Over the years, several of the links have changed or are no longer valid
so update them.  In addition, the default values were incorrect for a
couple of parameters.

Converted the text file to the reStructuredText (RST) format, since the
Linux kernel documentation now uses this format for documentation.
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>

There have been multiple reports of crashes that look like
kernel: RIP: 0010:[<ffffffff8110303f>] timecounter_read+0xf/0x50
[...]
kernel: Call Trace:
kernel:  [<ffffffffa0806b0f>] e1000e_phc_gettime+0x2f/0x60 [e1000e]
kernel:  [<ffffffffa0806c5d>] e1000e_systim_overflow_work+0x1d/0x80 [e1000e]
kernel:  [<ffffffff810992c5>] process_one_work+0x155/0x440
kernel:  [<ffffffff81099e16>] worker_thread+0x116/0x4b0
kernel:  [<ffffffff8109f422>] kthread+0xd2/0xf0
kernel:  [<ffffffff8163184f>] ret_from_fork+0x3f/0x70

These can be traced back to the fact that e1000e_systim_reset() skips the
timecounter_init() call if e1000e_get_base_timinca() returns -EINVAL, which
leads to a null deref in timecounter_read().

Commit 83129b37 ("e1000e: fix systim issues", v4.2-rc1) reworked
e1000e_get_base_timinca() in such a way that it can return -EINVAL for
e1000_pch_spt if the SYSCFI bit is not set in TSYNCRXCTL.

Some experimentation has shown that on I219 (e1000_pch_spt, "MAC: 12")
adapters, the E1000_TSYNCRXCTL_SYSCFI flag is unstable; TSYNCRXCTL reads
sometimes don't have the SYSCFI bit set. Retrying the read shortly after
finds the bit to be set. This was observed at boot (probe) but also link up
and link down.

Moreover, the phc (PTP Hardware Clock) seems to operate normally even after
reads where SYSCFI=0. Therefore, remove this register read and
unconditionally set the clock parameters.
Reported-by: Achim Mildenberger <admin@fph.physik.uni-karlsruhe.de>
Message-Id: <20180425065243.g5mqewg5irkwgwgv@f2>
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1075876
Fixes: 83129b37 ("e1000e: fix systim issues")
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Willem de Bruijn says:

====================
selftests/net: various

A few odds and ends to network tests:

- msg_zerocopy: run as part of kselftest
- udp gso:      add missing bounds test for minimal sizes
- psocket_snd:  initial basic conformance test
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add regression tests for PF_PACKET transmission using packet_snd.

The TPACKET ring interface has tests for transmission and reception.
This is an initial stab at the same for the send call based interface.

Packets are sent over loopback, then read twice. The entire packet is
read from another packet socket and compared. The packet is also
verified to arrive at a UDP socket for protocol conformance.

The test sends a packet over loopback, testing the following options
(not the full cross-product):

- SOCK_DGRAM
- SOCK_RAW
- vlan tag
- qdisc bypass
- bind() and sendto()
- virtio_net_hdr
- csum offload (NOT actual csum feature, ignored on loopback)
- gso

Besides these basic functionality tests, the test runs from a set
of bounds checks, positive and negative. Running over loopback, which
has dev->min_header_len, it cannot generate variable length hhlen.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Verify that udpgso can generate segments smaller than device mtu, down
to the extreme case of 1B gso_size.

Verify that irrespective of gso_size, udpgso restricts the number of
segments it will generate per call (UDP_MAX_SEGMENTS).
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The existing msg_zerocopy test takes additional protocol arguments.
Add a variant that takes no arguments and runs all supported variants.
Call this from kselftest.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the common free functions while return successfully.
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'wireless-drivers-next-for-davem-2018-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next

Kalle Valo says:

====================
wireless-drivers-next patches for 4.18

Hopefully the last pull request to 4.18 before the merge window.
Nothing major here, we have smaller new features and of course a lots
of fixes.

Major changes:

ath10k

* add memory dump support for QCA9888 and QCA99X0

* add support to configure channel dwell time

* support new DFS host confirmation feature in the firmware

ath

* update various regulatory mappings

wcn36xx

* various fixes to improve reliability

* add Factory Test Mode support

brmfmac

* add debugfs file for reading firmware capabilities

mwifiex

* support sysfs initiated device coredump
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

axienet_open no longer return -ENODEV when PHY cannot be connected to
since commit d7cc3163 ("net: axienet: Support phy-less mode of operation")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ncsi_rsp_handler_gc() allocates the filter arrays using GFP_KERNEL in
softirq context, causing the below backtrace. This allocation is only a
few dozen bytes during probing so allocate with GFP_ATOMIC instead.

