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Date:   Wed, 28 Jun 2023 14:45:50 -0600
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Subject: Re: [GIT PULL] bcachefs
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To:     Kent Overstreet <kent.overstreet@linux.dev>
Cc:     torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-bcachefs@vger.kernel.org,
        Christoph Hellwig <hch@lst.de>
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From:   Jens Axboe <axboe@kernel.dk>
In-Reply-To: <20230628175608.hap54mrx54owdkyg@moria.home.lan>
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On 6/28/23 11:56?AM, Kent Overstreet wrote:
> On Wed, Jun 28, 2023 at 09:22:15AM -0600, Jens Axboe wrote:
>> On 6/28/23 8:58?AM, Jens Axboe wrote:
>>> I should have something later today, don't feel like I fully understand
>>> all of it just yet.
>>
>> Might indeed be delayed_fput, just the flush is a bit broken in that it
>> races with the worker doing the flush. In any case, with testing that, I
>> hit this before I got an umount failure on loop 6 of generic/388:
>>
>> fsck from util-linux 2.38.1
>> recovering from clean shutdown, journal seq 14642
>> journal read done, replaying entries 14642-14642
>> checking allocations
>> starting journal replay, 0 keys
>> checking need_discard and freespace btrees
>> checking lrus
>> checking backpointers to alloc keys
>> checking backpointers to extents
>> backpointer for missing extent
>>   u64s 9 type backpointer 0:7950303232:0 len 0 ver 0: bucket=0:15164:0 btree=extents l=0 offset=0:0 len=88 pos=1342182431:5745:U32_MAX, not fixing
> 
> Known bug, but it's gotten difficult to reproduce - if generic/388 ends
> up being a better reproducer for this that'll be nice

Seems to reproduce in anywhere from 1..4 iterations for me.

-- 
Jens Axboe