drbd: Be more careful with SyncSource -> Ahead transitions

[pandora-kernel.git] / drivers / block / drbd / drbd_req.c

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 8891751..a3f6b04 100644 (file)
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1002,7 +1002,13 @@ allocate_barrier:
                        congested = 1;
                }
 
-               if (congested) {
+               if (congested && atomic_read(&mdev->rs_pending_cnt) == 0) {
+                       /* rs_pending_cnt must be zero, otherwise the two peers
+                          might get different bitmaps. With sane configurations
+                          the resync stalls long before we might want to go into
+                          AHEAD mode.
+                          We could force the resync into PAUSE mode here if
+                          rs_pending_cnt is > 0 ... */
                        queue_barrier(mdev);
 
                        if (mdev->net_conf->on_congestion == OC_PULL_AHEAD)