drbd: Implemented two new connection states Ahead/Behind

In this connection mode, the ahead node no longer replicates
application IO. The behind's disk becomes out dated.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index e81d009dd061..46f27d6c0b21 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -871,16 +871,19 @@ static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state
 
         if (ns.conn >= C_CONNECTED &&
             ((ns.disk == D_CONSISTENT || ns.disk == D_OUTDATED) ||
-             (ns.disk == D_NEGOTIATING && ns.conn == C_WF_BITMAP_T))) {
+             (ns.disk == D_NEGOTIATING && ns.conn == C_WF_BITMAP_T) ||
+             ns.conn >= C_AHEAD)) {
                 switch (ns.conn) {
                 case C_WF_BITMAP_T:
                 case C_PAUSED_SYNC_T:
+                case C_BEHIND:
                         ns.disk = D_OUTDATED;
                         break;
                 case C_CONNECTED:
                 case C_WF_BITMAP_S:
                 case C_SYNC_SOURCE:
                 case C_PAUSED_SYNC_S:
+                case C_AHEAD:
                         ns.disk = D_UP_TO_DATE;
                         break;
                 case C_SYNC_TARGET:
@@ -893,16 +896,18 @@ static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state
         }
 
         if (ns.conn >= C_CONNECTED &&
-            (ns.pdsk == D_CONSISTENT || ns.pdsk == D_OUTDATED)) {
+            (ns.pdsk == D_CONSISTENT || ns.pdsk == D_OUTDATED || ns.conn >= C_AHEAD)) {
                 switch (ns.conn) {
                 case C_CONNECTED:
                 case C_WF_BITMAP_T:
                 case C_PAUSED_SYNC_T:
                 case C_SYNC_TARGET:
+                case C_BEHIND:
                         ns.pdsk = D_UP_TO_DATE;
                         break;
                 case C_WF_BITMAP_S:
                 case C_PAUSED_SYNC_S:
+                case C_AHEAD:
                         /* remap any consistent state to D_OUTDATED,
                          * but disallow "upgrade" of not even consistent states.
                          */
@@ -1374,6 +1379,9 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
         if (os.conn == C_WF_REPORT_PARAMS && ns.conn >= C_CONNECTED)
                 drbd_send_state(mdev);
 
+        if (os.conn != C_AHEAD && ns.conn == C_AHEAD)
+                drbd_send_state(mdev);
+
         /* We are in the progress to start a full sync... */
         if ((os.conn != C_STARTING_SYNC_T && ns.conn == C_STARTING_SYNC_T) ||
             (os.conn != C_STARTING_SYNC_S && ns.conn == C_STARTING_SYNC_S))