[libvirt] [PATCH] Ignore thin pool LVM devices

[Cole Robinson]

On 09/20/2013 10:38 PM, Dusty Mabe wrote:
> 
> For BZ 924672 the problem stems from the fact that thin pool logical
> volume devices show up in /sbin/lvs output just like normal logical
> volumes do. Since the thin pool devices show up libvirt assumes they are
> just normal logical volumes and assumes there will be a corresponding
> /dev/vgname/lvname device that has been created. This is not the case and
> you will receive the following error when starting the storage pool:
> 
> error: cannot stat file '/dev/vgvirt/thinpool': No such file or directory
> 
> This patch modifies virStorageBackendLogicalMakeVol() to ignore thin pool
> backing devices.
> 
> 
> ---
>  src/storage/storage_backend_logical.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/src/storage/storage_backend_logical.c b/src/storage/storage_backend_logical.c
> index a1a37a1..74d26bd 100644
> --- a/src/storage/storage_backend_logical.c
> +++ b/src/storage/storage_backend_logical.c
> @@ -85,6 +85,10 @@ virStorageBackendLogicalMakeVol(virStoragePoolObjPtr pool,
>      if (attrs[4] != 'a')
>          return 0;
>  
> +    /* BZ 924672 - Skip thin pools(t) and thin pool data(T) */
> +    if (attrs[0] == 't' || attrs[0] == 'T')
> +        return 0;
> +
>      /* See if we're only looking for a specific volume */
>      if (data != NULL) {
>          vol = data;
> 

Patch seems reasonable to me, and there's been a handful of complains about
that bug. Can you tweak it a bit and resend?

- Full bug link in the commit log
- Example lvs output in the commit log just for reference to what you are
keying off of.
- Drop the bug reference from the code comment, but expand the comment a bit
to explain that we can't handle thinpool/thinvolume because their paths aren't
always in /dev (or whatever the explanation is)

I'll ACK after that.

Thanks,
Cole