Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   "Benjamin Coddington" <bcodding@redhat.com>
To:     "Rue Mohr" <sn0297@sunshine.net>
Cc:     linux-nfs@vger.kernel.org
Subject: Re: nfs kernel server bug
Date:   Mon, 08 Feb 2021 06:58:38 -0500
Message-ID: <5B1E0F4D-F26F-4CB5-858A-E49D0819C864@redhat.com>
In-Reply-To: <602020C9.50705@sunshine.net>
References: <602020C9.50705@sunshine.net>
MIME-Version: 1.0
Content-Type: text/plain; format=flowed
Precedence: bulk

On 7 Feb 2021, at 12:18, Rue Mohr wrote:

> I'm having an issue where the kernel server is dishing out all zeros 
> for file content being read over NFS. The file byte count is correct.
> Writing files is fine.
> With the same client, a different server works just fine.
>
> I have been trying to pin this down, so far all I know is that the 
> packets from the server actually contain zeros for the file contents.
>
> The troubled server kernel is 5.4.1
>
> Has anyone encountered this or is it just me?

Haven't heard of this before, but sounds like a fascinating problem.

What version of nfs, and what security?  You're seeing READ operations 
returning
with rsize-ed blocks of all-zero data in a network capture?

Ben