[sheepdog] [PATCH] dog: allow vdi snapshot without snapshot tag

[Ruoyu]

On 2014年09月18日 14:54, Hitoshi Mitake wrote:
> The commit a21bf27906b23448b92cca9943e1019105ffac2f makes
> $ dog vdi snapshot <vdi>
> fail if the <vdi> is an ordinal vdi because newly created VDIs have
> snapid 0. This patch avoids the failure with checking the VDI is
> snapshot or not.
>
> Cc: Ruoyu <liangry at ucweb.com>
> Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
Thanks Hitoshi.
The original purpose is to forbid duplicated snapshot tag.
But I found it is not implemented after applying your patch.

$ dog/dog vdi snapshot test
liangry at linuxmint ~/github/sheepdog.orig $ dog/dog vdi list
Name Id Size Used Shared Creation time VDI id Copies Tag
s test 2 4.0 MB 0.0 MB 4.0 MB 2014-09-10 14:46 7c2b26 3
s test 3 4.0 MB 0.0 MB 4.0 MB 2014-09-10 15:30 7c2b27 3
s test 4 4.0 MB 0.0 MB 4.0 MB 2014-09-18 18:41 7c2b28 3
s test 5 4.0 MB 0.0 MB 4.0 MB 2014-09-18 18:41 7c2b29 3
test 0 4.0 MB 0.0 MB 4.0 MB 2014-09-18 18:43 7c2b2a 3

> ---
>   dog/vdi.c | 14 ++++++++++----
>   1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/dog/vdi.c b/dog/vdi.c
> index fa6130e..0a8a2e9 100644
> --- a/dog/vdi.c
> +++ b/dog/vdi.c
> @@ -567,6 +567,7 @@ static int vdi_snapshot(int argc, char **argv)
>   	int vs_count = 0;
>   	struct node_id owners[SD_MAX_COPIES];
>   	int nr_owners = 0, nr_issued_prevent_inode_update = 0;
> +	bool fail_if_snapshot = false;
>   
>   	if (vdi_cmd_data.snapshot_id != 0) {
>   		sd_err("Please specify a non-integer value for "
> @@ -584,6 +585,15 @@ static int vdi_snapshot(int argc, char **argv)
>   	case SD_RES_NO_TAG:
>   		break;
>   	default:
> +		fail_if_snapshot = true;
> +		break;
> +	}
> +
> +	ret = read_vdi_obj(vdiname, 0, "", &vid, inode, SD_INODE_HEADER_SIZE);
> +	if (ret != EXIT_SUCCESS)
> +		return ret;
> +
> +	if (fail_if_snapshot && vdi_is_snapshot(inode)) {
>   		sd_err("Failed to create snapshot for %s, maybe "
>   			"snapshot id (%d) or tag (%s) is existed",
>   			vdiname, vdi_cmd_data.snapshot_id,
> @@ -591,10 +601,6 @@ static int vdi_snapshot(int argc, char **argv)
>   		return EXIT_FAILURE;
>   	}
>   
> -	ret = read_vdi_obj(vdiname, 0, "", &vid, inode, SD_INODE_HEADER_SIZE);
> -	if (ret != EXIT_SUCCESS)
> -		return ret;
> -
>   	if (inode->store_policy) {
>   		sd_err("creating a snapshot of hypervolume is not supported");
>   		return EXIT_FAILURE;