From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id A2DC7231CA3 for ; Mon, 13 Jan 2025 09:18:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736759882; cv=none; b=ZrfjzzACU4XFd+/vGRlD7gT8hyj9DNsif+1k8zuTDY58qrbe6oHo0USYgGCwGTIpW6NvuuPyMm6dEheVSOYOI9W78yXRWms4+QQCbr1ftsL9F7LI0fVzyBLGzsluNzjVRmY9zg+O/mEfHAXA3LAw4vU2w7D81KgdHeM90r79Ssg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736759882; c=relaxed/simple; bh=43uGB/HhwRUKHgVKPWEkOb5cQyvFtE5S+GdS2in77D4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kU6m6t7bY6gnkWvRGIER4AP0lKRctrOZTBzx4UodlSB/yoeoNKsmUryEqDvap7HWv5QU7Hi3NnOuthmeIS4K39jwsfZSCMQ/b7DXi3W1ygJ4IVehQt7eLRDf3owIcpO3nB298QVGwdzzKYy2XtfgqPYqeswpG5Q2qnxiUeq9O3Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=no/r6dT6; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="no/r6dT6" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=WvlwDyPLi1RxE19yAabDwwBkEOxpzX3iFDREonTBLPY=; b=no/r6dT60vGmerSjMLpOQQHC1Z 8LASoHV6P6QofHZZO+KOs9BRMcPq2dcnZ/xxV2WAFYi/AfMmVG5D+BIRuntV04WcWU1fyg3Cj5SGD 8f2cXTs9X63wDhpLyeezRGkt9/aDTDq8bcj1rqau0f7fe3xTWxeNTrNCndtYnyh3kPRp852WkKolu tKX/lNk+xuNgDF87YrQAEUhFTy7mupx0x1/UKkljUJO/Lv/IwnBhVCC/immLlX5YFvdfjpeFeZz23 1KIm06oqKK2aeOWJuLEPDIT0fh9WZ1lhB56z6yugWLJhn0XrHvOFtqVkmzdxsagtmSL7KLGvvpB1f sLXyKYBQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tXGa8-00000004ZUz-0DgL; Mon, 13 Jan 2025 09:18:00 +0000 Date: Mon, 13 Jan 2025 01:18:00 -0800 From: Christoph Hellwig To: Ming Lei Cc: Christoph Hellwig , Jens Axboe , linux-block@vger.kernel.org, Kun Hu , Jiaji Qin Subject: Re: [PATCH] loop: don't call vfs_flush() with queue frozen Message-ID: References: <20250113022426.703537-1-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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Jan 13, 2025 at 04:22:51PM +0800, Ming Lei wrote: > On Sun, Jan 12, 2025 at 09:49:39PM -0800, Christoph Hellwig wrote: > > On Mon, Jan 13, 2025 at 10:24:26AM +0800, Ming Lei wrote: > > > If vfs_flush() is called with queue frozen, the queue freeze lock may be > > > connected with FS internal lock > > > > What "FS internal lock" ? > > Please see the report: > > https://lore.kernel.org/linux-block/359BC288-B0B1-4815-9F01-3A349B12E816@m.fudan.edu.cn/T/#u Please state the locks. Nothing fs internal here, that report is about i_rwsem. And a false positive because it is about ordering of i_rwsem on the upper file system sitting on the loop device vs the one on the lower file systems sitting below the block device. These obviously can't deadlock, we just need to tell lockdep about that fact.