From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932618AbaE2Kz0 (ORCPT ); Thu, 29 May 2014 06:55:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40964 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757218AbaE2KzY (ORCPT ); Thu, 29 May 2014 06:55:24 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <1400838223-30844-1-git-send-email-miklos@szeredi.hu> References: <1400838223-30844-1-git-send-email-miklos@szeredi.hu> To: Miklos Szeredi Cc: dhowells@redhat.com, viro@ZenIV.linux.org.uk, torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, apw@canonical.com, nbd@openwrt.org, neilb@suse.de, jordipujolp@gmail.com, ezk@fsl.cs.sunysb.edu, sedat.dilek@gmail.com, hooanon05@yahoo.co.jp, mszeredi@suse.cz Subject: Kernel errors with overlay filesystem v22 Date: Thu, 29 May 2014 11:54:41 +0100 Message-ID: <27993.1401360881@warthog.procyon.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When I run my unionmount testsuite against overlayfs, I get the following lockdep warning (unionmount is not in the kernel sources in this test): ================================================ [ BUG: lock held when returning to user space! ] 3.15.0-rc6-fsdevel+ #363 Tainted: G W ------------------------------------------------ mount/4183 is leaving the kernel with locks still held! 1 lock held by mount/4183: #0: (sb_writers#8){.+.+.+}, at: [] mnt_want_write+0x1c/0x40 The mounts involved look like: lower_layer /lower tmpfs ro,seclabel,relatime 0 0 upper_layer /upper tmpfs rw,seclabel,relatime 0 0 overlayfs /mnt overlayfs rw,relatime,lowerdir=/lower,upperdir=/upper/upper,workdir=/upper/work 0 0 I get a busy inodes warning on unmounting /upper (/mnt unmounts okay): BUG: Dentry ffff88002795feb8{i=2e8e,n=work} still in use (1) [unmount of tmpfs tmpfs] ------------[ cut here ]------------ WARNING: CPU: 0 PID: 2981 at /data/fs/linux-2.6-fscache/fs/dcache.c:1262 umount_check+0x76/0x7a() Modules linked in: CPU: 0 PID: 2981 Comm: umount Tainted: G W 3.15.0-rc6-fsdevel+ #363 Hardware name: /DG965RY, BIOS MQ96510J.86A.0816.2006.0716.2308 07/16/2006 0000000000000000 ffff8800383b7d38 ffffffff8148b669 0000000000000000 ffff8800383b7d70 ffffffff81038887 ffffffff81125407 ffff8800279368a0 00000000000005d0 ffff88003b76f630 ffff88002795feb8 ffff8800383b7d80 Call Trace: [] dump_stack+0x4d/0x66 [] warn_slowpath_common+0x7a/0x93 [] ? umount_check+0x76/0x7a [] warn_slowpath_null+0x15/0x17 [] umount_check+0x76/0x7a [] d_walk+0x134/0x2ff [] ? do_one_tree+0x21/0x34 [] ? dget_parent+0x13f/0x13f [] do_one_tree+0x21/0x34 [] shrink_dcache_for_umount+0x42/0x6b [] generic_shutdown_super+0x1c/0xe8 [] kill_anon_super+0xd/0x17 [] kill_litter_super+0x1e/0x21 [] deactivate_locked_super+0x27/0x48 [] deactivate_super+0x39/0x3c [] mntput_no_expire+0x237/0x258 [] ? SyS_umount+0x3ba/0x3db [] SyS_umount+0x3ba/0x3db [] ? tracesys+0xdd/0xe2 [] ? syscall_trace_enter+0x197/0x1eb [] tracesys+0xdd/0xe2 ---[ end trace 11bb9aeb6ce29610 ]--- VFS: Busy inodes after unmount of tmpfs. Self-destruct in 5 seconds. Have a nice day...