linux-kernel - Re: [PATCH v1 00/10] vfs: getname/putname overhaul

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Date:	Fri, 7 Sep 2012 20:54:18 -0400
From:	Jeff Layton <jlayton@...hat.com>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	viro@...iv.linux.org.uk, eparis@...hat.com, linux-audit@...hat.com,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 00/10] vfs: getname/putname overhaul

On Fri, 07 Sep 2012 14:26:56 -0700
Andi Kleen <andi@...stfloor.org> wrote:

> Jeff Layton <jlayton@...hat.com> writes:
> 
> > This patchset is a first pass at overhauling the getname/putname
> > interface to use a struct. The idea here is to add a new getname_info
> > struct that allow us to pass around some auxillary info along with
> > the string that getname() returns.
> 
> Couldn't you just use some of the free pointers in struct page?
> (lru etc.)
> 
> -Andi
> 

We could do that if these were page allocations. They're not, however.
__getname() does a PATH_MAX size allocation out of a slabcache. I get
the impression that at one point, this was done with page allocations.
I assume that this was changed over to a slabcache since not all arches
have a 4k PAGE_SIZE.

That's not a bad idea though. We could switch __getname over to doing a
page allocation instead, but it would mean quite a bit of wasted space
on arches with >4k pages. That said, these allocations are generally
quite short-lived so maybe that's not such a big deal.
-- 
Jeff Layton <jlayton@...hat.com>
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