Re: [Qemu-devel] [PATCH v8 08/12] block: Parse "backing" option to reference existing BDS

[Fam Zheng <famz@redhat.com>]

On 2014年01月03日 17:19, Stefan Hajnoczi wrote:
>>       }
>>
>> @@ -1682,7 +1696,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
>>       assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
>>       assert(bs_new->job == NULL);
>>       assert(bs_new->dev == NULL);
>> -    assert(bdrv_op_blocker_is_empty(bs_new));
>>       assert(bs_new->io_limits_enabled == false);
>>       assert(!throttle_have_timer(&bs_new->throttle_state));
>>
>> @@ -1701,7 +1714,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
>>       /* Check a few fields that should remain attached to the device */
>>       assert(bs_new->dev == NULL);
>>       assert(bs_new->job == NULL);
>> -    assert(bdrv_op_blocker_is_empty(bs_new));
>>       assert(bs_new->io_limits_enabled == false);
>>       assert(!throttle_have_timer(&bs_new->throttle_state));
>
> Why are these hunks part of this patch?  I guess it makes sense *not* to
> check for blockers in bdrv_swap().  Instead the high-level functions in
> blockdev.c and elsewhere should check blockers.
>

The two checks are here because of the mechanical replace of in_use. 
They are removed because it is no longer true for some valid cases, e.g 
with "block-commit". So we need these hunks here, or do this as a 
preceding in the series.

Will update the commit message and keep it as is.

Fam