From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 05F21156237 for ; Sun, 14 Dec 2025 10:14:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765707275; cv=none; b=IkkxCTHIYj5vnrvZdbBijxcWlh2UIs3YH4te5SCkFcO95uA3GWm2Fw3CBS0ygZxuWIFpHW2NEFa97435UJthJEf92uLZIrPs8BtzNiAHjsnUyLsyYoHpQ9DGMQVH3UHxTgWeQUUDU0n2QkYpf/nZYH6DHHc+/LwnNto1LyJLqzo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765707275; c=relaxed/simple; bh=obY+ADyZeTl/i8qaVGxzUr52hxpiHhwKYKbZAixu6V8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PY0rwVbuizHEVKfPeYkkm1rKQ7voIA9hgE/14DvvtZwjGhnpYK/23CTKL+OfbDTxX+KMUervlB/8QmrBYzskKqma8yZA68ourK7M1IMmZx2syhLTcH70zQf9RZkcQxEyvvG7PnPd0DWv4ogJ8v4+POpFbQaMXRhjHK2HUA899SY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 538DAC19421; Sun, 14 Dec 2025 10:14:33 +0000 (UTC) From: Yu Kuai To: axboe@kernel.dk, linux-block@vger.kernel.org, tj@kernel.org, nilay@linux.ibm.com, ming.lei@redhat.com Cc: yukuai@fnnas.com Subject: [PATCH v5 08/13] block/blk-rq-qos: add a new helper rq_qos_add_frozen() Date: Sun, 14 Dec 2025 18:14:03 +0800 Message-ID: <20251214101409.1723751-9-yukuai@fnnas.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251214101409.1723751-1-yukuai@fnnas.com> References: <20251214101409.1723751-1-yukuai@fnnas.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit queue should not be frozen under rq_qos_mutex, see example from commit 9730763f4756 ("block: correct locking order for protecting blk-wbt parameters"), which means current implementation of rq_qos_add() is problematic. Add a new helper and prepare to fix this problem in following patches. Signed-off-by: Yu Kuai --- block/blk-rq-qos.c | 21 +++++++++++++++++++++ block/blk-rq-qos.h | 2 ++ 2 files changed, 23 insertions(+) diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c index d7ce99ce2e80..c1a94c2a9742 100644 --- a/block/blk-rq-qos.c +++ b/block/blk-rq-qos.c @@ -322,6 +322,27 @@ void rq_qos_exit(struct request_queue *q) mutex_unlock(&q->rq_qos_mutex); } +int rq_qos_add_frozen(struct rq_qos *rqos, struct gendisk *disk, + enum rq_qos_id id, const struct rq_qos_ops *ops) +{ + struct request_queue *q = disk->queue; + + WARN_ON_ONCE(q->mq_freeze_depth == 0); + lockdep_assert_held(&q->rq_qos_mutex); + + if (rq_qos_id(q, id)) + return -EBUSY; + + rqos->disk = disk; + rqos->id = id; + rqos->ops = ops; + rqos->next = q->rq_qos; + q->rq_qos = rqos; + blk_queue_flag_set(QUEUE_FLAG_QOS_ENABLED, q); + + return 0; +} + int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, const struct rq_qos_ops *ops) { diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h index b538f2c0febc..8d9fb10ae526 100644 --- a/block/blk-rq-qos.h +++ b/block/blk-rq-qos.h @@ -87,6 +87,8 @@ static inline void rq_wait_init(struct rq_wait *rq_wait) int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, const struct rq_qos_ops *ops); +int rq_qos_add_frozen(struct rq_qos *rqos, struct gendisk *disk, + enum rq_qos_id id, const struct rq_qos_ops *ops); void rq_qos_del(struct rq_qos *rqos); typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data); -- 2.51.0