proc/bus.usb regression in : [NETNS]: Fix /proc/net breakage

[Giacomo Catenazzi <cate@cateee.net>]

Andrew Morton wrote:
> On Mon, 3 Dec 2007 19:00:25 GMT Linux Kernel Mailing List <linux-kernel@vger.kernel.org> wrote:
> 
>> Gitweb:     http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2b1e300a9dfc3196ccddf6f1d74b91b7af55e416
>> Commit:     2b1e300a9dfc3196ccddf6f1d74b91b7af55e416
>> Parent:     e03ba84adb62fbc6049325a5bc00ef6932fa5e39
>> Author:     Eric W. Biederman <ebiederm@xmission.com>
>> AuthorDate: Sun Dec 2 00:33:17 2007 +1100
>> Committer:  Herbert Xu <herbert@gondor.apana.org.au>
>> CommitDate: Sun Dec 2 00:33:17 2007 +1100
>>
>>     [NETNS]: Fix /proc/net breakage
>>     
>>     Well I clearly goofed when I added the initial network namespace support
>>     for /proc/net.  Currently things work but there are odd details visible to
>>     user space, even when we have a single network namespace.
>>     
>>     Since we do not cache proc_dir_entry dentries at the moment we can just
>>     modify ->lookup to return a different directory inode depending on the
>>     network namespace of the process looking at /proc/net, replacing the
>>     current technique of using a magic and fragile follow_link method.
>>     
>>     To accomplish that this patch:
>>     - introduces a shadow_proc method to allow different dentries to
>>       be returned from proc_lookup.
>>     - Removes the old /proc/net follow_link magic
>>     - Fixes a weakness in our not caching of proc generic dentries.
>>     
>>     As shadow_proc uses a task struct to decided which dentry to return we can
>>     go back later and fix the proc generic caching without modifying any code
>>     that uses the shadow_proc method.
> 
> This patch caused the binfmt_misc regression reported in
> http://bugzilla.kernel.org/show_bug.cgi?id=9504

This patch also doesn't allow to mount /proc/bus/usb

ciao
	cate