drbd: move bitmap write from resync_finished to after_state_change

We must not call it directly from resync_finished,
as we may be in either receiver or worker context there.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_main.c

@@ -1548,6 +1548,9 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
 	if (os.disk < D_UP_TO_DATE && os.conn >= C_SYNC_SOURCE && ns.conn == C_CONNECTED)
 		drbd_send_state(mdev);
 
+	if (os.conn > C_CONNECTED && ns.conn == C_CONNECTED)
+		drbd_queue_bitmap_io(mdev, &drbd_bm_write, NULL, "write from resync_finished");
+
 	/* free tl_hash if we Got thawed and are C_STANDALONE */
 	if (ns.conn == C_STANDALONE && !is_susp(ns) && mdev->tl_hash)
 		drbd_free_tl_hash(mdev);
@@ -3860,13 +3863,16 @@ int drbd_bmio_clear_n_write(struct drbd_conf *mdev)
 static int w_bitmap_io(struct drbd_conf *mdev, struct drbd_work *w, int unused)
 {
 	struct bm_io_work *work = container_of(w, struct bm_io_work, w);
-	int rv;
+	int rv = -EIO;
 
 	D_ASSERT(atomic_read(&mdev->ap_bio_cnt) == 0);
 
-	drbd_bm_lock(mdev, work->why);
-	rv = work->io_fn(mdev);
-	drbd_bm_unlock(mdev);
+	if (get_ldev(mdev)) {
+		drbd_bm_lock(mdev, work->why);
+		rv = work->io_fn(mdev);
+		drbd_bm_unlock(mdev);
+		put_ldev(mdev);
+	}
 
 	clear_bit(BITMAP_IO, &mdev->flags);
 	smp_mb__after_clear_bit();

drivers/block/drbd/drbd_worker.c

@@ -907,9 +907,6 @@ int drbd_resync_finished(struct drbd_conf *mdev)
 
 	drbd_md_sync(mdev);
 
-	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);