From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751530AbbJEXut (ORCPT ); Mon, 5 Oct 2015 19:50:49 -0400 Received: from mail-vk0-f41.google.com ([209.85.213.41]:35285 "EHLO mail-vk0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751294AbbJEXus (ORCPT ); Mon, 5 Oct 2015 19:50:48 -0400 MIME-Version: 1.0 In-Reply-To: <20150929065235.GB14911@lst.de> References: <1443287365-4244-1-git-send-email-akinobu.mita@gmail.com> <1443287365-4244-4-git-send-email-akinobu.mita@gmail.com> <20150929065235.GB14911@lst.de> Date: Tue, 6 Oct 2015 08:50:47 +0900 Message-ID: Subject: Re: [PATCH v4 3/7] blk-mq: Fix use after of free q->mq_map From: Akinobu Mita To: Christoph Hellwig Cc: LKML , Jens Axboe , Ming Lei Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2015-09-29 15:52 GMT+09:00 Christoph Hellwig : > Looks good, > > Reviewed-by: Christoph Hellwig > > Can you also add a patch that renames blk_mq_free_queue to > blk_mq_cleaup_queue and adds a comment that we should not free any memory > here? We had way too many bugs of this kinds unfortunately. Renaming blk_mq_free_queue to blk_mq_cleaup_queue sounds good because it is called from blk_cleanup_queue(). How about adding comment like below? /* * The resources allocated by blk_mq_init_allocated_queue() are released * by blk_mq_cleanup_queue() and blk_mq_release(). * * blk_mq_cleanup_queue() is called from blk_cleanup_queue(), so * the resources which may be used after blk_cleanup_queue() shouldn't * be released here. Instead, those should be released by blk_mq_release() * which is called from blk_release_queue(). * * For example, loop and md drivers call del_gendisk() after * blk_cleanup_queue(), so the resources used when accessing sysfs entries * for blk-mq shouldn't be released by blk_mq_cleanup_queue() as these sysfs * entries can be accessible before del_gendisk() is called. */