[dm-devel] [PATCH v2 04/11] dm: Fix dm_accept_partial_bio()
Hannes Reinecke
hare at suse.de
Thu May 20 05:53:04 UTC 2021
On 5/20/21 6:22 AM, 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 at wdc.com>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn at wdc.com>
> ---
> 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.
> *
> * dm_accept_partial_bio informs the dm that the target only wants to process
> * additional n_sectors sectors of the bio and the rest of the data should be
> @@ -1268,9 +1269,13 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
> {
> struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
> unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
> +
> BUG_ON(bio->bi_opf & REQ_PREFLUSH);
> + BUG_ON(op_is_zone_mgmt(bio_op(bio)));
> + BUG_ON(bio_op(bio) == REQ_OP_ZONE_APPEND);
> BUG_ON(bi_size > *tio->len_ptr);
> BUG_ON(n_sectors > bi_size);
> +
> *tio->len_ptr -= bi_size - n_sectors;
> bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
> }
>
Reviewed-by: Hannes Reinecke <hare at suse.de>
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare at suse.de +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
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