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Date: Thu, 19 Feb 2009 22:09:43 +0100
From: Ed Schouten <ed@80386.nl>
To: Roman Divacky <rdivacky@FreeBSD.org>
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Subject: Re: Making Linux stat() less evil
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* Roman Divacky <rdivacky@FreeBSD.org> wrote:
> why cant you use kern_statat() and perform this after it returns?
>=20
> +		if (S_ISCHR(sb.st_mode) && nd.ni_vp->v_un.vu_cdev !=3D NULL &&
> +		    linux_driver_get_major_minor(
> +		        nd.ni_vp->v_un.vu_cdev->si_name, &major, &minor) =3D=3D 0) {
> +			sb.st_rdev =3D (major << 8 | minor);
> +		}

Because I want to use the vnode used by kern_statat() directly. If we
perform a second lookup after the call to kern_statat(), it's a race.
There is no guarantee you're looking at the same vnode.

--=20
 Ed Schouten <ed@80386.nl>
 WWW: http://80386.nl/

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