Re: [Qemu-block] [PATCH 00/17] block: Convert common I/O path to BdrvChild

[Stefan Hajnoczi]

On Tue, Jun 21, 2016 at 11:21:17AM +0200, Kevin Wolf wrote:
> This series converts all I/O function in the core block layer up to
> bdrv_co_preadv/pwritev() to taking a BdrvChild as their first parameter
> instead of a BlockDriverState.
> 
> The original motivation for this change were op blockers, where one of
> the biggest problems is making sure that every user of block devices
> actually registers correctly with the op blockers system. If the I/O
> functions know which parent a request comes from (BdrvChild basically
> corresponds to an edge in our block device graph), it can use assertions
> to make sure that that parent has actually registered its activities and
> thereby ensured that it doesn't conflict with other users.
> 
> There are, however, more benefits we get from this change. The most
> important one is probably that it enforces important aspects of the
> block layer design like that external users go through a BlockBackend
> and request are internally routed along the edges of the graph. Accesses
> to random BDSes are no longer possible, you need to own an actual child
> reference so you can make a request.
> 
> The work on this series already led to a few cleanups and BlockBackend
> conversions in master, and this series contains a few more.
> 
> As a bonus, all the block drivers using bs->file->bs everywhere can now
> go back to bs->file, which is a little nicer to read.
> 
> Kevin Wolf (17):
>   vvfat: Use BdrvChild for s->qcow
>   blkreplay: Convert to byte-based I/O
>   vhdx: Some more BlockBackend use in vhdx_create()
>   block: Convert bdrv_co_readv() to BdrvChild
>   block: Convert bdrv_co_writev() to BdrvChild
>   block: Convert bdrv_aio_readv() to BdrvChild
>   block: Convert bdrv_aio_writev() to BdrvChild
>   block: Convert bdrv_co_do_readv/writev to BdrvChild
>   block: Move bdrv_commit() to block/commit.c
>   block: Use BlockBackend for I/O in bdrv_commit()
>   block: Convert bdrv_read() to BdrvChild
>   block: Convert bdrv_write() to BdrvChild
>   block: Convert bdrv_pread(v) to BdrvChild
>   block: Convert bdrv_pwrite(v/_sync) to BdrvChild
>   block: Convert bdrv_pwrite_zeroes() to BdrvChild
>   block: Convert bdrv_prwv_co() to BdrvChild
>   block: Convert bdrv_co_preadv/pwritev to BdrvChild
> 
>  block.c                        | 117 ++----------------------------------
>  block/Makefile.objs            |   3 +-
>  block/blkdebug.c               |   4 +-
>  block/blkreplay.c              |  18 +++---
>  block/blkverify.c              |   8 +--
>  block/block-backend.c          |   9 ++-
>  block/bochs.c                  |   8 +--
>  block/cloop.c                  |   8 +--
>  block/commit.c                 | 121 +++++++++++++++++++++++++++++++++++++
>  block/crypto.c                 |   6 +-
>  block/dmg.c                    |  21 +++----
>  block/io.c                     | 132 
> ++++++++++++++++++++++-------------------
>  block/parallels.c              |  16 ++---
>  block/qcow.c                   |  41 +++++++------
>  block/qcow2-cache.c            |   4 +-
>  block/qcow2-cluster.c          |  18 +++---
>  block/qcow2-refcount.c         |  36 +++++------
>  block/qcow2-snapshot.c         |  26 ++++----
>  block/qcow2.c                  |  50 +++++++++-------
>  block/qed-table.c              |   4 +-
>  block/qed.c                    |  22 +++----
>  block/quorum.c                 |   8 +--
>  block/raw_bsd.c                |   6 +-
>  block/vdi.c                    |  14 ++---
>  block/vhdx-log.c               |  12 ++--
>  block/vhdx.c                   |  85 ++++++++++++++------------
>  block/vmdk.c                   |  54 ++++++++---------
>  block/vpc.c                    |  24 ++++----
>  block/vvfat.c                  |  61 ++++++++++++-------
>  include/block/block.h          |  38 ++++++------
>  include/block/block_int.h      |   4 +-
>  include/sysemu/block-backend.h |   1 +
>  qemu-img.c                     |   2 +-
>  33 files changed, 522 insertions(+), 459 deletions(-)

Do you want to take it through your tree to avoid
conflicts/dependencies?

Acked-by: Stefan Hajnoczi <address@hidden>

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