drbd: Introduce "peer_device" object between "device" and "connection"

In a setup where a device (aka volume) can replicate to multiple peers and one
connection can be shared between multiple devices, we need separate objects to
represent devices on peer nodes and network connections.

As a first step to introduce multiple connections per device, give each
drbd_device object a single drbd_peer_device object which connects it to a
drbd_connection object.

Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>

1 files changed, 37 insertions, 36 deletions

diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index ecc63cf85d85..22c4e7d57a80 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -237,10 +237,10 @@ drbd_change_state(struct drbd_device *device, enum chg_state_flags f,
 	union drbd_state ns;
 	enum drbd_state_rv rv;
 
-	spin_lock_irqsave(&device->connection->req_lock, flags);
+	spin_lock_irqsave(&first_peer_device(device)->connection->req_lock, flags);
 	ns = apply_mask_val(drbd_read_state(device), mask, val);
 	rv = _drbd_set_state(device, ns, f, NULL);
-	spin_unlock_irqrestore(&device->connection->req_lock, flags);
+	spin_unlock_irqrestore(&first_peer_device(device)->connection->req_lock, flags);
 
 	return rv;
 }
@@ -271,7 +271,7 @@ _req_st_cond(struct drbd_device *device, union drbd_state mask,
 	if (test_and_clear_bit(CL_ST_CHG_FAIL, &device->flags))
 		return SS_CW_FAILED_BY_PEER;
 
-	spin_lock_irqsave(&device->connection->req_lock, flags);
+	spin_lock_irqsave(&first_peer_device(device)->connection->req_lock, flags);
 	os = drbd_read_state(device);
 	ns = sanitize_state(device, apply_mask_val(os, mask, val), NULL);
 	rv = is_valid_transition(os, ns);
@@ -283,12 +283,12 @@ _req_st_cond(struct drbd_device *device, union drbd_state mask,
 	if (rv == SS_UNKNOWN_ERROR) {
 		rv = is_valid_state(device, ns);
 		if (rv >= SS_SUCCESS) {
-			rv = is_valid_soft_transition(os, ns, device->connection);
+			rv = is_valid_soft_transition(os, ns, first_peer_device(device)->connection);
 			if (rv >= SS_SUCCESS)
 				rv = SS_UNKNOWN_ERROR; /* cont waiting, otherwise fail. */
 		}
 	}
-	spin_unlock_irqrestore(&device->connection->req_lock, flags);
+	spin_unlock_irqrestore(&first_peer_device(device)->connection->req_lock, flags);
 
 	return rv;
 }
@@ -317,20 +317,20 @@ drbd_req_state(struct drbd_device *device, union drbd_state mask,
 	if (f & CS_SERIALIZE)
 		mutex_lock(device->state_mutex);
 
-	spin_lock_irqsave(&device->connection->req_lock, flags);
+	spin_lock_irqsave(&first_peer_device(device)->connection->req_lock, flags);
 	os = drbd_read_state(device);
 	ns = sanitize_state(device, apply_mask_val(os, mask, val), NULL);
 	rv = is_valid_transition(os, ns);
 	if (rv < SS_SUCCESS) {
-		spin_unlock_irqrestore(&device->connection->req_lock, flags);
+		spin_unlock_irqrestore(&first_peer_device(device)->connection->req_lock, flags);
 		goto abort;
 	}
 
 	if (cl_wide_st_chg(device, os, ns)) {
 		rv = is_valid_state(device, ns);
 		if (rv == SS_SUCCESS)
-			rv = is_valid_soft_transition(os, ns, device->connection);
-		spin_unlock_irqrestore(&device->connection->req_lock, flags);
+			rv = is_valid_soft_transition(os, ns, first_peer_device(device)->connection);
+		spin_unlock_irqrestore(&first_peer_device(device)->connection->req_lock, flags);
 
 		if (rv < SS_SUCCESS) {
 			if (f & CS_VERBOSE)
@@ -353,17 +353,17 @@ drbd_req_state(struct drbd_device *device, union drbd_state mask,
 				print_st_err(device, os, ns, rv);
 			goto abort;
 		}
-		spin_lock_irqsave(&device->connection->req_lock, flags);
+		spin_lock_irqsave(&first_peer_device(device)->connection->req_lock, flags);
 		ns = apply_mask_val(drbd_read_state(device), mask, val);
 		rv = _drbd_set_state(device, ns, f, &done);
 	} else {
 		rv = _drbd_set_state(device, ns, f, &done);
 	}
 
-	spin_unlock_irqrestore(&device->connection->req_lock, flags);
+	spin_unlock_irqrestore(&first_peer_device(device)->connection->req_lock, flags);
 
 	if (f & CS_WAIT_COMPLETE && rv == SS_SUCCESS) {
-		D_ASSERT(current != device->connection->worker.task);
+		D_ASSERT(current != first_peer_device(device)->connection->worker.task);
 		wait_for_completion(&done);
 	}
 
@@ -519,12 +519,12 @@ is_valid_state(struct drbd_device *device, union drbd_state ns)
 		put_ldev(device);
 	}
 
-	nc = rcu_dereference(device->connection->net_conf);
+	nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
 	if (nc) {
 		if (!nc->two_primaries && ns.role == R_PRIMARY) {
 			if (ns.peer == R_PRIMARY)
 				rv = SS_TWO_PRIMARIES;
-			else if (conn_highest_peer(device->connection) == R_PRIMARY)
+			else if (conn_highest_peer(first_peer_device(device)->connection) == R_PRIMARY)
 				rv = SS_O_VOL_PEER_PRI;
 		}
 	}
@@ -565,7 +565,7 @@ is_valid_state(struct drbd_device *device, union drbd_state ns)
 		rv = SS_NO_VERIFY_ALG;
 
 	else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
-		  device->connection->agreed_pro_version < 88)
+		  first_peer_device(device)->connection->agreed_pro_version < 88)
 		rv = SS_NOT_SUPPORTED;
 
 	else if (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE)
@@ -871,7 +871,7 @@ static union drbd_state sanitize_state(struct drbd_device *device, union drbd_st
 	    (ns.role == R_PRIMARY && ns.conn < C_CONNECTED && ns.pdsk > D_OUTDATED))
 		ns.susp_fen = 1; /* Suspend IO while fence-peer handler runs (peer lost) */
 
-	if (device->connection->res_opts.on_no_data == OND_SUSPEND_IO &&
+	if (first_peer_device(device)->connection->res_opts.on_no_data == OND_SUSPEND_IO &&
 	    (ns.role == R_PRIMARY && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE))
 		ns.susp_nod = 1; /* Suspend IO while no data available (no accessible data available) */
 
@@ -899,7 +899,7 @@ void drbd_resume_al(struct drbd_device *device)
 /* helper for __drbd_set_state */
 static void set_ov_position(struct drbd_device *device, enum drbd_conns cs)
 {
-	if (device->connection->agreed_pro_version < 90)
+	if (first_peer_device(device)->connection->agreed_pro_version < 90)
 		device->ov_start_sector = 0;
 	device->rs_total = drbd_bm_bits(device);
 	device->ov_position = 0;
@@ -962,9 +962,9 @@ __drbd_set_state(struct drbd_device *device, union drbd_state ns,
 			   this happen...*/
 
 			if (is_valid_state(device, os) == rv)
-				rv = is_valid_soft_transition(os, ns, device->connection);
+				rv = is_valid_soft_transition(os, ns, first_peer_device(device)->connection);
 		} else
-			rv = is_valid_soft_transition(os, ns, device->connection);
+			rv = is_valid_soft_transition(os, ns, first_peer_device(device)->connection);
 	}
 
 	if (rv < SS_SUCCESS) {
@@ -981,7 +981,8 @@ __drbd_set_state(struct drbd_device *device, union drbd_state ns,
 	   sanitize_state(). Only display it here if we where not called from
 	   _conn_request_state() */
 	if (!(flags & CS_DC_SUSP))
-		conn_pr_state_change(device->connection, os, ns, (flags & ~CS_DC_MASK) | CS_DC_SUSP);
+		conn_pr_state_change(first_peer_device(device)->connection, os, ns,
+				     (flags & ~CS_DC_MASK) | CS_DC_SUSP);
 
 	/* if we are going -> D_FAILED or D_DISKLESS, grab one extra reference
 	 * on the ldev here, to be sure the transition -> D_DISKLESS resp.
@@ -994,25 +995,25 @@ __drbd_set_state(struct drbd_device *device, union drbd_state ns,
 	did_remote = drbd_should_do_remote(device->state);
 	device->state.i = ns.i;
 	should_do_remote = drbd_should_do_remote(device->state);
-	device->connection->susp = ns.susp;
-	device->connection->susp_nod = ns.susp_nod;
-	device->connection->susp_fen = ns.susp_fen;
+	first_peer_device(device)->connection->susp = ns.susp;
+	first_peer_device(device)->connection->susp_nod = ns.susp_nod;
+	first_peer_device(device)->connection->susp_fen = ns.susp_fen;
 
 	/* put replicated vs not-replicated requests in seperate epochs */
 	if (did_remote != should_do_remote)
-		start_new_tl_epoch(device->connection);
+		start_new_tl_epoch(first_peer_device(device)->connection);
 
 	if (os.disk == D_ATTACHING && ns.disk >= D_NEGOTIATING)
 		drbd_print_uuids(device, "attached to UUIDs");
 
