On Fri, Oct 15, 2021 at 11:07:40AM +0900, Shin'ichiro Kawasaki wrote:
> To fix the issues, call the helper function disk_has_partitions() in
> place of disk->part_tbl empty check. Since the function was removed with
> the commit a33df75c6328, reimplement it to walk through entries in the
> xarray disk->part_tbl.
Looks good,
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Matthew,
we talked about possiblig adding a xa_nr_entries helper a while ago.
This would be a good place for it, as we could just check
xa_nr_entries() > 1 for example.
>
> Fixes: a33df75c6328 ("block: use an xarray for disk->part_tbl")
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # v5.14+
> ---
> block/blk-settings.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index a7c857ad7d10..b880c70e22e4 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -842,6 +842,24 @@ bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
> }
> EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
>
> +static bool disk_has_partitions(struct gendisk *disk)
> +{
> + unsigned long idx;
> + struct block_device *part;
> + bool ret = false;
> +
> + rcu_read_lock();
> + xa_for_each(&disk->part_tbl, idx, part) {
> + if (bdev_is_partition(part)) {
> + ret = true;
> + break;
> + }
> + }
> + rcu_read_unlock();
> +
> + return ret;
> +}
> +
> /**
> * blk_queue_set_zoned - configure a disk queue zoned model.
> * @disk: the gendisk of the queue to configure
> @@ -876,7 +894,7 @@ void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model)
> * we do nothing special as far as the block layer is concerned.
> */
> if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||
> - !xa_empty(&disk->part_tbl))
> + disk_has_partitions(disk))
> model = BLK_ZONED_NONE;
> break;
> case BLK_ZONED_NONE:
> --
> 2.31.1
---end quoted text---
