[Sheepdog] [PATCH v4 6/6] remove oids from object list cache when deleting a vdi

[MORITA Kazutaka]

At Thu,  3 May 2012 18:25:49 +0800,
levin li wrote:
> 
> Cluster recovery may cause objects migrated from one node
> to another, but the object list cache doesn't change, when
> deleting an object we can not find the right node in whose
> cache the id stays, so we need to notify the deletion list
> to all the node to make them delete the specified object id
> from object list cache.
> 
> Signed-off-by: levin li <xingke.lwp at taobao.com>
> ---
>  include/sheep.h           |    1 +
>  sheep/object_list_cache.c |   17 ++++++++++++++
>  sheep/ops.c               |   17 ++++++++++++++
>  sheep/sheep_priv.h        |    1 +
>  sheep/vdi.c               |   57 ++++++++++++++++++++++++++++++++++++++++++---
>  5 files changed, 90 insertions(+), 3 deletions(-)

I don't like the idea to call process_main() in worker threads since
we shouldn't make the current thread model more complicated.  In
addition, it is not good to take a long time in the cluster operations
even if it is in the worker threads because it blocks the succeeding
events (e.g. vdi creation) for a long time.

I guess it is better to create another work queue, and call
queue_work() in process_main() of SD_OP_NOTIFY_VDI_DEL like
start_deletion().  I wonder there would be other simpler and different
approaches, though.

Thanks,

Kazutaka