[GIT] CIFS Fixes

[Steve French]

SMB3 "validate negotiate" is needed to prevent certain types of
downgrade attacks.
Also changes SMB2/SMB3 copy offload from using the BTRFS copy ioctl
(BTRFS_IOC_CLONE) to a cifs specific ioctl (CIFS_IOC_COPYCHUNK_FILE)
to address Christoph's comment that there are semantic differences between
requesting copy offload in which copy-on-write is mandatory (as in the
BTRFS ioctl) and optional in the SMB2/SMB3 case. Also fixes SMB2/SMB3
copychunk for large files.

The following changes since commit 2d3c627502f2a9b0a7de06a5a2df2365542a72c9:

Revert "init/Kconfig: add option to disable kernel compression"
(2013-11-17 11:17:36 -0800)

are available in the git repository at:

git://git.samba.org/sfrench/cifs-2.6.git for-next

for you to fetch changes up to f19e84df37bda502a2248d507a9cf2b9e693279e:

[CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload
(2013-11-25 09:50:31 -0600)

----------------------------------------------------------------
Steve French (4):
CIFS: Fix SMB2/SMB3 Copy offload support (refcopy) for large files
Removed duplicated (and unneeded) goto
Check SMB3 dialects against downgrade attacks
[CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload

fs/cifs/cifsglob.h | 1 +
fs/cifs/ioctl.c | 6 ++--
fs/cifs/smb2ops.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++-------
fs/cifs/smb2pdu.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++---
fs/cifs/smb2pdu.h | 12 +++++--
fs/cifs/smb2proto.h | 1 +
fs/cifs/smbfsctl.h | 2 +-
7 files changed, 189 insertions(+), 24 deletions(-)