mount.cifs stopped working after last kernel upgrade

Question

Yesterday (05/21) I upgraded my Ubuntu 12.04 kernel:

uname -a:

Linux vi 3.2.0-24-generic #37-Ubuntu SMP Wed Apr 25 08:43:22 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

After the reboot all my mounts of external Samba shares stopped working.

When I execute:

sudo mount -t cifs //192.168.101.168/video /mnt/video

The result is:

mount error: cifs filesystem not supported by the system
mount error(19): No such device
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

And dmesg shows:

[ 2785.792456] cifs: Unknown symbol locks_delete_block (err 0)

If I execute:

sudo modprobe cifs

The result is:

FATAL: Error inserting cifs (/lib/modules/3.2.0-24-generic/kernel/fs/cifs/cifs.ko): Unknown symbol in module, or unknown parameter (see dmesg)

And dmesg shows again:

[ 5811.742563] cifs: Unknown symbol locks_delete_block (err 0)

Is there any known workaround for this?

Solution 1

Reinstall cifs-utils and reboot. This works for me.

sudo apt-get --reinstall install cifs-utils && sudo reboot

Solution 2

Problem solved!

While trying to resolve this issue I broke my computer's GRUB. I could not find time to restore the system until an hour ago, so please, excuse me for the delay in my answer.

Thanks a lot, reverendj1 & Bruno!

reverendj1: The different kernel version was the correct clue, it produced the missing symbol in cifs.ko.

The problem, incredibly, was the consequence of an undetected USB disk: The one I use to boot Ubuntu up on a RAID.

As Ubuntu fails to mount the USB disk (that I have on fstab mounted to /boot), it creates a dummy /boot on the raid that of course does not exist during startup phase at BIOS, but it is the only one that exist during normal computer operation.

As I updated the kernel, the updated kernel (#38) was written to the dummy boot. The "real" (during startup) kernel (the older #37) remained in the external USB disk that is visible only during startup.

The only effect that I could perceive from this kernel mismatch was that the cifs driver could not load.

Solution 3

Have you tried to reboot? I really, really hate asking that about Linux, but it fixed it for me.

Solution 4

I would try to reinstall smbfs:

sudo apt-get --reinstall install cifs-utils

View more solutions

Comments

[Gustavo V.]

Thanks for the suggestion. but it did not work.

[reverendj1]

Have you tried a full update?, as in sudo apt-get update && sudo apt-get dist-upgrade

[Bruno Pereira]

@GustavoV. The package should be called cifs-utils not smbfs, try re installing cifs-utils as sugested here and shoot any errors in to your question if you see them

[reverendj1]

I updated the answer with the correct package. I always get confused between those.

[Gustavo V.]

I am still checking the full update... one minute please.

[Gustavo V.]

I tried both: no changes (same errors)

[Gustavo V.]

... neither reinstall nor full update produced any errors or warning.

[reverendj1]

Does this file exist, /lib/modules/3.2.0-24-generic/kernel/fs/cifs/cifs.ko?

[Gustavo V.]

Yes: -rw-r--r-- 1 root root 503816 may 1 18:59 /lib/modules/3.2.0-24-generic/kernel/fs/cifs/cifs.ko

[reverendj1]

Well, Im at a loss, that's what mine is too -rw-r--r-- 1 root root 503816 May 1 12:59 /lib/modules/3.2.0-24-generic/kernel/fs/cifs/cifs.ko

[Gustavo V.]

Thanks reverendj1, I assume your kernel is the same as mine too.

[reverendj1]

It is, but mine says #38, and I'm not exactly sure what that number is referring to: Linux hol-w-johnw1 3.2.0-24-generic #38-Ubuntu SMP Tue May 1 16:18:50 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux. Also, I regularly use Samba shares too and they seem to be working fine.

[Gustavo V.]

That is a clue. My kernel looks a bit older.

[Gustavo V.]

... please give me some time to look for your kernel on another Ubuntu repository.

[php-ajax]

The reinstall is immaterial. It's the reboot that's important.

[Gustavo V.]

Thanks, you can see above that the problem was a bit harder to resolve.

[Gustavo V.]

You can see bellow that reverendj1 made the same suggestion yesterday. Thanks anyway.

[Robbie]

Every time I upgrade my kernel, I have to reboot before my CIFS mounts will work. Do you happen to know why a reboot fixes this? [Also, reloading the module in question seems to fail silently.] It'd be great if I could work around this without a reboot.