Re: [Qemu-devel] [PATCH v3 23/23] block: Make device model's references to BlockBackend strong

[Markus Armbruster]

Kevin Wolf <address@hidden> writes:

> Am 16.09.2014 um 20:12 hat Markus Armbruster geschrieben:
>> Doesn't make a difference just yet, but it's the right thing to do.
>> 
>> Signed-off-by: Markus Armbruster <address@hidden>
>> ---
>>  block/block-backend.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>> 
>> diff --git a/block/block-backend.c b/block/block-backend.c
>> index d49c988..5646628 100644
>> --- a/block/block-backend.c
>> +++ b/block/block-backend.c
>> @@ -253,6 +253,7 @@ int blk_attach_dev(BlockBackend *blk, void *dev)
>>      if (blk->dev) {
>>          return -EBUSY;
>>      }
>> +    blk_ref(blk);
>>      blk->dev = dev;
>>      bdrv_iostatus_reset(blk->bs);
>>  
>> @@ -281,9 +282,10 @@ void blk_detach_dev(BlockBackend *blk, void *dev)
>>  /* TODO change to DeviceState *dev when all users are qdevified */
>>  {
>>      assert(blk->dev == dev);
>> -    blk->dev = NULL;
>>      blk->dev_ops = NULL;
>>      blk->dev_opaque = NULL;
>> +    blk->dev = NULL;
>
> Is the move of blk->dev intentional or a rebase artifact?

Artifact, already cleaned up in my tree.

>> +    blk_unref(blk);
>>      bdrv_set_guest_block_size(blk->bs, 512);
>>      qemu_coroutine_adjust_pool_size(-COROUTINE_POOL_RESERVATION);
>>  }
>
> hw/sd/sd.c calls blk_attach_dev_nofail(), but never detaches the BB
> again. The reference count will therefore never become zero.

Feature!

>                                                              Probably
> okay for a device that isn't unpluggable, bdrv_close_all() should still
> do everything that is important for a clean shutdown.

Yes, that's its mission.

> Reviewed-by: Kevin Wolf <address@hidden>

Thanks!