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>

Since we can now use a lock stateid or a delegation stateid, that
differs from the context stateid, we need to change the test in
nfs4_layoutget_handle_exception() to take this into account.

This fixes an infinite layoutget loop in the NFS client whereby
it keeps retrying the initial layoutget using the same broken
stateid.

Fixes: 70d2f7b1 ("pNFS: Use the standard I/O stateid when...")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Check for a NULL dsaddr in filelayout_free_lseg() before calling
nfs4_fl_put_deviceid().  This fixes the following oops:

[ 1967.645207] BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
[ 1967.646010] IP: [<ffffffffc06d6aea>] nfs4_put_deviceid_node+0xa/0x90 [nfsv4]
[ 1967.646010] PGD c08bc067 PUD 915d3067 PMD 0
[ 1967.753036] Oops: 0000 [#1] SMP
[ 1967.753036] Modules linked in: nfs_layout_nfsv41_files ext4 mbcache jbd2 loop rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache amd64_edac_mod ipmi_ssif edac_mce_amd edac_core kvm_amd sg kvm ipmi_si ipmi_devintf irqbypass pcspkr k8temp ipmi_msghandler i2c_piix4 shpchp nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod crc_t10dif crct10dif_generic crct10dif_common amdkfd amd_iommu_v2 radeon i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops mptsas ttm scsi_transport_sas mptscsih drm mptbase serio_raw i2c_core bnx2 dm_mirror dm_region_hash dm_log dm_mod
[ 1967.790031] CPU: 2 PID: 1370 Comm: ls Not tainted 3.10.0-709.el7.test.bz1463784.x86_64 #1
[ 1967.790031] Hardware name: IBM BladeCenter LS21 -[7971AC1]-/Server Blade, BIOS -[BAE155AUS-1.10]- 06/03/2009
[ 1967.790031] task: ffff8800c42a3f40 ti: ffff8800c4064000 task.ti: ffff8800c4064000
[ 1967.790031] RIP: 0010:[<ffffffffc06d6aea>]  [<ffffffffc06d6aea>] nfs4_put_deviceid_node+0xa/0x90 [nfsv4]
[ 1967.790031] RSP: 0000:ffff8800c4067978  EFLAGS: 00010246
[ 1967.790031] RAX: ffffffffc062f000 RBX: ffff8801d468a540 RCX: dead000000000200
[ 1967.790031] RDX: ffff8800c40679f8 RSI: ffff8800c4067a0c RDI: 0000000000000000
[ 1967.790031] RBP: ffff8800c4067980 R08: ffff8801d468a540 R09: 0000000000000000
[ 1967.790031] R10: 0000000000000000 R11: ffffffffffffffff R12: ffff8801d468a540
[ 1967.790031] R13: ffff8800c40679f8 R14: ffff8801d5645300 R15: ffff880126f15ff0
[ 1967.790031] FS:  00007f11053c9800(0000) GS:ffff88012bd00000(0000) knlGS:0000000000000000
[ 1967.790031] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1967.790031] CR2: 0000000000000030 CR3: 0000000094b55000 CR4: 00000000000007e0
[ 1967.790031] Stack:
[ 1967.790031]  ffff8801d468a540 ffff8800c4067990 ffffffffc062d2fe ffff8800c40679b0
[ 1967.790031]  ffffffffc062b5b4 ffff8800c40679f8 ffff8801d468a540 ffff8800c40679d8
[ 1967.790031]  ffffffffc06d39af ffff8800c40679f8 ffff880126f16078 0000000000000001
[ 1967.790031] Call Trace:
[ 1967.790031]  [<ffffffffc062d2fe>] nfs4_fl_put_deviceid+0xe/0x10 [nfs_layout_nfsv41_files]
