If the attempt to recall the delegation fails because the inode is
in the process of being evicted from cache, then use NFS4ERR_DELAY
to ask the server to retry later.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Since the LAYOUTGET on OPEN can be sent without prior inode information,
existing methods to prevent LAYOUTGET from being sent while processing
CB_LAYOUTRECALL don't work.  Track if a recall occurred while LAYOUTGET
was being sent, and if so ignore the results.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Passing a pointer to a unsigned integer to test_bit() is broken.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Bool initializations should use true and false. Bool tests don't need
comparisons.
Signed-off-by: NThomas Meyer <thomas@m3y3r.de>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Rather than forcing us to take the inode->i_lock just in order to bump
the number.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Instead declare all functions with the proper methods signature.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Instead declare all functions with the proper methods signature.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The intention in the original patch was to release the lock when
we put the inode, however something got screwed up.
Reported-by: NJason Yan <yanaijie@huawei.com>
Fixes: 7b410d9c ("pNFS: Delay getting the layout header in..")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

In addition to removing the dprintk(), this patch also initializes "res"
to the default return value instead of doing this through an else
condition.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Removing the dprintk()s lets us simplify the function by removing the
else condition entirely and returning the status of
initiate_{file,bulk}_draining() directly.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Instead of grabbing the layout, we want to get the inode so that we
can reduce races between layoutget and layoutrecall when the server
does not support call referring.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Add a waitqueue head to the client structure. Have clients set a wait
on that queue prior to requesting a lock from the server. If the lock
is blocked, then we can use that to wait for wakeups.

Note that we do need to do this "manually" since we need to set the
wait on the waitqueue prior to requesting the lock, but requesting a
lock can involve activities that can block.

However, only do that for NFSv4.1 locks, either by compiling out
all of the waitqueue handling when CONFIG_NFS_V4_1 is disabled, or
skipping all of it at runtime if we're dealing with v4.0, or v4.1
servers that don't send lock callbacks.

Note too that even when we expect to get a lock callback, RFC5661
section 20.11.4 is pretty clear that we still need to poll for them,
so we do still sleep on a timeout. We do however always poll at the
longest interval in that case.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
[Anna: nfs4_retry_setlk() "status" should default to -ERESTARTSYS]
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

For now, the callback doesn't do anything. Support for that will be
added in later patches.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

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

If CB_SEQUENCE tells us that the processing of this request depends on
the completion of one or more referring triples (see RFC 5661 Section
2.10.6.3), delay the callback processing until after the RPC requests
being referred to have completed.
If we end up delaying for more than 1/2 second, then fall back to
returning NFS4ERR_DELAY in reply to the callback.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The slot table hasn't been an array since v3.7. Ensure that we
use nfs4_lookup_slot() to access the slot correctly.

Fixes: 87dda67e ("NFSv4.1: Allow SEQUENCE to resize the slot table...")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v3.8+

That's already being taken care of in pnfs_layout_remove_lseg().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We want to evaluate in this order:

If the client holds no layout for this inode, then return
NFS4ERR_NOMATCHING_LAYOUT; it probably forgot the layout.

If the client finds the inode among the list of layouts, but the corresponding
stateid has not yet been initialised, then return NFS4ERR_DELAY to ask the
server to retry once the outstanding LAYOUTGET is complete.

If the current layout stateid's "other" field does not match the recalled
stateid, return NFS4ERR_BAD_STATEID.

If already processing a layout recall with a newer stateid, return
NFS4ERR_OLD_STATEID. This can only happens for servers that are
non-compliant with the NFSv4.1 protocol.

If already processing a layout recall with an older stateid, return
NFS4ERR_DELAY to ask the server to retry once the outstanding
LAYOUTRETURN is complete. Again, this is technically incompliant with
the NFSv4.1 protocol.

If the current layout sequence id is newer than the recalled stateid's
sequence id, return NFS4ERR_OLD_STATEID. This too implies protocol
non-compliance.

If the current layout sequence id is older than the recalled stateid's
sequence id+1, return NFS4ERR_DELAY.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

LAYOUTRETURN is "special" in that servers and clients are expected to
work with old stateids. When the client sends a LAYOUTRETURN with an old
stateid in it then the server is expected to only tear down layout
segments that were present when that seqid was current. Ensure that the
client handles its accounting accordingly.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Commit 80f96427 ("NFSv4.x: Enforce the ca_maxreponsesize_cached
on the back channel") causes an oops when it receives a callback with
cachethis=yes.

