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Date:   Wed, 3 Jul 2019 03:35:36 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Christoph Hellwig <hch@lst.de>, Matias Bjorling <mb@lightnvm.io>,
        linux-block@vger.kernel.org
Subject: Re: remove bi_phys_segments and related cleanups
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On Tue, Jul 02, 2019 at 07:32:40PM -0600, Jens Axboe wrote:
> The issue is a discard request, 4kb, with a bio but no bi_io_vec.
> The sync is a red herring, apart from the fact that it triggers
> the ext4 discards.
> 
> I'm guessing, when you tried to reproduce, that you didn't have discard
> enabled?

I didn't run with online discard, but I tried FITRIM (with XFS).

I'll try looking into ext4.  I remember we had some weird one offs in that
area for the different ways the physical segments are calculated, so this
makes sense.  Off to dinner now, but I'll look into it tomorrow.