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Date:   Mon, 8 Mar 2021 11:01:01 +0800
From:   Gao Xiang <hsiangkao@redhat.com>
To:     Chao Yu <yuchao0@huawei.com>
Cc:     Gao Xiang <hsiangkao@aol.com>, linux-erofs@lists.ozlabs.org,
        Chao Yu <chao@kernel.org>, linux-kernel@vger.kernel.org,
        Martin DEVERA <devik@eaxlabs.cz>
Subject: Re: [PATCH v2] erofs: fix bio->bi_max_vecs behavior change
Message-ID: <20210308030101.GB3537842@xiangao.remote.csb>
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On Mon, Mar 08, 2021 at 10:52:19AM +0800, Chao Yu wrote:
> On 2021/3/8 10:36, Gao Xiang wrote:
> > Hi Chao,
> > 
> > On Mon, Mar 08, 2021 at 09:29:30AM +0800, Chao Yu wrote:
> > > On 2021/3/6 12:04, Gao Xiang wrote:
> > > > From: Gao Xiang <hsiangkao@redhat.com>
> > > > 
> > > > Martin reported an issue that directory read could be hung on the
> > > > latest -rc kernel with some certain image. The root cause is that
> > > > commit baa2c7c97153 ("block: set .bi_max_vecs as actual allocated
> > > > vector number") changes .bi_max_vecs behavior. bio->bi_max_vecs
> > > > is set as actual allocated vector number rather than the requested
> > > > number now.
> > > > 
> > > > Let's avoid using .bi_max_vecs completely instead.
> > > > 
> > > > Reported-by: Martin DEVERA <devik@eaxlabs.cz>
> > > > Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
> > > 
> > > Looks good to me, btw, it needs to Cc stable mailing list?
> > > 
> > > Reviewed-by: Chao Yu <yuchao0@huawei.com>
> > > 
> > 
> > Thanks for your review. <= 5.11 kernels are not impacted.
> > For now, this only impacts 5.12-rc due to a bio behavior
> > change (see commit baa2c7c97153). So personally I think
> > just leave as it is is fine.
> 
> Okay, so that's fine if you send pull request before 5.12 formal release. ;)

Yeah, it's an urgent commit and have very negative impact.
I pushed out -fixes branch just now. After leaving in linux-next
for days, will upstream it then asap... :-(

Thanks,
Gao Xiang

> 
> Thanks,
> 
> > 
> > Thanks,
> > Gao Xiang
> > 
> > > Thanks,
> > > 
> > 
> > .
> > 
>