[sheepdog] [PATCH] sheep: don't recycle VDI ID

[Liu Yuan]

On Sun, Jun 01, 2014 at 11:23:18PM +0900, Hitoshi Mitake wrote:
> Recycling VDI IDs of deleted VDIs is a completely wrong idea. It
> breaks relations between inode objects and data objects. For example,
> it can cause a problem of corrupting cloned VDIs (see related
> issue). This patch forbids the recycling.
> 
> Related issue:
> https://bugs.launchpad.net/sheepdog-project/+bug/1317755
> 
> Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
> ---
>  sheep/vdi.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/sheep/vdi.c b/sheep/vdi.c
> index baac2f9..3e60da3 100644
> --- a/sheep/vdi.c
> +++ b/sheep/vdi.c
> @@ -556,13 +556,6 @@ static int fill_vdi_info_range(uint32_t left, uint32_t right,
>  		if (ret != SD_RES_SUCCESS)
>  			goto out;
>  
> -		if (vdi_is_deleted(inode)) {
> -			/* Recycle the deleted inode for fresh vdi create */
> -			if (!iocb->create_snapshot)
> -				info->free_bit = i;
> -			continue;
> -		}
> -
>  		if (!strncmp(inode->name, name, sizeof(inode->name))) {
>  			sd_debug("%s = %s, %u = %u", iocb->tag, inode->tag,
>  				 iocb->snapid, inode->snap_id);

This looks a valid problem to me, but this is very old policy introduced by
Kazutaka, so let's hear his voice first.

Thanks
Yuan