linux-kernel - Re: [PATCH 10/23] md: add a new recovery_flag MD_RECOVERY_LAZY

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2c120387-cf9e-23e5-9442-ffcf320cf611@huaweicloud.com>
Date: Tue, 27 May 2025 16:00:16 +0800
From: Yu Kuai <yukuai1@...weicloud.com>
To: Hannes Reinecke <hare@...e.de>, Yu Kuai <yukuai1@...weicloud.com>,
 hch@....de, xni@...hat.com, colyli@...nel.org, song@...nel.org
Cc: linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-raid@...r.kernel.org, yi.zhang@...wei.com, yangerkun@...wei.com,
 johnny.chenyi@...wei.com, "yukuai (C)" <yukuai3@...wei.com>
Subject: Re: [PATCH 10/23] md: add a new recovery_flag
 MD_RECOVERY_LAZY_RECOVER

Hi,

在 2025/05/27 14:17, Hannes Reinecke 写道:
> On 5/24/25 08:13, Yu Kuai wrote:
>> From: Yu Kuai <yukuai3@...wei.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@...wei.com>
>> Reviewed-by: Christoph Hellwig <hch@....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@...e.de>
> 
> Cheers,
> 
> Hannes