From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 834B7210FB for ; Wed, 30 Apr 2025 04:36:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745987796; cv=none; b=nQf+FB9Jk3NwVRZsde9VNjLMnGvsOqz/zZ66+i9d7F4i5juNcm0GjE8yoPzIEYONoiap6Hxc5fo9EvVRDJvkSK7S3SSMnEHSZhX43AtK2nJtsEjxDmEXLNrs2C7xrJct5Ry+cJxCcUJvEKzXnSZWYHYq/52Sd5KPxnKsRQAK2Bg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745987796; c=relaxed/simple; bh=ea29uL+XlcCQUkhX1Ht5TXKy+Chtqw/fZZdjgzzapwo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jL2fv+GPAJNU9rEOy4dBoboUcmk/OqSSaFD0v3P9F9VUngjZZwctGsmZTJCHNf7h/d9GtC/bEtmV4ReX1R4sy+gY8f0vPm8RXf9smlVTGPbo5S3yaNy+DudcCRouP+gVaSO+tBlgbQqqH6w0Zrr4slF3UKy3Vduv5nwzKKTJy4Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=b9VKTUMa; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="b9VKTUMa" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1745987793; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RKQGHX1XUtyaB/hW7dg6IsmzJJG8CsUq2174gXjiW8U=; b=b9VKTUMaSHAnRiYqqllqGlbW5ooeAdxjmkBA3104C8rYs6F2kfvTPZVgMZvDjKzZrtgHIN G2bhYJRKhArG1biqnHad/MN5s4PR+umK6o70+m7p6Pg4CWgrYHVV4CSkyRQmvgZLMO/Tmo p0AtuFe7vR1vxQTO5euDrgfAlTH1Bso= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-495-jw_SaIMqMBK-spt5aAcImw-1; Wed, 30 Apr 2025 00:36:27 -0400 X-MC-Unique: jw_SaIMqMBK-spt5aAcImw-1 X-Mimecast-MFC-AGG-ID: jw_SaIMqMBK-spt5aAcImw_1745987786 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5E7761956094; Wed, 30 Apr 2025 04:36:26 +0000 (UTC) Received: from localhost (unknown [10.72.116.48]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 58DB418001DA; Wed, 30 Apr 2025 04:36:24 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Nilay Shroff , Shinichiro Kawasaki , =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Christoph Hellwig , Ming Lei , Hannes Reinecke Subject: [PATCH V4 13/24] block: move queue freezing & elevator_lock into elevator_change() Date: Wed, 30 Apr 2025 12:35:15 +0800 Message-ID: <20250430043529.1950194-14-ming.lei@redhat.com> In-Reply-To: <20250430043529.1950194-1-ming.lei@redhat.com> References: <20250430043529.1950194-1-ming.lei@redhat.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 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Move queue freezing & elevator_lock into elevator_change(), and prepare for using elevator_change() for setting up & tearing down default elevator too. Also add lockdep_assert_held() in __elevator_change() because either read or write lock is required for changing elevator. Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Nilay Shroff Signed-off-by: Ming Lei --- block/elevator.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index d7c9e1d2f305..df1f5451fc5e 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -676,10 +676,19 @@ static int elevator_switch(struct request_queue *q, const char *name) */ static int elevator_change(struct request_queue *q, const char *elevator_name) { - if (q->elevator && elevator_match(q->elevator->type, elevator_name)) - return 0; + unsigned int memflags; + int ret = 0; - return elevator_switch(q, elevator_name); + lockdep_assert_held(&q->tag_set->update_nr_hwq_lock); + + memflags = blk_mq_freeze_queue(q); + mutex_lock(&q->elevator_lock); + if (!(q->elevator && elevator_match(q->elevator->type, + elevator_name))) + ret = elevator_switch(q, elevator_name); + mutex_unlock(&q->elevator_lock); + blk_mq_unfreeze_queue(q, memflags); + return ret; } /* @@ -718,7 +727,6 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf, char elevator_name[ELV_NAME_MAX]; char *name; int ret; - unsigned int memflags; struct request_queue *q = disk->queue; struct blk_mq_tag_set *set = q->tag_set; @@ -737,13 +745,9 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf, elv_iosched_load_module(name); down_read_nested(&set->update_nr_hwq_lock, 1); - memflags = blk_mq_freeze_queue(q); - mutex_lock(&q->elevator_lock); ret = elevator_change(q, name); if (!ret) ret = count; - mutex_unlock(&q->elevator_lock); - blk_mq_unfreeze_queue(q, memflags); up_read(&set->update_nr_hwq_lock); return ret; } -- 2.47.0