drbd: bitmap keep track of changes vs on-disk bitmap

When we set or clear bits in a bitmap page,
also set a flag in the page->private pointer.

This allows us to skip writes of unchanged pages.

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

1 files changed, 2 insertions, 5 deletions

diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 9fe3e890da0f..d17f2ed777ce 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -907,10 +907,8 @@ out:
 
         drbd_md_sync(mdev);
 
-        if (test_and_clear_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags)) {
-                dev_info(DEV, "Writing the whole bitmap\n");
-                drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished");
-        }
+        dev_info(DEV, "Writing changed bitmap pages\n");
+        drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished");
 
         if (khelper_cmd)
                 drbd_khelper(mdev, khelper_cmd);
@@ -1127,7 +1125,6 @@ void drbd_ov_oos_found(struct drbd_conf *mdev, sector_t sector, int size)
                 mdev->ov_last_oos_size = size>>9;
         }
         drbd_set_out_of_sync(mdev, sector, size);
-        set_bit(WRITE_BM_AFTER_RESYNC, &mdev->flags);
 }
 
 int w_e_end_ov_reply(struct drbd_conf *mdev, struct drbd_work *w, int cancel)