回复: [PATCH v1] block/stream:add flush l2_table_cache,ensure data integrity

[张承]

>On 25.07.23 18:13, Denis V. Lunev wrote:
>>On 7/25/23 16:25, Vladimir Sementsov-Ogievskiy wrote:
>>>On 24.07.23 10:30, Evanzhang wrote:
>>>> On 7/26/23 01:41, Vladimir Sementsov-Ogievskiy wrote:
>>>>block_stream will not actively flush l2_table_cache,when qemu 
>>>> process exception exit,causing disk data loss
>>>>
>>>>Signed-off-by: Evanzhang <Evanzhang@archeros.com>
>>>>---
>>>>   block/stream.c | 6 ++++++
>>>>   1 file changed, 6 insertions(+)
>>>>
>>> >diff --git a/block/stream.c b/block/stream.c index e522bbd..a5e08da 
>>>>100644
>>>> --- a/block/stream.c
>>>> +++ b/block/stream.c
>>>>@@ -207,6 +207,12 @@ static int coroutine_fn stream_run(Job *job, 
>>>> Error **errp)
>>>>           }
>>>>       }
>>>>   +    /*
>>>> +     * Complete stream_populate,force flush l2_table_cache,to
>>>> +     * avoid unexpected termination of process, l2_table loss
>>>> +     */
>>>> +    qcow2_cache_flush(bs, ((BDRVQcow2State 
>>>> +*)bs->opaque)->l2_table_cache);
>>>> +
>>>>       /* Do not remove the backing file if an error was there but 
>>>> ignored. */
>>>>       return error;
>>>>   }
>>>
>>> Hi!
>>>
>>> I think, it's more correct just call bdrv_co_flush(bs), which should do all 
>>> the job. Also, stream_run() should fail if flush fails.
>>>
>>> Also, I remember I've done it for all (or at least several) blockjobs 
>>> generically, so that any blockjob must succesfully flush target to report 
>>> success.. But now I can find neither my patches nor the code :( Den, Kevin, 
>>> Hanna, don't you remember this topic?
>>>
>> This was a part of compressed write cache series, which was postponed.
>> 
>> https://lore.kernel.org/all/20210305173507.393137-1-vsementsov@virtuoz
>> zo.com/T/#m87315593ed5ab16e5d0e4e7a5ae6d776fbbaec77
>> 
>> We have it ported to 7.0 QEMU.
>> 
>> Not a problem to port to master and resend.
>> Will this make a sense?
>> 

>O, thanks! Patch 01 applies with a little conflict to master, so I'll just 
>resend it myself.
>

Thanks all ! 
With best regards !