Jean reported another crash, similar to the one fixed by feaff8e5:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000148
    IP: [<ffffffff8124ef7f>] locks_get_lock_context+0xf/0xa0
    PGD 0
    Oops: 0000 [#1] SMP
    Modules linked in: nfsv3 nfs_layout_flexfiles rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache vmw_vsock_vmci_transport vsock cfg80211 rfkill coretemp crct10dif_pclmul ppdev vmw_balloon crc32_pclmul crc32c_intel ghash_clmulni_intel pcspkr vmxnet3 parport_pc i2c_piix4 microcode serio_raw parport nfsd floppy vmw_vmci acpi_cpufreq auth_rpcgss shpchp nfs_acl lockd grace sunrpc vmwgfx drm_kms_helper ttm drm mptspi scsi_transport_spi mptscsih ata_generic mptbase i2c_core pata_acpi
    CPU: 0 PID: 329 Comm: kworker/0:1H Not tainted 4.1.0-rc7+ #2
    Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/30/2013
    Workqueue: rpciod rpc_async_schedule [sunrpc]
    30ec000
    RIP: 0010:[<ffffffff8124ef7f>]  [<ffffffff8124ef7f>] locks_get_lock_context+0xf/0xa0
    RSP: 0018:ffff8802330efc08  EFLAGS: 00010296
    RAX: ffff8802330efc58 RBX: ffff880097187c80 RCX: 0000000000000000
    RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
    RBP: ffff8802330efc18 R08: ffff88023fc173d8 R09: 3038b7bf00000000
    R10: 00002f1a02000000 R11: 3038b7bf00000000 R12: 0000000000000000
    R13: 0000000000000000 R14: ffff8802337a2300 R15: 0000000000000020
    FS:  0000000000000000(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000148 CR3: 000000003680f000 CR4: 00000000001407f0
    Stack:
     ffff880097187c80 ffff880097187cd8 ffff8802330efc98 ffffffff81250281
     ffff8802330efc68 ffffffffa013e7df ffff8802330efc98 0000000000000246
     ffff8801f6901c00 ffff880233d2b8d8 ffff8802330efc58 ffff8802330efc58
    Call Trace:
     [<ffffffff81250281>] __posix_lock_file+0x31/0x5e0
     [<ffffffffa013e7df>] ? rpc_wake_up_task_queue_locked.part.35+0xcf/0x240 [sunrpc]
     [<ffffffff8125088b>] posix_lock_file_wait+0x3b/0xd0
     [<ffffffffa03890b2>] ? nfs41_wake_and_assign_slot+0x32/0x40 [nfsv4]
     [<ffffffffa0365808>] ? nfs41_sequence_done+0xd8/0x300 [nfsv4]
     [<ffffffffa0367525>] do_vfs_lock+0x35/0x40 [nfsv4]
     [<ffffffffa03690c1>] nfs4_locku_done+0x81/0x120 [nfsv4]
     [<ffffffffa013e310>] ? rpc_destroy_wait_queue+0x20/0x20 [sunrpc]
     [<ffffffffa013e310>] ? rpc_destroy_wait_queue+0x20/0x20 [sunrpc]
     [<ffffffffa013e33c>] rpc_exit_task+0x2c/0x90 [sunrpc]
     [<ffffffffa0134400>] ? call_refreshresult+0x170/0x170 [sunrpc]
     [<ffffffffa013ece4>] __rpc_execute+0x84/0x410 [sunrpc]
     [<ffffffffa013f085>] rpc_async_schedule+0x15/0x20 [sunrpc]
     [<ffffffff810add67>] process_one_work+0x147/0x400
     [<ffffffff810ae42b>] worker_thread+0x11b/0x460
     [<ffffffff810ae310>] ? rescuer_thread+0x2f0/0x2f0
     [<ffffffff810b35d9>] kthread+0xc9/0xe0
     [<ffffffff81010000>] ? perf_trace_xen_mmu_set_pmd+0xa0/0x160
     [<ffffffff810b3510>] ? kthread_create_on_node+0x170/0x170
     [<ffffffff8173c222>] ret_from_fork+0x42/0x70
     [<ffffffff810b3510>] ? kthread_create_on_node+0x170/0x170
    Code: a5 81 e8 85 75 e4 ff c6 05 31 ee aa 00 01 eb 98 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 54 49 89 fc 53 <48> 8b 9f 48 01 00 00 48 85 db 74 08 48 89 d8 5b 41 5c 5d c3 83
    RIP  [<ffffffff8124ef7f>] locks_get_lock_context+0xf/0xa0
     RSP <ffff8802330efc08>
    CR2: 0000000000000148
    ---[ end trace 64484f16250de7ef ]---

The problem is almost exactly the same as the one fixed by feaff8e5.
We must take a reference to the struct file when running the LOCKU
compound to prevent the final fput from running until the operation is
complete.
Reported-by: NJean Spector <jean@primarydata.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It is possible to have an active open with one mode, and a delegation
for the same file with a different mode.
In particular, a WR_ONLY open and an RD_ONLY delegation.
This happens if a WR_ONLY open is followed by a RD_ONLY open which
provides a delegation, but is then close.

When returning the delegation, we currently try to claim opens for
every open type (n_rdwr, n_rdonly, n_wronly).  As there is no harm
in claiming an open for a mode that we already have, this is often
simplest.

However if the delegation only provides a subset of the modes that we
currently have open, this will produce an error from the server.

So when claiming open modes prior to returning a delegation, skip the
open request if the mode is not covered by the delegation - the open_stateid
must already cover that mode, so there is nothing to do.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Make it so, by checking the return value for NFS4ERR_MOTSUPP and
caching the information as a server capability.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

According to the spec, the server is only returning the status,
which we decode in the op header.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

hdr->good_bytes needs to be set to the length of the request, not
zero.

Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This patch ensures that we record the value of 'ffl_flags' from
the layout, and then checks for the presence of the
FF_FLAGS_NO_LAYOUTCOMMIT flag before deciding whether or not to
call pnfs_set_layoutcommit().

The effect is that servers now can decide whether or not they want
the client to call layoutcommit before returning a writeable layout.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

* layoutstats:
  pnfs/flexfiles: protect ktime manipulation with mirror lock
  nfs: provide pnfs_report_layoutstat when NFS42 is disabled
  pnfs/flexfiles: report layoutstat regularly
  nfs42: serialize LAYOUTSTATS calls of the same file
  pnfs/flexfiles: encode LAYOUTSTATS flexfiles specific data
  pnfs/flexfiles: add ff_layout_prepare_layoutstats
  pNFS/flexfiles: track when layout is first used
  pNFS/flexfiles: add layoutstats tracking
  pNFS/flexfiles: Remove unused struct members user_name, group_name
  pnfs: add pnfs_report_layoutstat helper function
  pNFS: fill in nfs42_layoutstat_ops
  NFSv.2/pnfs Add a LAYOUTSTATS rpc function

It looks as if xchg() and cmpxchg() are not available for 64-bit integers on sparc32:

> New breakage seen in linux-next today:
>
> ERROR: "__xchg_called_with_bad_pointer" [fs/nfs/flexfilelayout/nfs_layout_flexfiles.ko] undefined!
> ERROR: "__cmpxchg_called_with_bad_pointer" [fs/nfs/flexfilelayout/nfs_layout_flexfiles.ko] undefined!
> make[2]: *** [__modpost] Error 1
> make[1]: *** [modules] Error 2

Given that mirror ktime manipulation is already under mirror->lock, let's make use of the fact.
Reported-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

kbuild test robot reported:
   fs/built-in.o: In function `pnfs_report_layoutstat':
>> (.text+0x151a1c): undefined reference to `nfs42_proc_layoutstats_generic'
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Commit 9597c13b forbade opens with O_APPEND|O_DIRECT for NFSv4:

    nfs: verify open flags before allowing an atomic open

    Currently, you can open a NFSv4 file with O_APPEND|O_DIRECT, but cannot
    fcntl(F_SETFL,...) with those flags. This flag combination is explicitly
    forbidden on NFSv3 opens, and it seems like it should also be on NFSv4.

