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From:   Benjamin Coddington <bcodding@redhat.com>
To:     Anna Schumaker <anna@kernel.org>
Cc:     trond.myklebust@hammerspace.com, linux-nfs@vger.kernel.org
Subject: Re: [PATCH 2/2] NFS: drop unused nfs_direct_req bytes_left
Date:   Fri, 17 Nov 2023 06:21:01 -0500
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On 16 Nov 2023, at 17:11, Anna Schumaker wrote:

> On Thu, Nov 16, 2023 at 5:03 PM Benjamin Coddington <bcodding@redhat.com> wrote:
>>
>> On 16 Nov 2023, at 16:44, Anna Schumaker wrote:
>>
>>> Hi Ben,
>>>
>>> On Wed, Nov 15, 2023 at 4:34 PM Benjamin Coddington <bcodding@redhat.com> wrote:
>>>>
>>>> Now that we're calculating how large a remaining IO should be based
>>>> on the current request's offset, we no longer need to track bytes_left on
>>>> each struct nfs_direct_req.  Drop the field, and clean up the direct
>>>> request tracepoints.
>>>
>>> I've been having problems with xfstests generic/465 on all NFS
>>> versions after applying this patch. Looking at wireshark, the client
>>> appears to be resending the same reads over and over again. Have you
>>> seen anything like this in your testing?
>>
>> I have generic/465 failing before and after these two patches on pNFS SCSI..
>> but at least it completes.  If I run it without pNFS I can see the same
>> thing.. it just sends the same reads over and over.  I'll figure out why.
>
> Thanks! I have it failing normally as well, so that's expected. It's
> the hanging forever that's not :)

The direct read is returning 0 when there's data on the device.

Oh, the problem is probably that patch drops the update of dreq->max_count,
which I overlooked because of the double assignment.  Shame on me.

Ben