For loosely coupled pNFS/flexfiles systems, there is often no advantage
at all in going through the MDS for I/O, since the MDS is subject to
the same limitations as all other clients when talking to DSes. If a
DS is unresponsive, I/O through the MDS will fail.

For such systems, the only scalable solution is to have the pNFS clients
retry doing pNFS, and so the protocol now provides a flag that allows
the pNFS server to signal this.

If LAYOUTGET returns FF_FLAGS_NO_IO_THRU_MDS, then we should assume that
the MDS wants the client to retry using these devices, even if they were
previously marked as being unavailable. To do so, we add a helper,
ff_layout_mark_devices_valid() that will be called from layoutget.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the pNFS/flexfiles file is mirrored, and a read to one mirror fails,
then we should bump the mirror index, so that we retry to a different
mirror. Once we've iterated through all mirrors and all failed, we can
return the layout and issue a new LAYOUTGET.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If non rpc-based layout driver return bad length of data, nfs retries
by calling rpc_restart_call_prepare() that cause an NULL reference panic.

This patch lets nfs retry through MDS for non rpc-based layout driver
return bad length of data.

[13034.883329] BUG: unable to handle kernel NULL pointer dereference at           (null)
[13034.884902] IP: [<ffffffffa00db372>] rpc_restart_call_prepare+0x62/0x90 [sunrpc]
[13034.886558] PGD 0
[13034.888126] Oops: 0000 [#1] KASAN
[13034.889710] Modules linked in: blocklayoutdriver(OE) nfsv4(OE) nfs(OE) fscache(E) nfsd(OE) xfs libcrc32c coretemp btrfs crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel ppdev vmw_balloon auth_rpcgss shpchp nfs_acl lockd vmw_vmci parport_pc xor raid6_pq grace parport sunrpc i2c_piix4 vmwgfx drm_kms_helper ttm drm mptspi e1000 serio_raw scsi_transport_spi mptscsih mptbase ata_generic pata_acpi [last unloaded: fscache]
[13034.898260] CPU: 0 PID: 10112 Comm: kworker/0:1 Tainted: G           OE   4.3.0-rc5+ #279
[13034.899932] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
[13034.903342] Workqueue: events bl_read_cleanup [blocklayoutdriver]
[13034.905059] task: ffff88006a9148c0 ti: ffff880035e90000 task.ti: ffff880035e90000
[13034.906827] RIP: 0010:[<ffffffffa00db372>]  [<ffffffffa00db372>] rpc_restart_call_prepare+0x62/0x90 [sunrpc]
[13034.910522] RSP: 0018:ffff880035e97b58  EFLAGS: 00010282
[13034.912378] RAX: fffffbfff04a5a94 RBX: ffff880068fe4858 RCX: 0000000000000003
[13034.914339] RDX: dffffc0000000000 RSI: 0000000000000003 RDI: 0000000000000282
[13034.916236] RBP: ffff880035e97b68 R08: 0000000000000001 R09: 0000000000000001
[13034.918229] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
[13034.920007] R13: ffff880068fe4858 R14: ffff880068fe4a60 R15: 0000000000001000
[13034.921845] FS:  0000000000000000(0000) GS:ffffffff82247000(0000) knlGS:0000000000000000
[13034.923645] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[13034.925525] CR2: 0000000000000000 CR3: 00000000063dd000 CR4: 00000000001406f0
[13034.932808] Stack:
[13034.934813]  ffff880068fe4780 0000000000001000 ffff880035e97ba8 ffffffffa08800d2
[13034.936675]  ffffffffa088029d ffff880068fe4780 ffff880068fe4858 ffffffffa089c0a0
[13034.938593]  ffff880068fe47e0 ffff88005d59faf0 ffff880035e97be0 ffffffffa087e08f
[13034.940454] Call Trace:
[13034.942388]  [<ffffffffa08800d2>] nfs_readpage_result+0x112/0x200 [nfs]
[13034.944317]  [<ffffffffa088029d>] ? nfs_readpage_done+0xdd/0x160 [nfs]
[13034.946267]  [<ffffffffa087e08f>] nfs_pgio_result+0x9f/0x120 [nfs]
[13034.948166]  [<ffffffffa09266cc>] pnfs_ld_read_done+0x7c/0x1e0 [nfsv4]
[13034.950247]  [<ffffffffa03b07ee>] bl_read_cleanup+0x2e/0x60 [blocklayoutdriver]
[13034.952156]  [<ffffffff810ebf62>] process_one_work+0x412/0x870
[13034.954102]  [<ffffffff810ebe84>] ? process_one_work+0x334/0x870
[13034.955949]  [<ffffffff810ebb50>] ? queue_delayed_work_on+0x40/0x40
[13034.957985]  [<ffffffff810ec441>] worker_thread+0x81/0x6a0
[13034.959817]  [<ffffffff810ec3c0>] ? process_one_work+0x870/0x870
[13034.961785]  [<ffffffff810f43bd>] kthread+0x17d/0x1a0
[13034.963544]  [<ffffffff810f4240>] ? kthread_create_on_node+0x330/0x330
[13034.965479]  [<ffffffff81100428>] ? finish_task_switch+0x88/0x220
[13034.967223]  [<ffffffff810f4240>] ? kthread_create_on_node+0x330/0x330
[13034.968929]  [<ffffffff81b6ae5f>] ret_from_fork+0x3f/0x70
[13034.970534]  [<ffffffff810f4240>] ? kthread_create_on_node+0x330/0x330
[13034.972176] Code: c7 43 50 40 84 0d a0 e8 3d fe 1c e1 48 8d 7b 58 c7 83 e4 00 00 00 00 00 00 00 e8 ca fe 1c e1 4c 8b 63 58 4c 89 e7 e8 be fe 1c e1 <49> 83 3c 24 00 74 12 48 c7 43 50 f0 a2 0e a0 b8 01 00 00 00 5b
[13034.977148] RIP  [<ffffffffa00db372>] rpc_restart_call_prepare+0x62/0x90 [sunrpc]
[13034.978780]  RSP <ffff880035e97b58>
[13034.980399] CR2: 0000000000000000
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Blocklayout uses file offset for the read-back page's offset of first writing,
it's definitely wrong, it writes data to bad address of page that cause userspace
application segment fault. It must be the page base stored in header->args.pgbase.

