drbd: use dynamic_dev_dbg to optionally log uuid changes

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

1 files changed, 31 insertions, 1 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 2e6a07e3848d..bbe3bff2cad6 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -3557,6 +3557,28 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
         return rv;
 }
 
+static void debug_drbd_uuid(struct drbd_conf *mdev, enum drbd_uuid_index index)
+{
+        static char *uuid_str[UI_EXTENDED_SIZE] = {
+                [UI_CURRENT] = "CURRENT",
+                [UI_BITMAP] = "BITMAP",
+                [UI_HISTORY_START] = "HISTORY_START",
+                [UI_HISTORY_END] = "HISTORY_END",
+                [UI_SIZE] = "SIZE",
+                [UI_FLAGS] = "FLAGS",
+        };
+
+        if (index >= UI_EXTENDED_SIZE) {
+                dev_warn(DEV, " uuid_index >= EXTENDED_SIZE\n");
+                return;
+        }
+
+        dynamic_dev_dbg(DEV, " uuid[%s] now %016llX\n",
+                 uuid_str[index],
+                 (unsigned long long)mdev->ldev->md.uuid[index]);
+}
+
+
 /**
  * drbd_md_mark_dirty() - Mark meta data super block as dirty
  * @mdev:       DRBD device.
@@ -3586,8 +3608,10 @@ static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)
 {
         int i;
 
-        for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++)
+        for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++) {
                 mdev->ldev->md.uuid[i+1] = mdev->ldev->md.uuid[i];
+                debug_drbd_uuid(mdev, i+1);
+        }
 }
 
 void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
@@ -3602,6 +3626,7 @@ void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
         }
 
         mdev->ldev->md.uuid[idx] = val;
+        debug_drbd_uuid(mdev, idx);
         drbd_md_mark_dirty(mdev);
 }
 
@@ -3611,6 +3636,7 @@ void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
         if (mdev->ldev->md.uuid[idx]) {
                 drbd_uuid_move_history(mdev);
                 mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[idx];
+                debug_drbd_uuid(mdev, UI_HISTORY_START);
         }
         _drbd_uuid_set(mdev, idx, val);
 }
@@ -3629,6 +3655,7 @@ void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local)
         dev_info(DEV, "Creating new current UUID\n");
         D_ASSERT(mdev->ldev->md.uuid[UI_BITMAP] == 0);
         mdev->ldev->md.uuid[UI_BITMAP] = mdev->ldev->md.uuid[UI_CURRENT];
+        debug_drbd_uuid(mdev, UI_BITMAP);
 
         get_random_bytes(&val, sizeof(u64));
         _drbd_uuid_set(mdev, UI_CURRENT, val);
@@ -3643,6 +3670,8 @@ void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local)
                 drbd_uuid_move_history(mdev);
                 mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP];
                 mdev->ldev->md.uuid[UI_BITMAP] = 0;
+                debug_drbd_uuid(mdev, UI_HISTORY_START);
+                debug_drbd_uuid(mdev, UI_BITMAP);
         } else {
                 if (mdev->ldev->md.uuid[UI_BITMAP])
                         dev_warn(DEV, "bm UUID already set");
@@ -3650,6 +3679,7 @@ void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local)
                 mdev->ldev->md.uuid[UI_BITMAP] = val;
                 mdev->ldev->md.uuid[UI_BITMAP] &= ~((u64)1);
 
+                debug_drbd_uuid(mdev, UI_BITMAP);
         }
         drbd_md_mark_dirty(mdev);
 }