[ 1967.790031]  [<ffffffffc062b5b4>] filelayout_free_lseg+0x24/0x90 [nfs_layout_nfsv41_files]
[ 1967.790031]  [<ffffffffc06d39af>] pnfs_free_lseg_list+0x5f/0x80 [nfsv4]
[ 1967.790031]  [<ffffffffc06d5a67>] _pnfs_return_layout+0x157/0x270 [nfsv4]
[ 1967.790031]  [<ffffffffc06c17dd>] nfs4_evict_inode+0x4d/0x70 [nfsv4]
[ 1967.790031]  [<ffffffff8121de19>] evict+0xa9/0x180
[ 1967.790031]  [<ffffffff8121e729>] iput+0xf9/0x190
[ 1967.790031]  [<ffffffffc0652cea>] nfs_dentry_iput+0x3a/0x50 [nfs]
[ 1967.790031]  [<ffffffff8121ab4f>] shrink_dentry_list+0x20f/0x490
[ 1967.790031]  [<ffffffff8121b018>] d_invalidate+0xd8/0x150
[ 1967.790031]  [<ffffffffc065446b>] nfs_readdir_page_filler+0x40b/0x600 [nfs]
[ 1967.790031]  [<ffffffffc0654bbd>] nfs_readdir_xdr_to_array+0x20d/0x3b0 [nfs]
[ 1967.790031]  [<ffffffff811f3482>] ? __mem_cgroup_commit_charge+0xe2/0x2f0
[ 1967.790031]  [<ffffffff81183208>] ? __add_to_page_cache_locked+0x48/0x170
[ 1967.790031]  [<ffffffffc0654d60>] ? nfs_readdir_xdr_to_array+0x3b0/0x3b0 [nfs]
[ 1967.790031]  [<ffffffffc0654d82>] nfs_readdir_filler+0x22/0x90 [nfs]
[ 1967.790031]  [<ffffffff8118351f>] do_read_cache_page+0x7f/0x190
[ 1967.790031]  [<ffffffff81215d30>] ? fillonedir+0xe0/0xe0
[ 1967.790031]  [<ffffffff8118366c>] read_cache_page+0x1c/0x30
[ 1967.790031]  [<ffffffffc0654f9b>] nfs_readdir+0x1ab/0x6b0 [nfs]
[ 1967.790031]  [<ffffffffc06bd1c0>] ? nfs4_xdr_dec_layoutget+0x270/0x270 [nfsv4]
[ 1967.790031]  [<ffffffff81215d30>] ? fillonedir+0xe0/0xe0
[ 1967.790031]  [<ffffffff81215c20>] vfs_readdir+0xb0/0xe0
[ 1967.790031]  [<ffffffff81216045>] SyS_getdents+0x95/0x120
[ 1967.790031]  [<ffffffff816b9449>] system_call_fastpath+0x16/0x1b
[ 1967.790031] Code: 90 31 d2 48 89 d0 5d c3 85 f6 74 f5 8d 4e 01 89 f0 f0 0f b1 0f 39 f0 74 e2 89 c6 eb eb 0f 1f 40 00 66 66 66 66 90 55 48 89 e5 53 <48> 8b 47 30 48 89 fb a8 04 74 3b 8b 57 60 83 fa 02 74 19 8d 4a
[ 1967.790031] RIP  [<ffffffffc06d6aea>] nfs4_put_deviceid_node+0xa/0x90 [nfsv4]
[ 1967.790031]  RSP <ffff8800c4067978>
[ 1967.790031] CR2: 0000000000000030
Signed-off-by: NScott Mayhew <smayhew@redhat.com>
Fixes: 1ebf9801 ("NFS/filelayout: Fix racy setting of fl->dsaddr...")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Michael Sterrett reports a NULL pointer dereference on NFSv3 mounts when
CONFIG_NFS_V4 is not set because the NFS UOC rpc_wait_queue has not been
initialized.  Move the initialization of the queue out of the CONFIG_NFS_V4
conditional setion.

Fixes: 7d6ddf88 ("NFS: Add an iocounter wait function for async RPC tasks")
Cc: stable@vger.kernel.org # 4.11+
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

nfs_idmap_get_desc() can't actually return zero.  But if it did then
we would return ERR_PTR(0) which is NULL and the caller,
nfs_idmap_get_key(), doesn't expect that so it leads to a NULL pointer
dereference.