[   42.813372] BUG: sleeping function called from invalid context at mm/slab.h:416
[   42.820900] in_atomic(): 1, irqs_disabled(): 0, pid: 213, name: kworker/0:1
[   42.827893] INFO: lockdep is turned off.
[   42.832023] CPU: 0 PID: 213 Comm: kworker/0:1 Tainted: G        W       4.13.16-01441-gad99b38 #65
[   42.841007] Hardware name: Generic DT based system
[   42.845966] Workqueue: events ncsi_dev_work
[   42.850251] [<8010a494>] (unwind_backtrace) from [<80107510>] (show_stack+0x20/0x24)
[   42.858046] [<80107510>] (show_stack) from [<80612770>] (dump_stack+0x20/0x28)
[   42.865309] [<80612770>] (dump_stack) from [<80148248>] (___might_sleep+0x230/0x2b0)
[   42.873241] [<80148248>] (___might_sleep) from [<80148334>] (__might_sleep+0x6c/0xac)
[   42.881129] [<80148334>] (__might_sleep) from [<80240d6c>] (__kmalloc+0x210/0x2fc)
[   42.888737] [<80240d6c>] (__kmalloc) from [<8060ad54>] (ncsi_rsp_handler_gc+0xd0/0x170)
[   42.896770] [<8060ad54>] (ncsi_rsp_handler_gc) from [<8060b454>] (ncsi_rcv_rsp+0x16c/0x1d4)
[   42.905314] [<8060b454>] (ncsi_rcv_rsp) from [<804d86c8>] (__netif_receive_skb_core+0x3c8/0xb50)
[   42.914158] [<804d86c8>] (__netif_receive_skb_core) from [<804d96cc>] (__netif_receive_skb+0x20/0x7c)
[   42.923420] [<804d96cc>] (__netif_receive_skb) from [<804de4b0>] (netif_receive_skb_internal+0x78/0x6a4)
[   42.932931] [<804de4b0>] (netif_receive_skb_internal) from [<804df980>] (netif_receive_skb+0x78/0x158)
[   42.942292] [<804df980>] (netif_receive_skb) from [<8042f204>] (ftgmac100_poll+0x43c/0x4e8)
[   42.950855] [<8042f204>] (ftgmac100_poll) from [<804e094c>] (net_rx_action+0x278/0x4c4)
[   42.958918] [<804e094c>] (net_rx_action) from [<801016a8>] (__do_softirq+0xe0/0x4c4)
[   42.966716] [<801016a8>] (__do_softirq) from [<8011cd9c>] (do_softirq.part.4+0x50/0x78)
[   42.974756] [<8011cd9c>] (do_softirq.part.4) from [<8011cebc>] (__local_bh_enable_ip+0xf8/0x11c)
[   42.983579] [<8011cebc>] (__local_bh_enable_ip) from [<804dde08>] (__dev_queue_xmit+0x260/0x890)
[   42.992392] [<804dde08>] (__dev_queue_xmit) from [<804df1f0>] (dev_queue_xmit+0x1c/0x20)
[   43.000689] [<804df1f0>] (dev_queue_xmit) from [<806099c0>] (ncsi_xmit_cmd+0x1c0/0x244)
[   43.008763] [<806099c0>] (ncsi_xmit_cmd) from [<8060dc14>] (ncsi_dev_work+0x2e0/0x4c8)
[   43.016725] [<8060dc14>] (ncsi_dev_work) from [<80133dfc>] (process_one_work+0x214/0x6f8)
[   43.024940] [<80133dfc>] (process_one_work) from [<80134328>] (worker_thread+0x48/0x558)
[   43.033070] [<80134328>] (worker_thread) from [<8013ba80>] (kthread+0x130/0x174)
[   43.040506] [<8013ba80>] (kthread) from [<80102950>] (ret_from_fork+0x14/0x24)

Fixes: 062b3e1b ("net/ncsi: Refactor MAC, VLAN filters")
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If statement has make sure the 'slave->phy' is NULL
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix to return error code -EINVAL instead of 0 if optlen is invalid.

Fixes: 01d2f7e2 ("net/smc: sockopts TCP_NODELAY and TCP_CORK")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following sparse warning:

drivers/net/ethernet/mellanox/mlx5/core/fpga/tls.c:199:6: warning:
 symbol 'mlx5_fpga_tls_send_teardown_cmd' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix to return a negative error code from the failover register fail
error handling case instead of 0, as done elsewhere in this function.

