drbd: fix regression, we need to close drbd epochs during normal operation
commit e2041475e6ddb081734d161f6421977323f5a9b9
drbd: Starting with protocol 96 we can allow app-IO while receiving the bitmap
Contained a bad chunk that tried to optimize away drbd barriers during
bitmap exchange, but accidentally dropped them for normal mode as well.
Impact: depending on activity log size and access pattern, activity log
extents may not be recycled in time, causeing IO to block indefinetely.
Fix: skip drbd barriers only if there is no connection to send them on,
or the request being completed has not been on the network at all.
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_req.c b/drivers/block/drbd/drbd_req.c
index 4cb8247..de5fe70 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -140,9 +140,14 @@
struct hlist_node *n;
struct hlist_head *slot;
- /* before we can signal completion to the upper layers,
- * we may need to close the current epoch */
- if (mdev->state.conn >= C_WF_BITMAP_T && mdev->state.conn < C_AHEAD &&
+ /* Before we can signal completion to the upper layers,
+ * we may need to close the current epoch.
+ * We can skip this, if this request has not even been sent, because we
+ * did not have a fully established connection yet/anymore, during
+ * bitmap exchange, or while we are C_AHEAD due to congestion policy.
+ */
+ if (mdev->state.conn >= C_CONNECTED &&
+ (s & RQ_NET_SENT) != 0 &&
req->epoch == mdev->newest_tle->br_number)
queue_barrier(mdev);