From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751206AbdBFGAj (ORCPT ); Mon, 6 Feb 2017 01:00:39 -0500 Received: from scorn.kernelslacker.org ([45.56.101.199]:57474 "EHLO scorn.kernelslacker.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750962AbdBFGAh (ORCPT ); Mon, 6 Feb 2017 01:00:37 -0500 Date: Mon, 6 Feb 2017 01:00:32 -0500 From: Dave Jones To: Linus Torvalds Cc: Linux Kernel Mailing List , Christoph Hellwig Subject: Re: Linux 4.10-rc7 Message-ID: <20170206060032.f7ktrvogksxl4ppy@codemonkey.org.uk> Mail-Followup-To: Dave Jones , Linus Torvalds , Linux Kernel Mailing List , Christoph Hellwig References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) X-Spam-Score: -1.1 (-) X-Spam-Report: Spam detection software, running on the system "scorn.kernelslacker.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: On Sun, Feb 05, 2017 at 03:41:54PM -0800, Linus Torvalds wrote: > Hey, look at that - it's all been very quiet, and unless anything bad > happens, we're all back to the regular schedule with this being the > last rc. [...] Content analysis details: (-1.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.8 RDNS_NONE Delivered to internal network by a host with no rDNS Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Feb 05, 2017 at 03:41:54PM -0800, Linus Torvalds wrote: > Hey, look at that - it's all been very quiet, and unless anything bad > happens, we're all back to the regular schedule with this being the > last rc. .. > Christoph Hellwig (1): > nfsd: special case truncates some more This one smells funny to me. [ 145.983182] ============================================= [ 145.983201] [ INFO: possible recursive locking detected ] [ 145.983220] 4.10.0-rc7+ #1 Not tainted [ 145.983236] --------------------------------------------- [ 145.984868] nfsd/865 is trying to acquire lock: [ 145.986497] (sb_writers#7){.+.+.+}, at: [] mnt_want_write+0x25/0x50 [ 145.988153] but task is already holding lock: [ 145.991350] (sb_writers#7){.+.+.+}, at: [] mnt_want_write+0x25/0x50 [ 145.992931] other info that might help us debug this: [ 145.995991] Possible unsafe locking scenario: [ 145.998936] CPU0 [ 146.000358] ---- [ 146.001749] lock(sb_writers#7); [ 146.003109] lock(sb_writers#7); [ 146.004431] *** DEADLOCK *** [ 146.008179] May be due to missing lock nesting notation [ 146.010541] 1 lock held by nfsd/865: [ 146.011681] #0: (sb_writers#7){.+.+.+}, at: [] mnt_want_write+0x25/0x50 [ 146.012820] stack backtrace: [ 146.015033] CPU: 0 PID: 865 Comm: nfsd Not tainted 4.10.0-rc7+ #1 [ 146.016147] Call Trace: [ 146.017225] dump_stack+0x68/0xa0 [ 146.018273] __lock_acquire+0x6ea/0x11d0 [ 146.019251] ? trace_hardirqs_on_caller+0xef/0x1b0 [ 146.020119] lock_acquire+0x109/0x270 [ 146.020957] ? mnt_want_write+0x25/0x50 [ 146.021770] __sb_start_write+0xd8/0x230 [ 146.022555] ? mnt_want_write+0x25/0x50 [ 146.023313] ? nfsd_permission+0x7f/0x110 [ 146.024042] mnt_want_write+0x25/0x50 [ 146.024745] vfs_truncate+0x4e/0x200 [ 146.025421] nfsd_setattr+0x13a/0x300 [ 146.026070] nfsd4_setattr+0x109/0x130 [ 146.026690] nfsd4_proc_compound+0x443/0x6e0 [ 146.027286] nfsd_dispatch+0x91/0x170 [ 146.027853] svc_process+0x6e6/0xa00 [ 146.028393] nfsd+0x193/0x2a0 [ 146.028903] ? nfsd+0x5/0x2a0 [ 146.029448] kthread+0x111/0x150 [ 146.029964] ? nfsd_destroy+0x190/0x190 [ 146.030474] ? __kthread_create_on_node+0x250/0x250 [ 146.030988] ret_from_fork+0x2e/0x40 I'll double check that it's that commit in the morning, but nfs+truncate seems to point in this direction.. Dave