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Subject: Re: [Virtio-fs] [PATCH 00/18] virtiofs: Fix various races and
 cleanups round 1
To:     Miklos Szeredi <miklos@szeredi.hu>,
        Stefan Hajnoczi <stefanha@redhat.com>
CC:     "Michael S. Tsirkin" <mst@redhat.com>,
        <linux-kernel@vger.kernel.org>, <virtio-fs@redhat.com>,
        <linux-fsdevel@vger.kernel.org>,
        <virtualization@lists.linux-foundation.org>,
        Vivek Goyal <vgoyal@redhat.com>
References: <20190905194859.16219-1-vgoyal@redhat.com>
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 <CAJfpegudNVZitQ5L8gPvA45mRPFDk9fhyboceVW6xShpJ4mLww@mail.gmail.com>
From:   piaojun <piaojun@huawei.com>
Message-ID: <866a1469-2c4b-59ce-cf3f-32f65e861b99@huawei.com>
Date:   Sun, 8 Sep 2019 19:53:55 +0800
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On 2019/9/6 19:52, Miklos Szeredi wrote:
> On Fri, Sep 6, 2019 at 12:36 PM Stefan Hajnoczi <stefanha@redhat.com> wrote:
>>
>> On Fri, Sep 06, 2019 at 10:15:14AM +0200, Miklos Szeredi wrote:
>>> On Thu, Sep 5, 2019 at 9:49 PM Vivek Goyal <vgoyal@redhat.com> wrote:
>>>>
>>>> Hi,
>>>>
>>>> Michael Tsirkin pointed out issues w.r.t various locking related TODO
>>>> items and races w.r.t device removal.
>>>>
>>>> In this first round of cleanups, I have taken care of most pressing
>>>> issues.
>>>>
>>>> These patches apply on top of following.
>>>>
>>>> git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git#virtiofs-v4
>>>>
>>>> I have tested these patches with mount/umount and device removal using
>>>> qemu monitor. For example.
>>>
>>> Is device removal mandatory?  Can't this be made a non-removable
>>> device?  Is there a good reason why removing the virtio-fs device
>>> makes sense?
>>
>> Hot plugging and unplugging virtio PCI adapters is common.  I'd very
>> much like removal to work from the beginning.
> 
> Can you give an example use case?

I think VirtFS migration need hot plugging, or it may cause QEMU crash
or some problems.

Thanks,
Jun