drbd_bm_lock
drbd_bm_lock(device, "resize", BM_LOCKED_MASK);
extern void drbd_bm_lock(struct drbd_device *device, char *why, enum bm_flag flags);
drbd_bm_lock(device, work->why, work->flags);
drbd_bm_lock(device, why, flags);
drbd_bm_lock(device, "receive bitmap", BM_LOCKED_SET_ALLOWED);
drbd_bm_lock(device, why, flags);