I’ve been running withy my workflow that is known to trigger the issue reliably for about 6 hours now. This is longer than it worked before.
I’m leaving the office for today and will leave things running over night and report back tomorrow.
Christian
> On 11. Nov 2024, at 09:00, Christian Theune <ct@xxxxxxxxxxxxxxx> wrote:
>
> Hi,
>
> I’m trying this with 6.11.7 today.
>
> Christian
>
>> On 9. Nov 2024, at 12:35, Xiao Ni <xni@xxxxxxxxxx> wrote:
>>
>> On Thu, Nov 7, 2024 at 3:55 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
>>>
>>> Hi!
>>>
>>> 在 2024/11/06 14:40, Christian Theune 写道:
>>>> Hi,
>>>>
>>>>> On 6. Nov 2024, at 07:35, Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> 在 2024/11/05 18:15, Christian Theune 写道:
>>>>>> Hi,
>>>>>> after about 2 hours it stalled again. Here’s the full blocked process dump. (Tell me if this isn’t helpful, otherwise I’ll keep posting that as it’s the only real data I can show)
>>>>>
>>>>> This is bad news :(
>>>>
>>>> Yeah. But: the good new is that we aren’t eating any data so far … ;)
>>>>
>>>>> While reviewing related code, I come up with a plan to move bitmap
>>>>> start/end write ops to the upper layer. Make sure each write IO from
>>>>> upper layer only start once and end once, this is easy to make sure
>>>>> they are balanced and can avoid many calls to improve performance as
>>>>> well.
>>>>
>>>> Sounds like a plan!
>>>>
>>>>> However, I need a few days to cooke a patch after work.
>>>>
>>>> Sure thing! I’ll switch off bitmaps for that time - I’m happy we found a workaround so we can take time to resolve it cleanly. :)
>>>
>>> I wrote a simple and crude version, please give it a test again.
>>>
>>> Thanks,
>>> Kuai
>>>
>>> diff --git a/drivers/md/md.c b/drivers/md/md.c
>>> index d3a837506a36..5e1a82b79e41 100644
>>> --- a/drivers/md/md.c
>>> +++ b/drivers/md/md.c
>>> @@ -8753,6 +8753,30 @@ void md_submit_discard_bio(struct mddev *mddev,
>>> struct md_rdev *rdev,
>>> }
>>> EXPORT_SYMBOL_GPL(md_submit_discard_bio);
>>>
>>> +static bool is_raid456(struct mddev *mddev)
>>> +{
>>> + return mddev->pers->level == 4 || mddev->pers->level == 5 ||
>>> + mddev->pers->level == 6;
>>> +}
>>> +
>>> +static void bitmap_startwrite(struct mddev *mddev, struct bio *bio)
>>> +{
>>> + if (!is_raid456(mddev) || !mddev->bitmap)
>>> + return;
>>> +
>>> + md_bitmap_startwrite(mddev->bitmap, bio_offset(bio),
>>> bio_sectors(bio),
>>> + 0);
>>> +}
>>> +
>>> +static void bitmap_endwrite(struct mddev *mddev, struct bio *bio,
>>> sector_t sectors)
>>> +{
>>> + if (!is_raid456(mddev) || !mddev->bitmap)
>>> + return;
>>> +
>>> + md_bitmap_endwrite(mddev->bitmap, bio_offset(bio), sectors,o
>>> + bio->bi_status == BLK_STS_OK, 0);
>>> +}
>>> +
>>> static void md_end_clone_io(struct bio *bio)
>>> {
>>> struct md_io_clone *md_io_clone = bio->bi_private;
>>> @@ -8765,6 +8789,7 @@ static void md_end_clone_io(struct bio *bio)
>>> if (md_io_clone->start_time)
>>> bio_end_io_acct(orig_bio, md_io_clone->start_time);
>>>
