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Date:   Thu, 16 Apr 2020 14:32:15 +0200
From:   Jan Kara <jack@suse.cz>
To:     Christoph Hellwig <hch@lst.de>
Cc:     axboe@kernel.dk, yuyufen@huawei.com, tj@kernel.org, jack@suse.cz,
        bvanassche@acm.org, tytso@mit.edu, gregkh@linuxfoundation.org,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/8] bdi: move bdi_dev_name out of line
Message-ID: <20200416123215.GO23739@quack2.suse.cz>
References: <20200416071519.807660-1-hch@lst.de>
 <20200416071519.807660-2-hch@lst.de>
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On Thu 16-04-20 09:15:12, Christoph Hellwig wrote:
> bdi_dev_name is not a fast path function, move it out of line.  This
> prepares for using it from modular callers without having to export
> an implementation detail like bdi_unknown_name.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  include/linux/backing-dev.h |  9 +--------
>  mm/backing-dev.c            | 10 +++++++++-
>  2 files changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
> index f88197c1ffc2..c9ad5c3b7b4b 100644
> --- a/include/linux/backing-dev.h
> +++ b/include/linux/backing-dev.h
> @@ -505,13 +505,6 @@ static inline int bdi_rw_congested(struct backing_dev_info *bdi)
>  				  (1 << WB_async_congested));
>  }
>  
> -extern const char *bdi_unknown_name;
> -
> -static inline const char *bdi_dev_name(struct backing_dev_info *bdi)
> -{
> -	if (!bdi || !bdi->dev)
> -		return bdi_unknown_name;
> -	return dev_name(bdi->dev);
> -}
> +const char *bdi_dev_name(struct backing_dev_info *bdi);
>  
>  #endif	/* _LINUX_BACKING_DEV_H */
> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> index c81b4f3a7268..c2c44c89ee5d 100644
> --- a/mm/backing-dev.c
> +++ b/mm/backing-dev.c
> @@ -21,7 +21,7 @@ struct backing_dev_info noop_backing_dev_info = {
>  EXPORT_SYMBOL_GPL(noop_backing_dev_info);
>  
>  static struct class *bdi_class;
> -const char *bdi_unknown_name = "(unknown)";
> +static const char *bdi_unknown_name = "(unknown)";
>  
>  /*
>   * bdi_lock protects bdi_tree and updates to bdi_list. bdi_list has RCU
> @@ -1043,6 +1043,14 @@ void bdi_put(struct backing_dev_info *bdi)
>  }
>  EXPORT_SYMBOL(bdi_put);
>  
> +const char *bdi_dev_name(struct backing_dev_info *bdi)
> +{
> +	if (!bdi || !bdi->dev)
> +		return bdi_unknown_name;
> +	return dev_name(bdi->dev);
> +}
> +EXPORT_SYMBOL_GPL(bdi_dev_name);
> +
>  static wait_queue_head_t congestion_wqh[2] = {
>  		__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
>  		__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
> -- 
> 2.25.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR