Re: [PATCH 10/23] md: add a new recovery_flag MD_RECOVERY_LAZY_RECOVER

[Yu Kuai <yukuai1@huaweicloud.com>]

Hi,

在 2025/05/27 14:17, Hannes Reinecke 写道:
> On 5/24/25 08:13, Yu Kuai wrote:
>> From: Yu Kuai <yukuai3@huawei.com>
>>
>> This flag is used by llbitmap in later patches to skip raid456 initial
>> recover and delay building initial xor data to first write.
>>
>> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>> ---
>>   drivers/md/md.c | 12 +++++++++++-
>>   drivers/md/md.h |  2 ++
>>   2 files changed, 13 insertions(+), 1 deletion(-)
>>
> Wouldn't it be enough to check for the 'blocks_synced' callback to check
> if the array supports lazy recovery?

I think no, just to check the array supports lazy recovery is not
enough, we still have to distinguish the normal recovery and the lazy
recovery by new bitmap. For example:

+		if (test_bit(MD_RECOVERY_LAZY_RECOVER, &mddev->recovery) &&
+		    start == MaxSector)
+			start = 0;

For normal recovery, there is nothing to do, and for lazy recovery,
we'll register a new sync_thread later to recover bits that are
written the first time.

Thanks,
Kuai

> 
> Otherwise:
> 
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> 
> Cheers,
> 
> Hannes