>>> + bitmap_endwrite(mddev, orig_bio, md_io_clone->sectors);
>>> bio_put(bio);
>>> bio_endio(orig_bio);
>>> percpu_ref_put(&mddev->active_io);
>>> @@ -8778,6 +8803,7 @@ static void md_clone_bio(struct mddev *mddev,
>>> struct bio **bio)
>>> bio_alloc_clone(bdev, *bio, GFP_NOIO,
>>> &mddev->io_clone_set);
>>>
>>> md_io_clone = container_of(clone, struct md_io_clone, bio_clone);
>>> + md_io_clone->sectors = bio_sectors(*bio);
>>> md_io_clone->orig_bio = *bio;
>>> md_io_clone->mddev = mddev;
>>> if (blk_queue_io_stat(bdev->bd_disk->queue))
>>> @@ -8790,6 +8816,7 @@ static void md_clone_bio(struct mddev *mddev,
>>> struct bio **bio)
>>>
>>> void md_account_bio(struct mddev *mddev, struct bio **bio)
>>> {
>>> + bitmap_startwrite(mddev, *bio);
>>> percpu_ref_get(&mddev->active_io);
>>> md_clone_bio(mddev, bio);
>>> }
>>> @@ -8807,6 +8834,8 @@ void md_free_cloned_bio(struct bio *bio)
>>> if (md_io_clone->start_time)
>>> bio_end_io_acct(orig_bio, md_io_clone->start_time);
>>>
>>> + bitmap_endwrite(mddev, orig_bio, md_io_clone->sectors);
>>> +
>>> bio_put(bio);
>>> percpu_ref_put(&mddev->active_io);
>>> }
>>> diff --git a/drivers/md/md.h b/drivers/md/md.h
>>> index a0d6827dced9..0c2794230e0a 100644
>>> --- a/drivers/md/md.h
>>> +++ b/drivers/md/md.h
>>> @@ -837,6 +837,7 @@ struct md_io_clone {
>>> struct mddev *mddev;
>>> struct bio *orig_bio;
>>> unsigned long start_time;
>>> + sector_t sectors;
>>> struct bio bio_clone;
>>> };
>>> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
>>> index c14cf2410365..4f009e32f68a 100644
>>> --- a/drivers/md/raid5.c
>>> +++ b/drivers/md/raid5.c
>>> @@ -3561,12 +3561,6 @@ static void __add_stripe_bio(struct stripe_head
>>> *sh, struct bio *bi,
>>> * is added to a batch, STRIPE_BIT_DELAY cannot be changed
>>> * any more.
>>> */
>>> - set_bit(STRIPE_BITMAP_PENDING, &sh->state);
>>> - spin_unlock_irq(&sh->stripe_lock);
>>> - md_bitmap_startwrite(conf->mddev->bitmap, sh->sector,
>>> - RAID5_STRIPE_SECTORS(conf), 0);
>>> - spin_lock_irq(&sh->stripe_lock);
>>> - clear_bit(STRIPE_BITMAP_PENDING, &sh->state);
>>> if (!sh->batch_head) {
>>> sh->bm_seq = conf->seq_flush+1;
>>> set_bit(STRIPE_BIT_DELAY, &sh->state);
>>> @@ -3621,7 +3615,6 @@ handle_failed_stripe(struct r5conf *conf, struct
>>> stripe_head *sh,
>>> BUG_ON(sh->batch_head);
>>> for (i = disks; i--; ) {
>>> struct bio *bi;
>>> - int bitmap_end = 0;
>>>
>>> if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
>>> struct md_rdev *rdev = conf->disks[i].rdev;
>>> @@ -3646,8 +3639,6 @@ handle_failed_stripe(struct r5conf *conf, struct
>>> stripe_head *sh,
>>> sh->dev[i].towrite = NULL;
>>> sh->overwrite_disks = 0;
>>> spin_unlock_irq(&sh->stripe_lock);
>>> - if (bi)
>>> - bitmap_end = 1;
>>>
>>> log_stripe_write_finished(sh);
>>> @@ -3662,10 +3653,6 @@ handle_failed_stripe(struct r5conf *conf, struct
>>> stripe_head *sh,
>>> bio_io_error(bi);
>>> bi = nextbi;
>>> }
>>> - if (bitmap_end)
>>> - md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
>>> - RAID5_STRIPE_SECTORS(conf),
