Re: [PATCH] md/raid1: protect sequential read hints for read balance

[yu kuai]

在 2026/6/23 15:59, Chen Cheng 写道:

> The patch just suppress KCSAN noise. No functional change.
>
> KCSAN reports a race, point to update_read_sectors() update next_seq_sect vs.
> read next_seq_sect.
>
> Protect next_seq_sect and seq_start with READ_ONCE/WRITE_ONCE, otherwise,
> read balance see stale sequential-read hints.
>
> KCSAN report:
> ==============
>   BUG: KCSAN: data-race in raid1_read_request / raid1_read_request
>
>   write to 0xffff8e3a2d6736d0 of 8 bytes by task 593784 on cpu 10:
>    raid1_read_request+0xe5a/0x19f0
>    raid1_make_request+0xdf/0x1990
>    md_handle_request+0x4a2/0xa40
>    [...]
>
>   read to 0xffff8e3a2d6736d0 of 8 bytes by task 593776 on cpu 11:
>    raid1_read_request+0xe3f/0x19f0
>    raid1_make_request+0xdf/0x1990
>    md_handle_request+0x4a2/0xa40
>    [...]
>
>   value changed: 0x0000000000356368 -> 0x0000000000356370
>
> Signed-off-by: Chen Cheng<chencheng@xxxxxxxxx>
> ---
>   drivers/md/raid1.c | 18 ++++++++++--------
>   1 file changed, 10 insertions(+), 8 deletions(-)
Reviewed-by: Yu Kuai <yukuai@xxxxxxx>

-- 
Thanks,
Kuai