From: Yu Kuai <[email protected]>
stop_sync_thread() will interrupt md_do_sync(), and md_do_sync() must
set MD_RECOVERY_DONE, so that follow up md_check_recovery() will
unregister sync_thread, clear MD_RECOVERY_RUNNING and wake up
stop_sync_thread().
Before this patch, if MD_RECOVERY_WAIT is set or the array is read-only,
md_do_sync() will return without setting MD_RECOVERY_DONE, hence use
stop_sync_thread() directly will hang because md_check_recovery() can't
clear MD_RECOVERY_RUNNING, which is possible for dm-raid.
Signed-off-by: Yu Kuai <[email protected]>
---
drivers/md/md.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 6906d023f1d6..ba45c7be3dbe 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8788,12 +8788,13 @@ void md_do_sync(struct md_thread *thread)
int ret;
/* just incase thread restarts... */
- if (test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
- test_bit(MD_RECOVERY_WAIT, &mddev->recovery))
+ if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
return;
- if (!md_is_rdwr(mddev)) {/* never try to sync a read-only array */
+
+ if (test_bit(MD_RECOVERY_WAIT, &mddev->recovery) ||
+ !md_is_rdwr(mddev)) {/* never try to sync a read-only array */
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
- return;
+ goto out;
}
if (mddev_is_clustered(mddev)) {
@@ -9171,6 +9172,7 @@ void md_do_sync(struct md_thread *thread)
mddev->array_sectors);
}
+out:
spin_lock(&mddev->lock);
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
/* We completed so min/max setting can be forgotten if used. */
--
2.39.2
Hi all
MD_RECOVERY_WAIT was introduced in d5d885fd5. From this patch,
MD_RECOVERY_WAIT only has one usage during creating raid device.
resync job needs to wait until pers->start finishes(The only place
which is checked). If we remove it from md_do_sync, will it break the
logic? Or we don't need this flag anymore? If so can we remove this
flag?
dm-raid uses this bit in patch 644e2537f (dm raid: fix stripe adding
reshape deadlock). It's the reason why md_do_sync can't set
MD_RECOVERY_DONE. Now we stop sync thread asynchronously, can we
revert this patch?
Best Regards
Xiao
On Sat, Jan 20, 2024 at 6:41 PM Yu Kuai <[email protected]> wrote:
>
> From: Yu Kuai <[email protected]>
>
> stop_sync_thread() will interrupt md_do_sync(), and md_do_sync() must
> set MD_RECOVERY_DONE, so that follow up md_check_recovery() will
> unregister sync_thread, clear MD_RECOVERY_RUNNING and wake up
> stop_sync_thread().
>
> Before this patch, if MD_RECOVERY_WAIT is set or the array is read-only,
> md_do_sync() will return without setting MD_RECOVERY_DONE, hence use
> stop_sync_thread() directly will hang because md_check_recovery() can't
> clear MD_RECOVERY_RUNNING, which is possible for dm-raid.
>
> Signed-off-by: Yu Kuai <[email protected]>
> ---
> drivers/md/md.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 6906d023f1d6..ba45c7be3dbe 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -8788,12 +8788,13 @@ void md_do_sync(struct md_thread *thread)
> int ret;
>
> /* just incase thread restarts... */
> - if (test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
> - test_bit(MD_RECOVERY_WAIT, &mddev->recovery))
> + if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
> return;
> - if (!md_is_rdwr(mddev)) {/* never try to sync a read-only array */
> +
> + if (test_bit(MD_RECOVERY_WAIT, &mddev->recovery) ||
> + !md_is_rdwr(mddev)) {/* never try to sync a read-only array */
> set_bit(MD_RECOVERY_INTR, &mddev->recovery);
> - return;
> + goto out;
> }
>
> if (mddev_is_clustered(mddev)) {
> @@ -9171,6 +9172,7 @@ void md_do_sync(struct md_thread *thread)
> mddev->array_sectors);
> }
>
> +out:
> spin_lock(&mddev->lock);
> if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
> /* We completed so min/max setting can be forgotten if used. */
> --
> 2.39.2
>
>
Hi,
在 2024/01/24 10:58, Xiao Ni 写道:
> Hi all
>
> MD_RECOVERY_WAIT was introduced in d5d885fd5. From this patch,
> MD_RECOVERY_WAIT only has one usage during creating raid device.
> resync job needs to wait until pers->start finishes(The only place
> which is checked). If we remove it from md_do_sync, will it break the
> logic? Or we don't need this flag anymore? If so can we remove this
> flag?
>
> dm-raid uses this bit in patch 644e2537f (dm raid: fix stripe adding
> reshape deadlock). It's the reason why md_do_sync can't set
> MD_RECOVERY_DONE. Now we stop sync thread asynchronously, can we
> revert this patch?
I made some changes that will be sent for v2 that sync_thread is frozen
from dm suspend to resume, so I think the flag can be removed, and I
actually tried that, howver, dm-raid tests failed because ext4 is
corrupted. Anyway, let's focus on dm-raid regression for now and we can
try to remove this flag later.
Thanks,
Kuai
>
> Best Regards
> Xiao
>
> On Sat, Jan 20, 2024 at 6:41 PM Yu Kuai <[email protected]> wrote:
>>
>> From: Yu Kuai <[email protected]>
>>
>> stop_sync_thread() will interrupt md_do_sync(), and md_do_sync() must
>> set MD_RECOVERY_DONE, so that follow up md_check_recovery() will
>> unregister sync_thread, clear MD_RECOVERY_RUNNING and wake up
>> stop_sync_thread().
>>
>> Before this patch, if MD_RECOVERY_WAIT is set or the array is read-only,
>> md_do_sync() will return without setting MD_RECOVERY_DONE, hence use
>> stop_sync_thread() directly will hang because md_check_recovery() can't
>> clear MD_RECOVERY_RUNNING, which is possible for dm-raid.
>>
>> Signed-off-by: Yu Kuai <[email protected]>
>> ---
>> drivers/md/md.c | 10 ++++++----
>> 1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/md/md.c b/drivers/md/md.c
>> index 6906d023f1d6..ba45c7be3dbe 100644
>> --- a/drivers/md/md.c
>> +++ b/drivers/md/md.c
>> @@ -8788,12 +8788,13 @@ void md_do_sync(struct md_thread *thread)
>> int ret;
>>
>> /* just incase thread restarts... */
>> - if (test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
>> - test_bit(MD_RECOVERY_WAIT, &mddev->recovery))
>> + if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
>> return;
>> - if (!md_is_rdwr(mddev)) {/* never try to sync a read-only array */
>> +
>> + if (test_bit(MD_RECOVERY_WAIT, &mddev->recovery) ||
>> + !md_is_rdwr(mddev)) {/* never try to sync a read-only array */
>> set_bit(MD_RECOVERY_INTR, &mddev->recovery);
>> - return;
>> + goto out;
>> }
>>
>> if (mddev_is_clustered(mddev)) {
>> @@ -9171,6 +9172,7 @@ void md_do_sync(struct md_thread *thread)
>> mddev->array_sectors);
>> }
>>
>> +out:
>> spin_lock(&mddev->lock);
>> if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
>> /* We completed so min/max setting can be forgotten if used. */
>> --
>> 2.39.2
>>
>>
>
> .
>