Re: [PATCH -next v2 3/7] md: delay choosing sync direction to md_start_sync()

[Yu Kuai <yukuai1@huaweicloud.com>]

Hi,

在 2023/08/15 23:54, Song Liu 写道:
> On Tue, Aug 15, 2023 at 2:00 PM Yu Kuai <yukuai1@huaweicloud.com> wrote:
> [...]
>>> +
>>> +not_running:
>>> +     clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
>>> +     clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
>>> +     clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
>>> +     clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
>>> +     clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
>>> +     mddev_unlock(mddev);
>>> +
>>> +     wake_up(&resync_wait);
>>> +     if (test_and_clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery) &&
>>> +         mddev->sysfs_action)
>>> +             sysfs_notify_dirent_safe(mddev->sysfs_action);
>>>    }
>>>
>>>    /*
>>> @@ -9379,7 +9402,6 @@ void md_check_recovery(struct mddev *mddev)
>>>                return;
>>>
>>>        if (mddev_trylock(mddev)) {
>>> -             int spares = 0;
>>>                bool try_set_sync = mddev->safemode != 0;
>>>
>>>                if (!mddev->external && mddev->safemode == 1)
>>> @@ -9467,29 +9489,11 @@ void md_check_recovery(struct mddev *mddev)
>>>                clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
>>>
>>>                if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
>>> -                 test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
>>> -                     goto not_running;
>>> -             if (!md_choose_sync_direction(mddev, &spares))
>>> -                     goto not_running;
>>> -             if (mddev->pers->sync_request) {
>>> -                     if (spares) {
>>> -                             /* We are adding a device or devices to an array
>>> -                              * which has the bitmap stored on all devices.
>>> -                              * So make sure all bitmap pages get written
>>> -                              */
>>> -                             md_bitmap_write_all(mddev->bitmap);
>>> -                     }
>>> +                 test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
>>
>> Sorry that I made a mistake here while rebasing v2, here should be
>>
>> !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)
>>
>> With this fixed, there are no new regression for mdadm tests using loop
>> devicein my VM.
> 
>                  if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
>                      !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
>                          queue_work(md_misc_wq, &mddev->sync_work);
>                  } else {
> 
> This doesn't look right. Should we do
> 
>                  if (test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) &&
>                      !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
>                          queue_work(md_misc_wq, &mddev->sync_work);
>                  } else {
> 
> instead?
> 

Yes you're right, this is exactly what I did in v1, sorry that I keep
making mistake while rebasing.

Thanks,
Kuai

> Thanks,
> Song
> .
>