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Date:   Mon, 2 Oct 2023 08:21:59 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Wouter Verhelst <w@uter.be>
Cc:     Christoph Hellwig <hch@lst.de>,
        Samuel Holland <samuel.holland@sifive.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
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        Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Subject: Re: [PATCH 07/17] nbd: call blk_mark_disk_dead in
 nbd_clear_sock_ioctl
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On Sun, Oct 01, 2023 at 07:10:53PM +0200, Wouter Verhelst wrote:
> > So what are the semantics of clearing the socket?
> > 
> > The <= 6.5 behavior of invalidating fs caches, but not actually marking
> > the fs shutdown is pretty broken, especially if this expects to resurrect
> > the device and thus the file system later on.
> 
> nbd-client -d calls
> 
> ioctl(nbd, NBD_DISCONNECT);
> ioctl(nbd, NBD_CLEAR_SOCK);
> 
> (error handling removed for clarity)
> 
> where "nbd" is the file handle to the nbd device. This expects that the
> device is cleared and that then the device can be reused for a different
> connection, much like "losetup -d". Expecting that the next connection
> would talk to the same file system is wrong.

So a fs shutdown seems like a the right thing.  So I'm a little confused
on what actualy broke here.