blockcount_read
old = blockcount_read(bc);
KASSERT(blockcount_read(&obj->paging_in_progress) >= bp->b_npages,
blockcount_read(&obj->paging_in_progress), bp->b_npages));
MPASS(blockcount_read(&fs->first_object->paging_in_progress) > 0);
MPASS(blockcount_read(&fs->first_object->paging_in_progress) > 0);
("object %p busy = %d", object, blockcount_read(&object->busy)));
KASSERT(blockcount_read(&(object)->paging_in_progress) != 0, \
return (blockcount_read(&object->busy) != 0);
MPASS(blockcount_read(&object->paging_in_progress) > 0);
blockcount_read(&object->paging_in_progress) > 0)