CIFS may be old, slow and insecure. But as the only SMB version that supports the "Unix Extensions" in practice, it is the only version I found which actually

CIFS may be old, slow and insecure. But as the only SMB version that supports the "Unix Extensions" in practice, it is the only version I found which actually works between a Linux client and Samba serving a unix filesystem that is shared with other things, keeping the basic unix file attributes (symlinks, rwx permissions, etc) intact. I tried SMB 2 and SMB 3, and many combinations of options on the client side and in Samba. Surely something would yield adequate if not perfect unix file attributes. But no combination worked adequately. Only CIFS. In theory, SMB 3.1.1 has unix extensions that are supported by the Linux client module. In practice, I found this didn't work. Perhaps it will work one day. Which is why I have a CIFS mount on my laptop at the moment. It's used every day for work, and I don't know what else I could use to get the same functionality. You may be thinking, "this is what NFS is for". Alas it's not flexible enough. Samba is being used for its id remapping capabilities (and to a lesser extent to constrain permissions), which are sorely lacking in NFS if you don't have NFSv4, which the file server does not support. (Even if it did it would be difficult to set up adequately.) Ironically, Samba is re-exporting an NFS mount in this case, with Samba configured to provide the id-mapping and permissions-constraining that NFS won't do, and CIFS has to be used to maintain the unix file attributes.