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Subject: Re: [syzbot] possible deadlock in del_gendisk
To:     Tyler Hicks <tyhicks@linux.microsoft.com>,
        Petr Vorel <pvorel@suse.cz>,
        Pavel Tatashin <pasha.tatashin@soleen.com>
Cc:     Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Stefan Haberland <sth@linux.ibm.com>,
        Jan Hoeppner <hoeppner@linux.ibm.com>,
        linux-block <linux-block@vger.kernel.org>,
        syzbot <syzbot+61e04e51b7ac86930589@syzkaller.appspotmail.com>,
        Tejun Heo <tj@kernel.org>
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From:   Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
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On 2021/06/10 1:46, Tyler Hicks wrote:
> Thanks for doing this. I haven't had a chance to retry this commit with
> lockdep but I did re-review it and didn't think that it would be the
> cause of this lockdep report since it strictly reduced the usage of the
> loop_ctl_mutex.

Well, I made commit 310ca162d779efee ("block/loop: Use global lock for ioctl() operation.")
because per device lock was not sufficient. Did commit 6cc8e7430801fa23 ("loop: scale loop
device by introducing per device lock") take this problem into account?