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Date:   Tue, 18 May 2021 15:00:44 -0700
From:   Jeff Johnson <jjohnson@codeaurora.org>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-wireless@vger.kernel.org, Kalle Valo <kvalo@codeaurora.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Jason Gunthorpe <jgg@ziepe.ca>, Chao Yu <chao@kernel.org>,
        Leon Romanovsky <leon@kernel.org>, b43-dev@lists.infradead.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        jjohnson=codeaurora.org@codeaurora.org
Subject: Re: [PATCH v2] b43: don't save dentries for debugfs
In-Reply-To: <891f28e4c1f3c24ed1b257de83cbb3a0@codeaurora.org>
References: <20210518163304.3702015-1-gregkh@linuxfoundation.org>
 <891f28e4c1f3c24ed1b257de83cbb3a0@codeaurora.org>
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On 2021-05-18 12:29, Jeff Johnson wrote:
> On 2021-05-18 09:33, Greg Kroah-Hartman wrote:
>> There is no need to keep around the dentry pointers for the debugfs
>> files as they will all be automatically removed when the subdir is
>> removed.  So save the space and logic involved in keeping them around 
>> by
>> just getting rid of them entirely.
>> 
>> By doing this change, we remove one of the last in-kernel user that 
>> was
>> storing the result of debugfs_create_bool(), so that api can be 
>> cleaned
>> up.
> 
> Question not about this specific change, but the general concept
> of keeping (or not keeping) dentry pointers. In the ath drivers,
> as well as in an out-of-tree driver for Android, we keep a
> debugfs dentry pointer to use as a param to relay_open().
> 
> Will we still be able to have a dentry pointer for this purpose?
> Or better, is there a recommended way to get a dentry pointer
> NOT associated with debugfs at all (which would be ideal for
> Android where debugfs is disabled).

Answering one of my questions: The dentry passed to relay_open() comes
from debugfs_create_dir() which is expected to return a dentry.

Would still like guidance on if there is a recommended way to get a
dentry not associated with debugfs.

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