From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail3-167.sinamail.sina.com.cn (mail3-167.sinamail.sina.com.cn [202.108.3.167]) (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 AD89A3203B6 for ; Sun, 2 Aug 2026 08:19:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.108.3.167 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785658788; cv=none; b=Ex27FULamF8Xodhjmr7Mo8Nj0woJLXwqgMqMwT4KlIh+R4NiBxBFFwV3dUMErxJP6x3NAPxw7XvCwf429+vpMFl0TJNpAf1ruW738VXaHSqsbIu7wQM2S/VwMh9OXhMuQKwGTaFN/ygPU6ENw7Fpw3i4yEmnhqGqva5TApL4DJo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785658788; c=relaxed/simple; bh=aLJiJecCJ7atov2VSjRLjPtXXK8Ip7dbtwDYnPEY4Io=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=eeAfZ/eORbAoGbOHbsOWOrNviOhX47Twixc9YP/WShs0ixj/S+s7s8Lbp6qkzNF9jvA/cQsfalxEw6VfeesjMBpG9KbXXQaJ2+zX4PFMHUoOa8aecImgWAF6utSCPOiJCbq0NjhZr85s92xO98rNyURnhRSBYJx3CBLqaiFFH6A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=L6gwU3E4; arc=none smtp.client-ip=202.108.3.167 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="L6gwU3E4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1785658784; bh=aLJiJecCJ7atov2VSjRLjPtXXK8Ip7dbtwDYnPEY4Io=; h=From:Subject:Date:Message-ID; b=L6gwU3E462HD5yToYDZYXmEf+117YUqHAGzWd4vdI/rYsY/WWYfYv9XvJtOrmCiBp QSh5BukjeXafEBJNPFeZ92affg4UaJ439zaLnZLXWPXmb28cdizjTfB0OITGS8sPpF sCWU6kIll6j4MS1REV+FgWmJEVRwp++btt/cAND4= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([221.216.154.155]) by sina.com (10.54.253.33) with ESMTP id 6A6EFD930000654E; Sun, 2 Aug 2026 16:19:34 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 461466685505 X-SMAIL-UIID: E9AF4BED424341229E17DB1745947D0B-20260802-161934-1 From: Hillf Danton To: Hillf Danton Cc: Eric Dumazet , Deepanshu Kartikey , linux-block@vger.kernel.org, nbd@other.debian.org, linux-kernel@vger.kernel.org, syzbot+6b85d1e39a5b8ed9a954@syzkaller.appspotmail.com Subject: Re: [PATCH] nbd: don't warn when reclassifying a busy socket lock Date: Sun, 2 Aug 2026 16:19:20 +0800 Message-ID: <20260802081922.840-1-hdanton@sina.com> In-Reply-To: <20260728045340.770-1-hdanton@sina.com> References: 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-Transfer-Encoding: 8bit On Tue, 28 Jul 2026 12:53:37 +0800 Hillf Danton wrote: >On Mon, 20 Jul 2026 10:39:17 +0800 Hillf Danton wrote: >>On Mon, 20 Jul 2026 10:23:43 +0800 Hillf Danton wrote: >>>On Sun, Jun 28, 2026 at 10:29 PM Hillf Danton wrote: >>>> For archive purpose, syzbot report [1] where udp was not invovled defies >>>> what is fixed in d532cddb6c60 ("nbd: Reclassify sockets to avoid lockdep >>>> circular dependency") -- "Since the UDP socket and the NBD TCP/TLS socket >>>> are different, this is a false positive." >>>> >>>> >>>> [1] Subject: [syzbot] [net?] possible deadlock in inet_shutdown (3) >>>> https://lore.kernel.org/lkml/69c37e6a.a70a0220.234938.0045.GAE@google.com/ >>>> >>>For archive purpose, syzbot report [2] shows deadlock without either udp or >>>tcp invovled. But it sounds false positive because kernfs node is removed >>>while the filesystem is filling super block. >>> >>>[2] Subject: [syzbot] [kernfs?] possible deadlock in kernfs_remove_by_name_ns (2) >>>https://lore.kernel.org/lkml/6a5ca0b7.f1649fcc.2a4208.03f3.GAE@google.com/ >>> >>For archive purpose, syzbot reports [3,4] show deadlock without either udp or >>tcp invovled. >> >>[3] Subject: [syzbot] [kernfs?] possible deadlock in kernfs_iop_permission (2) >>https://lore.kernel.org/lkml/6a5d14b8.42649fcc.6186.0078.GAE@google.com/ >> >>[4] Subject: [syzbot] [kernel?] possible deadlock in netif_reset_xps_queues_gt (3) >>https://lore.kernel.org/lkml/6a5d14b9.42649fcc.6186.0079.GAE@google.com/ >> >For archive purpose, syzbot report [5] shows deadlock without lock_sock invovled. > >[5] Subject: [syzbot] [pm?] possible deadlock in thermal_zone_device_set_mode >https://lore.kernel.org/lkml/6a676313.073198cf.94f0f.0033.GAE@google.com/ > For archive purpose, syzbot report [6] shows deadlock without nbd invovled. [6] Subject: [syzbot] [block?] [cgroups?] possible deadlock in blkcg_deactivate_policy (2) https://lore.kernel.org/lkml/6a6e8a06.6ce73036.24301b.0015.GAE@google.com/ BTW Eric do you see how difficult it is to fix the fking deadlock?