Samba changes file ownership! How do I get rid of that problem?

Question

I am running a Samba Server (Version 3.5.6). The file sharing is OK until I realize that Samba changes file ownership when another user (not the original owner) edit the file and saves it. This is particularly true, if I have set admin users parameter to administrate the share.

The strange thing is only the file ownership get changed but 'directory ownership' remain unchanged (which is desirable) :)

Options like force user and force group are not going to work here because, sharing directory have a different sub-directories that belong to many users.

Configuration for the share looks like this

[staff]

    comment = "Staff members only"
    path = /path/to/staff
    browseable = yes
    valid users = @staff, @managers, @moderators
    write list = @staff, @managers
    create mask = 0640
    directory mask = 0750
    admin users = @moderators`

As you can see, members in above-mentioned groups are allowed to read others data but only members of @moderators can do changes to file & directories.

Problem arises when a member of @moderators modifies a file (not a directory) that belong to another user (belong to @staff or @managers), the ownership of that edited file changes to root!!! which is totally undesirable.

I want to preserve the ownership of the file to its original creator even after a member of @moderators modifies it. How Do I Achieve This???

Thank you in advanced.

Answer 1

Do not use "admin users" for the file modifications, because members of this setting operate as root on the filesystem. Quoting from smb.conf man page:

admin users (S) This is a list of users who will be granted administrative privileges on the share. This means that they will do all file operations as the super-user (root). You should use this option very carefully, as any user in this list will be able to do anything they like on the share, irrespective of file permissions.