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Date:   Thu, 24 Mar 2022 18:11:48 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Jan Kara <jack@suse.cz>
Cc:     Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Josef Bacik <josef@toxicpanda.com>,
        Minchan Kim <minchan@kernel.org>,
        Nitin Gupta <ngupta@vflare.org>,
        Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
        "Darrick J . Wong" <djwong@kernel.org>,
        Ming Lei <ming.lei@redhat.com>, linux-block@vger.kernel.org,
        nbd@other.debian.org
Subject: Re: [PATCH 01/13] nbd: use the correct block_device in nbd_ioctl
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References: <20220324075119.1556334-1-hch@lst.de> <20220324075119.1556334-2-hch@lst.de> <20220324122041.itc55zladc5sax5p@quack3.lan> <20220324132322.2t3y4evcxunlpvzm@quack3.lan>
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On Thu, Mar 24, 2022 at 02:23:22PM +0100, Jan Kara wrote:
> Should't we call __invalidate_device() for the partition bdev here? Because
> if the NBD device has partitions, filesystem will be mounted on this
> partition and we want to invalidate it. Similarly the partition buffer
> cache is different from the buffer cache of the whole device and we should
> invalidate the partition one. In fact in cases like this I think we need
> to invalidate all the partitions and filesystems that are there on this
> disk so neither the old, nor the new code looks quite correct to me. Am I
> missing something?

Well, that assumes just one partition is used, which kinda defeats the
purpose of partitions.  I can exclude the __invalidate_device to not
change from one kind of broken to another, but I suspect the real
question is why we have this __invalidate_device call at all.