Fixes: 1ff78076 ("netvsc: refactor notifier/event handling code to use the failover framework")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Filling in the padding slot in the bpf structure as a bug fix in 'ne'
overlapped with actually using that padding area for something in
'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>

We can bail out immediately also in case of PHY_IGNORE_INTERRUPT because
phy_mac_interupt() informs us once the link is up.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for your net-next tree:

1) Get rid of nf_sk_is_transparent(), use inet_sk_transparent() instead.
   From Máté Eckl.

2) Move shared tproxy infrastructure to nf_tproxy_ipv4 and nf_tproxy_ipv6.
   Also from Máté.

3) Add hashtable to speed up chain lookups by name, from Florian Westphal.

4) Patch series to add connlimit support reusing part of the
   nf_conncount infrastructure. This includes preparation changes such
   passing context to the object and expression destroy interface;
   garbage collection for expressions embedded into set elements, and
   the introduction of the clone_destroy interface for expressions.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull networking fixes from David Miller:

 1) Infinite loop in _decode_session6(), from Eric Dumazet.

 2) Pass correct argument to nla_strlcpy() in netfilter, also from Eric
    Dumazet.

 3) Out of bounds memory access in ipv6 srh code, from Mathieu Xhonneux.

 4) NULL deref in XDP_REDIRECT handling of tun driver, from Toshiaki
    Makita.

 5) Incorrect idr release in cls_flower, from Paul Blakey.

 6) Probe error handling fix in davinci_emac, from Dan Carpenter.

 7) Memory leak in XPS configuration, from Alexander Duyck.

 8) Use after free with cloned sockets in kcm, from Kirill Tkhai.

 9) MTU handling fixes fo ip_tunnel and ip6_tunnel, from Nicolas
    Dichtel.

10) Fix UAPI hole in bpf data structure for 32-bit compat applications,
    from Daniel Borkmann.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (33 commits)
  bpf: fix uapi hole for 32 bit compat applications
  net: usb: cdc_mbim: add flag FLAG_SEND_ZLP
  ip6_tunnel: remove magic mtu value 0xFFF8
  ip_tunnel: restore binding to ifaces with a large mtu
  net: dsa: b53: Add BCM5389 support
  kcm: Fix use-after-free caused by clonned sockets
  net-sysfs: Fix memory leak in XPS configuration
  ixgbe: fix parsing of TC actions for HW offload
  net: ethernet: davinci_emac: fix error handling in probe()
  net/ncsi: Fix array size in dumpit handler
  cls_flower: Fix incorrect idr release when failing to modify rule
  net/sonic: Use dma_mapping_error()
  xfrm Fix potential error pointer dereference in xfrm_bundle_create.
  vhost_net: flush batched heads before trying to busy polling
  tun: Fix NULL pointer dereference in XDP redirect
  be2net: Fix error detection logic for BE3
  net: qmi_wwan: Add Netgear Aircard 779S
  mlxsw: spectrum: Forbid creation of VLAN 1 over port/LAG
  atm: zatm: fix memcmp casting
  iwlwifi: pcie: compare with number of IRQs requested for, not number of CPUs
  ...

If there is a significant amount of chains list search is too slow, so
add an rhlist table for this.

This speeds up ruleset loading: for every new rule we have to check if
the name already exists in current generation.

We need to be able to cope with duplicate chain names in case a transaction
drops the nfnl mutex (for request_module) and the abort of this old
transaction is still pending.

The list is kept -- we need a way to iterate chains even if hash resize is
in progress without missing an entry.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This features which allows you to limit the maximum number of
connections per arbitrary key. The connlimit expression is stateful,
therefore it can be used from meters to dynamically populate a set, this
provides a mapping to the iptables' connlimit match. This patch also
comes that allows you define static connlimit policies.

This extension depends on the nf_conncount infrastructure.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Pull SCSI fix from James Bottomley:
 "Eve of merge window fix: The original code was so bogus as to be
  casting the wrong generic device to an rport and proceeding to take
  actions based on the bogus values it found.

