Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 18 Sep 2005 19:07:05 -0400
From:      Kris Kennaway <kris@obsecurity.org>
To:        Erez Zadok <ezk@cs.sunysb.edu>
Cc:        freebsd-fs@freebsd.org, christos@zoulas.com
Subject:   Re: turning off the NFS attribute cache
Message-ID:  <20050918230705.GA54054@xor.obsecurity.org>
In-Reply-To: <200509182257.j8IMvqgb008168@agora.fsl.cs.sunysb.edu>
References:  <200509182257.j8IMvqgb008168@agora.fsl.cs.sunysb.edu>

next in thread | previous in thread | raw e-mail | index | archive | help

--zYM0uCDKw75PZbzx
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Sun, Sep 18, 2005 at 06:57:52PM -0400, Erez Zadok wrote:

> After fixing this in Amd, I went on to verify that things work for other
> OSs.  When I got to FreeBSD 4.6, I found that it always caches directory
> entries, and there is no way to turn it off completely.  Specifically, if I
> set the ac{reg,dir}{min,max} fields in struct nfs_args all to zero, the
> kernel seems to cache the entries for a default number of seconds (I counted
> something like 5 seconds).  On some OSs, setting these four fields to 0
> turns off the attribute cache, but not on FreeBSD 4.6.  I was able to verify
> this using Amd and a script that exercises the interaction of the kernel's
> attrcache and Amd.  I didn't look at the kernel sources (yet) but I'm pretty
> certain of this behavior.

FreeBSD 4.6 is, frankly, ancient..are you certain this still applies
to modern versions?

Kris

--zYM0uCDKw75PZbzx
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2 (FreeBSD)

iD8DBQFDLfMYWry0BWjoQKURAuPZAJ4mmuTjutcTlrASTsMjJogD4cPD7wCfW9wX
ivA394W6wtdqa+G3rB9A/zc=
=wQ4m
-----END PGP SIGNATURE-----

--zYM0uCDKw75PZbzx--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050918230705.GA54054>