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Date:   Mon, 18 Oct 2021 17:35:14 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Coly Li <colyli@suse.de>
Cc:     Christoph Hellwig <hch@lst.de>, linux-bcache@vger.kernel.org
Subject: Re: [PATCH 1/4] bcache: remove the cache_dev_name field from
 struct cache
Message-ID: <20211018153514.GA32633@lst.de>
References: <20211018060934.1816088-1-hch@lst.de> <20211018060934.1816088-2-hch@lst.de> <dc8601a6-21a5-3680-7489-1430d14788db@suse.de> <20211018152127.GA31195@lst.de> <8c9e20f7-7a58-9ee7-c592-63d5a6162f94@suse.de>
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On Mon, Oct 18, 2021 at 11:32:26PM +0800, Coly Li wrote:
> It was in Linux v4.17 time, when I did the device failure handling. If the 
> underlying device broken and gone, printing the device name string will be 
> a "null" string in kmesg. But the device name was necessary for proper 
> device failure information, we stored the device name string when it was 
> initialized.

I'm pretty sure that was before the %pg specifier and the
hd_struct/block_device unification.  With the current code there is no
way it could print null.