From: ebiederm@xmission•com (Eric W. Biederman)
To: Johannes Berg <johannes@sipsolutions•net>
Cc: Greg KH <gregkh@suse•de>,
Andrew Morton <akpm@linux-foundation•org>,
"Rafael J. Wysocki" <rjw@sisk•pl>,
"Maciej W. Rozycki" <macro@linux-mips•org>,
Kay Sievers <kay.sievers@vrfy•org>, Greg KH <greg@kroah•com>,
netdev <netdev@vger•kernel.org>
Subject: Re: [PATCH] sysfs: Don't allow the creation of symlinks we can't remove
Date: Thu, 22 Jul 2010 03:35:29 -0700 [thread overview]
Message-ID: <m1mxtjztvy.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <1279793435.12439.3.camel@jlt3.sipsolutions.net> (Johannes Berg's message of "Thu\, 22 Jul 2010 12\:10\:34 +0200")
Johannes Berg <johannes@sipsolutions•net> writes:
> On Thu, 2010-07-22 at 03:05 -0700, Eric W. Biederman wrote:
>
>> >> Detect this problem up front and simply don't create symlinks we won't
>> >> be able to remove later. This prevents symlink leakage and fails in
>> >> a much clearer and more understandable way.
>> >
>> > Eric, I was looking into sysfs netns support for wireless, and with this
>> > patch applied I just get the warning and no network interfaces.
>>
>> The warning patch just makes things fail faster. Although I get some of the
>> wireless interfaces for hwsim when I use this one.
>
> Hmm, I didn't.
To be clear I just get hwsim0. Not wlan0 or wlan1.
>> > Was there any patch that was supposed to fix hwsim?
>>
>> - If you have my patches that fix CONFIG_SYSFS_DEPRECATED,
>> you should find everything works there.
>
> But then I was carrying those two patches too.
>
>> As for a proper fix I have just resent my one liner to
>> drives/base/core.c I can't think of a better option right now.
>>
>> For hwsim it is arguable, but the behaviour of sysfs for the
>> bluetooth bnep driver is very clearly a 3 year old regression,
>> and the cause is exactly the same.
>
> Right, it actually starts working again with that patch you sent.
> However, netns support is really broken:
>
> <create net namespace, put phy0/wlan0 into it>
Do we have a convenient command line tool to do this?
I remember there being a different netlink message from
normal network devices.
> root@kvm:~# ip link
> 3: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
> link/ether 02:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
> 7: lo: <LOOPBACK> mtu 16436 qdisc noop state DOWN
> link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
> root@kvm:~# ls /sys/class/net/
> eth0 hwsim0 lo wlan1 wlan2
I think this is actually the output of something working.
I expect after you created a new netns you didn't mount
a new instance of /sys. /sys remembers which netns you
had when you mounted it. So you have to mount /sys again
so you can see the /sys/class/net for the network namespace
you are in.
Eric
next prev parent reply other threads:[~2010-07-22 10:35 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <bug-16257-10286@https.bugzilla.kernel.org/>
[not found] ` <20100621150826.762ac9f2.akpm@linux-foundation.org>
2010-06-21 22:22 ` [Bugme-new] [Bug 16257] New: sysfs changes break hwsim and bnep drivers Eric W. Biederman
2010-06-21 22:29 ` Greg KH
2010-06-21 22:55 ` Eric W. Biederman
2010-06-21 23:10 ` Greg KH
2010-06-22 0:05 ` Eric W. Biederman
2010-06-22 3:56 ` Greg KH
2010-07-08 16:31 ` [PATCH] sysfs: Don't allow the creation of symlinks we can't remove Eric W. Biederman
2010-07-08 16:37 ` [RFC][PATCH] mac80211_hwsim: No parent is better than an illegimate one Eric W. Biederman
2010-07-12 6:46 ` Johannes Berg
2010-07-12 14:23 ` Eric W. Biederman
2010-07-12 14:29 ` Johannes Berg
2010-07-08 21:19 ` [PATCH] sysfs: Don't allow the creation of symlinks we can't remove Greg KH
2010-07-08 22:28 ` Eric W. Biederman
2010-07-08 23:06 ` Greg KH
2010-07-19 20:34 ` Andrew Morton
2010-07-20 20:13 ` Greg KH
2010-07-21 5:08 ` [PATCH 0/2] Support untagged symlinks to tagged directories Eric W. Biederman
2010-07-21 5:10 ` [PATCH 1/2] sysfs: sysfs_delete_link handle symlinks from untagged " Eric W. Biederman
2010-07-21 5:12 ` [PATCH 2/2] sysfs: allow creating " Eric W. Biederman
2010-07-21 19:02 ` [PATCH 0/2] Support untagged symlinks " Greg KH
2010-07-21 20:20 ` Eric W. Biederman
2010-07-21 20:36 ` Greg KH
2010-07-22 9:16 ` [PATCH] Driver-core: Fix bluetooth network device rename regression Eric W. Biederman
2010-07-22 13:38 ` Kay Sievers
2010-07-22 14:10 ` Johannes Berg
2010-07-22 15:30 ` Kay Sievers
2010-07-22 17:18 ` Eric W. Biederman
2010-07-22 17:44 ` Kay Sievers
2010-07-22 18:20 ` Johannes Berg
2010-07-22 18:28 ` Greg KH
2010-07-22 18:36 ` Johannes Berg
2010-07-22 18:54 ` Greg KH
2010-07-23 1:31 ` Eric W. Biederman
2010-07-26 18:09 ` Greg KH
2010-07-27 9:10 ` Kay Sievers
2010-07-27 13:49 ` Greg KH
2010-07-27 13:59 ` Johannes Berg
2010-07-27 15:09 ` Greg KH
2010-07-27 15:32 ` Kay Sievers
2010-07-27 18:17 ` Eric W. Biederman
2010-07-27 18:24 ` Kay Sievers
2010-07-27 18:36 ` Greg KH
2010-07-27 18:44 ` Eric W. Biederman
2010-07-27 18:54 ` Kay Sievers
2010-07-27 20:53 ` Eric W. Biederman
2010-07-28 4:41 ` Kay Sievers
2010-07-28 5:12 ` Eric W. Biederman
2010-07-28 5:26 ` Kay Sievers
2010-07-28 7:57 ` Eric W. Biederman
2010-07-25 5:43 ` [PATCH] Driver-core: Always create class directories for classses that support namespaces Eric W. Biederman
2010-07-26 18:07 ` Greg KH
2010-07-22 23:03 ` [PATCH] Driver-core: Fix bluetooth network device rename regression Kay Sievers
2010-07-10 22:30 ` [PATCH] sysfs: Don't allow the creation of symlinks we can't remove Maciej W. Rozycki
2010-07-22 9:54 ` Johannes Berg
2010-07-22 10:05 ` Eric W. Biederman
2010-07-22 10:10 ` Johannes Berg
2010-07-22 10:35 ` Eric W. Biederman [this message]
2010-07-22 10:41 ` Johannes Berg
2010-07-22 11:27 ` Eric W. Biederman
2010-07-22 11:30 ` Johannes Berg
2010-07-08 16:55 ` [Bugme-new] [Bug 16257] New: sysfs changes break hwsim and bnep drivers Eric W. Biederman
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