Also, the pg_offset has no influence with isect and extent length.

Note: The offset of the non-first page is always zero.

Ps: A test program will segment fault at read() as,
#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

int main(int argc, char **argv)
{
        char buf[2049];
        char *filename = NULL;
        int fd = -1;

        if (argc < 2) {
                printf("Usage: %s filename\n", argv[0]);
                return 0;
        }

        filename = argv[1];
        fd = open(filename, O_RDONLY | O_DIRECT);
        if (fd < 0) {
                printf("Open %s fail: %m\n", filename);
                return 1;
        }

        lseek(fd, 2048, SEEK_SET);
        if (read(fd, buf, sizeof(buf) - 1) != (sizeof(buf) - 1))
                printf("Read 4096 bityes data from %s fail: %m\n", filename);
out:
        close(fd);
        return 0;
}
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

encode_sessionid() may return error, nfs needs process the return value.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The taglen should be checked with CB_OP_TAGLEN_MAXSZ directly.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

As CB_OP_TAGLEN_MAXSZ, all XXX_MAXSZ should be defined as bit.
Each operation should not cantains CB_OP_TAGLEN_MAXSZ.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It's no need to define a temporary variables for NFS4_MAX_SESSIONID_LEN.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It's not needed to checking NFS_DEBUG before define NFSDBG_FACILITY, remove it.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Commit 778be232 "NFS do not find client in NFSv4 pg_authenticate" has remove
the define and using of nfs4_set_callback_sessionid(), and
commit 36281caa "NFSv4: Further clean-ups of delegation stateid validation"
has update the checking of stateid, and move the code to nfs4proc.c.

This patch remove those function defines left in callback.h
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Commit bbe0a3aa "NFS: make nfs_callback_tcpport per network context" has
make nfs_callback_tcpport per network, but left the global nfs_callback_tcpport,
remove it.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Commit c36fca52 "NFS refactor nfs_find_client and reference client
across callback processing" has store clp in cb_process_state
which is set in cb_sequence.

So that, it's unneeded to store address pointer in any callback arguments.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

although NFS_MAXPATHLEN is defined to 1024, nfs client hopes to accept
a 1024 byte path, but nfs_root_parms is limited to 256, and the nfs path
will truncated when a user inputs nfs path from kernel cmdline

enlarge nfs_root_parms to 1024, to make it accept the 1024 bytes long
directory name, since nfs_root_parms is defined as _initdata, it will
be released after system bootup
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It follows btrfs BTRFS_IOC_CLONE_RANGE lead on ioctl number and
arguments.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

draft-ietf-nfsv4-minorversion2-38.txt says:
   Both cl_src_offset and
   cl_dst_offset must be aligned to the clone block size Section 12.2.1.
   The number of bytes to be cloned must be a multiple of the clone
   block size, except in the case in which cl_src_offset plus the number
   of bytes to be cloned is equal to the source file size.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

NFSv42 CLONE operation is supposed to respect it.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It can be called by user space to CLONE two files.
Follow btrfs lead and define NFS_IOC_CLONE same as BTRFS_IOC_CLONE.
Thus we don't mess up userspace with too many ioctls.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

xdr definitions per draft-ietf-nfsv4-minorversion2-38.txt
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

They now only differ in the way we handle waiting, so let's unify.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The code needs to be able to work from inside an asynchronous context.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

For symmetry with the synchronous handler, and so that we can potentially
handle errors such as NFS4ERR_BADNAME.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Currently, we only do so for asynchronous delays.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Prepare for unification of the synchronous and asynchronous error
handling.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Running xfstest generic/013 with the tracepoint nfs:nfs4_open_file
enabled produces a NULL-pointer dereference when calculating fileid and
filehandle of the opened file.  Fix this by checking if state is NULL
before trying to use the inode pointer.
Reported-by: NOlga Kornievskaia <aglo@umich.edu>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Update modinfo cifs.ko version number to 2.08
Signed-off-by: NSteve French <steve.french@primarydata.com>

When the client goes to return a delegation, it should always update any
nfs4_state currently set up to use that delegation stateid to instead
use the open stateid. It already does do this in some cases,
particularly in the state recovery code, but not currently when the
delegation is voluntarily returned (e.g. in advance of a RENAME).  This
causes the client to try to continue using the delegation stateid after
the DELEGRETURN, e.g. in LAYOUTGET.

Set the nfs4_state back to using the open stateid in
nfs4_open_delegation_recall, just before clearing the
NFS_DELEGATED_STATE bit.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Since commit 5cae02f4 an OPEN_CONFIRM should
have a privileged sequence in the recovery case to allow nograce recovery to
proceed for NFSv4.0.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We need to warn against broken NFSv4.1 servers that try to hand out
delegations in response to NFS4_OPEN_CLAIM_DELEG_CUR_FH.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Currently, we don't test if the state owner is in use before we try to
recover it. The problem is that if the refcount is zero, then the
state owner will be waiting on the lru list for garbage collection.
The expectation in that case is that if you bump the refcount, then
you must also remove the state owner from the lru list. Otherwise
the call to nfs4_put_state_owner will corrupt that list by trying
to add our state owner a second time.

Avoid the whole problem by just skipping state owners that hold no
state.
Reported-by: NAndrew W Elble <aweits@rit.edu>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If all other conditions in nfs_can_extend_write() are met, and there
are no locks, then we should be able to assume close-to-open semantics
and the ability to extend our write to cover the whole page.

With this patch, the xfstests generic/074 test completes in 242s instead
of >1400s on my test rig.