 	/* Wake up role changes, that were delayed because of connection establishing */
 	if (os.conn == C_WF_REPORT_PARAMS && ns.conn != C_WF_REPORT_PARAMS &&
-	    no_peer_wf_report_params(device->connection))
-		clear_bit(STATE_SENT, &device->connection->flags);
+	    no_peer_wf_report_params(first_peer_device(device)->connection))
+		clear_bit(STATE_SENT, &first_peer_device(device)->connection->flags);
 
 	wake_up(&device->misc_wait);
 	wake_up(&device->state_wait);
-	wake_up(&device->connection->ping_wait);
+	wake_up(&first_peer_device(device)->connection->ping_wait);
 
 	/* Aborted verify run, or we reached the stop sector.
 	 * Log the last position, unless end-of-device. */
@@ -1101,21 +1102,21 @@ __drbd_set_state(struct drbd_device *device, union drbd_state ns,
 
 	/* Receiver should clean up itself */
 	if (os.conn != C_DISCONNECTING && ns.conn == C_DISCONNECTING)
-		drbd_thread_stop_nowait(&device->connection->receiver);
+		drbd_thread_stop_nowait(&first_peer_device(device)->connection->receiver);
 
 	/* Now the receiver finished cleaning up itself, it should die */
 	if (os.conn != C_STANDALONE && ns.conn == C_STANDALONE)
-		drbd_thread_stop_nowait(&device->connection->receiver);
+		drbd_thread_stop_nowait(&first_peer_device(device)->connection->receiver);
 
 	/* Upon network failure, we need to restart the receiver. */
 	if (os.conn > C_WF_CONNECTION &&
 	    ns.conn <= C_TEAR_DOWN && ns.conn >= C_TIMEOUT)
-		drbd_thread_restart_nowait(&device->connection->receiver);
+		drbd_thread_restart_nowait(&first_peer_device(device)->connection->receiver);
 
 	/* Resume AL writing if we get a connection */
 	if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED) {
 		drbd_resume_al(device);
-		device->connection->connect_cnt++;
+		first_peer_device(device)->connection->connect_cnt++;
 	}
 
 	/* remember last attach time so request_timer_fn() won't
@@ -1133,7 +1134,7 @@ __drbd_set_state(struct drbd_device *device, union drbd_state ns,
 		ascw->w.cb = w_after_state_ch;
 		ascw->w.device = device;
 		ascw->done = done;
-		drbd_queue_work(&device->connection->sender_work, &ascw->w);
+		drbd_queue_work(&first_peer_device(device)->connection->sender_work, &ascw->w);
 	} else {
 		dev_err(DEV, "Could not kmalloc an ascw\n");
 	}
@@ -1181,7 +1182,7 @@ int drbd_bitmap_io_from_worker(struct drbd_device *device,
 {
 	int rv;
 
-	D_ASSERT(current == device->connection->worker.task);
+	D_ASSERT(current == first_peer_device(device)->connection->worker.task);
 
 	/* open coded non-blocking drbd_suspend_io(device); */
 	set_bit(SUSPEND_IO, &device->flags);
@@ -1228,7 +1229,7 @@ static void after_state_ch(struct drbd_device *device, union drbd_state os,
 	   state change. This function might sleep */
 
 	if (ns.susp_nod) {
-		struct drbd_connection *connection = device->connection;
+		struct drbd_connection *connection = first_peer_device(device)->connection;
 		enum drbd_req_event what = NOTHING;
 
 		spin_lock_irq(&connection->req_lock);
@@ -1250,7 +1251,7 @@ static void after_state_ch(struct drbd_device *device, union drbd_state os,
 	}
 
 	if (ns.susp_fen) {
-		struct drbd_connection *connection = device->connection;
+		struct drbd_connection *connection = first_peer_device(device)->connection;
 
 		spin_lock_irq(&connection->req_lock);
 		if (connection->susp_fen && conn_lowest_conn(connection) >= C_CONNECTED) {
@@ -1277,7 +1278,7 @@ static void after_state_ch(struct drbd_device *device, union drbd_state os,
 	 * which is unexpected. */
 	if ((os.conn != C_SYNC_SOURCE && os.conn != C_PAUSED_SYNC_S) &&
 	    (ns.conn == C_SYNC_SOURCE || ns.conn == C_PAUSED_SYNC_S) &&
-	    device->connection->agreed_pro_version >= 96 && get_ldev(device)) {
+	    first_peer_device(device)->connection->agreed_pro_version >= 96 && get_ldev(device)) {
 		drbd_gen_and_send_sync_uuid(device);
 		put_ldev(device);
 	}