[dm-devel] Re: [PATCH] dm: remove all 'next_ordered' work-arounds

[Kiyoshi Ueda]

Thank you for this, Mike.

On 2009/07/11 3:08 +0900, Mike Snitzer wrote:
> bio-based DM was changed to work-around the previously misplaced
> next_ordered check with this commit:
> 99360b4c18f7675b50d283301d46d755affe75fd
> 
> request-based DM does not yet support barriers but reacted to the above
> bio-based DM change with this commit:
> 5d67aa2366ccb8257d103d0b43df855605c3c086
> 
> The above changes are no longer needed given Neil Brown's recent fix to
> put the next_ordered check in the __make_request path:
> db64f680ba4b5c56c4be59f0698000df89ff0281
> 
> This patch removes DM's bio-based vs request-based conditional setting
> of next_ordered.  For bio-based DM the next_ordered check is no longer a
> concern (as that check is now in the __make_request path).  For
> request-based DM the default of QUEUE_ORDERED_NONE is appropriate.
> 
> Signed-off-by: Mike Snitzer <snitzer at redhat.com>
> Cc: Mikulas Patocka <mpatocka at redhat.com>
> Cc: Kiyoshi Ueda <k-ueda at ct.jp.nec.com> 
> Cc: Jun'ichi Nomura <j-nomura at ce.jp.nec.com>
> Cc: NeilBrown <neilb at suse.de>
> ---
> 
> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> index 2cba557..5d16d06 100644
> --- a/drivers/md/dm-table.c
> +++ b/drivers/md/dm-table.c
> @@ -830,11 +830,6 @@ unsigned dm_table_get_type(struct dm_table *t)
>  	return t->type;
>  }
>  
> -bool dm_table_bio_based(struct dm_table *t)
> -{
> -	return dm_table_get_type(t) == DM_TYPE_BIO_BASED;
> -}
> -
>  bool dm_table_request_based(struct dm_table *t)
>  {
>  	return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index 9acd54a..8a311ea 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -2203,16 +2203,6 @@ int dm_swap_table(struct mapped_device *md, struct dm_table *table)
>  		goto out;
>  	}
>  
> -	/*
> -	 * It is enought that blk_queue_ordered() is called only once when
> -	 * the first bio-based table is bound.
> -	 *
> -	 * This setting should be moved to alloc_dev() when request-based dm
> -	 * supports barrier.
> -	 */
> -	if (!md->map && dm_table_bio_based(table))
> -		blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN, NULL);
> -
>  	__unbind(md);
>  	r = __bind(md, table, &limits);
>  
> diff --git a/drivers/md/dm.h b/drivers/md/dm.h
> index 23278ae..a7663eb 100644
> --- a/drivers/md/dm.h
> +++ b/drivers/md/dm.h
> @@ -61,7 +61,6 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits);
>  int dm_table_any_busy_target(struct dm_table *t);
>  int dm_table_set_type(struct dm_table *t);
>  unsigned dm_table_get_type(struct dm_table *t);
> -bool dm_table_bio_based(struct dm_table *t);
>  bool dm_table_request_based(struct dm_table *t);
>  int dm_table_alloc_md_mempools(struct dm_table *t);
>  void dm_table_free_md_mempools(struct dm_table *t);

Acked-by: Kiyoshi Ueda <k-ueda at ct.jp.nec.com>