Subject: Re: problem with tmpfs and linux emulation?
To: Bill Studenmund <email@example.com>
From: Perry E. Metzger <firstname.lastname@example.org>
Date: 11/12/2005 12:58:41
Bill Studenmund <email@example.com> writes:
> On Thu, Nov 10, 2005 at 10:50:07PM +0000, Matthias Scheler wrote:
>> In article <43722C24.firstname.lastname@example.org>,
>> Matt Thomas <email@example.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 itself.
>> Yes, indeed.
>> > This would be filesystem independent. And ugly as hell.
>> Why? Figuring out that it is a directory can be done by looking on the vnode.
> I think the problem is that the layering doesn't make this convenient. The
> level that can easily see the vnode, the vn layer, is deep past the place
> where we abstract away the emulation. So we either add a hook to determine
> emulation, teach all emulations how to read directories, or cook up a way
> so that linux opens of directories get a different vn vector which will do
> the right thing.
Could the linux emulation version of open do an implicit fstat as its