Re: [PATCH 1/8] bdi: move bdi_dev_name out of line

From: Jan Kara
Date: Thu Apr 16 2020 - 08:32:42 EST


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@xxxxxx>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

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@xxxxxxxx>
SUSE Labs, CR