Are VFS modules stackable?

[Jeremy Allison]

On Mon, Apr 07, 2014 at 07:39:12PM +0200, Jiri Sasek wrote:
> Hi all,
> 
> SAM-QFS 5.3 has NFSv4 ACL (based on Solaris acl(2) interface
> ...similar to ZFS) so I was testing the following (share)
> configuration:
> 
> [samfs]
>    path = /samfs1/.....
>    comment = SAM-QFS share
>    browseable = yes
>    readonly = no
>    inherit permissions = yes
>    inherit acls = yes
>    acl map full control = no
>    dos filemode = yes
> ; To store the DOS attributes in extended attributes.
> ; https://bugzilla.samba.org/show_bug.cgi?id=5135#c5
> ...
> 
> ; set the VFS module
>    vfs objects = zfsacl
> ...
> 
> ;  store the alternate data stream in ext-attributes
>    vfs objects = streams_xattr
> 
> ;  AIO
>    aio read  size = 1
>    aio write size = 1
>    vfs objects = aio_pthread
> 
> ; Off-line files support
>    vfs objects = samfs
> 
> ...and it looks only *one* module (first used  ...Solaris uses
> lazy-load by default) was available / share.
> 
> Did I configured anything wrong or only one/share VFS module is
> available in Samba?
> 
> Please correct me if I am wrong but I remember something like a
> opaque/transparent calls in VFS modules  ...so I was convinced about
> stack-ability of VFS modules.

You're doing it wrong :-).

Each new 'vfs objects = ' will override
the previous one.

To stack you need to have :

vfs objects = zfsacl, samfs, aio_pthread

(put the aio_pthread last as that's not
a stackable module).

on *one* line.

Jeremy