From owner-freebsd-hackers  Tue Sep  4 10:55: 2 2001
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Date: Wed, 5 Sep 2001 03:54:29 +1000 (EST)
From: Bruce Evans <bde@zeta.org.au>
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To: Maxim Sobolev <sobomax@FreeBSD.ORG>
Cc: Poul-Henning Kamp <phk@critter.freebsd.dk>,
	Brent Verner <brent@rcfile.org>, <current@FreeBSD.ORG>,
	<hackers@FreeBSD.ORG>
Subject: Re: Junior Kernel Hacker task: improve vnode->v_tag
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On Tue, 4 Sep 2001, Maxim Sobolev wrote:

> > [neither Maxim Sobolev nor Brent Verner wrote]
> > In message <20010904081337.A8968@rcfile.org>, Brent Verner writes:
> > >#include <newbie_kernel_hacker_warning.h>
> > >
> > >I've done a /cursory/ look over how this v_tag is used.  I'm not sure
> > >this is a simple/clean as you propose, since this is used in the
> > >IS_LOCKING_VFS macro, as well as in union_subr.c...
> >
> > Well, that is just too bad, because IS_LOCKING_VFS is wrong then.
> >
> > The places which inspect v_tag will have to be changed to use
> > strcmp() then...
>
> I think that we can add a new vnode flag, say VCANLOCK, so that each
> particular VFS can set it if it supports locking, which should allow
> to remove pre-defined VFS list from the IS_LOCKING_VFS macro. I can
> produce a patch if it sounds reasonably.

Since IS_LOCKING_VFS() is a temporary kludge, the correct fix is to remove
it (after fixing whatever it was for), not to add more cruft.

Bruce


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