Subject: Re: port-xen/29775: Cannot use a vnode disk for domU
To: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: tech-kern
Date: 03/31/2005 12:23:44
On Thu, Mar 31, 2005 at 08:43:07AM +0900, YAMAMOTO Takashi wrote:
> > > i believe it's a problem in xbd, not in vnd.
> > > doing vnode operations from interrupt context is evil.
> > 
> > Yes, but it's vnd that is doing those from interrupt context.
> 
> xbd does VOP_STRATEGY.  it's the root of the problem in this PR.

It does VOP_STRATEGY() against a vnode which points to a device, so
it should be the same as DEV_STRATEGY(), isn't it ?

When xbd points to a vnd, it will call vndstrategy() from interrupt
context (though VOP_STRATEGY() on a vnode pointing to /dev/vnd0?).
This is what this PR is about.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--