Re: [Qemu-devel] [PATCH v2 0/9] block: replace .bdrv_is_allocated() with .bdrv_co_is_allocated()

[Kevin Wolf]

Am 14.11.2011 13:44, schrieb Stefan Hajnoczi:
> The bdrv_is_allocated() interface is not suitable for use while the VM is
> running.  It is a synchronous interface so it may block the running VM for
> arbitrary amounts of time.  It also assumes it is the only block driver
> operation and there is a risk that internal state could be corrupted if
> asynchronous I/O is currently pending.
> 
> This patch series refactors the block layer so that the bdrv_is_allocated()
> operation is performed internally in coroutine context.  We can then introduce
> a new public bdrv_co_is_allocated() function that is suitable for use when the
> VM is running.
> 
> Making these changes without breaking git bisect means we need to first
> introduce BlockDriver .bdrv_co_is_allocated() and add wrapper code into
> bdrv_is_allocated() so existing callers can use converted BlockDrivers.
> 
> After converting all block drivers there are no .bdrv_is_allocated() functions
> left and the interface can be removed from BlockDriver.
> 
> Finally, we can add the new public bdrv_co_is_allocated() public interface and
> turn the old bdrv_is_allocated() into a wrapper.
> 
> This series is a prerequisite for copy-on-read, which needs to check whether
> sectors are allocated while the VM is running.
> 
> v2:
>  * Rebased on kevin/block and resolved conflicts
> 
> Stefan Hajnoczi (9):
>   block: use public bdrv_is_allocated() interface
>   block: add .bdrv_co_is_allocated()
>   qed: convert to .bdrv_co_is_allocated()
>   block: convert qcow2, qcow2, and vmdk to .bdrv_co_is_allocated()
>   vvfat: convert to .bdrv_co_is_allocated()
>   vdi: convert to .bdrv_co_is_allocated()
>   cow: convert to .bdrv_co_is_allocated()
>   block: drop .bdrv_is_allocated() interface
>   block: add bdrv_co_is_allocated() interface
> 
>  block.c       |   58 +++++++++++++++++++++++++++++++++++++++++++++++++++-----
>  block.h       |    2 +
>  block/cow.c   |    8 +++---
>  block/qcow.c  |    8 ++++--
>  block/qcow2.c |   13 +++++++----
>  block/qed.c   |   15 ++++++++++---
>  block/vdi.c   |    6 ++--
>  block/vmdk.c  |    8 ++++--
>  block/vvfat.c |    4 +-
>  block_int.h   |    4 +-
>  10 files changed, 94 insertions(+), 32 deletions(-)

Thanks, applied all to the block branch (for 1.1)

Kevin