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Subject: Re: splice: infinite busy loop lockup bug
To:     Ming Lei <ming.lei@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>
Cc:     syzkaller-bugs@googlegroups.com,
        syzbot <syzbot+61acc40a49a3e46e25ea@syzkaller.appspotmail.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
References: <00000000000084b59f05abe928ee@google.com>
 <29de15ff-15e9-5c52-cf87-e0ebdfa1a001@I-love.SAKURA.ne.jp>
 <20200807122727.GR1236603@ZenIV.linux.org.uk>
 <20200807123854.GS1236603@ZenIV.linux.org.uk> <20200807134114.GA2114050@T590>
From:   Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Message-ID: <af338ab6-6a35-4306-9521-57f3c769f677@i-love.sakura.ne.jp>
Date:   Fri, 7 Aug 2020 23:17:32 +0900
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On 2020/08/07 22:41, Ming Lei wrote:
>> FWIW, my preference would be to have for_each_bvec() advance past zero-length
>> segments; I'll need to go through its uses elsewhere in the tree first, though
>> (after I grab some sleep),
> 
> Usually block layer doesn't allow/support zero bvec, however we can make
> for_each_bvec() to support it only.
> 
> Tetsuo, can you try the following patch?

Yes, this patch solves the lockup. Thank you.