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Date:   Thu, 1 Jul 2021 11:49:16 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Ming Lei <ming.lei@redhat.com>
Cc:     Christoph Hellwig <hch@lst.de>, axboe@kernel.dk,
        linux-block@vger.kernel.org
Subject: Re: [PATCH 1/2] block: grab a device refcount in disk_uevent
Message-ID: <20210701094915.GA2066@lst.de>
References: <20210701081638.246552-1-hch@lst.de> <20210701081638.246552-2-hch@lst.de> <YN2CrbtFEKwDGff0@T590> <20210701090232.GA31321@lst.de> <YN2IIiKUvquxqx6k@T590> <YN2KiYTtA0ribi9i@T590>
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On Thu, Jul 01, 2021 at 05:27:37PM +0800, Ming Lei wrote:
> 
> Maybe the reason is that sending uevent needs the device/kobject not
> 'released' in viewpoint of driver core world, other device resource(such
> as device name) may be referred but have been freed.
> 
> If that is the reason, this patch looks fine, and
> kobject_get_unless_zero() may be replaced with get_device() since the
> referred memory isn't freed yet.

Yes, sorry.  Braino while looking up the cause.  But there isn't much
of a point in sending a uevent to a partition already deleted, so
I think the unless_zero here still makes sense.