drbd: Move list of epochs from mdev to tconn

This is necessary since the transfer_log on the sending is also
per tconn.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_int.h

@@ -859,6 +859,9 @@ struct drbd_tconn {			/* is a resource from the config file */
 	void *int_dig_in;
 	void *int_dig_vv;
 
+	struct drbd_epoch *current_epoch;
+	spinlock_t epoch_lock;
+	unsigned int epochs;
 	enum write_ordering_e write_ordering;
 
 	struct drbd_thread receiver;
@@ -962,9 +965,6 @@ struct drbd_conf {
 
 	int open_cnt;
 	u64 *p_uuid;
-	struct drbd_epoch *current_epoch;
-	spinlock_t epoch_lock;
-	unsigned int epochs;
 
 	struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */
 	struct list_head sync_ee;   /* IO in progress (P_RS_DATA_REPLY gets written to disk) */

drivers/block/drbd/drbd_main.c

@@ -2082,7 +2082,6 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
 
 	spin_lock_init(&mdev->al_lock);
 	spin_lock_init(&mdev->peer_seq_lock);
-	spin_lock_init(&mdev->epoch_lock);
 
 	INIT_LIST_HEAD(&mdev->active_ee);
 	INIT_LIST_HEAD(&mdev->sync_ee);
@@ -2142,9 +2141,6 @@ void drbd_mdev_cleanup(struct drbd_conf *mdev)
 		dev_err(DEV, "ASSERT FAILED: receiver t_state == %d expected 0.\n",
 				mdev->tconn->receiver.t_state);
 
-	/* no need to lock it, I'm the only thread alive */
-	if (atomic_read(&mdev->current_epoch->epoch_size) !=  0)
-		dev_err(DEV, "epoch_size:%d\n", atomic_read(&mdev->current_epoch->epoch_size));
 	mdev->al_writ_cnt  =
 	mdev->bm_writ_cnt  =
 	mdev->read_cnt     =
@@ -2377,7 +2373,6 @@ void drbd_minor_destroy(struct kref *kref)
 	kfree(mdev->p_uuid);
 	/* mdev->p_uuid = NULL; */
 
-	kfree(mdev->current_epoch);
 	if (mdev->bitmap) /* should no longer be there. */
 		drbd_bm_cleanup(mdev);
 	__free_page(mdev->md_io_page);
@@ -2624,6 +2619,12 @@ struct drbd_tconn *conn_create(const char *name, struct res_opts *res_opts)
 	if (!tl_init(tconn))
 		goto fail;
 
+	tconn->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
+	if (!tconn->current_epoch)
+		goto fail;
+	INIT_LIST_HEAD(&tconn->current_epoch->list);
+	tconn->epochs = 1;
+	spin_lock_init(&tconn->epoch_lock);
 	tconn->write_ordering = WO_bdev_flush;
 
 	tconn->cstate = C_STANDALONE;
@@ -2649,6 +2650,7 @@ struct drbd_tconn *conn_create(const char *name, struct res_opts *res_opts)
 	return tconn;
 
 fail:
+	kfree(tconn->current_epoch);
 	tl_cleanup(tconn);
 	free_cpumask_var(tconn->cpu_mask);
 	drbd_free_socket(&tconn->meta);
@@ -2663,6 +2665,10 @@ void conn_destroy(struct kref *kref)
 {
 	struct drbd_tconn *tconn = container_of(kref, struct drbd_tconn, kref);
 
+	if (atomic_read(&tconn->current_epoch->epoch_size) !=  0)
+		conn_err(tconn, "epoch_size:%d\n", atomic_read(&tconn->current_epoch->epoch_size));
+	kfree(tconn->current_epoch);
+
 	idr_destroy(&tconn->volumes);
 
 	free_cpumask_var(tconn->cpu_mask);
@@ -2744,13 +2750,6 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor,
 	mdev->read_requests = RB_ROOT;
 	mdev->write_requests = RB_ROOT;
 
