Mounting smb with CIFS ignores file_mode and dir_mode

Question

I'm having trouble with permissions involving an SMB share hosted on another machine on my local network. It appears that no matter what options I provide in the /etc/fstab or in a mount command, ls -l always yields:

drwxr-xr-x

Here's the current /etc/fstab entry:

//this-is-my-server.local/share-folder    /mnt/smb    cifs    credentials=<some-cred-file>,uid=0,gid=100,file_mode=0775,dir_mode=0775    0    4

Here's the aforementioned (and redacted) credentials file:

username=myusername
password=mypassword

Here's the smb.conf share configuration on the hosting server:

[share]
   path = /some/path
   browseable = yes
   writeable = yes
   create mask = 0775
   directory mask = 0775

To clarify, I can mount the share just fine, but I cannot write or create any files without sudo on the Pi. Note that a Windows machine which has the drive mapped can write and create files just fine.

Am I missing something in my setup here? Or, are the directory and file permissions being overridden elsewhere?

Edit: Running Raspbian 8 on a RasberryPi 3.

Answer 1

Try adding to the mount options also "forceuid, forcegid". You therefore should have something like:

//this-is-my-server.local/share-folder    /mnt/smb    cifs    credentials=<some-cred-file>,uid=0,gid=100,file_mode=0775,dir_mode=0775,forceuid,forcegid    0    4

BTW, if I'm not wrong you should also use the full names for UID and GUID (i.e. "root" instead of "0" etc), but I'm not sure it makes any difference.

Answer 2

uid=0,gid=100,file_mode=0775,dir_mode=0775

With uid=0, you are explicitly telling your machine that every file should be owned by root.

With file_mode=0775, you are telling your machine that "everyone" else should only have read access, not write access.

For a single-user machine, it probably makes more sense to set your uid= option to be your user's uid, not root's uid. Either that, or set your file/dir modes to 777, granting write access to "everyone".