From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E6FA3EA3F0F for ; Tue, 10 Feb 2026 06:59:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Content-Transfer-Encoding:Content-Type:References:Mime-Version:Date: Message-Id:Subject:From:Cc:To:In-Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=EjD+pRaHTolG3P0dFiBqPrhrRtG+Zz+PQwJlGziWUZ8=; b=tX9Qjej5jqWB0R rnzZGnjaVJ4VubqQMpRkmiKtwBPVYLBQ7yzspfatZEnN90w1aQHREzuAirXHvsM6smgVobeP1h4w6 IshOLDzNMkeTYhGu/UGjY83a4IX3TC1Bpz4E+V+hUBEWiYiUu6Yub7/ckTpZ+nDvjLh9KWEDyzLr5 +zgA0MO3RxpZdi9+wpweCBjZKr8GksFzZ+Q5T174HKcVt9wQE2y4PIof1vwLhDDmZd7F6GL5wxD0X 9mX/AFLNsI06Y3aUjQ1IjHiOjK1PZhv0xAar1hwK5i6mq6QDPFC04gWGemor+lQZmAIrJiD7bXPtT U7N425epH6XlROFeRKQA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vphiu-0000000GZ2i-2KIf; Tue, 10 Feb 2026 06:59:48 +0000 Received: from sg-1-14.ptr.blmpb.com ([118.26.132.14]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vphip-0000000GZ1T-2oLB for linux-arm-kernel@lists.infradead.org; Tue, 10 Feb 2026 06:59:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=s1; d=fnnas-com.20200927.dkim.feishu.cn; t=1770706777; h=from:subject:mime-version:from:date:message-id:subject:to:cc: reply-to:content-type:mime-version:in-reply-to:message-id; bh=EjD+pRaHTolG3P0dFiBqPrhrRtG+Zz+PQwJlGziWUZ8=; b=ozVs0UXOFBlEeE2cBk9Rw2e5fJAokY5WmKHFGqvTR2oGGrenp8IRHeek84EpSLAjuSJl7i FwZneB+jhpJQvl+5seJnAL8je83y2+pbb36AkWFYEZXkhAcv7lDwOZ8ypoorrlka6h8nlK d6NBY7lRD7KNlLplpzXTQC+H4TSGhk4nkWG48y6mpREx6RDHTbMPWAKgWsN/f9Lyt6SbQ0 GKWtA3YUgPfTcPVp2pQ3XgmWt/zfRQtwfbYgVisYCmDFo/0/arFz0cD6lyyPdeJ3cTA7IL 9EOCBzmL/KkLN0b5N6LZC328TcPIgQdngzM68hFiN4kl6zeHLp+JA1m99JNdzw== In-Reply-To: User-Agent: Mozilla Thunderbird To: "Bart Van Assche" , "Keith Busch" Cc: , , , , , , , , , , , , , From: "Yu Kuai" Subject: Re: [PATCH 4/4] blk-mq: use blk_queue_enter/exit to protect debugfs file creation Message-Id: Date: Tue, 10 Feb 2026 14:59:32 +0800 Mime-Version: 1.0 Received: from [192.168.1.104] ([39.182.0.137]) by smtp.feishu.cn with ESMTPS; Tue, 10 Feb 2026 14:59:34 +0800 X-Lms-Return-Path: X-Original-From: Yu Kuai References: <20260209082953.3053721-1-yukuai@fnnas.com> <20260209082953.3053721-5-yukuai@fnnas.com> <6b18e0bc-efa7-4bd5-b12b-a313941d2ba1@acm.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260209_225944_556099_4DC2BACC X-CRM114-Status: UNSURE ( 9.22 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: yukuai@fnnas.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, =E5=9C=A8 2026/2/10 1:51, Bart Van Assche =E5=86=99=E9=81=93: > On 2/9/26 9:33 AM, Keith Busch wrote: >> I had to look up the original commit that introduced the WARN, >> 65d466b629847. The commit message says "Creating new debugfs entries can >> trigger fs reclaim", so that must be the path that enters back into the >> block layer request_queue. > > Thanks Keith. It's probably a good idea to integrate this information in > the source code comment above the blk_queue_enter() call. Yeah, I'll add the information in the next version. BTW, I'd like to add something. The original lockdep report is: [REPORT] Possible circular locking dependency on 6.18-rc2 in=20 blkg_conf_open_bdev_frozen+0x80/0xa0 - David Wei And we see there some contexts like wbt/nbd can freeze queue fist and then = create debugfs entries, and it's fixed by the thread: [PATCH v9 0/8] blk-mq: fix possible deadlocks - Yu Kuai And the warning is added in this thread. > > Bart. --=20 Thansk, Kuai