I've cleaned this up by changing the "<=" to "<" so it's more clear that
we don't return ERR_PTR(0).
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The units of RPC_MAX_AUTH_SIZE is bytes, not 4-byte words.  This causes
the client to request a larger-than-necessary session replay slot size.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

1/ remove 'start' and 'end' args from nfs_file_fsync_commit().
   They aren't used.

2/ Make nfs_context_set_write_error() a "static inline" in internal.h
   so we can...

3/ Use nfs_context_set_write_error() instead of mapping_set_error()
   if nfs_pageio_add_request() fails before sending any request.
   NFS generally keeps errors in the open_context, not the mapping,
   so this is more consistent.

4/ If filemap_write_and_write_range() reports any error, still
   check ctx->error.  The value in ctx->error is likely to be
   more useful.  As part of this, NFS_CONTEXT_ERROR_WRITE is
   cleared slightly earlier, before nfs_file_fsync_commit() is called,
   rather than at the start of that function.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Tools like tcpdump and rpcdebug can be very useful. But there are
plenty of environments where they are difficult or impossible to
use. For example, we've had customers report I/O failures during
workloads so heavy that collecting network traffic or enabling
RPC debugging are themselves onerous.

The kernel's static tracepoints are lightweight (less likely to
introduce timing changes) and efficient (the trace data is compact).
They also work in scenarios where capturing network traffic is not
possible due to lack of hardware support (some InfiniBand HCAs) or
where data or network privacy is a concern.

Introduce tracepoints that show when an NFS READ, WRITE, or COMMIT
is initiated, and when it completes. Record the arguments and
results of each operation, which are not shown by existing sunrpc
module's tracepoints.

For instance, the recorded offset and count can be used to match an
"initiate" event to a "done" event. If an NFS READ result returns
fewer bytes than requested or zero, seeing the EOF flag can be
probative. Seeing an NFS4ERR_BAD_STATEID result is also indication
of a particular class of problems. The timing information attached
to each event record can often be useful as well.

Usage example:

[root@manet tmp]# trace-cmd record -e nfs:*initiate* -e nfs:*done
/sys/kernel/debug/tracing/events/nfs/*initiate*/filter
/sys/kernel/debug/tracing/events/nfs/*done/filter
Hit Ctrl^C to stop recording
^CKernel buffer statistics:
  Note: "entries" are the entries left in the kernel ring buffer and are not
        recorded in the trace data. They should all be zero.

CPU: 0
entries: 0
overrun: 0
commit overrun: 0
bytes: 3680
oldest event ts:    78.367422
now ts:   100.124419
dropped events: 0
read events: 74

... and so on.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Instead of having a private method for copying the open/delegation stateid,
use the same call that is used for standard I/O through the MDS.

Note that this means we transmit the stateid with a zero seqid, avoiding
issues with NFS4ERR_OLD_STATEID.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we skip a subrequest due to a zero refcount, we should still count
the byte range that it covered so that we accurately reconstruct the
original request size.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

That can deadlock if this is the last reference since
nfs_page_group_destroy() calls nfs_page_group_sync_on_bit().
Note that even if the page was removed from the subpage list,
the req->wb_head could still be pointing to the old head.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It's pretty much a duplicate of nfs_scan_commit_list() that also
clears the PG_COMMIT_TO_DS flag.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Since the commit list is not ordered, it is possible for nfs_scan_commit_list
to hold a request that nfs_lock_and_join_requests() is waiting for, while
at the same time trying to grab a request that nfs_lock_and_join_requests
already holds.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The writeback code wants to send a commit after processing the pages,
which is why we want to delay releasing the struct path until after
that's done.

