Re: [Qemu-devel] [PATCH 0/2] block: allow commit active as top

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

于 2013-7-22 11:46, Fam Zheng 写道:
> Previously live commit of active block device is not supported, this series
> implements it and updates corresponding qemu-iotests cases.
> 
> Please see commit messages for implementation details.
> 
> Fam Zheng (2):
>    block: allow live commit of active image
>    qemu-iotests: update test cases for commit active
> 
>   block.c                | 102 ++++++++++---------------------
>   block/commit.c         | 160 +++++++++++++++++++++++++------------------------
>   include/block/block.h  |   5 +-
>   tests/qemu-iotests/040 |  68 ++++++++-------------
>   4 files changed, 141 insertions(+), 194 deletions(-)
> 
  I have thought the commit with top issue before, a question comes to
me: what is the relationship with block-stream?

for example:
base->mid->top

you can block-stream mid to top(if I remember correctly), result is:
base->(mid+top)

with this patch, you can block-commit top to mid, result is:
base->(mod+top)

it seems the function is duplicated. Maybe you can raise another
good user case. I must say it may help user to do every thing
with block-commit, but if you find it is too much to make it work,
maybe you can postpond it, since block-stream is available.

-- 
Best Regards

Wenchao Xia