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Date: Fri, 26 Aug 2011 01:34:59 +0400
From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Vasiliy Kulikov <segoon@openwall.com>, Nathan Lynch <ntl@pobox.com>,
        Oren Laadan <orenl@cs.columbia.edu>,
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        Zan Lynx <zlynx@acm.org>, Andi Kleen <andi@firstfloor.org>
Subject: Re: [RFC] fs, proc: Introduce the /proc/<pid>/map_files/ directory v2
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On Thu, Aug 25, 2011 at 11:12:13PM +0200, Tejun Heo wrote:
> Hello, again.
> 
> On Thu, Aug 25, 2011 at 10:54:26PM +0200, Tejun Heo wrote:
> > Another thing is, I don't really see why we need vm_start, or fd for
> > that matter, in proc_inode at all.  proc_inode is created on the fly
> > only as dentry gets instantiated on demand, which means we always have
> > d_name on hand to tell what the file is supposed to point to.  In
> > fact, the code already uses name_to_int() to extract fd from d_name.
> > Hmmm... well yeah, it actually seems that proc_inode->fd is never used
> > and we can simply remove it.
> 
> Unfortunately, not quite as easy as I expected.  The information still
> seems redundant but it seems we'll need to change
> proc_inode->get_link() to take dentry instead of inode before doing
> away with proc_inode->fd, but, at any rate, I don't think this is a
> big deal one way or the other.
> 

Hohum... picking up an additional reference to dentry might be dangerous
I think. How exactly you imagine we would do that? (without this problem
I guess we indeed may drop or rather not change proc-inode).

	Cyrill