Since drbd-8.4.0 it is possible to change the allow-two-primaries
network option while the connection is established.
The sequence code used to partially order packets from the
data socket with packets from the meta-data socket, still assued
that the allow-two-primaries option is constant while the
connection is established.
I.e.
On a node that has the RESOLVE_CONFLICTS bits set, after enabling
allow-two-primaries, when receiving the next data packet it timed out
while waiting for the necessary packets on the data socket to arrive
(wait_for_and_update_peer_seq() function).
Fixed that by always tracking the sequence number, but only waiting
for it if allow-two-primaries is set.
Signed-off-by: Philipp Reisner <philipp.reis...@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenb...@linbit.com>
---
drivers/block/drbd/drbd_receiver.c | 39 +++++++++++++++---------------------
1 file changed, 16 insertions(+), 23 deletions(-)
diff --git a/drivers/block/drbd/drbd_receiver.c
b/drivers/block/drbd/drbd_receiver.c
index cc29cd3..12c59eb 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1890,29 +1890,11 @@ static u32 seq_max(u32 a, u32 b)
return seq_greater(a, b) ? a : b;
}
-static bool need_peer_seq(struct drbd_conf *mdev)
-{
- struct drbd_tconn *tconn = mdev->tconn;
- int tp;
-
- /*
- * We only need to keep track of the last packet_seq number of our peer
- * if we are in dual-primary mode and we have the resolve-conflicts
flag set; see
- * handle_write_conflicts().
- */
-
- rcu_read_lock();
- tp = rcu_dereference(mdev->tconn->net_conf)->two_primaries;
- rcu_read_unlock();
-
- return tp && test_bit(RESOLVE_CONFLICTS, &tconn->flags);
-}
-
static void update_peer_seq(struct drbd_conf *mdev, unsigned int peer_seq)
{
unsigned int newest_peer_seq;
- if (need_peer_seq(mdev)) {
+ if (test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags)) {
spin_lock(&mdev->peer_seq_lock);
newest_peer_seq = seq_max(mdev->peer_seq, peer_seq);
mdev->peer_seq = newest_peer_seq;
@@ -1972,22 +1954,31 @@ static int wait_for_and_update_peer_seq(struct
drbd_conf *mdev, const u32 peer_s
{
DEFINE_WAIT(wait);
long timeout;
- int ret;
+ int ret = 0, tp;
- if (!need_peer_seq(mdev))
+ if (!test_bit(RESOLVE_CONFLICTS, &mdev->tconn->flags))
return 0;
spin_lock(&mdev->peer_seq_lock);
for (;;) {
if (!seq_greater(peer_seq - 1, mdev->peer_seq)) {
mdev->peer_seq = seq_max(mdev->peer_seq, peer_seq);
- ret = 0;
break;
}
+
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
+
+ rcu_read_lock();
+ tp = rcu_dereference(mdev->tconn->net_conf)->two_primaries;
+ rcu_read_unlock();
+
+ if (!tp)
+ break;
+
+ /* Only need to wait if two_primaries is enabled */
prepare_to_wait(&mdev->seq_wait, &wait, TASK_INTERRUPTIBLE);
spin_unlock(&mdev->peer_seq_lock);
rcu_read_lock();
@@ -2228,8 +2219,10 @@ static int receive_Data(struct drbd_tconn *tconn, struct
packet_info *pi)
}
goto out_interrupted;
}
- } else
+ } else {
+ update_peer_seq(mdev, peer_seq);
spin_lock_irq(&mdev->tconn->req_lock);
+ }
list_add(&peer_req->w.list, &mdev->active_ee);
spin_unlock_irq(&mdev->tconn->req_lock);
--
1.7.9.5
--
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