Fixes: bd61e0a9 ("locks: convert posix locks to file_lock_context")
Cc: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Currently, we are crediting all the calls to nfs_writepages_callback()
(i.e. the nfs_writepages() callback) to nfs_writepage(). Aside from
being inconsistent with the behaviour of the equivalent readpage/readpages
accounting, this also means that we cannot distinguish between bulk writes
and single page writebacks (which confuses the 'nfsiostat -p' tool).
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The error paths in set_file_size for cifs and smb3 are incorrect.

In the unlikely event that a server did not support set file info
of the file size, the code incorrectly falls back to trying SMBWriteX
(note that only the original core SMB Write, used for example by DOS,
can set the file size this way - this actually  does not work for the more
recent SMBWriteX).  The idea was since the old DOS SMB Write could set
the file size if you write zero bytes at that offset then use that if
server rejects the normal set file info call.

Fortunately the SMBWriteX will never be sent on the wire (except when
file size is zero) since the length and offset fields were reversed
in the two places in this function that call SMBWriteX causing
the fall back path to return an error. It is also important to never call
an SMB request from an SMB2/sMB3 session (which theoretically would
be possible, and can cause a brief session drop, although the client
recovers) so this should be fixed.  In practice this path does not happen
with modern servers but the error fall back to SMBWriteX is clearly wrong.

Removing the calls to SMBWriteX in the error paths in cifs_set_file_size

Pointed out by PaX/grsecurity team
Signed-off-by: NSteve French <steve.french@primarydata.com>
Reported-by: NPaX Team <pageexec@freemail.hu>
CC: Emese Revfy <re.emese@gmail.com>
CC: Brad Spengler <spender@grsecurity.net>
CC: Stable <stable@vger.kernel.org>

Commit 46c043ed ("mm: take i_mmap_lock in unmap_mapping_range() for
DAX") moved some code in __dax_pmd_fault() that was responsible for
zeroing newly allocated PMD pages.  The new location didn't properly set
up 'kaddr', so when run this code resulted in a NULL pointer BUG.

