From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [patch 03/15] cgroup: dont call vfs_mkdir
Date: Mon, 5 May 2008 07:00:16 -0400
Message-ID: <20080505110016.GC20910@infradead.org>
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To: Miklos Szeredi <miklos@szeredi.hu>
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On Mon, May 05, 2008 at 11:54:44AM +0200, Miklos Szeredi wrote:
> From: Miklos Szeredi <mszeredi@suse.cz>
> 
> cgroup_clone() calls vfs_mkdir() to create a directory in the cgroup
> filesystem.  Replace with explicit call to cgroup_mkdir() and
> fsnotify_mkdir().
> 
> This is equivalent, except that the following functions are not called
> before cgroup_mkdir():
> 
>  - may_create()
>  - security_inode_mkdir()
>  - DQUOT_INIT()
> 
> Permission to clone the cgroup has already been checked in
> copy_namespaces() (requiring CAP_SYS_ADMIN).  Additional file system
> related capability checks are inappropriate and confusing.
> 
> The quota check is unnecessary, as quotas don't make any sense for
> this filesystem.

Looks correct but I don't think it's a good idea.  Spreading more logic
into filesystems without a good reason is rarely a good idea.