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Subject: Re: [PROBLEM] nbd requests become stuck when devices watched by
 inotify emit udev uevent changes
To:     Matthew Ruffell <matthew.ruffell@canonical.com>,
        Josef Bacik <josef@toxicpanda.com>
CC:     Jens Axboe <axboe@kernel.dk>,
        linux-block <linux-block@vger.kernel.org>,
        nbd <nbd@other.debian.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>
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From:   "yukuai (C)" <yukuai3@huawei.com>
Message-ID: <0eb5ff67-b1f0-a8c4-281c-55a5ded58662@huawei.com>
Date:   Fri, 13 May 2022 11:20:46 +0800
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在 2022/05/13 10:56, Matthew Ruffell 写道:
> Hi Josef,
> 
> Just a friendly ping, I am more than happy to test a patch, if you send it
> inline in the email, since the pastebin you used expired after 1 day, and I
> couldn't access it.
> 
> I came across and tested Yu Kuai's patches [1][2] which are for the same issue,
> and they indeed fix the hang. Thank you Yu.
Hi, Matthew

Thanks for your test.
> 
> [1] nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed
> https://lists.debian.org/nbd/2022/04/msg00212.html
> 
> [2] nbd: fix io hung while disconnecting device
> https://lists.debian.org/nbd/2022/04/msg00207.html
> 
> I am also happy to test any patches to fix the I/O errors.

Sorry that I missed this thread. IMO, if inflight requests is cleared by
ioctl NBD_CLEAR_SOCK after my patch [2](or other callers for
nbd_clear_que()), such io will return as error. Thus I don't think such
io errors need to be fixed.

Josef, do you have other suggestions?

Thanks,
Kuai