Hi Xiao,
Thanks for review.

On Mon, 31 Jan 2022 16:29:27 +0800
Xiao Ni [off-list ref] wrote:

quoted

+
        if (test_bit(In_sync, &rdev->flags) && !mddev->fail_last_dev
            && !enough(conf, rdev->raid_disk)) {

The check of mddev->fail_last_dev should be removed here.

Ohh, my bad. I mainly tested it on RAID1 and didn't notice it.
Thanks!

quoted

-               /*
-                * Don't fail the drive, just return an IO error.
-                */

It's the same. These comments can directly give people notes. raid10
will return bio here with an error. Is it better to keep them here?

Sure, let wait for Song opinion first and then I will send v4.

Mariusz