-	mdev->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
-	if (!mdev->current_epoch)
-		goto out_no_epoch;
-
-	INIT_LIST_HEAD(&mdev->current_epoch->list);
-	mdev->epochs = 1;
-
 	if (!idr_pre_get(&minors, GFP_KERNEL))
 		goto out_no_minor_idr;
 	if (idr_get_new_above(&minors, mdev, minor, &minor_got))
@@ -2786,8 +2785,6 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor,
 	idr_remove(&minors, minor_got);
 	synchronize_rcu();
 out_no_minor_idr:
-	kfree(mdev->current_epoch);
-out_no_epoch:
 	drbd_bm_cleanup(mdev);
 out_no_bitmap:
 	__free_page(mdev->md_io_page);

drivers/block/drbd/drbd_proc.c

@@ -271,7 +271,7 @@ static int drbd_seq_show(struct seq_file *seq, void *v)
 			   atomic_read(&mdev->rs_pending_cnt),
 			   atomic_read(&mdev->unacked_cnt),
 			   atomic_read(&mdev->ap_bio_cnt),
-			   mdev->epochs,
+			   mdev->tconn->epochs,
 			   write_ordering_chars[mdev->tconn->write_ordering]
 			);
 			seq_printf(seq, " oos:%llu\n",

drivers/block/drbd/drbd_receiver.c

@@ -1128,8 +1128,9 @@ static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *mdev,
 	int epoch_size;
 	struct drbd_epoch *next_epoch;
 	enum finish_epoch rv = FE_STILL_LIVE;
+	struct drbd_tconn *tconn = mdev->tconn;
 
-	spin_lock(&mdev->epoch_lock);
+	spin_lock(&tconn->epoch_lock);
 	do {
 		next_epoch = NULL;
 
@@ -1151,18 +1152,18 @@ static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *mdev,
 		    atomic_read(&epoch->active) == 0 &&
 		    (test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags) || ev & EV_CLEANUP)) {
 			if (!(ev & EV_CLEANUP)) {
-				spin_unlock(&mdev->epoch_lock);
+				spin_unlock(&tconn->epoch_lock);
 				drbd_send_b_ack(epoch->mdev, epoch->barrier_nr, epoch_size);
-				spin_lock(&mdev->epoch_lock);
+				spin_lock(&tconn->epoch_lock);
 			}
 			if (test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags))
 				dec_unacked(epoch->mdev);
 
-			if (mdev->current_epoch != epoch) {
+			if (tconn->current_epoch != epoch) {
 				next_epoch = list_entry(epoch->list.next, struct drbd_epoch, list);
 				list_del(&epoch->list);
 				ev = EV_BECAME_LAST | (ev & EV_CLEANUP);
-				mdev->epochs--;
+				tconn->epochs--;
 				kfree(epoch);
 
 				if (rv == FE_STILL_LIVE)
@@ -1183,7 +1184,7 @@ static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *mdev,
 		epoch = next_epoch;
 	} while (1);
 
-	spin_unlock(&mdev->epoch_lock);
+	spin_unlock(&tconn->epoch_lock);
 
 	return rv;
 }
@@ -1348,9 +1349,9 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
 
 	inc_unacked(mdev);
 
-	mdev->current_epoch->barrier_nr = p->barrier;
-	mdev->current_epoch->mdev = mdev;
-	rv = drbd_may_finish_epoch(mdev, mdev->current_epoch, EV_GOT_BARRIER_NR);
+	tconn->current_epoch->barrier_nr = p->barrier;
+	tconn->current_epoch->mdev = mdev;
+	rv = drbd_may_finish_epoch(mdev, tconn->current_epoch, EV_GOT_BARRIER_NR);
 
 	/* P_BARRIER_ACK may imply that the corresponding extent is dropped from
 	 * the activity log, which means it would not be resynced in case the
@@ -1376,13 +1377,13 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
 		drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
 		drbd_flush(tconn);
 
