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Date:   Thu, 22 Jul 2021 10:34:23 -0400
From:   "bfields@fieldses.org" <bfields@fieldses.org>
To:     Trond Myklebust <trondmy@hammerspace.com>
Cc:     "schumakeranna@gmail.com" <schumakeranna@gmail.com>,
        "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
        "bfields@redhat.com" <bfields@redhat.com>,
        "daire@dneg.com" <daire@dneg.com>
Subject: Re: [PATCH 3/3] nfs: don't allow reexport reclaims
Message-ID: <20210722143423.GB4552@fieldses.org>
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On Mon, Jun 14, 2021 at 09:03:35PM +0000, Trond Myklebust wrote:
> I want to avoid the kind of issues we've be met with earlier when
> mixing types just because they happened to be integer valued.
> 
> We introduced the mixing of POSIX/Linux and NFS errors in the NFS
> client back in the 1990s, and that was a mistake that we're still
> paying for. For instance, the value ERR_PTR(-NFSERR_NO_GRACE) will be
> happily declared as a valid pointer by the IS_ERR() test, and every so
> often we find an Oops around that issue because someone used the return
> value from a function that they thought was POSIX/Linux error valued,
> because it usually is returning POSIX errors.

I did this, by the way, but also ran across a couple more bugs in
testing.

At this point I've got connectathon locking tests passing on a
re-export--I need to do a little more cleanup and then I'll repost.

--b.