission.com>, Serge Hallyn <serue@us.ibm.com>,
       linux-kernel@vger.kernel.org, Tejun Heo <htejun@gmail.com>,
       Al Viro <viro@ftp.linux.org.uk>, Daniel Lezcano <dlezcano@fr.ibm.com>
Subject: Re: [PATCH 09/10] netns: Enable tagging for net_class directories
	in sysfs
References: <20080602134438.224352910@theryb.frec.bull.fr>
	<20080602134439.782528644@theryb.frec.bull.fr>
	<20080603040818.GA18507@suse.de> <48456225.6070505@bull.net>
	<20080603163514.GB544@suse.de>
In-Reply-To: <20080603163514.GB544@suse.de>
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Quoting Greg KH <gregkh@suse.de>:

> On Tue, Jun 03, 2008 at 05:24:21PM +0200, Benjamin Thery wrote:
>> Greg KH wrote:
>>> On Mon, Jun 02, 2008 at 03:46:08PM +0200, Benjamin Thery wrote:
>>>> net: Enable tagging for net_class directories in sysfs
>>>>
>>>> The problem.  Network devices show up in sysfs and with the network
>>>> namespace active multiple devices with the same name can show up in
>>>> the same directory, ouch!
>>>>
>>>> To avoid that problem and allow existing applications in network
>>>> namespaces
>>>> to see the same interface that is currently presented in sysfs, this
>>>> patch enables the tagging directory support in sysfs.
>>>>
>>>> By using the network namespace pointers as tags to separate out the
>>>> the sysfs directory entries we ensure that we don't have conflicts
>>>> in the directories and applications only see a limited set of
>>>> the network devices.
>>> I don't like it how the network subsystem is starting to leach into the
>>> sysfs core here.  What happens when the next subsystem wants to do the
>>> same thing?  And then the next one?  Will they all have to do this kind
>>> of intrusive changes to sysfs?
>> >
>> > Can't this be done only in the network subsystem?
>>
>> I'm not sure to understand exactly what you mean.
>>
>> What you don't like is seeing these hunks of network code in
>> fs/sysfs/mount.c? And you prefer to see these bits of code resides in
>> the network subsystem instead and see only "generic" sysfs services in
>> fs/sysfs/mount.c?
>
> Yes, exactly.
>
> I don't want the problem that if more subsystems want to implement
> something like this, they too need to modify the sysfs core.
>
> And the mess with the #ifdef, that's not nice either :)

OK. This is clear now :)

>> If this is it, I have some idea to implement a less intrusive
>> sysfs_net_exit(), which can be shared with the other namespaces.
>> Serge introduces the same kind of changes in patch 10 to fix an issue in
>> user namespace. I think we can share a bit of code and move the parts
>> specific to each namespace in their own subsystems.
>
> I think that would be a good idea.  Care to redo the series?

I'm already working on it.
I'll try to re-post in a couple of days.

Benjamin

>
> thanks,
>
> greg k-h
>
>


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