From mboxrd@z Thu Jan  1 00:00:00 1970
From: hch@infradead.org (Christoph Hellwig)
Date: Thu, 11 Apr 2019 08:34:11 -0700
Subject: Some new bio merging behaviors in __bio_try_merge_page
In-Reply-To: <20190411080953.GE421@ming.t460p>
References: <85c5fa1a-a506-e26f-c354-1554d47d8b2b@huawei.com>
 <20190411070807.GA421@ming.t460p>
 <cb392476-a00e-09ce-fa6b-9e088242ecc6@huawei.com>
 <20190411080953.GE421@ming.t460p>
Message-ID: <20190411153411.GA16987@infradead.org>

On Thu, Apr 11, 2019@04:09:54PM +0800, Ming Lei wrote:
> I don't think it is a good behaviour to use bio->bi_max_vecs to limit
> max allowed page, you may see the idea from the naming simply...
> 
> If there were other such drivers, we may fix it easily, and the following
> patch should fix your issue:

Yep.  Consumers of the block layer really have no business at all
looking at bi_vcnt.