Re: [Qemu-devel] [PATCH 1/6] snapshot: export function in block.c

[Kevin Wolf <kwolf@redhat.com>]

Am 08.01.2013 03:25, schrieb Wenchao Xia:
> 于 2013-1-8 0:43, Kevin Wolf 写道:
>> Am 17.12.2012 07:25, schrieb Wenchao Xia:
>>>    This patch moves bdrv_snapshotfind from savevm.c to block.c and export
>>> it, also added bdrv_deappend in block.c.
>>>
>>> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
>>
>> Should be two separate patches.
>>
>    OK, it have been split into two patches in V2.
> 
>>> ---
>>>   block.c  |   30 ++++++++++++++++++++++++++++++
>>>   block.h  |    3 +++
>>>   savevm.c |   22 ----------------------
>>>   3 files changed, 33 insertions(+), 22 deletions(-)
>>>
>>> diff --git a/block.c b/block.c
>>> index 0668c4b..61c7c6a 100644
>>> --- a/block.c
>>> +++ b/block.c
>>> @@ -1376,6 +1376,13 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
>>>               bs_new->drv ? bs_new->drv->format_name : "");
>>>   }
>>>
>>> +/* revert the action */
>>> +void bdrv_deappend(BlockDriverState *bs_new, BlockDriverState *bs_top)
>>> +{
>>> +    bdrv_swap(bs_new, bs_top);
>>> +    /* this is enough? */
>>> +}
>>
>> What will this be used for? Maybe it's better to introduce a function
>> simple as this only when it's actually used.
>>
>    If bdrv_append is called before, this function should revert it, so
> new file created at the top of the backing file chain is dropped.

Yes, I understand that. I meant which functionality/feature will make
use of the function?

Kevin