From patchwork Wed Feb 5 14:44:48 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nilay Shroff X-Patchwork-Id: 13961255 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 1A0691DDC0D for ; Wed, 5 Feb 2025 14:45:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738766724; cv=none; b=pHMDpt+eMqVProIMkLkBismmAQEK14P613ZgWlS9yzVQMkhuE1OrQ3m3X9vpXc78h6sypObJDEFTnk41j5B0p6LYRcat0XAu/5Cepkrd3VOMhDQ18/BsBN757wfnVgwRP9mtrDq0F6/piY/Hn31yv0yBVOidngMQm8XhjOao67o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738766724; c=relaxed/simple; bh=yYa+OhlQ/D3XNZEcqwqG67PXMdrpmIYlETBeOj9tQ04=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EWK8QM6rifuPuNDacrHUPwanOEYIYgV0XOgfBmowSjtFrYkbWCmsKZzLrYrDQHCzjf018/5aPWjDBIxfnyeuosDcXLGrCoNHRVcfkOJgZJf6RhePWsutv976MInrfi514TPKA03Do0BPjVkrCLT8c1DvvxbiOMrOh1GzCpwj5X4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=plwOtRUJ; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="plwOtRUJ" Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 5157Wu5L000943; Wed, 5 Feb 2025 14:45:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=wmFEtqyD424Su6E5c 0GAQWtG2N0V1k7BnxvIWYExLF0=; b=plwOtRUJ5rr1FjLk4Brp5FDt6pwb8FGZZ WRMpbUfA2H34h2uLJwAOo9IVCgxdWHHS3wpP23yPA+xZhr5D6fZDXSRh0OhAujVB B1xeCICa2+yqTw8nKOSwUPvr8uivZ0nnP7Ak7Wb84HTVgUjQ5J3jjAjkNcfLqElX UbhwHlSN+SzkYHfU1ekBaclTYbgEJXNwTONntC/EG5y5O2EZ0JoNU53Clar6mxMg LdXA6d2uYdyRJu0oqLhCQlVkdfG5wiJPSlCETtpX6bpl/0QVfh8kG8sn4j0tu61M Rz+abSfYpbu1cqZzJUPg7sLwI4MVl1chmspOAye1ZURYVp+jYQ6gA== Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 44m3pnt07w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 05 Feb 2025 14:45:16 +0000 (GMT) Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 515CdKSQ024461; Wed, 5 Feb 2025 14:45:15 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 44hxxn983c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 05 Feb 2025 14:45:15 +0000 Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 515EjDfV29557246 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 5 Feb 2025 14:45:13 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CF1C520043; Wed, 5 Feb 2025 14:45:13 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3A42F20040; Wed, 5 Feb 2025 14:45:12 +0000 (GMT) Received: from li-c9696b4c-3419-11b2-a85c-f9edc3bf8a84.ibm.com.com (unknown [9.171.80.122]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 5 Feb 2025 14:45:12 +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: [PATCH 2/2] block: avoid acquiring q->sysfs_lock while accessing sysfs attributes Date: Wed, 5 Feb 2025 20:14:48 +0530 Message-ID: <20250205144506.663819-3-nilay@linux.ibm.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250205144506.663819-1-nilay@linux.ibm.com> References: <20250205144506.663819-1-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: 2_n2PXnYK9Q3iJ37skxZnKrIHpdw0TbM X-Proofpoint-GUID: 2_n2PXnYK9Q3iJ37skxZnKrIHpdw0TbM 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=2025-02-05_06,2025-02-05_02,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 lowpriorityscore=0 phishscore=0 malwarescore=0 mlxlogscore=963 spamscore=0 mlxscore=0 suspectscore=0 adultscore=0 priorityscore=1501 bulkscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2501170000 definitions=main-2502050114 The sysfs attributes are already protected with sysfs/kernfs internal locking. So acquiring q->sysfs_lock is not needed while accessing sysfs attribute files. So this change helps avoid holding q->sysfs_lock while accessing sysfs attribute files. Signed-off-by: Nilay Shroff --- block/blk-mq-sysfs.c | 6 +----- block/blk-sysfs.c | 10 +++------- 2 files changed, 4 insertions(+), 12 deletions(-) diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 3feeeccf8a99..da53397d99fa 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -52,7 +52,6 @@ static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj, struct blk_mq_hw_ctx_sysfs_entry *entry; struct blk_mq_hw_ctx *hctx; struct request_queue *q; - ssize_t res; entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr); hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj); @@ -61,10 +60,7 @@ static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj, if (!entry->show) return -EIO; - mutex_lock(&q->sysfs_lock); - res = entry->show(hctx, page); - mutex_unlock(&q->sysfs_lock); - return res; + return entry->show(hctx, page); } static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx, diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 6f548a4376aa..2b8e7b311c61 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -664,14 +664,11 @@ queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) { struct queue_sysfs_entry *entry = to_queue(attr); struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj); - ssize_t res; if (!entry->show) return -EIO; - mutex_lock(&disk->queue->sysfs_lock); - res = entry->show(disk, page); - mutex_unlock(&disk->queue->sysfs_lock); - return res; + + return entry->show(disk, page); } static ssize_t @@ -710,11 +707,10 @@ queue_attr_store(struct kobject *kobj, struct attribute *attr, return length; } - mutex_lock(&q->sysfs_lock); memflags = blk_mq_freeze_queue(q); res = entry->store(disk, page, length); blk_mq_unfreeze_queue(q, memflags); - mutex_unlock(&q->sysfs_lock); + return res; }