NAME¶
vfs_gpfs - gpfs specific samba extensions like acls
SYNOPSIS¶
vfs objects = gpfs
DESCRIPTION¶
This VFS module is part of the samba(7) suite.
The gpfs VFS module is the home for all gpfs extensions that Samba
requires for proper integration with GPFS. It uses the GPL library
interfaces provided by GPFS.
Currently the gpfs vfs module provides extensions in following
areas :
•NFSv4 ACL Interfaces with configurable options
for GPFS
•Kernel oplock support on GPFS
•Lease support on GPFS
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. 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 NFS4 ACLs. 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:
•simple(default) - use OWNER@ and GROUP@ special
IDs for non inheriting ACEs only.
•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 NFS4 ACLs. They allow creating duplicate ACEs with
different bits for same ID, which may confuse the Windows clients.
Following is the behaviour of Samba for different values :
•dontcare - copy the ACEs as they come
•reject (deprecated) - stop operation and exit
with error on ACL set op
•ignore (deprecated) - don't include the second
matching ACE
•merge (default) - 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 :
•yes - Enable chown if as supported by the under
filesystem
•no (default) - Disable chown
gpfs:sharemodes = [ yes | no ]
Enable/Disable cross node sharemode handling for GPFS.
•yes(default) - propagate sharemodes across all
GPFS nodes.
•no - do not propagate sharemodes across all GPFS
nodes. This should only be used if the GPFS file system is exclusively
exported by Samba. Access by local unix application or NFS exports could lead
to corrupted files.
gpfs:leases = [ yes | no ]
Enable/Disable cross node leases (oplocks) for GPFS. You
should also set the oplocks and kernel oplocks options to the same value.
•yes(default) - propagate leases across all GPFS
nodes.
•no - do not propagate leases across all GPFS
nodes. This should only be used if the GPFS file system is exclusively
exported by Samba. Access by local unix application or NFS exports could lead
to corrupted files.
gpfs:hsm = [ yes | no ]
Enable/Disable announcing if this FS has HSM enabled.
•no(default) - Do not announce HSM.
•yes - Announce HSM.
gpfs:recalls = [ yes | no ]
When this option is set to no, an attempt to open an
offline file will be rejected with access denied. This helps preventing recall
storms triggered by careless applications like Finder and Explorer.
•yes(default) - Open files that are offline. This
will recall the files from HSM.
•no - Reject access to offline files with access
denied. This will prevent recalls of files from HSM. Using this setting also
requires gpfs:hsm to be set to yes.
gpfs:getrealfilename = [ yes | no ]
Enable/Disable usage of the gpfs_get_realfilename_path()
function. This improves the casesensitive wildcard file name access.
•yes(default) - use
gpfs_get_realfilename_path().
•no - do not use gpfs_get_realfilename_path(). It
seems that gpfs_get_realfilename_path() doesn't work on AIX.
gpfs:winattr = [ yes | no ]
Enable/Disable usage of the windows attributes in GPFS.
GPFS is able to store windows file attributes e.g. HIDDEN, READONLY, SYSTEM
and others natively. That means Samba doesn't need to map them to permission
bits or extended attributes.
•no(default) - do not use GPFS windows
attributes.
•yes - use GPFS windows attributes.
gpfs:acl = [ yes | no ]
This option lets Samba use or ignore GPFS ACLs.
•yes(default) - use GPFS ACLs.
•no - do not use GPFS ACLs and pass everything to
the next SMB_VFS module.
gpfs:check_fstype = [ yes | no ]
Check for a mounted GPFS file system on access to a SMB
share.
•yes(default) - Check that the SMB share path is
on a GPFS file system. Share access will be denied when a different file
system is found.
•no - skip check for GPFS file system on SMB share
path.
gpfs:dfreequota = [ yes | no ]
Adjust reporting of the size and free space of a share
according to quotas. If this setting is "yes", a request for size
and free space will also evaluate the user quota of the user requesting the
data and the group quota of the primary group of the user. Fileset quotas are
not queried, since GPFS already provides the option --dfreequota to reflect
the fileset quota in the free space query. Please use that option to include
fileset quotas in the reported disk space.
If any of the soft or hard quota limits has been reached, the free
space will be reported as 0. If a quota is in place, but the limits have not
been reached, the free space will be reported according to the space left in
the quota. If more than one quota applies the free space will be reported as
the smallest space left in those quotas. The size of the share will be
reported according to the quota usage. If more than one quota applies, the
smallest size will be reported for the share size according to these
quotas.
•yes - include the quotas when reporting the share
size and free space
•no(default) - do not include quotas, simply
report the size and free space of the file system
gpfs:settimes = [ yes | no ]
Use the gpfs_set_times API when changing the timestamps
of a file or directory. If the GPFS API is not available the old method of
using utime and the GPFS winattr call will be used instead.
•yes(default) - Use gpfs_set_times. Fall back to
utime and winattr when it is not available.
•no - Do not use gpfs_set_times.
gpfs:syncio = [yes|no]
This parameter makes Samba open all files with O_SYNC.
This triggers optimizations in GPFS for workloads that heavily share files.
Following is the behaviour of Samba for different values:
•yes - Open files with O_SYNC
•no (default) - Open files as normal Samba would
do
EXAMPLES¶
A GPFS mount can be exported via Samba as follows :
[samba_gpfs_share]
vfs objects = gpfs
path = /test/gpfs_mount
nfs4: mode = special
nfs4: acedup = merge
CAVEATS¶
Depending on the version of gpfs, the libgpfs_gpl library or the
libgpfs library is needed at runtime by the gpfs VFS module: Starting with
gpfs 3.2.1 PTF8, the complete libgpfs is available as open source and
libgpfs_gpl does no longer exist. With earlier versions of gpfs, only the
libgpfs_gpl library was open source and could be used at run time.
At build time, only the header file gpfs_gpl.h is required, which
is a symlink to gpfs.h in gpfs versions newer than 3.2.1 PTF8.
VERSION¶
This man page is part of version 4.19.4 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.
The GPFS VFS module was created with contributions from Volker
Lendecke and the developers at IBM.
This manpage was created by the IBM FSCC team