Subject: Re: problem with tmpfs and linux emulation?
To: Matthias Scheler <tron@zhadum.org.uk>
From: Bill Studenmund <wrstuden@netbsd.org>
List: current-users
Date: 11/10/2005 16:05:02
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On Thu, Nov 10, 2005 at 10:50:07PM +0000, Matthias Scheler wrote:
> In article <43722C24.7020308@3am-software.com>,
> 	Matt Thomas <matt@3am-software.com> writes:
> > This implies that the linux_sys_read syscall (and friends) needs to know
> > if it's reading from a directory, and if so, do the getdents dance itse=
lf.
>=20
> Yes, indeed.
>=20
> > This would be filesystem independent.  And ugly as hell.
>=20
> Why? Figuring out that it is a directory can be done by looking on the vn=
ode.

I think the problem is that the layering doesn't make this convenient. The=
=20
level that can easily see the vnode, the vn layer, is deep past the place=
=20
where we abstract away the emulation. So we either add a hook to determine=
=20
emulation, teach all emulations how to read directories, or cook up a way=
=20
so that linux opens of directories get a different vn vector which will do=
=20
the right thing.

Take care,

Bill

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