Re: [Qemu-devel] [PATCH 01/16] block: Introduce BDS.file_child

[Max Reitz]

On 22.09.2015 19:14, Max Reitz wrote:
> On 17.09.2015 15:48, Kevin Wolf wrote:
>> Store the BdrvChild for bs->file. At this point, bs->file_child->bs just
>> duplicates the bs->file pointer. Later, it will completely replace it.
>>
>> Signed-off-by: Kevin Wolf <address@hidden>
>> ---
>>  block.c                   | 12 +++++++++---
>>  include/block/block_int.h |  1 +
>>  2 files changed, 10 insertions(+), 3 deletions(-)
> 
> Reviewed-by: Max Reitz <address@hidden>
> 
> Although I have a small comment below:
> 
>>
>> diff --git a/block.c b/block.c
>> index 6268e37..2e9e5e2 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -1487,11 +1487,17 @@ static int bdrv_open_inherit(BlockDriverState **pbs, 
>> const char *filename,
>>  
>>          assert(file == NULL);
> 
> This looks strange now, without the direct connection to
> bdrv_open_image(). I'd drop this...
> 
>>          bs->open_flags = flags;
>> -        ret = bdrv_open_image(&file, filename, options, "file",
>> -                              bs, &child_file, true, &local_err);
>> -        if (ret < 0) {
>> +
>> +        bs->file_child = bdrv_open_child(filename, options, "file", bs,
>> +                                         &child_file, true, &local_err);
>> +        if (local_err) {
>> +            ret = -EINVAL;
>>              goto fail;
>>          }
>> +
>> +        if (bs->file_child) {
>> +            file = bs->file_child->bs;
>> +        }
> 
> And make this file = bs->file_child ? bs->file_child->bs : NULL (or the
> respective long form, i.e.
> if (bs->file_child) { ... } else { file = NULL; }).
> 
> We could even put this after this if block and drop the NULL
> initialization of file, but that might go overboard.

And expecting something like this, I skipped ahead to patch 5, which
drops this altogether. An R-b without any comments it is, then. :-)

Max

>>      }
>>  
>>      /* Image format probing */
>> diff --git a/include/block/block_int.h b/include/block/block_int.h
>> index 14ad4c3..d0dd93e 100644
>> --- a/include/block/block_int.h
>> +++ b/include/block/block_int.h
>> @@ -381,6 +381,7 @@ struct BlockDriverState {
>>      BlockDriverState *backing_hd;
>>      BdrvChild *backing_child;
>>      BlockDriverState *file;
>> +    BdrvChild *file_child;
>>  
>>      NotifierList close_notifiers;
>>  
>>
> 
>

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