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Tue, 18 Feb 2025 08:29:22 +0000 Received: from smtpav04.fra02v.mail.ibm.com (smtpav04.fra02v.mail.ibm.com [10.20.54.103]) by smtprelay01.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 51I8TKYD50594222 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 18 Feb 2025 08:29:20 GMT Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A7EFE2004B; Tue, 18 Feb 2025 08:29:20 +0000 (GMT) Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4A04220040; Tue, 18 Feb 2025 08:29:19 +0000 (GMT) Received: from li-c9696b4c-3419-11b2-a85c-f9edc3bf8a84.in.ibm.com (unknown [9.109.198.198]) by smtpav04.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 18 Feb 2025 08:29:19 +0000 (GMT) From: Nilay Shroff To: linux-block@vger.kernel.org Cc: hch@lst.de, ming.lei@redhat.com, dlemoal@kernel.org, axboe@kernel.dk, gjoyce@ibm.com Subject: [PATCHv2 5/6] blk-sysfs: protect wbt_lat_usec using q->elevator_lock Date: Tue, 18 Feb 2025 13:58:58 +0530 Message-ID: <20250218082908.265283-6-nilay@linux.ibm.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250218082908.265283-1-nilay@linux.ibm.com> References: <20250218082908.265283-1-nilay@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: Ib5anEazT31f6EQxCZ_pr4-72qlR1bdP X-Proofpoint-GUID: Ib5anEazT31f6EQxCZ_pr4-72qlR1bdP X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-02-18_03,2025-02-18_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 mlxscore=0 clxscore=1015 lowpriorityscore=0 phishscore=0 priorityscore=1501 spamscore=0 adultscore=0 impostorscore=0 bulkscore=0 malwarescore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2501170000 definitions=main-2502180065 The wbt latency and state could be updated while initializing the elevator or exiting the elevator. The elevator code path is now protected with q->elevator_lock. So we should now protect the access to sysfs attribute wbt_lat_usec using q->elevator_lock instead of q->sysfs_lock. Signed-off-by: Nilay Shroff --- block/blk-sysfs.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 37ac73468d4e..876376bfdac3 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -567,7 +567,7 @@ static ssize_t queue_wb_lat_show(struct gendisk *disk, char *page) { int ret; - mutex_lock(&disk->queue->sysfs_lock); + mutex_lock(&disk->queue->elevator_lock); if (!wbt_rq_qos(disk->queue)) { ret = -EINVAL; @@ -581,7 +581,7 @@ static ssize_t queue_wb_lat_show(struct gendisk *disk, char *page) div_u64(wbt_get_min_lat(disk->queue), 1000)); out: - mutex_unlock(&disk->queue->sysfs_lock); + mutex_unlock(&disk->queue->elevator_lock); return ret; } @@ -594,8 +594,8 @@ static ssize_t queue_wb_lat_store(struct gendisk *disk, const char *page, s64 val; unsigned int memflags; - mutex_lock(&q->sysfs_lock); memflags = blk_mq_freeze_queue(q); + mutex_lock(&q->elevator_lock); ret = queue_var_store64(&val, page); if (ret < 0) @@ -634,8 +634,8 @@ static ssize_t queue_wb_lat_store(struct gendisk *disk, const char *page, blk_mq_unquiesce_queue(q); out: + mutex_unlock(&q->elevator_lock); blk_mq_unfreeze_queue(q, memflags); - mutex_unlock(&q->sysfs_lock); return ret; } @@ -907,11 +907,11 @@ int blk_register_queue(struct gendisk *disk) mutex_unlock(&q->elevator_lock); goto out_crypto_sysfs_unregister; } + wbt_enable_default(disk); } mutex_unlock(&q->elevator_lock); blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q); - wbt_enable_default(disk); /* Now everything is ready and send out KOBJ_ADD uevent */ kobject_uevent(&disk->queue_kobj, KOBJ_ADD);