From nobody Wed Sep 17 17:51:09 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69DB5C4332F for ; Sat, 17 Dec 2022 02:48:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230228AbiLQCsr (ORCPT ); Fri, 16 Dec 2022 21:48:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230181AbiLQCsa (ORCPT ); Fri, 16 Dec 2022 21:48:30 -0500 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D70AFB1E5; Fri, 16 Dec 2022 18:48:29 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4NYr4m1k4gz4f3npg; Sat, 17 Dec 2022 10:48:24 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.127.227]) by APP4 (Coremail) with SMTP id gCh0CgB3m9j5LZ1jmxh7CQ--.11469S6; Sat, 17 Dec 2022 10:48:27 +0800 (CST) From: Yu Kuai To: tj@kernel.org, hch@infradead.org, josef@toxicpanda.com, axboe@kernel.dk Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com Subject: [PATCH -next 2/4] block/rq_qos: fail rq_qos_add() after del_gendisk() Date: Sat, 17 Dec 2022 11:09:06 +0800 Message-Id: <20221217030908.1261787-3-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20221217030908.1261787-1-yukuai1@huaweicloud.com> References: <20221217030908.1261787-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgB3m9j5LZ1jmxh7CQ--.11469S6 X-Coremail-Antispam: 1UD129KBjvJXoW7CF15XrWkCF15trWxGr1ftFb_yoW8CrW7pa 1xKr13Aayvgrs7WaykGw4rXasxC34rKryfCFWxWrWSvF4j9F1j9F10yFWUWayrZFZ3AF4f Xr4rAr95Cr48GwUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPj14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jryl82xGYIkIc2 x26xkF7I0E14v26r4j6ryUM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v2 6r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2 Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_ Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8Jw CI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUe1v3UUUU U X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Yu Kuai rq_qos_add() can still succeed after rq_qos_exit() is done, which will cause memory leak because such rq_qos will never be removed. t1 t2 // configure iocost blk_iocost_init //remove device del_gendisk rq_qos_exit // done nothing because rq_qos doesn't exist rq_qos_add // will succeed, and rq_qos won't be removed rq_qos_add() will also be called from blkcg_init_disk() from __alloc_disk_node(), and GD_DEAD can distinguish between disk allocation and disk deletion. Fix the problem by checking GD_DEAD in rq_qos_add(). Signed-off-by: Yu Kuai --- block/blk-rq-qos.h | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h index 1ef1f7d4bc3c..81e087139ffb 100644 --- a/block/blk-rq-qos.h +++ b/block/blk-rq-qos.h @@ -87,6 +87,7 @@ static inline void rq_wait_init(struct rq_wait *rq_wait) =20 static inline int rq_qos_add(struct request_queue *q, struct rq_qos *rqos) { + int err; /* * No IO can be in-flight when adding rqos, so freeze queue, which * is fine since we only support rq_qos for blk-mq queue. @@ -97,8 +98,16 @@ static inline int rq_qos_add(struct request_queue *q, st= ruct rq_qos *rqos) blk_mq_freeze_queue(q); =20 spin_lock_irq(&q->queue_lock); - if (rq_qos_id(q, rqos->id)) - goto ebusy; + if (rq_qos_id(q, rqos->id)) { + err =3D -EBUSY; + goto err; + } + + if (q->disk && test_bit(GD_DEAD, &q->disk->state)) { + err =3D -ENODEV; + goto err; + } + rqos->next =3D q->rq_qos; q->rq_qos =3D rqos; spin_unlock_irq(&q->queue_lock); @@ -112,10 +121,10 @@ static inline int rq_qos_add(struct request_queue *q,= struct rq_qos *rqos) } =20 return 0; -ebusy: +err: spin_unlock_irq(&q->queue_lock); blk_mq_unfreeze_queue(q); - return -EBUSY; + return err; =20 } =20 --=20 2.31.1