Re: [Qemu-block] [PATCH 3/8] raw: Reflect read-only protocol layer

[Paolo Bonzini]

On 07/11/2017 04:02, Eric Blake wrote:
> We forbid operations like a zero-length write zero or a discard
> at the protocol layer when it is marked read-only, but those
> same operations were succeeding at the format layer because the
> raw format was not reflecting the underlying read-only status
> to the block layer, which then took short circuit paths on
> zero-length operations.
> 
> Signed-off-by: Eric Blake <address@hidden>
> ---
>  block/raw-format.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/block/raw-format.c b/block/raw-format.c
> index 830243a8e4..717b8eff65 100644
> --- a/block/raw-format.c
> +++ b/block/raw-format.c
> @@ -418,6 +418,12 @@ static int raw_open(BlockDriverState *bs, QDict 
> *options, int flags,
>          bs->file->bs->supported_write_flags;
>      bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
>          bs->file->bs->supported_zero_flags;
> +    if (bdrv_is_read_only(bs->file->bs)) {
> +        ret = bdrv_set_read_only(bs, true, errp);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +    }
> 
>      if (bs->probed && !bdrv_is_read_only(bs)) {
>          fprintf(stderr,
> 

Kevin, perhaps this should be done straight in block.c?

Thanks,

Paolo