# \[PATCH\] monitor: Make sure that last\_checkpoint is set to 0 after sync

- From: Pawel Baldysiak \<hidden\>
- Date: 2016-06-16 09:12:20 
- List: linux-raid
- Page: https://ratatoskr.run/linux-raid/2016/06/6632281
- Thread: https://ratatoskr.run/linux-raid/2016/06/6632281/t.md

```text
In a case of successful completion of a resync (in the last step)
- read_and_act sometimes still reads sync_action as "resync"
but sync_completed already is set to component_size.
When this race occurs, sync operation is
marked as finished, but last_checkpoint is
overwritten with sync_completed. It will cause next
sync operation (ie. reshape) to be reported as complete immediately
after start - mdmon will write successful completion of the reshape
to metadata. This patch sets last_checkpoint to 0 once the sync
is completed to stop it happening.

Signed-off-by: Pawel Baldysiak <redacted>
---
 monitor.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/monitor.c b/monitor.c
index 870cc1a..4c79ce2 100644
--- a/monitor.c
+++ b/monitor.c
@@ -420,6 +420,9 @@ static int read_and_act(struct active_array *a)
 	if (sync_completed > a->last_checkpoint)
 		a->last_checkpoint = sync_completed;
 
+	if (sync_completed >= a->info.component_size)
+		a->last_checkpoint = 0;
+
 	a->container->ss->sync_metadata(a->container);
 	dprintf("(%d): state:%s action:%s next(", a->info.container_member,
 		array_states[a->curr_state], sync_actions[a->curr_action]);

```