-		if (atomic_read(&mdev->current_epoch->epoch_size)) {
+		if (atomic_read(&tconn->current_epoch->epoch_size)) {
 			epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
 			if (epoch)
 				break;
 		}
 
-		epoch = mdev->current_epoch;
+		epoch = tconn->current_epoch;
 		wait_event(mdev->ee_wait, atomic_read(&epoch->epoch_size) == 0);
 
 		D_ASSERT(atomic_read(&epoch->active) == 0);
@@ -1398,16 +1399,16 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
 	atomic_set(&epoch->epoch_size, 0);
 	atomic_set(&epoch->active, 0);
 
-	spin_lock(&mdev->epoch_lock);
-	if (atomic_read(&mdev->current_epoch->epoch_size)) {
-		list_add(&epoch->list, &mdev->current_epoch->list);
-		mdev->current_epoch = epoch;
-		mdev->epochs++;
+	spin_lock(&tconn->epoch_lock);
+	if (atomic_read(&tconn->current_epoch->epoch_size)) {
+		list_add(&epoch->list, &tconn->current_epoch->list);
+		tconn->current_epoch = epoch;
+		tconn->epochs++;
 	} else {
 		/* The current_epoch got recycled while we allocated this one... */
 		kfree(epoch);
 	}
-	spin_unlock(&mdev->epoch_lock);
+	spin_unlock(&tconn->epoch_lock);
 
 	return 0;
 }
@@ -2103,7 +2104,7 @@ static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi)
 
 		err = wait_for_and_update_peer_seq(mdev, peer_seq);
 		drbd_send_ack_dp(mdev, P_NEG_ACK, p, pi->size);
-		atomic_inc(&mdev->current_epoch->epoch_size);
+		atomic_inc(&tconn->current_epoch->epoch_size);
 		err2 = drbd_drain_block(mdev, pi->size);
 		if (!err)
 			err = err2;
@@ -2131,11 +2132,11 @@ static int receive_Data(struct drbd_tconn *tconn, struct packet_info *pi)
 	if (dp_flags & DP_MAY_SET_IN_SYNC)
 		peer_req->flags |= EE_MAY_SET_IN_SYNC;
 
-	spin_lock(&mdev->epoch_lock);
-	peer_req->epoch = mdev->current_epoch;
+	spin_lock(&tconn->epoch_lock);
+	peer_req->epoch = tconn->current_epoch;
 	atomic_inc(&peer_req->epoch->epoch_size);
 	atomic_inc(&peer_req->epoch->active);
-	spin_unlock(&mdev->epoch_lock);
+	spin_unlock(&tconn->epoch_lock);
 
 	rcu_read_lock();
 	tp = rcu_dereference(mdev->tconn->net_conf)->two_primaries;
@@ -4359,6 +4360,11 @@ static void conn_disconnect(struct drbd_tconn *tconn)
 	}
 	rcu_read_unlock();
 
+	if (!list_empty(&tconn->current_epoch->list))
+		conn_err(tconn, "ASSERTION FAILED: tconn->current_epoch->list not empty\n");
+	/* ok, no more ee's on the fly, it is safe to reset the epoch_size */
+	atomic_set(&tconn->current_epoch->epoch_size, 0);
+
 	conn_info(tconn, "Connection closed\n");
 
 	if (conn_highest_role(tconn) == R_PRIMARY && conn_highest_pdsk(tconn) >= D_UNKNOWN)
@@ -4446,10 +4452,6 @@ static int drbd_disconnected(struct drbd_conf *mdev)
 	D_ASSERT(list_empty(&mdev->sync_ee));
 	D_ASSERT(list_empty(&mdev->done_ee));
 
-	/* ok, no more ee's on the fly, it is safe to reset the epoch_size */
-	atomic_set(&mdev->current_epoch->epoch_size, 0);
-	D_ASSERT(list_empty(&mdev->current_epoch->list));
-
 	return 0;
 }