However, you can still open a file with O_DIRECT|O_APPEND if there exists a
cached dentry for the file because nfs4_file_open() is used instead of
nfs_atomic_open() and the check is bypassed.  Add the check in
nfs4_file_open() as well.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

A ds can be associated with more than one mirror, but we currently skip
setting a mirror's credentials if we find that it's already set up with
a connected client.

The upshot is that we can end up sending DS writes with MDS credentials
instead of properly setting them up. Fix nfs4_ff_layout_prepare_ds to
always verify that the mirror's credentials are set up, even when we
have a DS that's already connected.
Reported-by: NTom Haynes <thomas.haynes@primarydata.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we have two tasks racing to update a mirror's credentials, then they
can end up leaking one (or more) sets of credentials. The first task
will set mirror->cred and then the second task will just overwrite it.

Use a cmpxchg to ensure that the creds are only set once. If we get to
the point where we would set mirror->cred and find that they're already
set, then we just release the creds that were just found.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

As a simple scheme, report every minute if IO is still going on.
Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

There is no need to report concurrently.
Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It fills in the generic part of LAYOUTSTATS call. One thing to note
is that we don't really track if IO is continuous or not. So just fake
to use the completed bytes for it.

Still missing flexfiles specific part, which will be included in the next patch.
Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

So that we can report cumulative time since the beginning
of statistics collection of the layout.
Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Reviewed-by: NJeff Layton <jeff.layton@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>

* bugfixes:
  NFS: Ensure we set NFS_CONTEXT_RESEND_WRITES when requeuing writes
  pNFS: Fix a memory leak when attempted pnfs fails
  NFS: Ensure that we update the sequence id under the slot table lock
  nfs: Initialize cb_sequenceres information before validate_seqid()
  nfs: Only update callback sequnce id when CB_SEQUENCE success
  NFSv4: nfs4_handle_delegation_recall_error should ignore EAGAIN

Use the TCP_USER_TIMEOUT socket option to advertise to the server
how long we will keep the connection open if there is unacknowledged
data. See RFC5482.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This fixes a regression introduced by commit caf4ccd4 ("SUNRPC:
Make xs_tcp_close() do a socket shutdown rather than a sock_release").
Prior to that commit, the autoclose feature would ensure that an
idle connection would result in the socket being both disconnected and
released, whereas now only gets disconnected.

While the current behaviour is harmless, it does leave the port bound
until either RPC traffic resumes or the RPC client is shut down.
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the back channel is disconnected, we can and should just fail the
transmission. The expectation is that the NFSv4.1 server will always
retransmit any outstanding callbacks once the connection is
re-established.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Don't opencode sg_init_one()
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If a write attempt fails, and the write is queued up for resending to
the server, as opposed to being dropped, then we need to set the
appropriate flag so that nfs_file_fsync() does the right thing.

Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

pnfs_do_write() expects the call to pnfs_write_through_mds() to free the
pgio header and to release the layout segment before exiting. The problem
is that nfs_pgio_data_destroy() doesn't actually do this; it only frees
the memory allocated by nfs_generic_pgio().

Ditto for pnfs_do_read()...

Fix in both cases is to add a call to hdr->release(hdr).

Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

NFS: NFSoRDMA Client Changes

These patches continue to build up for improving the rsize and wsize that the
NFS client uses when talking over RDMA.  In addition, these patches also add
in scalability enhancements and other bugfixes.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

* tag 'nfs-rdma-for-4.2' of git://git.linux-nfs.org/projects/anna/nfs-rdma: (142 commits)
  xprtrdma: Reduce per-transport MR allocation
  xprtrdma: Stack relief in fmr_op_map()
  xprtrdma: Split rb_lock
  xprtrdma: Remove rpcrdma_ia::ri_memreg_strategy
  xprtrdma: Remove ->ro_reset
  xprtrdma: Remove unused LOCAL_INV recovery logic
  xprtrdma: Acquire MRs in rpcrdma_register_external()
  xprtrdma: Introduce an FRMR recovery workqueue
  xprtrdma: Acquire FMRs in rpcrdma_fmr_register_external()
  xprtrdma: Introduce helpers for allocating MWs
  xprtrdma: Use ib_device pointer safely
  xprtrdma: Remove rr_func
  xprtrdma: Replace rpcrdma_rep::rr_buffer with rr_rxprt
  xprtrdma: Warn when there are orphaned IB objects
  ...

Ensure that we fix the non-NULL stateid case as well.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Client can receives stateid-type error (eg., BAD_STATEID) on SETATTR when
delegation stateid was used. When no open state exists, in case of application
calling truncate() on the file, client has no state to recover and fails with
EIO.

Instead, upon such error, return the bad delegation and then resend the
SETATTR with a zero stateid.

Signed-off: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

A truncated fsid showing from /proc/fs/nfsfs/volumes as,
NV SERVER   PORT DEV     FSID              FSC
v4 c0a80881  801 0:43    34931f044c2a439b  no

It should be as,
NV SERVER   PORT DEV          FSID                              FSC
v4 c0a80881  801 0:43         34931f044c2a439b:954c5d830fa4be8c no

The max buffer length for storing "%llx:%llx" format should be
 16 + 1 + 16 + 1 = 34 (16 for %llx, 1 for ':', 1 for '\0').

Also, for storing "%u:%u" of MAJOR() and MINOR() should be
 8 + 1 + 3 + 1 = 13 (8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0').

v2, add comments for dev/fsid buffer and use sizeof in snprintf.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Change the uniform client string generator to dynamically allocate the
NFSv4 client name string buffer. With this patch, we can eliminate the
buffers that are embedded within the "args" structs and simply use the
name string that is hanging off the client.

This uniform string case is a little simpler than the nonuniform since
we don't need to deal with RCU, but we do have two different cases,
depending on whether there is a uniquifier or not.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The way the *_client_string functions work is a little goofy. They build
the string in an on-stack buffer and then use kstrdup to copy it. This
is not only stack-heavy but artificially limits the size of the client
name string. Change it so that we determine the length of the string,
allocate it and then scnprintf into it.

Since the contents of the nonuniform string depend on rcu-managed data
structures, it's possible that they'll change between when we allocate
the string and when we go to fill it. If that happens, free the string,
recalculate the length and try again. If it the mismatch isn't resolved
on the second try then just give up and return -EINVAL.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The spec allows for up to NFS4_OPAQUE_LIMIT (1k). While we'll almost
certainly never use that much, these ops are generally the only ones
in the compound so we might as well allow for them to be that large.

Also, the existing code didn't add in a word for the opaque length
field for either name string. Fix that while we're in there.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

...instead of buffers that are part of their arg structs. We already
hold a reference to the client, so we might as well use the allocated
buffer. In the event that we can't allocate the clp->cl_owner_id, then
just return -ENOMEM.

Note too that we switch from a GFP_KERNEL allocation here to GFP_NOFS.
It's possible we could end up trying to do a SETCLIENTID or EXCHANGE_ID
in order to reclaim some memory, and the GFP_KERNEL allocations in the
existing code could cause recursion back into NFS reclaim.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The current buffer is much too small if you have a relatively long
hostname. Bring it up to the size of the one that SETCLIENTID has.

Cc: <stable@vger.kernel.org>
Reported-by: NMichael Skralivetsky <michael.skralivetsky@primarydata.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>