From owner-freebsd-arch  Wed Apr  4 17:23: 8 2001
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From: Terry Lambert <tlambert@primenet.com>
Message-Id: <200104050022.RAA02886@usr08.primenet.com>
Subject: Re: Eliminate crget() from nfs kernel code?
To: dillon@earth.backplane.com (Matt Dillon)
Date: Thu, 5 Apr 2001 00:22:52 +0000 (GMT)
Cc: rwatson@FreeBSD.ORG (Robert Watson), freebsd-arch@FreeBSD.ORG
In-Reply-To: <200104032129.f33LTmj70619@earth.backplane.com> from "Matt Dillon" at Apr 03, 2001 02:29:48 PM
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[NFS use of crget()]

>     Hmm.  It's hard to say.  The standard doesn't say anything about
>     the credential needing to be root/wheel over the wire for statfs(),
>     but if we change it we will probably break someone somewhere.

It's implicit in the fact that results caching is permitted; that
means that the results you get need to be valid for everyone.  The
only way to assure this is to use a credential that can always get
results.  The only alternative is not to cache.

You convert the results based on local application of the credentials
to the information.

Yes, I know the status of caching and stacking layer based implied
caching in FreeBSD-current.  It does not refute the argument.


>     I think you want to keep crget()/crfree() if possible, just so you
>     don't have to worry about the data being sent over the wire breaking
>     some poor sod.  But if you want to bite the bullet and use the process
>     ucred I'd say go for it - keep a careful watch for complaints of
>     FreeBSD suddenly failing against various NFS servers though.

Note that this means you must keep the processes from which you
derive the data around, so if you have a stalled call blocked on
a server reboot (for example), you cause a lot of problems.


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.

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