Samba mount is empty when mounted with nounix

Question

For years this has worked and today it stopped.

I have a Debian 8 server running Samba 4.2.10 to provide some shares to Windows 10 and Ubuntu 16.04 machines on a LAN.

This morning the ubuntu machines have apparently mounted shares but they're empty.

Server smb.conf:

[global]
  workgroup = PAP
  server string = Hello there.
  obey pam restrictions = Yes
  pam password change = Yes
  unix password sync = Yes
  syslog = 0
  log file = /var/log/samba/log
  log level = 3
  socket options = TCP_NODELAY SO_SNDBUF=16384
  dns proxy = No
  wins support = Yes
  valid users = pap,rich
  hosts allow = 10.0., 127.
  # shares default to rw, pap.pap, open perms
  read only = No
  force user = pap
  force group = pap
  create mask = 0666
  force create mode = 0666
  directory mask = 0777
  force directory mode = 02777

[org]
  comment = Main Files Space
  path = /home/org

And on the Ubuntu client (cifs-utils v6.4), I've been connecting with

mount -t cifs -o rw,nobrl,gid=pap,username=pap,password=****,file_mode=0666,dir_mode=0666,nounix \
   //server/org /mnt/org

If I mount without the nounix option then I can see the files. The nounix option is important because symlinks are otherwise treated differently between Windows and Ubuntu machines. No errors are generated AFAICS.

Edit: what do the logs say?

Server

The (Debian 8) server does not append anything to the logs (at /var/log/samba/*) when the share is mounted with or without nounix. Neither does anything show up monitoring journalctl -u smbd

I did ramp up Samba's logging on the server but it's kinda all or nothing and I did not see anything pertaining to the mount that was of help.

Client

The client (Ubuntu 16.04) does not appear to log anything in /var/log/syslog.

Following instructions on what looks like an old but remarkably similar bug report which are:

echo 1 | sudo tee /proc/fs/cifs/cifsFYI
sudo dmesg -c >/dev/null
sudo mount ...
sudo ls /mount-point/
sudo dmesg -c

outputs nothing.

I also ran these commands after doing echo 1 | sudo tee /proc/fs/cifs/traceSMB. This did generate output (lots of hexdumped binary). I can post these hexdumps with and without the nounix if they're of interest...

Have you tried to mount with `nounix,noserverino` options? One thing that happens when you specify `nounix` is that inode numbers you get from the server are typically larger than 32-bit integers.. — Peter Zhabin, Feb 22 '17 at 20:18
Yes, Thanks, I've tried that option, same behaviour as I experienced without it. I think everything is running 64 bit. — artfulrobot, Feb 22 '17 at 20:24
Change at the client end more likely. Server only gets security updates and I would have noticed if that broke it. Nothing deliberately changed by me so hard to tell. — artfulrobot, Mar 01 '17 at 08:02
Two clients, same kernel, same OS, same samba version, same cifs-utils version, same perms on mount point, same share on server: one works with `nounix`, one gives the empty dir. I'm well and truly stumped. — artfulrobot, Mar 02 '17 at 17:20

Samba mount is empty when mounted with nounix

Edit: what do the logs say?

Server

Client

0 Answers0