Re: [PATCH] dm: use READ_ONCE in dm_blk_report_zones

[Benjamin Marzinski <bmarzins@redhat.com>]

On Thu, Jan 08, 2026 at 08:56:20PM +0100, Mikulas Patocka wrote:
> The functon dm_blk_report_zones reads md->zone_revalidate_map, however it
> may change while the function is running. Use READ_ONCE.
> 
> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
> Fixes: 37f53a2c60d0 ("dm: fix dm_blk_report_zones")

Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>

> 
> ---
>  drivers/md/dm-zone.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux-2.6/drivers/md/dm-zone.c
> ===================================================================
> --- linux-2.6.orig/drivers/md/dm-zone.c	2026-01-06 22:57:00.000000000 +0100
> +++ linux-2.6/drivers/md/dm-zone.c	2026-01-06 22:57:00.000000000 +0100
> @@ -50,7 +50,7 @@ int dm_blk_report_zones(struct gendisk *
>  {
>  	struct mapped_device *md = disk->private_data;
>  	struct dm_table *map;
> -	struct dm_table *zone_revalidate_map = md->zone_revalidate_map;
> +	struct dm_table *zone_revalidate_map = READ_ONCE(md->zone_revalidate_map);
>  	int srcu_idx, ret = -EIO;
>  	bool put_table = false;
>