On Wed, May 19, 2021 at 4:28 PM Peter Lieven <p...@kamp.de> wrote:
>
> Signed-off-by: Peter Lieven <p...@kamp.de>
> ---
> block/rbd.c | 37 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 36 insertions(+), 1 deletion(-)
>
> diff --git a/block/rbd.c b/block/rbd.c
> index 0d8612a988..ee13f08a74 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -63,7 +63,8 @@ typedef enum {
> RBD_AIO_READ,
> RBD_AIO_WRITE,
> RBD_AIO_DISCARD,
> - RBD_AIO_FLUSH
> + RBD_AIO_FLUSH,
> + RBD_AIO_WRITE_ZEROES
> } RBDAIOCmd;
>
> typedef struct BDRVRBDState {
> @@ -705,6 +706,10 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict
> *options, int flags,
> }
> }
>
> +#ifdef LIBRBD_SUPPORTS_WRITE_ZEROES
> + bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
I wonder if we should also set BDRV_REQ_NO_FALLBACK here since librbd
does not really have a notion of non-efficient explicit zeroing.
Thanks,
Ilya
