[Qemu-devel] [PATCH 0/8] blockdev: (Nearly) free clean-up work

[Max Reitz <mreitz@redhat.com>]

After a lot has been restructed in the block layer in the past, we can
now reap at least one of the fruits: Make bdrv_open() return a BDS!

I tried to squeeze patch 8 of this series into my bdrv_close_all()
series but noticed that won't work because bdrv_open_inherit() still has
one instance of bdrv_close() which is actually pretty reasonable.
Therefore, that was impossible there.

However, that instance exists only because bdrv_open_inherit() does not
always create a new BDS but sometimes takes an existing one and opens a
file "into" that BDS, basically. That is ugly and we've tried to get rid
of that for a long time now. Then I noticed that nearly all the callers
of bdrv_open()/bdrv_open_inherit() no longer need that feature, there
was only one show-stopper left: blk_new_open(). That functions creates a
BDS using blk_new_with_bs(), which in turn uses bdrv_new_root() instead
of a plain bdrv_new().

However, the sole difference between bdrv_new_root() and bdrv_new() is
gone as of my "Further BlockBackend work" series, so we can make
blk_new_open() reuse the BDS creation capabilities of bdrv_open() as
well. And that's it!

And with bdv_open_inherit() always creating the BDS, we no longer need
to call bdrv_close() there, which allows us to assert that any BDS given
to bdrv_close() will have a refcount of 0 (i.e. is about to be deleted).


As hinted before, this series depends on v2 of my previous series
"blockdev: Further BlockBackend work".


Max Reitz (8):
  qapi: Drop QERR_UNKNOWN_BLOCK_FORMAT_FEATURE
  block: Drop useless bdrv_new() calls
  block: Let bdrv_open_inherit() return the snapshot
  block: Drop BB name from bad option error
  block: Drop blk_new_with_bs()
  block: Drop bdrv_new_root()
  block: Make bdrv_open() return a BDS
  block: Assert !bs->refcnt in bdrv_close()

 block.c                    | 139 ++++++++++++++++++---------------------------
 block/block-backend.c      |  31 +++-------
 block/parallels.c          |   9 +--
 block/qcow.c               |  15 ++---
 block/qcow2.c              |  53 ++++++-----------
 block/qed.c                |  18 ++----
 block/sheepdog.c           |  16 +++---
 block/vdi.c                |   7 +--
 block/vhdx.c               |   8 +--
 block/vmdk.c               |  31 +++++-----
 block/vpc.c                |   7 +--
 block/vvfat.c              |   9 ++-
 blockdev.c                 |  38 +++++--------
 include/block/block.h      |   6 +-
 include/qapi/qmp/qerror.h  |   3 -
 tests/qemu-iotests/036.out |  16 +++---
 tests/qemu-iotests/051.out |   8 +--
 17 files changed, 153 insertions(+), 261 deletions(-)

-- 
2.6.2