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Date: Sun, 20 May 2018 11:04:07 +0200
From: Greg KH <gregkh@linuxfoundation.org>
To: Kai Krakow <kai@kaishome.de>
Cc: colyli@suse.de, axboe@kernel.dk, kent.overstreet@gmail.com,
        massimo.b@gmx.net, stable@vger.kernel.org
Subject: Re: FAILED: patch "[PATCH] bcache: return 0 from bch_debug_init() if
 CONFIG_DEBUG_FS=n" failed to apply to 4.16-stable tree
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On Sun, May 20, 2018 at 10:59:32AM +0200, Kai Krakow wrote:
> Hey Greg!
> 
> The v1 version applied for me but it shows a compiler warning. I didn't try
> the newer version yet.
> 
> I could prepare a back-ported version.

Backported would be good.

Also, the code really is wrong even with this change.  No code path
should ever do anything different if debugfs is enabled or not, or based
on the return value of a debugfs call.  No need to check anything here
at all, the function should be:

void __init bch_debug_init(void)
{
	bcache_debug = debugfs_create_dir("bcache", NULL);
}

That's it, no checking, and all is fine and good.  Any result of a
debugfs call can always be fed back into another debugfs call with no
harm or errors happening.

thanks,

greg k-h