  Fortunately it seems the location that is dereferenced always exists,
  so the code hasn't oopsed yet, but it certainly annoys the memory
  checkers"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: scsi_transport_srp: Fix shost to rport translation

Pull drm fixes from Dave Airlie:
 "A few final fixes:

  i915:
   - fix for potential Spectre vector in the new query uAPI
   - fix NULL pointer deref (FDO #106559)
   - DMI fix to hide LVDS for Radiant P845 (FDO #105468)

  amdgpu:
   - suspend/resume DC regression fix
   - underscan flicker fix on fiji
   - gamma setting fix after dpms

  omap:
   - fix oops regression

  core:
   - fix PSR timing

  dw-hdmi:
   - fix oops regression"

* tag 'drm-fixes-for-v4.17-rc8' of git://people.freedesktop.org/~airlied/linux:
  drm/amd/display: Update color props when modeset is required
  drm/amd/display: Make atomic-check validate underscan changes
  drm/bridge/synopsys: dw-hdmi: fix dw_hdmi_setup_rx_sense
  drm/amd/display: Fix BUG_ON during CRTC atomic check update
  drm/i915/query: nospec expects no more than an unsigned long
  drm/i915/query: Protect tainted function pointer lookup
  drm/i915/lvds: Move acpi lid notification registration to registration phase
  drm/i915: Disable LVDS on Radiant P845
  drm/omap: fix NULL deref crash with SDI displays
  drm/psr: Fix missed entry in PSR setup time table.

Before this patch, cloned expressions are released via ->destroy. This
is a problem for the new connlimit expression since the ->destroy path
drop a reference on the conntrack modules and it unregisters hooks. The
new ->destroy_clone provides context that this expression is being
released from the packet path, so it is mirroring ->clone(), where
neither module reference is dropped nor hooks need to be unregistered -
because this done from the control plane path from the ->init() path.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Use garbage collector to schedule removal of elements based of feedback
from expression that this element comes with. Therefore, the garbage
collector is not guided by timeout expirations in this new mode.

The new connlimit expression sets on the NFT_EXPR_GC flag to enable this
behaviour, the dynset expression needs to explicitly enable the garbage
collector via set->ops->gc_init call.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

nft_set_elem_destroy() can be called from call_rcu context. Annotate
netns and table in set object so we can populate the context object.
Moreover, pass context object to nf_tables_set_elem_destroy() from the
commit phase, since it is already available from there.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

This patch provides an interface to maintain the list of connections and
the lookup function to obtain the number of connections in the list.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The new connlimit object needs this to properly deal with conntrack
dependencies.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The extracted functions will likely be usefull to implement tproxy
support in nf_tables.

Extrancted functions:
	- nf_tproxy_sk_is_transparent
	- nf_tproxy_laddr4
	- nf_tproxy_handle_time_wait4
	- nf_tproxy_get_sock_v4
	- nf_tproxy_laddr6
	- nf_tproxy_handle_time_wait6
	- nf_tproxy_get_sock_v6

(nf_)tproxy_handle_time_wait6 also needed some refactor as its current
implementation was xtables-specific.
Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

There is a function in include/net/netfilter/nf_socket.h to decide if a
socket has IP(V6)_TRANSPARENT socket option set or not. However this
does the same as inet_sk_transparent() in include/net/tcp.h

include/net/tcp.h:1733
/* This helper checks if socket has IP_TRANSPARENT set */
static inline bool inet_sk_transparent(const struct sock *sk)
{
	switch (sk->sk_state) {
	case TCP_TIME_WAIT:
		return inet_twsk(sk)->tw_transparent;
	case TCP_NEW_SYN_RECV:
		return inet_rsk(inet_reqsk(sk))->no_srccheck;
	}
	return inet_sk(sk)->transparent;
}

tproxy_sk_is_transparent has also been refactored to use this function
instead of reimplementing it.
Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Two last minute DC fixes for 4.17.  A fix for underscan on fiji and
a fix for gamma settings getting after dpms.

* 'drm-fixes-4.17' of git://people.freedesktop.org/~agd5f/linux:
  drm/amd/display: Update color props when modeset is required
  drm/amd/display: Make atomic-check validate underscan changes

Pull MIPS fixes from James Hogan:
 "A final few MIPS fixes for 4.17:

   - drop Lantiq gphy reboot/remove reset (4.14)

   - prctl(PR_SET_FP_MODE): Disallow PRE without FR (4.0)

   - ptrace(PTRACE_PEEKUSR): Fix 64-bit FGRs (3.15)"

* tag 'mips_fixes_4.17_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: ptrace: Fix PTRACE_PEEKUSR requests for 64-bit FGRs
  MIPS: prctl: Disallow FRE without FR with PR_SET_FP_MODE requests
  MIPS: lantiq: gphy: Drop reboot/remove reset asserts

Pull VFIO fix from Alex Williamson:
 "Revert a pfn page mapping optimization identified as introducing a bad
  page state regression (Alex Williamson)"

* tag 'vfio-v4.17' of git://github.com/awilliam/linux-vfio:
  Revert "vfio/type1: Improve memory pinning process for raw PFN mapping"

Pull char/misc driver fixes from Greg KH:
 "Here are four small bugfixes for some char/misc drivers. Well, really
  three fixes and one fix for one of those fixes due to problems found
  by 0-day.

