Subject: Re: vop_symlink and unused vpp?
To: Assar Westerlund <assar@netbsd.org>
From: Bill Studenmund <wrstuden@zembu.com>
List: tech-kern
Date: 07/19/2001 10:19:11
On 19 Jul 2001, Assar Westerlund wrote:
> I did vop_mknod too, and I got another question for you. Is
> layer_bypass going to be happy and should I apply this comment fix?
The important line of the comment is the one which got left out. :-)
* So all the calls which get us here have a locked vpp. :-)
As I believe you were changing the locking rules so that the *vpp comes
back locked, all will be well.
The one thing I'm unclear on (partly as I wasn't fully paying
attention :-) is that one of the other comments will hold true (just above
it):
* (Assumes that the lower layer always returns
* a VREF'ed vpp unless it gets an error.)
i.e. we always get passed a &vp - we never pass in NULL - and the lower fs
always fills one in if it doesn't return an error.
Take care,
Bill
> /assar
>
> Index: layer_vnops.c
> ===================================================================
> RCS file: /cvsroot/syssrc/sys/miscfs/genfs/layer_vnops.c,v
> retrieving revision 1.6
> diff -u -w -u -w -r1.6 layer_vnops.c
> --- layer_vnops.c 2001/06/07 13:32:47 1.6
> +++ layer_vnops.c 2001/07/19 12:45:50
> @@ -393,8 +393,7 @@
> descp->vdesc_vpp_offset,ap);
> /*
> * Only vop_lookup, vop_create, vop_makedir, vop_bmap,
> - * vop_mknod, and vop_symlink return vpp's. The latter
> - * two are VPP_WILLRELE, so we won't get here, and vop_bmap
> + * vop_mknod, and vop_symlink return vpp's. vop_bmap
> * doesn't call bypass as the lower vpp is fine (we're just
> * going to do i/o on it). vop_loookup doesn't call bypass
> * as a lookup on "." would generate a locking error.
>