Re: ftruncate returning EPERM on vfat filesystem

[Alan Cox]

> +
> +       /* FAT cannot truncate to a longer file */
> +       if (attr->ia_valid & ATTR_SIZE) {
> +               if (attr->ia_size > inode->i_size)
> +                       return -EPERM;
> +       }
> 
>         error = inode_change_ok(inode, attr);
>         if (error)
> 
> Can someone tell me if this is the cause of my samba problems, and if
> so, why this was added and if this is safe to revert?

To stop a case where the fs gets corrupted otherwise. You can change that to
return 0 which is more correct but most not remove it.

(ftruncate is specified to make the file at most length bytes long, extending
the file is not a guaranteed side effect according to the docs I have)