Re: [PATCH 3/5] buffer_head: separate out create_bh_bio() from submit_bh_wbc()

From: Jan Kara
Date: Wed Oct 11 2017 - 03:54:21 EST


On Tue 10-10-17 08:54:39, Tejun Heo wrote:
> submit_bh_wbc() creates a bio matching the specific @bh and submits it
> at the end. This patch separates out the bio creation part to its own
> function, create_bh_bio(), and reimplement submit_bh[_wbc]() using the
> function.
>
> As bio can now be manipulated before submitted, we can move out @wbc
> handling into submit_bh_wbc() and similarly this will make adding more
> submit_bh variants straight-forward.
>
> This patch is pure refactoring and doesn't cause any functional
> changes.
>
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
> Suggested-by: Jan Kara <jack@xxxxxxx>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza


> ---
> fs/buffer.c | 30 ++++++++++++++++++++++--------
> 1 file changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 170df85..b4b2169 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -3086,8 +3086,8 @@ void guard_bio_eod(int op, struct bio *bio)
> }
> }
>
> -static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
> - enum rw_hint write_hint, struct writeback_control *wbc)
> +struct bio *create_bh_bio(int op, int op_flags, struct buffer_head *bh,
> + enum rw_hint write_hint)
> {
> struct bio *bio;
>
> @@ -3109,11 +3109,6 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
> */
> bio = bio_alloc(GFP_NOIO, 1);
>
> - if (wbc) {
> - wbc_init_bio(wbc, bio);
> - wbc_account_io(wbc, bh->b_page, bh->b_size);
> - }
> -
> bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
> bio_set_dev(bio, bh->b_bdev);
> bio->bi_write_hint = write_hint;
> @@ -3133,13 +3128,32 @@ static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
> op_flags |= REQ_PRIO;
> bio_set_op_attrs(bio, op, op_flags);
>
> + return bio;
> +}
> +
> +static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh,
> + enum rw_hint write_hint, struct writeback_control *wbc)
> +{
> + struct bio *bio;
> +
> + bio = create_bh_bio(op, op_flags, bh, write_hint);
> +
> + if (wbc) {
> + wbc_init_bio(wbc, bio);
> + wbc_account_io(wbc, bh->b_page, bh->b_size);
> + }
> +
> submit_bio(bio);
> return 0;
> }
>
> int submit_bh(int op, int op_flags, struct buffer_head *bh)
> {
> - return submit_bh_wbc(op, op_flags, bh, 0, NULL);
> + struct bio *bio;
> +
> + bio = create_bh_bio(op, op_flags, bh, 0);
> + submit_bio(bio);
> + return 0;
> }
> EXPORT_SYMBOL(submit_bh);
>
> --
> 2.9.5
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR