nfs falls over during ftp connection since installing vsftpd

[Mausy5043]

I just installed vsftpd on my Ubuntu server. The contents of syslog suggests there is a problem. Previously no ftp-server software was installed.

First some basic info:

$ cat /proc/version_signature:
Ubuntu 3.13.0-39.66-generic 3.13.11.8

$ lsb_release -rd
Description: Ubuntu 14.04.1 LTS
Release: 14.04

$ apt-cache policy vsftpd
vsftpd:
  Installed: 3.0.2-1ubuntu2.14.04.1
  Candidate: 3.0.2-1ubuntu2.14.04.1
  Version table:
 *** 3.0.2-1ubuntu2.14.04.1 0
        500 http://nl.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     3.0.2-1ubuntu2 0
        500 http://nl.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

$ apt-cache policy nfs-common
nfs-common:
  Installed: 1:1.2.8-6ubuntu1.1
  Candidate: 1:1.2.8-6ubuntu1.1
  Version table:
 *** 1:1.2.8-6ubuntu1.1 0
        500 http://nl.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1:1.2.8-6ubuntu1 0
        500 http://nl.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

When logging in with ftp from a remote computer onto this server as an anonymous user, nfs seems to fall over causing this stacktrace:

[2014-11-22 21:13:35] ------------[ cut here ]------------
[2014-11-22 21:13:35] WARNING: CPU: 1 PID: 469 at /build/buildd/linux-3.13.0/fs/proc/generic.c:511 remove_proc_entry+0x139/0x1b0()
[2014-11-22 21:13:35] name 'fs/nfsfs'
[2014-11-22 21:13:35] Modules linked in: nfsd auth_rpcgss nfs_acl nfs lockd sunrpc fscache snd_hda_codec_realtek snd_hda_codec_hdmi kvm_amd kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd serio_raw k10temp snd_hda_intel i2c_piix4 snd_hda_codec radeon snd_hwdep ttm snd_pcm drm_kms_helper snd_page_alloc drm snd_timer video i2c_algo_bit snd soundcore nct6775 hwmon_vid lp parport mac_hid pata_acpi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor usb_storage hid_generic usbhid hid raid6_pq raid1 raid0 multipath alx linear mdio pata_atiixp ahci libahci
[2014-11-22 21:13:35] CPU: 1 PID: 469 Comm: kworker/u8:0 Tainted: G W 3.13.0-39-generic #66-Ubuntu
[2014-11-22 21:13:35] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./FM2A88X-ITX+, BIOS P2.10 01/17/2014
[2014-11-22 21:13:35] Workqueue: netns cleanup_net
[2014-11-22 21:13:35] 0000000000000009 ffff88033286dc80 ffffffff8171ece7 ffff88033286dcc8
[2014-11-22 21:13:35] ffff88033286dcb8 ffffffff8106773d 0000000000000000 0000000000000005
[2014-11-22 21:13:35] ffffffffa05b08a8 ffff88041f018ab0 0000000000000100 ffff88033286dd18
[2014-11-22 21:13:35] Call Trace:
[2014-11-22 21:13:35] [<ffffffff8171ece7>] dump_stack+0x45/0x56
[2014-11-22 21:13:35] [<ffffffff8106773d>] warn_slowpath_common+0x7d/0xa0
[2014-11-22 21:13:35] [<ffffffff810677ac>] warn_slowpath_fmt+0x4c/0x50
[2014-11-22 21:13:35] [<ffffffff81229889>] remove_proc_entry+0x139/0x1b0
[2014-11-22 21:13:35] [<ffffffffa05904e2>] nfs_fs_proc_net_exit+0x62/0x70 [nfs]
[2014-11-22 21:13:35] [<ffffffffa05965b2>] nfs_net_exit+0x12/0x20 [nfs]
[2014-11-22 21:13:35] [<ffffffff8161b3a9>] ops_exit_list.isra.1+0x39/0x60
[2014-11-22 21:13:35] [<ffffffff8161bc30>] cleanup_net+0x110/0x250
[2014-11-22 21:13:35] [<ffffffff810839c2>] process_one_work+0x182/0x450
[2014-11-22 21:13:35] [<ffffffff810847b1>] worker_thread+0x121/0x410
[2014-11-22 21:13:35] [<ffffffff81084690>] ? rescuer_thread+0x430/0x430
[2014-11-22 21:13:35] [<ffffffff8108b492>] kthread+0xd2/0xf0
[2014-11-22 21:13:35] [<ffffffff8108b3c0>] ? kthread_create_on_node+0x1c0/0x1c0
[2014-11-22 21:13:35] [<ffffffff8172f73c>] ret_from_fork+0x7c/0xb0
[2014-11-22 21:13:35] [<ffffffff8108b3c0>] ? kthread_create_on_node+0x1c0/0x1c0
[2014-11-22 21:13:35] ---[ end trace 2a658da59ed75c25 ]---

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1395371

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Mausy5043 (74938bcb)]

Tried to run `apport-collect #####`. The script doesn't work properly. The machine is a headless server, so I need to `ssh` into it. Couldn't persuade the server to run the command properly. Sorry.

BTW: `apport-cli` returns this:
No pending crash reports. Try --help for more information.

Hope this helps.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.18 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18-rc6-vivid/

[Mausy5043 (74938bcb)]

@jsalisbury : We're talking here about a production fileserver. So, I'd like to know a little bit more about the impact.

I'm not familiar with the status and stability of the mainline kernel.
Can I just download this kernel to /boot then add it to GRUB and run it from there without risking my data?
TIA!

[Mausy5043 (74938bcb)]

I *am* preparing an upgrade to 14.10. Would the 3.16 kernel do too?

[Mausy5043 (74938bcb)]

Bug seems to have disappeared with update to 3.13.0-40-generic