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Subject: Re: [PATCH] lib: dynamic_debug: no need to check return value of
 debugfs_create functions
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org
References: <20190612153534.GA21141@kroah.com>
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From:   Jason Baron <jbaron@akamai.com>
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Date:   Thu, 13 Jun 2019 12:09:00 -0400
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On 6/13/19 11:59 AM, Greg Kroah-Hartman wrote:
> On Thu, Jun 13, 2019 at 10:33:23AM -0400, Jason Baron wrote:
>> On 6/12/19 11:35 AM, Greg Kroah-Hartman wrote:
>>> When calling debugfs functions, there is no need to ever check the
>>> return value.  The function can work or not, but the code logic should
>>> never do something different based on this.
>>>
>>> Cc: Jason Baron <jbaron@akamai.com>
>>> Cc: linux-kernel@vger.kernel.org
>>> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>> ---
>>>  lib/dynamic_debug.c | 12 +++---------
>>>  1 file changed, 3 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
>>> index 8a16c2d498e9..c60409138e13 100644
>>> --- a/lib/dynamic_debug.c
>>> +++ b/lib/dynamic_debug.c
>>> @@ -993,20 +993,14 @@ static __initdata int ddebug_init_success;
>>>  
>>>  static int __init dynamic_debug_init_debugfs(void)
>>>  {
>>> -	struct dentry *dir, *file;
>>> +	struct dentry *dir;
>>>  
>>>  	if (!ddebug_init_success)
>>>  		return -ENODEV;
>>>  
>>>  	dir = debugfs_create_dir("dynamic_debug", NULL);
>>> -	if (!dir)
>>> -		return -ENOMEM;
>>> -	file = debugfs_create_file("control", 0644, dir, NULL,
>>> -					&ddebug_proc_fops);
>>> -	if (!file) {
>>> -		debugfs_remove(dir);
>>> -		return -ENOMEM;
>>> -	}
>>> +	debugfs_create_file("control", 0644, dir, NULL, &ddebug_proc_fops);
>>> +
>>>  	return 0;
>>>  }
>>>  
>>>
>>
>> Looks like debugfs_create_dir() can return NULL,
> 
> No it can not.
>

Ok, I looked at the wrong definition for failed_creating() :(
In that case:

Acked-by: Jason Baron <jbaron@akamai.com>

Thanks,

-Jason