[  109.667378] BUG: unable to handle kernel NULL pointer dereference at 00000000000002c8
[  109.669476] IP: [<ffffffffa08a3e68>] nfs4_callback_compound+0x4f8/0x690 [nfsv4]
[  109.671216] PGD 0
[  109.671736] Oops: 0000 [#1] SMP
[  109.705427] CPU: 1 PID: 3579 Comm: nfsv4.1-svc Not tainted 4.5.0-rc1+ #1
[  109.706987] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014
[  109.709468] task: ffff8800b4408000 ti: ffff88008448c000 task.ti: ffff88008448c000
[  109.711207] RIP: 0010:[<ffffffffa08a3e68>]  [<ffffffffa08a3e68>] nfs4_callback_compound+0x4f8/0x690 [nfsv4]
[  109.713521] RSP: 0018:ffff88008448fca0  EFLAGS: 00010286
[  109.714762] RAX: ffff880081ee202c RBX: ffff8800b7b5b600 RCX: 0000000000000001
[  109.716427] RDX: 0000000000000008 RSI: 0000000000000008 RDI: 0000000000000000
[  109.718091] RBP: ffff88008448fda8 R08: 0000000000000000 R09: 000000000b000000
[  109.719757] R10: ffff880137786000 R11: ffff8800b7b5b600 R12: 0000000001000000
[  109.721415] R13: 0000000000000002 R14: 0000000053270000 R15: 000000000000000b
[  109.723061] FS:  0000000000000000(0000) GS:ffff880139640000(0000) knlGS:0000000000000000
[  109.724931] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  109.726278] CR2: 00000000000002c8 CR3: 0000000034d50000 CR4: 00000000001406e0
[  109.727972] Stack:
[  109.728465]  ffff880081ee202c ffff880081ee201c 000000008448fcc0 ffff8800baccb800
[  109.730349]  ffff8800baccc800 ffffffffa08d0380 0000000000000000 0000000000000000
[  109.732211]  ffff8800b7b5b600 0000000000000001 ffffffff81d073c0 ffff880081ee3090
[  109.734056] Call Trace:
[  109.734657]  [<ffffffffa03795d4>] svc_process_common+0x5c4/0x6c0 [sunrpc]
[  109.736267]  [<ffffffffa0379a4c>] bc_svc_process+0x1fc/0x360 [sunrpc]
[  109.737775]  [<ffffffffa08a2c2c>] nfs41_callback_svc+0x10c/0x1d0 [nfsv4]
[  109.739335]  [<ffffffff810cb380>] ? prepare_to_wait_event+0xf0/0xf0
[  109.740799]  [<ffffffffa08a2b20>] ? nfs4_callback_svc+0x50/0x50 [nfsv4]
[  109.742349]  [<ffffffff810a6998>] kthread+0xd8/0xf0
[  109.743495]  [<ffffffff810a68c0>] ? kthread_park+0x60/0x60
[  109.744776]  [<ffffffff816abc4f>] ret_from_fork+0x3f/0x70
[  109.746037]  [<ffffffff810a68c0>] ? kthread_park+0x60/0x60
[  109.747324] Code: cc 45 31 f6 48 8b 85 00 ff ff ff 44 89 30 48 8b 85 f8 fe ff ff 44 89 20 48 8b 9d 38 ff ff ff 48 8b bd 30 ff ff ff 48 85 db 74 4c <4c> 8b af c8 02 00 00 4d 8d a5 08 02 00 00 49 81 c5 98 02 00 00
[  109.754361] RIP  [<ffffffffa08a3e68>] nfs4_callback_compound+0x4f8/0x690 [nfsv4]
[  109.756123]  RSP <ffff88008448fca0>
[  109.756951] CR2: 00000000000002c8
[  109.757738] ---[ end trace 2b8555511ab5dfb4 ]---
[  109.758819] Kernel panic - not syncing: Fatal exception
[  109.760126] Kernel Offset: disabled
[  118.938934] ---[ end Kernel panic - not syncing: Fatal exception

It doesn't unlock the table nor does it set the cps->clp pointer which
is later needed by nfs4_cb_free_slot().

Fixes: 80f96427 ("NFSv4.x: Enforce the ca_maxresponsesize_cached ...")
CC: stable@vger.kernel.org
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

We need to initialize cb_sequenceres information when reporting a
NFS4ERR_RETRY_UNCACHED_REP error, since that will apply to the
next operation, not to the CB_SEQUENCE itself.
Reported-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Hook the callback channel into the same session management machinery
as we use for the forward channel.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We need to make sure that we don't allow args->csa_sequenceid == 0.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We have no duplicate reply cache, so we always set the back channel
ca_maxresponsesize_cached to zero when negotiating the session.
That means we should always error out as soon as we see the server
set args->csa_cachethis.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

See RFC5661 Section 2.10.6.2: if retrying a request, and the old one is
still in progress, we must return NFS4ERR_DELAY as the reply to sequence.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Instead, use the values encoded in the slot table itself.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Peng Tao points out that the call to pnfs_mark_matching_lsegs_return()
could race with pnfs_put_lseg(), in which case the layout segment is
cleared, but no layoutreturn will be sent.
Fix is to replace the call to pnfs_mark_matching_lsegs_invalid().
Reported-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the layout segment is invalid, then we should not be adding more
write requests to the commit list. Instead, those writes should be
replayed after requesting a new layout.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The stateid is extremely valuable when debugging.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the client is promising to return the layout ASAP, then there is no
need to return DELAY and have the server retry. Instead default to the
normal procedure described in RFC5661.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The RFC requires us to check if the server is recalling a stateid that we
haven't yet received. If so, tell it to wait.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the client needs to delay the layout callback, then speed up the recall
process by marking the remaining layout segments to be actively returned
by the client.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This ensures that we don't reuse the stateid if a layout return or
implied layout return means that we've returned all layout segments
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>

Only support for single file layoutrecall for now.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

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

All these functions do is call nfs41_ping_server() without adding
anything.  Let's remove them and give nfs41_ping_server() a better name
instead.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Fix a callback slot table regression.

Fixes: e937ee71 ("nfs: Only update callback sequnce id when CB_SEQUENCE success")
Cc: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>