[PATCH 15/38] drbd: also bump UUIDs if a diskless primary connects

From: Philipp Reisner
Date: Wed Nov 25 2015 - 06:00:33 EST


From: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>

If for some reason the primary lost its disk *and* the replication link
before it is able to communicate the disk loss, probably blocked IO,
then later is able to re-establish the connection, the peer needs to
bump its UUIDs just like it does when peer only loses the disk
and is able to communicate this in time.

Otherwise, a later re-attach of the disk on the primary may start a
resync in the "wrong" direction.

Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
Signed-off-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
---
drivers/block/drbd/drbd_state.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index bc4b45b..06afd4d 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -1781,7 +1781,7 @@ static void after_state_ch(struct drbd_device *device, union drbd_state os,
}

if (ns.pdsk < D_INCONSISTENT && get_ldev(device)) {
- if (os.peer == R_SECONDARY && ns.peer == R_PRIMARY &&
+ if (os.peer != R_PRIMARY && ns.peer == R_PRIMARY &&
device->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
drbd_uuid_new_current(device);
drbd_send_uuids(peer_device);
--
1.9.1

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