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Message-ID: <ab1c2512-7dd6-5246-7213-077022a85c2f@squashfs.org.uk>
Date:   Mon, 3 Apr 2023 14:57:02 +0100
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Subject: Re: [PATCH 1/2] block: Rework bio_for_each_segment_all()
To:     Kent Overstreet <kent.overstreet@linux.dev>
Cc:     linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        willy@infradead.org, axboe@kernel.dk,
        Ming Lei <ming.lei@redhat.com>
References: <20230327174402.1655365-1-kent.overstreet@linux.dev>
 <20230327174402.1655365-2-kent.overstreet@linux.dev>
 <52a5bd5c-d3a1-71d7-e1e5-7965501818bd@squashfs.org.uk>
 <ZCXNDQ6Eslhj+9g5@moria.home.lan>
 <4753802a-685f-ab56-fed2-22d6eb4cfccd@squashfs.org.uk>
 <5ab59623-4317-5aff-5173-d7285b5b224c@squashfs.org.uk>
 <ZCeW6j44aHGI/v5Q@moria.home.lan>
From:   Phillip Lougher <phillip@squashfs.org.uk>
In-Reply-To: <ZCeW6j44aHGI/v5Q@moria.home.lan>
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On 01/04/2023 03:28, Kent Overstreet wrote:
> On Fri, Mar 31, 2023 at 02:10:15AM +0100, Phillip Lougher wrote:
>> On 30/03/2023 19:59, Phillip Lougher wrote:
>>> On 30/03/2023 18:55, Kent Overstreet wrote:
>>>> On Wed, Mar 29, 2023 at 05:50:27PM +0100, Phillip Lougher wrote:
>>>>> There is a problem with the above code, on testing I get the following
>>>>> results:
>>>>>
>>>>> Index 78018785329, offset 49, bvec.bv_len 1024: In same bio,
>>>>> metadata length
>>>>> 32780
>>>>
>>>> Could you share how you're doing your testing? I set up a basic test
>>>> (created images using every compression type, tested reading them) and
>>>> so far I'm not able to reproduce this.
>>>
>>> I use a very large Squashfs file that triggers the edge case.
>>>
>>> That is too big to post, and so I'll see if I can artifically generate
>>> a small Squashfs filesystem that triggers the edge case.
>>>
>>> Phillip
>>>
>>>
>>
>> Hi,
>>
>> This is a Google drive link to a file that triggers the issue.
>>
>> https://drive.google.com/file/d/1-3-a1BKq62hZGQ6ynioreMSWFMuCV9B4/view?usp=sharing
>>
>> To reproduce the issue
>>
>> % mount -t squashfs <the file> /mnt -o errors=panic
>>
>> then either one of the following will produce a panic
>>
>> % ls /mnt
>> % find /mnt -type f | xargs wc > /dev/null
> 
> Appears to be fixed now - updated version of the patchset is at
> https://evilpiepirate.org/git/bcachefs.git bio_folio_iter
> 
> Can you confirm, then I'll mail out the updated series?

Thw updated patch-set fixes the issues seen.

Phillip