Re: [Qemu-devel] [PATCH 4/7] block: distinguish id and name in bdrv_find_snapshot()

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

于 2013-4-26 22:34, Stefan Hajnoczi 写道:
> On Fri, Apr 26, 2013 at 05:31:12PM +0800, Wenchao Xia wrote:
>> To make it clear about id and name in searching, the API is changed
>> a bit to distinguish them, and caller can choose to search by id or name.
>> If not found, *errp will be set to tip why.
>>
>> Note that the caller logic is changed a bit:
>> 1) In del_existing_snapshots() called by do_savevm(), it travers twice
>
> s/travers/traverse/
>
> Also in comments in the code.
>
   OK.

>> to find the snapshot, instead once, so matching sequence may change
>> if there are unwisely chosen, mixed id and names.
>> 2) In do_savevm(), same with del_existing_snapshot(), when it tries to
>> find the snapshot to overwrite, matching sequence may change for same
>> reason.
>> 3) In load_vmstate(), first when it tries to find the snapshot to be loaded,
>> sequence may change for the same reason of above. Later in validation, the
>> logic is changed to be more strict to require both id and name matching.
>> 4) In do_info_snapshot(), in validation, the logic is changed to be more
>> strict to require both id and name matching.
>
> It's easy to avoid changing semantics: keep the old name or id behavior
> around.  Use the new name-and-id behavior for #3 and #4.
   You mean adding a new function, instead of change
bdrv_find_snapshot()?


>
> Please include a justification for breaking the search order.
>


-- 
Best Regards

Wenchao Xia