Re: [PATCH] btrfs: Annotate structs with __counted_by()

[Johannes Thumshirn]

On 12.08.24 12:37, Thorsten Blum wrote:
> Add the __counted_by compiler attribute to the flexible array member
> stripes to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
> CONFIG_FORTIFY_SOURCE.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxxx>
> ---
>   fs/btrfs/volumes.h | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
> index 37a09ebb34dd..f28fa318036b 100644
> --- a/fs/btrfs/volumes.h
> +++ b/fs/btrfs/volumes.h
> @@ -551,7 +551,7 @@ struct btrfs_io_context {
>   	 * stripes[data_stripes + 1]:	The Q stripe (only for RAID6).
>   	 */
>   	u64 full_stripe_logical;
> -	struct btrfs_io_stripe stripes[];
> +	struct btrfs_io_stripe stripes[] __counted_by(num_stripes);
>   };
>   
>   struct btrfs_device_info {
> @@ -591,7 +591,7 @@ struct btrfs_chunk_map {
>   	int io_width;
>   	int num_stripes;
>   	int sub_stripes;
> -	struct btrfs_io_stripe stripes[];
> +	struct btrfs_io_stripe stripes[] __counted_by(num_stripes);
>   };
>   
>   #define btrfs_chunk_map_size(n) (sizeof(struct btrfs_chunk_map) + \

Looks good to me,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>

Out of curiosity, have you encountered any issues with this patch applied?