Also, the layout code expects that we do not free the inode before
we've put the layout segments in pnfs_writehdr_free() and
pnfs_readhdr_free()

Fixes: 919e3bd9 ("NFS: Ensure we commit after writeback is complete")
Fixes: 4714fb51 ("nfs: remove pgio_header refcount, related cleanup")
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Since commit 18290650 ("NFS: Move buffered I/O locking into
nfs_file_write()") nfs_file_write() has not flushed the correct byte
range during synchronous writes.  generic_write_sync() expects that
iocb->ki_pos points to the right edge of the range rather than the
left edge.

To replicate the problem, open a file with O_DSYNC, have the client
write at increasing offsets, and then print the successful offsets.
Block port 2049 partway through that sequence, and observe that the
client application indicates successful writes in advance of what the
server received.

Fixes: 18290650 ("NFS: Move buffered I/O locking into nfs_file_write()")
Signed-off-by: NJacob Strauss <jsstraus@amazon.com>
Signed-off-by: NTarang Gupta <tarangg@amazon.com>
Tested-by: NTarang Gupta <tarangg@amazon.com>
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Patch series "Ranged pagevec lookup", v2.

In this series I make pagevec_lookup() update the index (to be
consistent with pagevec_lookup_tag() and also as a preparation for
ranged lookups), provide ranged variant of pagevec_lookup() and use it
in places where it makes sense.  This not only removes some common code
but is also a measurable performance win for some use cases (see patch
4/10) where radix tree is sparse and searching & grabing of a page after
the end of the range has measurable overhead.

This patch (of 10):

The callback doesn't ever get called.  Remove it.

Link: http://lkml.kernel.org/r/20170726114704.7626-2-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This field hasn't been used since commit 57b69181 ("NFS: Cache
access checks more aggressively").
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When a byte range lock (or flock) is taken out on an NFS file, the
validity of the cached data is checked and the inode is marked
NFS_INODE_INVALID_DATA.  However the cached data isn't flushed from
the page cache.

This is sufficient for future read() requests or mmap() requests as
they call nfs_revalidate_mapping() which performs the flush if
necessary.

However an existing mapping is not affected.  Accessing data through
that mapping will continue to return old data even though the inode is
marked NFS_INODE_INVALID_DATA.

This can easily be confirmed using the 'nfs' tool in
  git://github.com/okirch/twopence-nfs.git
and running

   nfs coherence FILENAME
on one client, and
   nfs coherence -r FILENAME
on another client.

It appears that prior to Linux 2.6.0 this worked correctly.

However commit:

http://git.kernel.org/cgit/linux/kernel/git/history/history.git/commit/?id=ca9268fe3ddd075714005adecd4afbd7f9ab87d0

removed the call to inode_invalidate_pages() from nfs_zap_caches().  I
haven't tested this code, but inspection suggests that prior to this
commit, file locking would invalidate all inode pages.

This patch adds a call to nfs_revalidate_mapping() after a
successful SETLK so that invalid data is flushed.  With this patch the
above test passes.  To minimize impact (and possibly avoid a GETATTR
call) this only happens if the mapping might be mapped into
userspace.

Cc: Olaf Kirch <okir@suse.com>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Commit fbe77c30 ("NFS: move rw_mode to nfs_pageio_header")
reintroduced some pointless code that commit 518662e0 ("NFS: fix
usage of mempools.") had recently removed.

Remove it again.

Cc: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Close an attack vector by moving the arrays of per-server methods to
read-only memory.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

For a while now any NFSv2 mount where sec= is specified uses
AUTH_NULL. If sec= is not specified, the mount uses AUTH_UNIX.
Commit e68fd7c8 ("mount: use sec= that was specified on the
command line") attempted to address a very similar problem with
NFSv3, and should have fixed this too, but it has a bug.

The MNTv1 MNT procedure does not return a list of security flavors,
so our client makes up a list containing just AUTH_NULL. This should
enable nfs_verify_authflavors() to assign the sec= specified flavor,
but instead, it incorrectly sets it to AUTH_NULL.

I expect this would also be a problem for any NFSv3 server whose
MNTv3 MNT procedure returned a security flavor list containing only
AUTH_NULL.

