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 2177233938B; Fri, 14 Aug 2026 06:30:32 +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=1786689036; cv=none; b=IpFCPFLp/fzvIXvXyqYLb/twDhBeGTQEPiiw+A+P0VDQlV8xCjCvW2Co35BZm1wsfabsBahwUVNsGZLj+QCQKYZIrv5IYYr+nkotCxHy+3EjB8MYKAcoWyZrTc28/b5dBI2b8h8f/+zQURKGa12miXii68VH1UcIedCAdVJzJLE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786689036; c=relaxed/simple; bh=00WqtERUtnYBEUzQd0/SsEG+LWqmr6egKXeBQhrAo2I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=t028Cac6kVHo1GIfHFe3j4mnRMcmtslVwvR9zYQypMCz6184HTKEL/ddOynpnD++Z59cevY8gdVAkf7EU7Qs7ltRy69tEGK7c8Z8zP2KeCp+0ToMhhb8rPO213ek8sReFDlOkUv2F3PmjXgqq34WC5M9Jo88zTwv3OUmRXbkrMI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=WsNtQ8Tn; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="WsNtQ8Tn" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Transfer-Encoding :Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=00WqtERUtnYBEUzQd0/SsEG+LWqmr6egKXeBQhrAo2I=; b=WsNtQ8TniakQxZNdnuggvJh74C OE+4sgkHXEZuda9o7TCIN8ZpLZKayt5lMhfPBdi9qDc9BllPvmwc41LE3Qr0O6NB/jVAV2LwQuFig FlIYI5FxGw1AG6pjRP5HOMuYO5WfUr8kHRcZ5XmnhP5l608QVpHTXsW/QRiOF9QYwFUb+EdK34tUE XdU8zGpWXJQx8aCNuUFimFxp5McV/biDcAuI44NAc+pepbC7nfgSfQjLeLxMmXbAsHtq7BhOwpN9J r7MJ/rT1jha6cCGI6WlKmC2yAcqtpZJ5m7y8EPyTIiQMCzeTMqJ9JXrKo+i+hgy46uCKXsdA/qzEI gu1YioiQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1wulR0-000000022L3-2Xh4; Fri, 14 Aug 2026 06:30:31 +0000 Date: Thu, 13 Aug 2026 23:30:30 -0700 From: Christoph Hellwig To: Daeho Jeong Cc: Bart Van Assche , Christoph Hellwig , linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com, Daeho Jeong , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, "Rafael J. Wysocki" , Pavel Machek , Len Brown , linux-pm@vger.kernel.org Subject: Re: [PATCH v2] f2fs: quiesce background threads during system suspend using PM notifier Message-ID: References: <20260806170108.2100312-1-daeho43@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Aug 10, 2026 at 09:53:14AM -0700, Daeho Jeong wrote: > On Mon, Aug 10, 2026 at 9:34 AM Bart Van Assche wrote: > > This information was shared earlier with Daeho > > (https://b.corp.google.com/issues/515470309#comment45): [ ... ] This does not seem to be information available to the public. > f2fs threads are already freezable: f2fs_gc and f2fs_discard are > already registered with set_freezable() and call try_to_freeze(). > However, a race window exists: a thread checks freezing() (false), > calls submit_bio(), and gets trapped inside __bio_queue_enter(). > Because it gets blocked before reaching try_to_freeze(), it triggers a > PM freezer timeout. This does sound very much like a block layer freezing issue. > Point taken. Aside from this f2fs patch, I agree that addressing this > at the block layer or PM subsystem level would be a much cleaner, > system-wide solution. > I’ll give more thought to how we can properly solve this race > condition for the entire system, and I'll loop in the relevant > PM/block maintainers if a viable generic approach emerges. Thanks, it would be great to fix this properly.