Re: [Qemu-devel] [PATCH 1/2] sheepdog: adopting protocol update for VDI locking

[Liu Yuan <namei.unix@gmail.com>]

On Thu, Aug 07, 2014 at 04:28:39PM +0900, Hitoshi Mitake wrote:
> The update is required for supporting iSCSI multipath. It doesn't
> affect behavior of QEMU driver but adding a new field to vdi request
> struct is required.
> 
> Cc: Kevin Wolf <kwolf@redhat.com>
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: Liu Yuan <namei.unix@gmail.com>
> Cc: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
> Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
> ---
>  block/sheepdog.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index 8d9350c..36f76f0 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -103,6 +103,9 @@
>  #define SD_INODE_SIZE (sizeof(SheepdogInode))
>  #define CURRENT_VDI_ID 0
>  
> +#define LOCK_TYPE_NORMAL 1
> +#define LOCK_TYPE_SHARED 2      /* for iSCSI multipath */

How about

#define LOCK_TYPE_NORMAL 0
#define LOCK_TYPE_SHARED 1

Then we don't need this patch. Since qemu won't make use of multipath for the
near future, we should avoid adding stuff related to multipath to qemu driver.

Thanks
Yuan

> +
>  typedef struct SheepdogReq {
>      uint8_t proto_ver;
>      uint8_t opcode;
> @@ -166,7 +169,8 @@ typedef struct SheepdogVdiReq {
>      uint8_t copy_policy;
>      uint8_t reserved[2];
>      uint32_t snapid;
> -    uint32_t pad[3];
> +    uint32_t type;
> +    uint32_t pad[2];
>  } SheepdogVdiReq;
>  
>  typedef struct SheepdogVdiRsp {
> @@ -1090,6 +1094,7 @@ static int find_vdi_name(BDRVSheepdogState *s, const char *filename,
>      memset(&hdr, 0, sizeof(hdr));
>      if (lock) {
>          hdr.opcode = SD_OP_LOCK_VDI;
> +        hdr.type = LOCK_TYPE_NORMAL;
>      } else {
>          hdr.opcode = SD_OP_GET_VDI_INFO;
>      }
> @@ -1793,6 +1798,7 @@ static void sd_close(BlockDriverState *bs)
>      memset(&hdr, 0, sizeof(hdr));
>  
>      hdr.opcode = SD_OP_RELEASE_VDI;
> +    hdr.type = LOCK_TYPE_NORMAL;
>      hdr.base_vdi_id = s->inode.vdi_id;
>      wlen = strlen(s->name) + 1;
>      hdr.data_length = wlen;
> -- 
> 1.8.3.2
>