Re: [Qemu-devel] [PATCH v2 08/20] block drivers: add discard/write_zeroes properties to bdrv_get_info implementation

[Peter Lieven <pl@kamp.de>]

On 19.11.2013 18:07, Paolo Bonzini wrote:
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   block/qcow2.c | 2 ++
>   block/qed.c   | 2 ++
>   block/vdi.c   | 3 +++
>   block/vhdx.c  | 3 +++
>   block/vpc.c   | 2 ++
>   5 files changed, 12 insertions(+)
>
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 2fe37ed..92ed895 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -1892,6 +1892,8 @@ static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
>   static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>   {
>       BDRVQcowState *s = bs->opaque;
> +    bdi->unallocated_blocks_are_zero = (bs->backing_hd == NULL);
> +    bdi->can_write_zeroes_with_unmap = (s->qcow_version >= 3);
>       bdi->cluster_size = s->cluster_size;
>       bdi->vm_state_offset = qcow2_vm_state_offset(s);
>       return 0;
> diff --git a/block/qed.c b/block/qed.c
> index adc2736..1f87420 100644
> --- a/block/qed.c
> +++ b/block/qed.c
> @@ -1475,6 +1475,8 @@ static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>       memset(bdi, 0, sizeof(*bdi));
>       bdi->cluster_size = s->header.cluster_size;
>       bdi->is_dirty = s->header.features & QED_F_NEED_CHECK;
> +    bdi->unallocated_blocks_are_zero = (bs->backing_hd == NULL);
> +    bdi->can_write_zeroes_with_unmap = true;
>       return 0;
>   }
>   
> diff --git a/block/vdi.c b/block/vdi.c
> index b6ec002..3a05027 100644
> --- a/block/vdi.c
> +++ b/block/vdi.c
> @@ -331,6 +331,9 @@ static int vdi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>       logout("\n");
>       bdi->cluster_size = s->block_size;
>       bdi->vm_state_offset = 0;
> +
> +    /* Backing file not supported yet.  */
> +    bdi->unallocated_blocks_are_zero = true;
If its not supported why not checking for

(bs->backing_hd == NULL)

in case its added later and this place is overseen.


>       return 0;
>   }
>   
> diff --git a/block/vhdx.c b/block/vhdx.c
> index 9ab2b39..d06585a 100644
> --- a/block/vhdx.c
> +++ b/block/vhdx.c
> @@ -1050,6 +1050,9 @@ static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>       bdi->cluster_size =
>           (s->logical_sector_size / BDRV_SECTOR_SIZE) * s->block_size;
>   
> +    bdi->unallocated_blocks_are_zero =
> +        (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0;
> +
>       return 0;
>   }
>   
> diff --git a/block/vpc.c b/block/vpc.c
> index 551876f..d6a47ef 100644
> --- a/block/vpc.c
> +++ b/block/vpc.c
> @@ -464,6 +464,8 @@ static int vpc_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>           bdi->cluster_size = s->block_size;
>       }
>   
> +    /* Backing file not supported yet.  */
> +    bdi->unallocated_blocks_are_zero = true;
same here.
>       return 0;
>   }
>   

Peter