drbd: flush drbd work queue before invalidate/invalidate remote
If you do back to back wait-sync/invalidate on a Primary in a tight loop,
during application IO load, you could trigger a race:
kernel: block drbd6: FIXME going to queue 'set_n_write from StartingSync'
but 'write from resync_finished' still pending?
Fix this by changing the order of the drbd_queue_work() and
the wake_up() in dec_ap_pending(), and adding the additional
drbd_flush_workqueue() before requesting the full sync.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index a68d9bf..c47df7c 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1977,9 +1977,11 @@
int retcode;
/* If there is still bitmap IO pending, probably because of a previous
- * resync just being finished, wait for it before requesting a new resync. */
+ * resync just being finished, wait for it before requesting a new resync.
+ * Also wait for it's after_state_ch(). */
drbd_suspend_io(mdev);
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
+ drbd_flush_workqueue(mdev);
retcode = _drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_T), CS_ORDERED);
@@ -2018,9 +2020,11 @@
int retcode;
/* If there is still bitmap IO pending, probably because of a previous
- * resync just being finished, wait for it before requesting a new resync. */
+ * resync just being finished, wait for it before requesting a new resync.
+ * Also wait for it's after_state_ch(). */
drbd_suspend_io(mdev);
wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));
+ drbd_flush_workqueue(mdev);
retcode = _drbd_request_state(mdev, NS(conn, C_STARTING_SYNC_S), CS_ORDERED);