  This resolves some reported issues with the hwtracing drivers, and a
  reported regression for the thunderbolt subsystem. All of these have
  been in linux-next for a while now with no reported problems"

* tag 'char-misc-4.17-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  hwtracing: stm: fix build error on some arches
  intel_th: Use correct device when freeing buffers
  stm class: Use vmalloc for the master map
  thunderbolt: Handle NULL boot ACL entries properly

Pull IIO driver fixes from Greg KH:
 "Here are some old IIO driver fixes that were sitting in my tree for a
  few weeks. Sorry about not getting them to you sooner. They fix a
  number of small IIO driver issues that have been reported.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'staging-4.17-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: adc: select buffer for at91-sama5d2_adc
  iio: hid-sensor-trigger: Fix sometimes not powering up the sensor after resume
  iio: adc: at91-sama5d2_adc: fix channel configuration for differential channels
  iio:kfifo_buf: check for uint overflow
  iio:buffer: make length types match kfifo types
  iio: adc: stm32-dfsdm: fix sample rate for div2 spi clock
  iio: adc: stm32-dfsdm: fix successive oversampling settings
  iio: ad7793: implement IIO_CHAN_INFO_SAMP_FREQ

Pull rdma fixes from Jason Gunthorpe:
 "Just three small last minute regressions that were found in the last
  week. The Broadcom fix is a bit big for rc7, but since it is fixing
  driver crash regressions that were merged via netdev into rc1, I am
  sending it.

   - bnxt netdev changes merged this cycle caused the bnxt RDMA driver
     to crash under certain situations

   - Arnd found (several, unfortunately) kconfig problems with the
     patches adding INFINIBAND_ADDR_TRANS. Reverting this last part,
     will fix it more fully outside -rc.

   - Subtle change in error code for a uapi function caused breakage in
     userspace. This was bug was subtly introduced cycle"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  IB/core: Fix error code for invalid GID entry
  IB: Revert "remove redundant INFINIBAND kconfig dependencies"
  RDMA/bnxt_re: Fix broken RoCE driver due to recent L2 driver changes

Pull i2c fixes from Wolfram Sang:
 "A documentation bugfix and a MAINTAINERS addition"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: ocores: update HDL sources URL
  i2c: xlp9xx: Add MAINTAINERS entry

Merge two fixes from Andrew Morton.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: fix the NULL mapping case in __isolate_lru_page()
  mm/huge_memory.c: __split_huge_page() use atomic ClearPageDirty()

George Boole would have noticed a slight error in 4.16 commit
69d763fc ("mm: pin address_space before dereferencing it while
isolating an LRU page").  Fix it, to match both the comment above it,
and the original behaviour.

Although anonymous pages are not marked PageDirty at first, we have an
old habit of calling SetPageDirty when a page is removed from swap
cache: so there's a category of ex-swap pages that are easily
migratable, but were inadvertently excluded from compaction's async
migration in 4.16.

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1805302014001.12558@eggly.anvils
Fixes: 69d763fc ("mm: pin address_space before dereferencing it while isolating an LRU page")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Ivan Kalvachev <ikalvachev@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Swapping load on huge=always tmpfs (with khugepaged tuned up to be very
eager, but I'm not sure that is relevant) soon hung uninterruptibly,
waiting for page lock in shmem_getpage_gfp()'s find_lock_entry(), most
often when "cp -a" was trying to write to a smallish file.  Debug showed
that the page in question was not locked, and page->mapping NULL by now,
but page->index consistent with having been in a huge page before.

Reproduced in minutes on a 4.15 kernel, even with 4.17's 605ca5ed
("mm/huge_memory.c: reorder operations in __split_huge_page_tail()") added
in; but took hours to reproduce on a 4.17 kernel (no idea why).

The culprit proved to be the __ClearPageDirty() on tails beyond i_size in
__split_huge_page(): the non-atomic __bitoperation may have been safe when
4.8's baa355fd ("thp: file pages support for split_huge_page()")
introduced it, but liable to erase PageWaiters after 4.10's 62906027
("mm: add PageWaiters indicating tasks are waiting for a page bit").

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1805291841070.3197@eggly.anvils
Fixes: 62906027 ("mm: add PageWaiters indicating tasks are waiting for a page bit")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>