Re: [PATCH md-6.12 0/7] md: enhance faulty chekcing for blocked handling

[Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>]

On Fri, 30 Aug 2024 15:27:14 +0800
Yu Kuai <yukuai1@huaweicloud.com> wrote:

> From: Yu Kuai <yukuai3@huawei.com>
> 
> The lifetime of badblocks:
> 
> - IO error, and decide to record badblocks, and record sb_flags;
> - write IO found rdev has badblocks and not yet acknowledged, then this
> IO is blocked;
> - daemon found sb_flags is set, update superblock and flush badblocks;
> - write IO continue;
> 
> Main idea is that badblocks will be set in memory fist, before badblocks
> are acknowledged, new write request must be blocked to prevent reading
> old data after power failure, and this behaviour is not necessary if rdev
> is faulty in the first place.
> 
> Yu Kuai (7):
>   md: add a new helper rdev_blocked()
>   md: don't wait faulty rdev in md_wait_for_blocked_rdev()
>   md: don't record new badblocks for faulty rdev
>   md/raid1: factor out helper to handle blocked rdev from
>     raid1_write_request()
>   md/raid1: don't wait for Faulty rdev in wait_blocked_rdev()
>   md/raid10: don't wait for Faulty rdev in wait_blocked_rdev()
>   md/raid5: don't set Faulty rdev for blocked_rdev
> 
>  drivers/md/md.c     |  8 +++--
>  drivers/md/md.h     | 24 +++++++++++++++
>  drivers/md/raid1.c  | 75 +++++++++++++++++++++++----------------------
>  drivers/md/raid10.c | 40 +++++++++++-------------
>  drivers/md/raid5.c  | 13 ++++----
>  5 files changed, 92 insertions(+), 68 deletions(-)
> 

Hi Song,
We need to test this with external metadata so please wait for our green light
before you will take this.
I checked the code and it looks safe but I need to double confirm it to avoid
hung tasks.

Thanks,
Mariusz