Fix this by getting the correct 'kaddr' via bdev_direct_access().
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reported-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes the following lockdep splat:
[    1.244527] =============================================
[    1.245193] [ INFO: possible recursive locking detected ]
[    1.245193] 4.2.0-rc1+ #37 Not tainted
[    1.245193] ---------------------------------------------
[    1.245193] cp/742 is trying to acquire lock:
[    1.245193]  (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff812b3f69>] ubifs_init_security+0x29/0xb0
[    1.245193]
[    1.245193] but task is already holding lock:
[    1.245193]  (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff81198e7f>] path_openat+0x3af/0x1280
[    1.245193]
[    1.245193] other info that might help us debug this:
[    1.245193]  Possible unsafe locking scenario:
[    1.245193]
[    1.245193]        CPU0
[    1.245193]        ----
[    1.245193]   lock(&sb->s_type->i_mutex_key#9);
[    1.245193]   lock(&sb->s_type->i_mutex_key#9);
[    1.245193]
[    1.245193]  *** DEADLOCK ***
[    1.245193]
[    1.245193]  May be due to missing lock nesting notation
[    1.245193]
[    1.245193] 2 locks held by cp/742:
[    1.245193]  #0:  (sb_writers#5){.+.+.+}, at: [<ffffffff811ad37f>] mnt_want_write+0x1f/0x50
[    1.245193]  #1:  (&sb->s_type->i_mutex_key#9){+.+.+.}, at: [<ffffffff81198e7f>] path_openat+0x3af/0x1280
[    1.245193]
[    1.245193] stack backtrace:
[    1.245193] CPU: 2 PID: 742 Comm: cp Not tainted 4.2.0-rc1+ #37
[    1.245193] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140816_022509-build35 04/01/2014
[    1.245193]  ffffffff8252d530 ffff88007b023a38 ffffffff814f6f49 ffffffff810b56c5
[    1.245193]  ffff88007c30cc80 ffff88007b023af8 ffffffff810a150d ffff88007b023a68
[    1.245193]  000000008101302a ffff880000000000 00000008f447e23f ffffffff8252d500
[    1.245193] Call Trace:
[    1.245193]  [<ffffffff814f6f49>] dump_stack+0x4c/0x65
[    1.245193]  [<ffffffff810b56c5>] ? console_unlock+0x1c5/0x510
[    1.245193]  [<ffffffff810a150d>] __lock_acquire+0x1a6d/0x1ea0
[    1.245193]  [<ffffffff8109fa78>] ? __lock_is_held+0x58/0x80
[    1.245193]  [<ffffffff810a1a93>] lock_acquire+0xd3/0x270
[    1.245193]  [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0
[    1.245193]  [<ffffffff814fc83b>] mutex_lock_nested+0x6b/0x3a0
[    1.245193]  [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0
[    1.245193]  [<ffffffff812b3f69>] ? ubifs_init_security+0x29/0xb0
[    1.245193]  [<ffffffff812b3f69>] ubifs_init_security+0x29/0xb0
[    1.245193]  [<ffffffff8128e286>] ubifs_create+0xa6/0x1f0
[    1.245193]  [<ffffffff81198e7f>] ? path_openat+0x3af/0x1280
[    1.245193]  [<ffffffff81195d15>] vfs_create+0x95/0xc0
[    1.245193]  [<ffffffff8119929c>] path_openat+0x7cc/0x1280
[    1.245193]  [<ffffffff8109ffe3>] ? __lock_acquire+0x543/0x1ea0
[    1.245193]  [<ffffffff81088f20>] ? sched_clock_cpu+0x90/0xc0
[    1.245193]  [<ffffffff81088c00>] ? calc_global_load_tick+0x60/0x90
[    1.245193]  [<ffffffff81088f20>] ? sched_clock_cpu+0x90/0xc0
[    1.245193]  [<ffffffff811a9cef>] ? __alloc_fd+0xaf/0x180
[    1.245193]  [<ffffffff8119ac55>] do_filp_open+0x75/0xd0
[    1.245193]  [<ffffffff814ffd86>] ? _raw_spin_unlock+0x26/0x40
[    1.245193]  [<ffffffff811a9cef>] ? __alloc_fd+0xaf/0x180
[    1.245193]  [<ffffffff81189bd9>] do_sys_open+0x129/0x200
[    1.245193]  [<ffffffff81189cc9>] SyS_open+0x19/0x20
[    1.245193]  [<ffffffff81500717>] entry_SYSCALL_64_fastpath+0x12/0x6f

While the lockdep splat is a false positive, becuase path_openat holds i_mutex
of the parent directory and ubifs_init_security() tries to acquire i_mutex
of a new inode, it reveals that taking i_mutex in ubifs_init_security() is
in vain because it is only being called in the inode allocation path
and therefore nobody else can see the inode yet.

Cc: stable@vger.kernel.org # 3.20-
Reported-and-tested-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-and-tested-by: NDongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: dedekind1@gmail.com

Pointed out by Dan Carpenter via smatch code analysis tool

CC: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NSteve French <steve.french@primarydata.com>

Signed-off-by: NSteve French <steve.french@primarydata.com>

Kerberos, which is very important for security, was only enabled for
CIFS not SMB2/SMB3 mounts (e.g. vers=3.0)

Patch based on the information detailed in
http://thread.gmane.org/gmane.linux.kernel.cifs/10081/focus=10307
to enable Kerberized SMB2/SMB3

a) SMB2_negotiate: enable/use decode_negTokenInit in SMB2_negotiate
b) SMB2_sess_setup: handle Kerberos sectype and replicate Kerberos
   SMB1 processing done in sess_auth_kerberos
Signed-off-by: NNoel Power <noel.power@suse.com>
Signed-off-by: NJim McDonough <jmcd@samba.org>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <steve.french@primarydata.com>

If we send a layoutreturn asynchronously before close, the close
might reach server first and layoutreturn would fail with BADSTATEID
because there is nothing keeping the layout stateid alive.

Also do not pretend sending layoutreturn if we are not.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>