drbd: fix "stalled" empty resync
With sync-after dependencies, given "lucky" timing of pause/unpause
events, and the end of an empty (0 bits set) resync was sometimes not
detected on the SyncTarget, leading to a "stalled" SyncSource state.
Fixed this by expecting not only "Inconsistent -> UpToDate" but also
"Consistent -> UpToDate" transitions for the peer disk state
to end a resync.
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_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 4004a68..aba04d7 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3748,9 +3748,14 @@
os = ns = drbd_read_state(mdev);
spin_unlock_irq(&mdev->tconn->req_lock);
- /* peer says his disk is uptodate, while we think it is inconsistent,
- * and this happens while we think we have a sync going on. */
- if (os.pdsk == D_INCONSISTENT && real_peer_disk == D_UP_TO_DATE &&
+ /* If this is the "end of sync" confirmation, usually the peer disk
+ * transitions from D_INCONSISTENT to D_UP_TO_DATE. For empty (0 bits
+ * set) resync started in PausedSyncT, or if the timing of pause-/
+ * unpause-sync events has been "just right", the peer disk may
+ * transition from D_CONSISTENT to D_UP_TO_DATE as well.
+ */
+ if ((os.pdsk == D_INCONSISTENT || os.pdsk == D_CONSISTENT) &&
+ real_peer_disk == D_UP_TO_DATE &&
os.conn > C_CONNECTED && os.disk == D_UP_TO_DATE) {
/* If we are (becoming) SyncSource, but peer is still in sync
* preparation, ignore its uptodate-ness to avoid flapping, it