@michaelcahill, I didn't change the ordering here (this function is really just the first 40 lines of __wt_evict_file separated out into a new function), but it's not clear to me why we're acquiring `evict_lock` before the call to `__wt_evict_clear_tree_walk`, I don't see any reason __wt_evict_clear_tree_walk needed evict_lock here, and we certainly call it in other places we don't hold evict_lock.