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From:   John Stultz <john.stultz@linaro.org>
Date:   Tue, 23 Feb 2021 14:46:13 -0800
Message-ID: <CALAqxLU5AU2jhEe=pa0=ye=8uYQeAw-4T86c36qCTipe9JE3OA@mail.gmail.com>
Subject: Re: [REGRESSION] "split bio_kmalloc from bio_alloc_bioset" causing
 crash shortly after bootup
To:     Christoph Hellwig <hch@lst.de>
Cc:     Johannes Thumshirn <johannes.thumshirn@wdc.com>,
        Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>,
        Damien Le Moal <damien.lemoal@wdc.com>,
        Jens Axboe <axboe@kernel.dk>,
        David Anderson <dvander@google.com>,
        Alistair Delva <adelva@google.com>,
        Todd Kjos <tkjos@google.com>,
        Amit Pundir <amit.pundir@linaro.org>,
        YongQin Liu <yongqin.liu@linaro.org>,
        lkml <linux-kernel@vger.kernel.org>, linux-block@vger.kernel.org,
        Satya Tangirala <satyat@google.com>
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Precedence: bulk

On Mon, Feb 22, 2021 at 11:22 PM Christoph Hellwig <hch@lst.de> wrote:
>
> On Tue, Feb 23, 2021 at 08:04:08AM +0100, Christoph Hellwig wrote:
> > The problem is that the blk-crypto fallback code calls bio_split
> > with a NULL bioset.  That was aready broken before, as the mempool
> > needed to guarantee forward progress was missing, but is not fatal.
> >
> > Satya, can you look into adding a mempool that can guarantees forward
> > progress here?
>
> Something like this would be the minimum viable fix:

This seems to work for me!

Tested-by: John Stultz <john.stultz@linaro.org>

thanks
-john