On Thu, Aug 07, 2014 at 04:28:40PM +0900, Hitoshi Mitake wrote:
> Recently, sheepdog revived its VDI locking functionality. This patch
> updates sheepdog driver of QEMU for this feature:
>
> 1. Improve error message when QEMU fails to acquire lock of
> VDI. Current sheepdog driver prints an error message "VDI isn't
> locked" when it fails to acquire lock. It is a little bit confusing
> because the mesage says VDI isn't locked but it is actually locked by
> other VM. This patch modifies this confusing message.
>
> 2. Change error code for a case of failed locking. -EBUSY is a
> suitable one.
>
> Reported-by: Valerio Pachera <siri...@gmail.com>
> Cc: Kevin Wolf <kw...@redhat.com>
> Cc: Stefan Hajnoczi <stefa...@redhat.com>
> Cc: Liu Yuan <namei.u...@gmail.com>
> Cc: MORITA Kazutaka <morita.kazut...@lab.ntt.co.jp>
> Signed-off-by: Hitoshi Mitake <mitake.hito...@lab.ntt.co.jp>
> ---
> block/sheepdog.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index 36f76f0..0b3f86d 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -1112,9 +1112,13 @@ static int find_vdi_name(BDRVSheepdogState *s, const
> char *filename,
>
> if (rsp->result != SD_RES_SUCCESS) {
> error_setg(errp, "cannot get vdi info, %s, %s %" PRIu32 " %s",
> + rsp->result == SD_RES_VDI_NOT_LOCKED ?
I'm puzzled by this check.
we use SD_RES_VDI_LOCKED to indicate vid is already locked, no?
> + "VDI is already locked by other VM" :
> sd_strerror(rsp->result), filename, snapid, tag);
> if (rsp->result == SD_RES_NO_VDI) {
> ret = -ENOENT;
> + } else if (rsp->result == SD_RES_VDI_NOT_LOCKED) {
> + ret = -EBUSY;
> } else {
> ret = -EIO;
> }
It is better to use switch case to handle the result.
Thanks
Yuan