>>> 0, 0);
>>> - bitmap_end = 0;
>>> /* and fail all 'written' */
>>> bi = sh->dev[i].written;
>>> sh->dev[i].written = NULL;
>>> @@ -3674,7 +3661,6 @@ handle_failed_stripe(struct r5conf *conf, struct
>>> stripe_head *sh,
>>> sh->dev[i].page = sh->dev[i].orig_page;
>>> }
>>>
>>> - if (bi) bitmap_end = 1;
>>> while (bi && bi->bi_iter.bi_sector <
>>> sh->dev[i].sector + RAID5_STRIPE_SECTORS(conf)) {
>>> struct bio *bi2 = r5_next_bio(conf, bi,
>>> sh->dev[i].sector);
>>> @@ -3708,9 +3694,6 @@ handle_failed_stripe(struct r5conf *conf, struct
>>> stripe_head *sh,
>>> bi = nextbi;
>>> }
>>> }
>>> - if (bitmap_end)
>>> - md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
>>> - RAID5_STRIPE_SECTORS(conf),
>>> 0, 0);
>>> /* If we were in the middle of a write the parity block
>>> might
>>> * still be locked - so just clear all R5_LOCKED flags
>>> */
>>> @@ -4059,10 +4042,6 @@ static void handle_stripe_clean_event(struct
>>> r5conf *conf,
>>> bio_endio(wbi);
>>> wbi = wbi2;
>>> }
>>> - md_bitmap_endwrite(conf->mddev->bitmap,
>>> sh->sector,
>>> -
>>> RAID5_STRIPE_SECTORS(conf),
>>> -
>>> !test_bit(STRIPE_DEGRADED, &sh->state),
>>> - 0);
>>> if (head_sh->batch_head) {
>>> sh =
>>> list_first_entry(&sh->batch_list,
>>> struct
>>> stripe_head,
>>> @@ -5788,13 +5767,6 @@ static void make_discard_request(struct mddev
>>> *mddev, struct bio *bi)
>>> }
>>> spin_unlock_irq(&sh->stripe_lock);
>>> if (conf->mddev->bitmap) {
>>> - for (d = 0;
>>> - d < conf->raid_disks - conf->max_degraded;
>>> - d++)
>>> - md_bitmap_startwrite(mddev->bitmap,
>>> - sh->sector,
>>> -
>>> RAID5_STRIPE_SECTORS(conf),
>>> - 0);
>>> sh->bm_seq = conf->seq_flush + 1;
>>> set_bit(STRIPE_BIT_DELAY, &sh->state);
>>> }
>>>
>>>
>>>
>>>>
>>>> Thanks a lot for your help!
>>>> Christian
>>>>
>>>
>>>
>>
>> Hi Kuai
>>
>> Maybe it's not good to put the bitmap operation from raid5 to md which
>> the new api is only used for raid5. And the bitmap region which raid5
>> needs to handle is based on the member disk. It should be calculated
>> rather than the bio address space. Because the bio address space is
>> for the whole array.
>>
>> We have a customer who reports a similar problem. There is a patch
>> from David. I put it in the attachment.
>>
>> @Christian, can you have a try with the patch? It can be applied
>> cleanly on 6.11-rc6
>>
>> Regards
>> Xiao
>> <md_raid5_one_bitmap_claim_per_stripe_head.patch>
>
> Liebe Grüße,
> Christian Theune
>
> --
> Christian Theune · ct@xxxxxxxxxxxxxxx · +49 345 219401 0
> Flying Circus Internet Operations GmbH · https://flyingcircus.io
> Leipziger Str. 70/71 · 06108 Halle (Saale) · Deutschland
> HR Stendal HRB 21169 · Geschäftsführer: Christian Theune, Christian Zagrodnick
>
Liebe Grüße,
Christian Theune
--
Christian Theune · ct@xxxxxxxxxxxxxxx · +49 345 219401 0
Flying Circus Internet Operations GmbH · https://flyingcircus.io
Leipziger Str. 70/71 · 06108 Halle (Saale) · Deutschland
HR Stendal HRB 21169 · Geschäftsführer: Christian Theune, Christian Zagrodnick
