Re: [Qemu-devel] [PATCH v5 0/8] Implement reference count for BlockDriverState [resend]

[Stefan Hajnoczi]

On Fri, Aug 09, 2013 at 06:01:53PM +0800, Fam Zheng wrote:
> [resend to the correct list]
> 
> BlockDriverState lifecycle management is needed by future features such as
> image fleecing and blockdev-add. This series adds reference count to
> BlockDriverState.
> 
> The first two patches clean up two odd BlockDriverState use cases, so all code
> uses bdrv_new() to create BlockDriverState instance.
> 
> Then implemented bdrv_ref() and bdrv_unref() to operate on refcnt: Initially,
> refcnt is 1, which means bdrv_unref is effectively a bdrv_delete() here. So
> patch 04 has a search and replace to convert bdrv_delete to bdrv_unref, before
> bdrv_ref is used anywhere. 05~08 patches calls bdrv_ref for device attach,
> block-migration and nbd.
> 
> The rule is: Either bdrv_ref() or bdrv_new() must have a matching
> bdrv_unref() call, and the last matching bdrv_unref deletes the bs.
> 
> v4:
>     08: Added, let block job use BDS reference.
>     02: Fix leak of bs.opaque
> 
> v3:
>     03: Removed unnecessary bdrv_close() call.
> 
> v2:
>     05: Removed: "block: use BlockDriverState refcnt for device attach/detach"
>     07: Fix xen_disk blk_disconnect() as it depended on device attach refcnt.

Sorry, can't merge this because it breaks qemu-iotests 041 and 055:

  $ ./check -qcow2 055 041

Please always run qemu-iotests before submitting patches.

Stefan