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David Disseldorp c4fd960166 vfs: add VFS_COPY_CHUNK_FL_IGNORE_LOCKS for dup extents
As confirmed by the Microsoft Protocol Open Specifications Team: Windows
Server 2016 (ReFS) ignores locks for FSCTL_DUPLICATE_EXTENTS_TO_FILE...

From: Jeff McCashland
To: David Disseldorp
CC: "cifs-protocol@lists.samba.org" <cifs-protocol@lists.samba.org>
Subject: RE: [116100414754619] FSCTL_DUPLICATE_EXTENTS_TO_FILE appears
	 to completely bypass file locks
Date: Mon, 12 Dec 2016 20:44:08 +0000

Hi David,

We have made the following spec changes for the next doc release:

In section 2.1.5.9.4 FSCTL_DUPLICATE_EXTENTS_TO_FILE behavior notes have
been added to the following paragraphs.

Before:
§ The object store MUST check for byte range lock conflicts on
Open.Stream using the algorithm described in section 2.1.4.10 with
ByteOffset set to InputBuffer.TargetFileOffset, Length set to
InputBuffer.ByteCount, IsExclusive set to TRUE, LockIntent set to FALSE,
and Open set to Open. If a conflict is detected, the operation MUST be
failed with STATUS_FILE_LOCK_CONFLICT.

§ The object store MUST check for byte range lock conflicts on Source
using the algorithm described in section 2.1.4.10 with ByteOffset set to
InputBuffer.SourceFileOffset, Length set to InputBuffer.ByteCount,
IsExclusive set to FALSE, LockIntent set to FALSE, and Open set to
InputBuffer.FileHandle. If a conflict is detected, the operation MUST be
failed with STATUS_FILE_LOCK_CONFLICT.

After:
§ The object store SHOULD<WBN1> check for byte range lock conflicts on
Open.Stream using the algorithm described in section 2.1.4.10 with
ByteOffset set to InputBuffer.TargetFileOffset, Length set to
InputBuffer.ByteCount, IsExclusive set to TRUE, LockIntent set to FALSE,
and Open set to Open. If a conflict is detected, the operation MUST be
failed with STATUS_FILE_LOCK_CONFLICT.

§ The object store SHOULD<WBN2> check for byte range lock conflicts on
Source using the algorithm described in section 2.1.4.10 with ByteOffset
set to InputBuffer.SourceFileOffset, Length set to
InputBuffer.ByteCount, IsExclusive set to FALSE, LockIntent set to
FALSE, and Open set to InputBuffer.FileHandle. If a conflict is
detected, the operation MUST be failed with STATUS_FILE_LOCK_CONFLICT.

WBN1: The ReFS file system in Windows Server 2016 does not check for
byte range lock conflicts on Open.Stream.
WBN2: The ReFS file system in Windows Server 2016 does not check for
byte range lock conflicts on Source.

Signed-off-by: David Disseldorp <ddiss@samba.org>
Reviewed-by: Ralph Böhme <slow@samba.org>
2017-05-10 08:22:19 +02:00
..
2016-09-27 04:03:02 +02:00

Configuring NFS4 ACLs in Samba3
===============================
Created: Peter Somogyi, 2006-JUN-06
Last modified: Alexander Werth, 2013-MAY-02
Revision no.: 4 
-------------------------------


Parameters in smb.conf:
=======================

Each parameter must have a prefix "nfs4:".
Each one affects the behaviour only when _setting_ an acl on a file/dir:

mode = [simple|special]
- simple: Use OWNER@ and GROUP@ special IDs for non inheriting ACEs only.
  This mode is the default.
- special: use OWNER@ and GROUP@ special IDs in ACEs instead of simple
  user&group ids. This mode is deprecated.

Note1: EVERYONE@ is always processed (if found such an ACE).
Note2: There is a side effect when _only_ chown is performed.
       Later this may be worked out.
Note3: Mode special inherits incorrect ACL entries when the user creating
       a file is different from the owner of the caurrent folder.
Note4: Mode simple uses inheriting OWNER@ and GROUP@ special IDs to
       support Creator Owner and Creator Group.

It's strongly advised to set "store dos attributes = yes" in smb.conf.

chown = [true|false]
- true => enable changing owner and group - default.
- false => disable support for changing owner or group

acedup = [dontcare|reject|ignore|merge]
- dontcare: copy ACEs as they come, don't care with "duplicate" records. Default.
- reject: stop operation, exit acl setter operation with an error
- ignore: don't include the second matching ACE
- merge: OR 2 ace.flag fields and 2 ace.mask fields of the 2 duplicate ACEs into 1 ACE

Two ACEs are considered here "duplicate" when their type and id fields are matching.

Example:

[smbtest]
path = /tests/psomogyi/smbtest
writable = yes
vfs objects = aixacl2
nfs4: mode = special
nfs4: chown = yes
nfs4: acedup = merge

Configuring AIX ACL support
==============================

Binaries: (default install path is [samba]/lib/vfs/)
- aixacl.so: provides AIXC ACL support only, can be compiled and works on all AIX platforms
- aixacl2.so: provides AIXC and JFS2-NFS4 ACL support, can be compiled and works only under AIX 5.3 and newer.
NFS4 acl currently has support only under JFS2 (ext. attr. format must be set to v2).
aixacl2.so always detects support for NFS4 acls and redirects to POSIX ACL handling automatically when NFS4 is not supported for a path.

Adding "vfs objects = aixacl2" to a share should be done only in case when NFS4 is really supported by the filesystem.
(Otherwise you may get performance loss.)

For configuration see also the example above.

General notes
=============

NFS4 handling logic is separated from AIX/jfs2 ACL parsing.

Samba and its VFS modules dosn't reorder ACEs. Windows clients do that (and the smbcacl tool). MSDN also says deny ACEs must come first.
NFS4 ACL's validity is checked by the system API, not by Samba.
NFS4 ACL rights are enforced by the OS or filesystem, not by Samba.

The flag INHERITED_ACE is never set (not required, as doesn't do WinNT/98/me, only since Win2k).
Win2k GUI behaves strangely when detecting inheritance (sometimes it doesn't detect, 
but after adding an ace it shows that - it's some GUI error).

Unknown (unmappable) SIDs are not accepted.

TODOs
=====
- Creator Owner & Group SID handling (same way as posix)
- the 4 generic rights bits support (GENERIC_RIGHT_READ_ACCESS, WRITE, EXEC, ALL)
- chown & no ACL, but we have ONWER@ and GROUP@
- DIALUP, ANONYMOUS, ... builtin SIDs
- audit & alarm support - in theory it's forwarded so it should work, but currently there's no platform which supports them to test
- support for a real NFS4 client (we don't have an accepted API yet)