[Qemu-devel] [PATCH v2 0/7] Implement reference count for BlockDriverState

[Fam Zheng <famz@redhat.com>]

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.

v2:
    05: Removed: "block: use BlockDriverState refcnt for device attach/detach"
    07: Fix xen_disk blk_disconnect() as it depended on device attach refcnt.

Fam Zheng (7):
  vvfat: use bdrv_new() to allocate BlockDriverState
  iscsi: use bdrv_new() instead of stack structure
  block: implement reference count for BlockDriverState
  block: make bdrv_delete() static
  migration: omit drive ref as we have bdrv_ref now
  xen_disk: simplify blk_disconnect with refcnt
  nbd: use BlockDriverState refcnt

 block-migration.c         |  4 ++--
 block.c                   | 45 ++++++++++++++++++++++++++++++++++-----------
 block/backup.c            |  2 +-
 block/blkverify.c         |  4 ++--
 block/cow.c               |  2 +-
 block/iscsi.c             | 14 +++++++-------
 block/mirror.c            |  2 +-
 block/qcow.c              |  2 +-
 block/qcow2.c             |  2 +-
 block/qed.c               |  2 +-
 block/sheepdog.c          |  6 +++---
 block/snapshot.c          |  2 +-
 block/stream.c            |  2 +-
 block/vmdk.c              | 10 +++++-----
 block/vvfat.c             |  6 +++---
 blockdev-nbd.c            | 10 +---------
 blockdev.c                | 14 +++++++-------
 hw/block/xen_disk.c       | 13 ++++++-------
 include/block/block.h     |  3 ++-
 include/block/block_int.h |  1 +
 nbd.c                     |  5 +++++
 qemu-img.c                | 26 +++++++++++++-------------
 qemu-io.c                 |  6 +++---
 23 files changed, 102 insertions(+), 81 deletions(-)

-- 
1.8.3.4