Re: [Qemu-devel] [PATCH 04/12] nbd: add support for NBD_CMD_FLUSH

[Kevin Wolf <kwolf@redhat.com>]

Am 08.09.2011 17:24, schrieb Paolo Bonzini:
> Note for the brace police: the style in this commit and the following
> is consistent with the rest of the file.  It is then fixed together with
> the introduction of coroutines.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  block/nbd.c |   31 +++++++++++++++++++++++++++++++
>  nbd.c       |   14 +++++++++++++-
>  2 files changed, 44 insertions(+), 1 deletions(-)
> 
> diff --git a/block/nbd.c b/block/nbd.c
> index ffc57a9..4a195dc 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -237,6 +237,36 @@ static int nbd_write(BlockDriverState *bs, int64_t sector_num,
>      return 0;
>  }
>  
> +static int nbd_flush(BlockDriverState *bs)
> +{
> +    BDRVNBDState *s = bs->opaque;
> +    struct nbd_request request;
> +    struct nbd_reply reply;
> +
> +    if (!(s->nbdflags & NBD_FLAG_SEND_FLUSH)) {
> +        return 0;
> +    }
> +
> +    request.type = NBD_CMD_FLUSH;
> +    request.handle = (uint64_t)(intptr_t)bs;
> +    request.from = 0;
> +    request.len = 0;
> +
> +    if (nbd_send_request(s->sock, &request) == -1)
> +        return -errno;
> +
> +    if (nbd_receive_reply(s->sock, &reply) == -1)
> +        return -errno;
> +
> +    if (reply.error !=0)

Missing space (this is not for consistency, right?)

> @@ -682,6 +683,18 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
>          TRACE("Request type is DISCONNECT");
>          errno = 0;
>          return 1;
> +    case NBD_CMD_FLUSH:
> +        TRACE("Request type is FLUSH");
> +
> +        if (bdrv_flush(bs) == -1) {

bdrv_flush is supposed to return -errno, so please check for < 0. (I see
that raw-posix needs to be fixed, but other block drivers already return
error values other than -1)

Kevin