Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756552AbZFOJzq (ORCPT ); Mon, 15 Jun 2009 05:55:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754627AbZFOJz2 (ORCPT ); Mon, 15 Jun 2009 05:55:28 -0400 Received: from sith.mimuw.edu.pl ([193.0.96.4]:29328 "EHLO sith.mimuw.edu.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754650AbZFOJzZ (ORCPT ); Mon, 15 Jun 2009 05:55:25 -0400 Date: Mon, 15 Jun 2009 11:55:28 +0200 From: Jan Rekorajski To: Valerie Aurora Cc: Jan Blunck , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, bharata@in.ibm.com, dwmw2@infradead.org, mszeredi@suse.cz Subject: Re: [PATCH 00/32] VFS based Union Mount (V3) Message-ID: <20090615095528.GG4379@sith.mimuw.edu.pl> Mail-Followup-To: Jan Rekorajski , Valerie Aurora , Jan Blunck , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, bharata@in.ibm.com, dwmw2@infradead.org, mszeredi@suse.cz References: <1242662968-11684-1-git-send-email-jblunck@suse.de> <20090521125419.GM30663@sith.mimuw.edu.pl> <20090608195752.GD4363@fsbox> <20090608224406.GA6801@sith.mimuw.edu.pl> <20090608224831.GF24586@fsbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090608224831.GF24586@fsbox> X-Operating-System: Linux 2.6.29.4 x86_64 User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4618 Lines: 102 On Mon, 08 Jun 2009, Valerie Aurora wrote: > On Tue, Jun 09, 2009 at 12:44:06AM +0200, Jan Rekorajski wrote: > > On Mon, 08 Jun 2009, Valerie Aurora wrote: > > > > > You'll get -EBUSY on the second mount of any NFS file system over > > > another - try it again with the --union flag. Support for NFS on NFS > > > union mount would have to change this. > > > > I did just that, --union didn't change standard NFS behaviour. > > Er, excuse me - I mean to type "try it again WITHOUT the --union > flag." My apologies! I did, see below. > > > > mount -t nfs server:/export/system /mnt > > mount --union -t nfs server:/export/profile /mnt > > mount.nfs: /mnt is busy or already mounted > > > > I did an experiment by using different IP of the server (same machine) > > when mounting the second fs, mount worked then, but 'ls -1 /mnt' oopsed. > > I can reproduce this and send you the oops next week. > > Interesting! Does this happen without the --union flag? Filesystems are exported ro, all mounts nfs3,ro,tcp. Without --union: mount -t nfs 10.1.0.4:/nfs/system /mnt -oro,nolock,vers=3,tcp OK mount -t nfs 10.1.0.4:/nfs/profile /mnt -oro,nolock,vers=3,tcp -EBUSY (as expected) mount -t nfs 10.1.0.3:/nfs/profile /mnt -oro,nolock,vers=3,tcp (notice different IP - but it's the same machine) Works, just overmounts /mnt, ls shown contents of /nfs/profile Now, --union: mount -t nfs 10.1.0.4:/nfs/system /mnt -oro,nolock,vers=3,tcp OK mount --union -t nfs 10.1.0.4:/nfs/profile /mnt -oro,nolock,vers=3,tcp -EBUSY (/mnt busy or already mounted) mount --union -t nfs 10.1.0.3:/nfs/profile /mnt -oro,nolock,vers=3,tcp (notice different IP - but it's the same machine) mount command works, ls Oopses: [ 61.766392] creating fallthru for opt [ 61.766417] BUG: unable to handle kernel NULL pointer dereference at (null) [ 61.766433] IP: [<(null)>] (null) [ 61.766482] *pdpt = 000000001e0e9001 *pde = 0000000000000000 [ 61.767324] Oops: 0010 [#1] PREEMPT SMP [ 61.767324] last sysfs file: /sys/kernel/uevent_seqnum [ 61.767324] Modules linked in: nfs nfsd lockd nfs_acl auth_rpcgss sunrpc sch_sfq thermal processor thermal_sys rtc_cmos rtc_core i2c_piix4 e1000 ac psmouse rtc_lib hwmon pcspkr button i2c_core sg sr_mod serio_raw evdev cdrom [ 61.767324] [ 61.767324] Pid: 2460, comm: ls Not tainted (2.6.29.3 #1) VirtualBox [ 61.767324] EIP: 0060:[<00000000>] EFLAGS: 00010286 CPU: 0 [ 61.767324] EIP is at 0x0 [ 61.767324] EAX: df6d23c0 EBX: df69d1b0 ECX: e105d3e0 EDX: df69d630 [ 61.767324] ESI: df69d630 EDI: de16d300 EBP: de1b1d18 ESP: de1b1d04 [ 61.767324] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0069 [ 61.767324] Process ls (pid: 2460, ti=de1b0000 task=de0ee3f0 task.ti=de1b0000) [ 61.767324] Stack: [ 61.767324] c02d03d9 c054f57d df69d698 00000002 00000000 de1b1d7c e10357f0 00000002 [ 61.767324] 00000000 0180677d 00000000 0000000a c02d0340 df69d1b0 00000000 00000002 [ 61.767324] 0180677d 00000000 df6d2128 de16d300 de1b1f08 de1b1f08 df69d5a0 de1b1ed4 [ 61.767324] Call Trace: [ 61.767324] [] union_copyup_dir_one+0x99/0xc0 [ 61.767324] [] nfs_do_filldir+0x210/0x570 [nfs] [ 61.767324] [] union_copyup_dir_one+0x0/0xc0 [ 61.767324] [] nfs_readdir+0x522/0xa10 [nfs] [ 61.767324] [] union_copyup_dir_one+0x0/0xc0 [ 61.767324] [] __mem_cgroup_commit_charge+0x42/0x100 [ 61.767324] [] mem_cgroup_charge_common+0x57/0x70 [ 61.767324] [] __put_nfs_open_context+0x28/0xb0 [nfs] [ 61.767324] [] rpcauth_lookup_credcache+0x152/0x1f0 [sunrpc] [ 61.767324] [] rpcauth_lookupcred+0x5d/0xb0 [sunrpc] [ 61.767324] [] nfs3_decode_dirent+0x0/0x220 [nfs] [ 61.767324] [] union_copyup_dir+0x111/0x160 [ 61.767324] [] filldir64+0x0/0x110 [ 61.767324] [] vfs_readdir+0xd5/0xf0 [ 61.767324] [] sys_getdents64+0x6d/0xc0 [ 61.767324] [] syscall_call+0x7/0xb [ 61.767324] Code: Bad EIP value. [ 61.767324] EIP: [<00000000>] 0x0 SS:ESP 0068:de1b1d04 [ 61.816597] ---[ end trace 60fb13bae2f23426 ]--- -- Jan Rekorajski | ALL SUSPECTS ARE GUILTY. PERIOD! bagginsmimuw.edu.pl | OTHERWISE THEY WOULDN'T BE SUSPECTS, WOULD THEY? BOFH, MANIAC | -- TROOPS by Kevin Rubio -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/