drbd: Considering that the two_primaries config flag can change
Now since it is possible to change the two_primaries config
flag while the connection is up, make sure we treat a peer_req
in a consistent way if the config flag changes while the peer_req
is under IO.
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_int.h b/drivers/block/drbd/drbd_int.h
index 83e6cad..3833d56 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -661,6 +661,9 @@
/* The peer wants a write ACK for this (wire proto C) */
__EE_SEND_WRITE_ACK,
+
+ /* Is set when net_conf had two_primaries set while creating this peer_req */
+ __EE_IN_INTERVAL_TREE,
};
#define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO)
#define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC)
@@ -669,6 +672,7 @@
#define EE_HAS_DIGEST (1<<__EE_HAS_DIGEST)
#define EE_RESTART_REQUESTS (1<<__EE_RESTART_REQUESTS)
#define EE_SEND_WRITE_ACK (1<<__EE_SEND_WRITE_ACK)
+#define EE_IN_INTERVAL_TREE (1<<__EE_IN_INTERVAL_TREE)
/* flag bits per mdev */
enum {
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 397f977..4665ad7 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1752,7 +1752,7 @@
}
/* we delete from the conflict detection hash _after_ we sent out the
* P_WRITE_ACK / P_NEG_ACK, to get the sequence number right. */
- if (mdev->tconn->net_conf->two_primaries) {
+ if (peer_req->flags & EE_IN_INTERVAL_TREE) {
spin_lock_irq(&mdev->tconn->req_lock);
D_ASSERT(!drbd_interval_empty(&peer_req->i));
drbd_remove_epoch_entry_interval(mdev, peer_req);
@@ -1811,14 +1811,19 @@
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 discard flag set; see
* handle_write_conflicts().
*/
- return tconn->net_conf->two_primaries &&
- test_bit(DISCARD_CONCURRENT, &tconn->flags);
+
+ rcu_read_lock();
+ tp = rcu_dereference(mdev->tconn->net_conf)->two_primaries;
+ rcu_read_unlock();
+
+ return tp && test_bit(DISCARD_CONCURRENT, &tconn->flags);
}
static void update_peer_seq(struct drbd_conf *mdev, unsigned int peer_seq)
@@ -2049,7 +2054,7 @@
u32 peer_seq = be32_to_cpu(p->seq_num);
int rw = WRITE;
u32 dp_flags;
- int err;
+ int err, tp;
mdev = vnr_to_mdev(tconn, pi->vnr);
if (!mdev)
@@ -2094,7 +2099,11 @@
atomic_inc(&peer_req->epoch->active);
spin_unlock(&mdev->epoch_lock);
- if (mdev->tconn->net_conf->two_primaries) {
+ rcu_read_lock();
+ tp = rcu_dereference(mdev->tconn->net_conf)->two_primaries;
+ rcu_read_unlock();
+ if (tp) {
+ peer_req->flags |= EE_IN_INTERVAL_TREE;
err = wait_for_and_update_peer_seq(mdev, peer_seq);
if (err)
goto out_interrupted;