vfs_zfsacl - ZFS ACL samba module
vfs objects = zfsacl
System Administration tools VFS_ZFSACL(8)
NAME
vfs_zfsacl - ZFS ACL samba module
SYNOPSIS
vfs objects = zfsacl
DESCRIPTION
This VFS module is part of the samba(7) suite.
The zfsacl VFS module is the home for all ACL extensions that Samba
requires for proper integration with ZFS.
Currently the zfsacl vfs module provides extensions in following areas
:
o NFSv4 ACL Interfaces with configurable options for ZFS
NOTE:This module follows the posix-acl behaviour and hence allows
permission stealing via chown. Samba might allow at a later point in
time, to restrict the chown via this module as such restrictions are
the responsibility of the underlying filesystem than of Samba.
This module makes use of the smb.conf parameter acl map full control =
acl map full control When set to yes (the default), this parameter will
add in the FILE_DELETE_CHILD bit on a returned ACE entry for a file
(not a directory) that already contains all file permissions except for
FILE_DELETE and FILE_DELETE_CHILD. This can prevent Windows
applications that request GENERIC_ALL access from getting ACCESS_DENIED
errors when running against a filesystem with NFSv4 compatible ACLs.
This module is stackable.
Since Samba 4.0 all options are per share options.
OPTIONS
nfs4:mode = [ simple | special ]
Controls substitution of special IDs (OWNER@ and GROUP@) on ZFS.
The use of mode simple is recommended. In this mode only non
inheriting ACL entries for the file owner and group are mapped to
special IDs.
The following MODEs are understood by the module:
o simple(default) - use OWNER@ and GROUP@ special IDs for
non inheriting ACEs only.
o special(deprecated) - use OWNER@ and GROUP@ special IDs
in ACEs for all file owner and group ACEs.
nfs4:acedup = [dontcare|reject|ignore|merge]
This parameter configures how Samba handles duplicate ACEs
encountered in ZFS ACLs. ZFS allows/creates duplicate ACE for
different bits for same ID.
Following is the behaviour of Samba for different values :
o dontcare (default) - copy the ACEs as they come
o reject (deprecated) - stop operation and exit with error
on ACL set op
o ignore (deprecated) - don't include the second matching
ACE
o merge - bitwise OR the 2 ace.flag fields and 2 ace.mask
fields of the 2 duplicate ACEs into 1 ACE
nfs4:chown = [yes|no]
This parameter allows enabling or disabling the chown supported by
the underlying filesystem. This parameter should be enabled with
care as it might leave your system insecure.
Some filesystems allow chown as a) giving b) stealing. It is the
latter that is considered a risk.
Following is the behaviour of Samba for different values :
o yes - Enable chown if as supported by the under
filesystem
o no (default) - Disable chown
zfsacl:denymissingspecial = [yes|no]
Prevent users from setting an ACL that lacks NFSv4 special entries
(owner@, group@, everyone@). ZFS will automatically generate these
these entries when calculating the inherited ACL of new files if
the ACL of the parent directory lacks an inheriting special entry.
This may result in user confusion and unexpected change in
permissions of files and directories as the inherited ACL is
generated.
o yes
o no (default)
zfsacl:block_special = [yes|no]
Prevent ZFS from automatically adding NFSv4 special entries
(owner@, group@, everyone@). ZFS will automatically generate these
these entries when calculating the inherited ACL of new files if
the ACL of the parent directory lacks an inheriting special entry.
This may result in user confusion and unexpected change in
permissions of files and directories as the inherited ACL is
generated. Blocking this behavior is achieved by setting an
inheriting everyone@ that grants no permissions and not adding the
entry to the file's Security Descriptor
o yes (default)
o no
zfsacl:map_dacl_protected = [yes|no]
If enabled and the ZFS ACL on the underlying filesystem does not
contain any inherited access control entires, then set the
SEC_DESC_DACL_PROTECTED flag on the Security Descriptor returned to
SMB clients. This ensures correct Windows client behavior when
disabling inheritance on directories.
Following is the behaviour of Samba for different values :
o yes - Enable mapping to SEC_DESC_DACL_PROTECTED
o no (default)
EXAMPLES
A ZFS mount can be exported via Samba as follows :
[samba_zfs_share]
vfs objects = zfsacl
path = /test/zfs_mount
nfs4: mode = simple
nfs4: acedup = merge
VERSION
This man page is part of version 4.13.17 of the Samba suite.
AUTHOR
The original Samba software and related utilities were created by
Andrew Tridgell. Samba is now developed by the Samba Team as an Open
Source project similar to the way the Linux kernel is developed.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+-----------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------------+
|Availability | service/network/samba |
+---------------+-----------------------+
|Stability | Volatile |
+---------------+-----------------------+
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://download.samba.org/pub/samba/stable/samba-4.13.17.tar.gz.
Further information about this software can be found on the open source
community website at http://www.samba.org/.
Samba 4.13.17 06/28/2022 VFS_ZFSACL(8)