On 06/12/2018 06:11 PM, John Snow wrote:
>
>
> On 06/12/2018 01:26 PM, Vladimir Sementsov-Ogievskiy wrote:
>> First: this variable was introduced to handle reopens. We need it on
>> following qcow2_do_open, to don't try loading bitmaps again. So, we are
>> fixing qcow2_invalidate_cache().
>>
>> However, if we fix only qcow2_invalidate_cache, iotest 169 fails on
>> case test__persistent__not_migbitmap__online_shared, because on first
>> target open, source is not yet closed, and is not yet stored bitmaps,
>> so, we are load nothing. And on second open, dirty_bitmaps_loaded is
>> already true, but we have no bitmaps to reopen with
>> qcow2_reopen_bitmaps_rw_hint(). So, we are fixing qcow2_do_open() too.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
>> ---
>> block/qcow2.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/block/qcow2.c b/block/qcow2.c
>> index 6fa5e1d71a..b4216a5830 100644
>> --- a/block/qcow2.c
>> +++ b/block/qcow2.c
>> @@ -1499,7 +1499,7 @@ static int coroutine_fn qcow2_do_open(BlockDriverState
>> *bs, QDict *options,
>> {
>> qcow2_reopen_bitmaps_rw_hint(bs, &header_updated, &local_err);
>> }
>> - } else {
>> + } else if (s->nb_bitmaps > 0) {
>> header_updated = qcow2_load_dirty_bitmaps(bs, &local_err);
>> s->dirty_bitmaps_loaded = true;
>> }
>> @@ -2178,6 +2178,7 @@ static void coroutine_fn
>> qcow2_co_invalidate_cache(BlockDriverState *bs,
>> QDict *options;
>> Error *local_err = NULL;
>> int ret;
>> + bool dirty_bitmaps_loaded = s->dirty_bitmaps_loaded;
>>
>> /*
>> * Backing files are read-only which makes all of their metadata
>> immutable,
>> @@ -2190,6 +2191,7 @@ static void coroutine_fn
>> qcow2_co_invalidate_cache(BlockDriverState *bs,
>> qcow2_close(bs);
>>
>> memset(s, 0, sizeof(BDRVQcow2State));
>> + s->dirty_bitmaps_loaded = dirty_bitmaps_loaded;
>> options = qdict_clone_shallow(bs->options);
>>
>> flags &= ~BDRV_O_INACTIVE;
>>
>
> Ah, tch... I didn't realize that invalidate completely wipes the qcow2
> metadata.
>
> I guess the other three fields, nb_bitmaps, bitmap_directory_size and
> bitmap_directory_offset get initialized again on re-open.
>
> (I suppose this means I need to rethink caching bm_list more carefully,
> too...)
>
> I think this looks correct mechanically.
>
Oh, I meant:
Reviewed-by: John Snow <js...@redhat.com>
