From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1CB0AC43603 for ; Thu, 5 Dec 2019 12:46:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED8B42464D for ; Thu, 5 Dec 2019 12:46:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729441AbfLEMqC (ORCPT ); Thu, 5 Dec 2019 07:46:02 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:7640 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729290AbfLEMqC (ORCPT ); Thu, 5 Dec 2019 07:46:02 -0500 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 96EE551B0A0F4371FE58; Thu, 5 Dec 2019 20:45:59 +0800 (CST) Received: from huawei.com (10.90.53.225) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.439.0; Thu, 5 Dec 2019 20:45:49 +0800 From: Hou Tao To: , CC: , , , Subject: [PATCH] bfq-iosched: Ensure bio->bi_blkg is valid before using it Date: Thu, 5 Dec 2019 20:53:11 +0800 Message-ID: <20191205125311.40616-1-houtao1@huawei.com> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.90.53.225] X-CFilter-Loop: Reflected Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org bio->bi_blkg will be NULL when the issue of the request has bypassed the block layer as shown in the following oops: Internal error: Oops: 96000005 [#1] SMP CPU: 17 PID: 2996 Comm: scsi_id Not tainted 5.4.0 #4 Call trace: percpu_counter_add_batch+0x38/0x4c8 bfqg_stats_update_legacy_io+0x9c/0x280 bfq_insert_requests+0xbac/0x2190 blk_mq_sched_insert_request+0x288/0x670 blk_execute_rq_nowait+0x140/0x178 blk_execute_rq+0x8c/0x140 sg_io+0x604/0x9c0 scsi_cmd_ioctl+0xe38/0x10a8 scsi_cmd_blk_ioctl+0xac/0xe8 sd_ioctl+0xe4/0x238 blkdev_ioctl+0x590/0x20e0 block_ioctl+0x60/0x98 do_vfs_ioctl+0xe0/0x1b58 ksys_ioctl+0x80/0xd8 __arm64_sys_ioctl+0x40/0x78 el0_svc_handler+0xc4/0x270 so ensure its validity before using it. Fixes: fd41e60331b1 ("bfq-iosched: stop using blkg->stat_bytes and ->stat_ios") Signed-off-by: Hou Tao --- block/bfq-cgroup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index cea0ae12f937..e1419edde2ec 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -351,6 +351,9 @@ void bfqg_stats_update_legacy_io(struct request_queue *q, struct request *rq) { struct bfq_group *bfqg = blkg_to_bfqg(rq->bio->bi_blkg); + if (!bfqg) + return; + blkg_rwstat_add(&bfqg->stats.bytes, rq->cmd_flags, blk_rq_bytes(rq)); blkg_rwstat_add(&bfqg->stats.ios, rq->cmd_flags, 1); } -- 2.22.0