Fixes: e68fd7c8 ("mount: use sec= that was specified on ... ")
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=310Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

An NFSv4.1 client might close a file after the user who opened it has
logged off.  In this case the user's credentials may no longer be
valid, if they are e.g. kerberos credentials that have expired.

NFSv4.1 has a mechanism to allow the client to use machine credentials
to close a file.  However due to a short-coming in the RFC, a CLOSE
with those credentials may not be possible if the file in question
isn't exported to the same security flavor - the required PUTFH must
be rejected when this is the case.

Specifically if a server and client support kerberos in general and
have used it to form a machine credential, but the file is only
exported to "sec=sys", a PUTFH with the machine credentials will fail,
so CLOSE is not possible.

As RPC_AUTH_UNIX (used by sec=sys) credentials can never expire, there
is no value in using the machine credential in place of them.
So in that case, just use the users credentials for CLOSE etc, as you would
in NFSv4.0
Signed-off-by: NNeil Brown <neilb@suse.com>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Now that the mirror allocation has been moved, the parameter can go.
Also remove the redundant symbol export.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

There are a number of callers of nfs_pageio_complete() that want to
continue using the nfs_pageio_descriptor without needing to call
nfs_pageio_init() again. Examples include nfs_pageio_resend() and
nfs_pageio_cond_complete().

The problem is that nfs_pageio_complete() also calls
nfs_pageio_cleanup_mirroring(), which frees up the array of mirrors.
This can lead to writeback errors, in the next call to
nfs_pageio_setup_mirroring().

Fix by simply moving the allocation of the mirrors to
nfs_pageio_setup_mirroring().

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196709Reported-by: NJianhongYin <yin-jianhong@163.com>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If a request is on the commit list, but is locked, we will currently skip
it, which can lead to livelocking when the commit count doesn't reduce
to zero.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Now that we no longer hold the inode->i_lock when manipulating the
commit lists, it is safe to call pnfs_put_lseg() again.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Switch from using the inode->i_lock for this to avoid contention with
other metadata manipulation.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

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

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>

The commit lists can get very large, so using the inode->i_lock can
end up affecting general metadata performance.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Split out the 2 cases so that we can treat the locking differently.
The issue is that the locking in the pageswapcache cache is highly
linked to the commit list locking.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Hide the locking from nfs_lock_and_join_requests() so that we can
separate out the requirements for swapcache pages.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Fix up the test in nfs_page_group_covers_page(). The simplest implementation
is to check that we have a set of intersecting or contiguous subrequests
that connect page offset 0 to nfs_page_length(req->wb_page).
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

nfs_page_group_lock() is now always called with the 'nonblock'
parameter set to 'false'.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

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

At this point, we only expect ever to potentially see PG_REMOVE and
PG_TEARDOWN being set on the subrequests.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Since nfs_page_group_destroy() does not take any locks on the requests
to be freed, we need to ensure that we don't inadvertently free the
request in nfs_destroy_unlinked_subrequests() while the last reference
is being released elsewhere.

Do this by:

1) Taking a reference to the request unless it is already being freed
2) Checking (under the page group lock) if PG_TEARDOWN is already set before
   freeing an unreferenced request in nfs_destroy_unlinked_subrequests()
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When locking the entire group in order to remove subrequests,
the locks are always taken in order, and with the page group
lock being taken after the page head is locked. The intention
is that:

1) The lock on the group head guarantees that requests may not
   be removed from the group (although new entries could be appended
   if we're not holding the group lock).
2) It is safe to drop and retake the page group lock while iterating
   through the list, in particular when waiting for a subrequest lock.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We should no longer need the inode->i_lock, now that we've
straightened out the request locking. The locking schema is now:

1) Lock page head request
2) Lock the page group
3) Lock the subrequests one by one

Note that there is a subtle race with nfs_inode_remove_request() due
to the fact that the latter does not lock the page head, when removing
it from the struct page. Only the last subrequest is locked, hence
we need to re-check that the PagePrivate(page) is still set after
we've locked all the subrequests.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>