Re: [PATCH v4 04/11] dm: Fix dm_accept_partial_bio()

[Christoph Hellwig <hch@infradead.org>]

On Tue, May 25, 2021 at 11:25:32AM +0900, Damien Le Moal wrote:
> Fix dm_accept_partial_bio() to actually check that zone management
> commands are not passed as explained in the function documentation
> comment. Also, since a zone append operation cannot be split, add
> REQ_OP_ZONE_APPEND as a forbidden command.
> 
> White lines are added around the group of BUG_ON() calls to make the
> code more legible.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> ---
>  drivers/md/dm.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index ca2aedd8ee7d..a9211575bfed 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -1237,8 +1237,9 @@ static int dm_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
>  
>  /*
>   * A target may call dm_accept_partial_bio only from the map routine.  It is
> - * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_RESET,
> - * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH.
> + * allowed for all bio types except REQ_PREFLUSH, zone management operations
> + * (REQ_OP_ZONE_RESET, REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and
> + * REQ_OP_ZONE_FINISH) and zone append writes.

Maybe shorten the REQ_OP_ZONE_* list to just say REQ_OP_ZONE_* ?