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Date: Wed, 1 Jun 2016 06:44:27 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Ming Lei <ming.lei@canonical.com>
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Cc: linux-block@vger.kernel.org, Michal Hocko <mhocko@suse.com>,
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Subject: Re: [Drbd-dev] [PATCH v6 0/8] block: prepare for multipage bvecs
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On Wed, Jun 01, 2016 at 08:38:41PM +0800, Ming Lei wrote:
> > be dm-crypt.c.  Maybe you've identified some indirect use of
> > BIO_MAX_SIZE?
> 
> I mean the recently introduced BIO_MAX_SIZE in -next tree:
> 
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/drivers/md/dm-crypt.c?id=4ed89c97b0706477b822ea2182827640c0cec486

The crazy bcache bios striking back once again.  I really think it's
harmful having a _MAX value and then having a minor driver
reinterpreting it and sending larger ones.  Until we can lift the
maximum limit in general nad have common code exercise it we really need
to stop bcache from sending these instead of littering the tree with
workarounds.