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Date:   Thu, 27 Aug 2020 11:39:48 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Denis Efremov <efremov@linux.com>,
        "David S. Miller" <davem@davemloft.net>,
        Song Liu <song@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-ide@vger.kernel.org, linux-raid@vger.kernel.org,
        linux-scsi@vger.kernel.org, linux-m68k@lists.linux-m68k.org
Subject: Re: [PATCH 01/19] char_dev: replace cdev_map with an xarray
Message-ID: <20200827093947.GA15976@lst.de>
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On Thu, Aug 27, 2020 at 11:18:59AM +0200, Greg Kroah-Hartman wrote:
> > I looked at it, but it does get registered and shows up in sysfs.
> 
> It does?  Where does that happen?  I see a bunch of kobject_init()
> calls, but nothing that registers it in sysfs that I can see.

Hmm, true.

> 
> Note, this is not the kobject that shows up in /sys/dev/char/ as a
> symlink, that comes from the driver core logic and is independent of the
> cdev code.
> 
> The kobject does handle the structure lifetime rules, but that should be
> able to be replaced with a simple kref instead.

Yeah.  I'll let you handle this stuff, as you obviously know the area
better than I do.