drbd: log UUIDs whenever they change

All decisions about sync, sync direction, and wether or not to
allow a connect or attach are based on our set of UUIDs to tag a
data generation.

Log changes to the UUIDs whenever they occur,
logging "new current UUID P:Q:R:S" is more useful
than "Creating new current UUID".

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

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index e9354931eace..e5686a81f42c 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3024,7 +3024,7 @@ static int receive_uuids(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned
 {
         struct p_uuids *p = &mdev->data.rbuf.uuids;
         u64 *p_uuid;
-        int i;
+        int i, updated_uuids = 0;
 
         p_uuid = kmalloc(sizeof(u64)*UI_EXTENDED_SIZE, GFP_NOIO);
 
@@ -3059,13 +3059,14 @@ static int receive_uuids(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned
                         _drbd_set_state(_NS2(mdev, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE),
                                         CS_VERBOSE, NULL);
                         drbd_md_sync(mdev);
+                        updated_uuids = 1;
                 }
                 put_ldev(mdev);
         } else if (mdev->state.disk < D_INCONSISTENT &&
                    mdev->state.role == R_PRIMARY) {
                 /* I am a diskless primary, the peer just created a new current UUID
                    for me. */
-                drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
+                updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
         }
 
         /* Before we test for the disk state, we should wait until an eventually
@@ -3074,7 +3075,10 @@ static int receive_uuids(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned
            new disk state... */
         wait_event(mdev->misc_wait, !test_bit(CLUSTER_ST_CHANGE, &mdev->flags));
         if (mdev->state.conn >= C_CONNECTED && mdev->state.disk < D_INCONSISTENT)
-                drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
+                updated_uuids |= drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
+
+        if (updated_uuids)
+                drbd_print_uuids(mdev, "receiver updated UUIDs to");
 
         return true;
 }
@@ -3305,6 +3309,7 @@ static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packets cmd, unsi
                 _drbd_uuid_set(mdev, UI_CURRENT, be64_to_cpu(p->uuid));
                 _drbd_uuid_set(mdev, UI_BITMAP, 0UL);
 
+                drbd_print_uuids(mdev, "updated sync uuid");
                 drbd_start_resync(mdev, C_SYNC_TARGET);
 
                 put_ldev(mdev);