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Date:   Thu, 15 Jun 2023 10:55:47 +0200
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Subject: Re: Regression: NULL pointer dereference after NFS_V4_2_READ_PLUS
 (commit 7fd461c47)
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From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To:     Anna Schumaker <schumaker.anna@gmail.com>
Cc:     Trond Myklebust <trondmy@hammerspace.com>,
        Anna Schumaker <Anna.Schumaker@netapp.com>,
        linux-nfs <linux-nfs@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "regressions@lists.linux.dev" <regressions@lists.linux.dev>
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On 15/06/2023 10:52, Krzysztof Kozlowski wrote:
> On 14/06/2023 22:55, Anna Schumaker wrote:
>>>>> Still null ptr (built on 420b2d4 with your patch):
>>>>
>>>> We're through the merge window and at rc1 now, so I can spend more
>>>> time scratching my head over your bug again. We've come up with a
>>>> patch (attached) that adds a bunch of printks to show us what the
>>>> kernel thinks is going on. Do you mind trying it out and letting us
>>>> know what gets printed out? You'll need to make sure
>>>> CONFIG_NFS_V4_2_READ_PLUS is enabled when compiling the kernel.
>>>
>>> The patch does not apply. I tried: v6.4-rc1, v6.4-rc5, next-20230609.
>>
>> Can you try the attached patch on top of my 3-patch series from the
>> other day, and let me know what gets printed out? It adds a bunch of
>> printk()s at strategic points to print out what is going on with the
>> xdr scratch buffer since it's suddenly a bad memory address after
>> working for a bit on your machine.
>>
> 
> Here you have entire log - attached (113 kB, I hope goes past mailing
> lists/spam filters).

As expected this bounced from the mailing lists, but I hope you got it.
If not, let me know.

Best regards,
Krzysztof