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 2FED7EA8133 for ; Tue, 10 Feb 2026 15:42:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=A0Ks/Jzg5dqDNmTkM32ohGElf6TmJXnAvPys3oCm4Tw=; b=tQOTzy46xpgvcqj+C5bZ+Y+Zy/ YgY0FYKgGW9XqTbYW7i/YV19KM/TMIFJqMBySvtWtudeu6otTfVSFRuoVKJ8QyCaNTHueWj3NaaIs vkC8c4UyGN2DNSLd1gWbplRZHDXiim0uUsvRp9LPEp+ceODOQqO3XVHcWnBL4qlyia7U3VIqyQy6k armgCYd5QFTUnexfkxWW7zwoS+s1mVjbdoyNxUQpXtiiFaAHAW4nIq6u9k7+NIZMIkP2eYwsKXdlG tANXB5RaPiKsWIOlPRWV1Ob4Wba+N0akMprKDJueiGZvimLradlvy/V/wogtx3kZlTvbpiGIsFmpF nrBOzTuQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vppsB-0000000H8e4-22BO; Tue, 10 Feb 2026 15:41:55 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vpps9-0000000H8dM-0vCf; Tue, 10 Feb 2026 15:41:54 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id B92D168CFE; Tue, 10 Feb 2026 16:41:50 +0100 (CET) Date: Tue, 10 Feb 2026 16:41:50 +0100 From: Christoph Hellwig To: Keith Busch Cc: Bart Van Assche , Yu Kuai , axboe@kernel.dk, hch@lst.de, sagi@grimberg.me, sven@kernel.org, j@jannau.net, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, tj@kernel.org, nilay@linux.ibm.com, ming.lei@redhat.com, neal@gompa.dev, asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 4/4] blk-mq: use blk_queue_enter/exit to protect debugfs file creation Message-ID: <20260210154150.GA2844@lst.de> References: <20260209082953.3053721-1-yukuai@fnnas.com> <20260209082953.3053721-5-yukuai@fnnas.com> <6b18e0bc-efa7-4bd5-b12b-a313941d2ba1@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260210_074153_402626_D2D443CD X-CRM114-Status: GOOD ( 14.92 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Feb 09, 2026 at 10:33:15AM -0700, Keith Busch wrote: > > This is not clear to me. Why are concurrent queue freezes not allowed > > while debugfs attributes are created? I don't see any code in debugfs > > that calls back into the block layer while creating debugfs attributes? > > Did I perhaps overlook something? > > 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 > blaock layer request_queue. Another way to solves this would be to scope all the debugs action as NOIO context.