[sheepdog] [Qemu-devel] [PATCH v4 03/10] sheepdog: check return values of qemu_co_recv/send correctly

[Stefan Hajnoczi]

On Fri, Jul 26, 2013 at 03:10:45PM +0900, MORITA Kazutaka wrote:
> If qemu_co_recv/send doesn't return the specified length, it means
> that an error happened.
> 
> Tested-and-reviewed-by: Liu Yuan <namei.unix at gmail.com>
> Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
> ---
>  block/sheepdog.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index 6a41ad9..c6e9b89 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -489,13 +489,13 @@ static coroutine_fn int send_co_req(int sockfd, SheepdogReq *hdr, void *data,
>      int ret;
>  
>      ret = qemu_co_send(sockfd, hdr, sizeof(*hdr));
> -    if (ret < sizeof(*hdr)) {
> +    if (ret != sizeof(*hdr)) {
>          error_report("failed to send a req, %s", strerror(errno));

Does this rely on qemu_co_send_recv() getting ret=-1 errno=EPIPE from
iov_send_recv()?  I want to check that I understand what happens when
the socket is closed by the other side.

Stefan