Instead of using platform device and deferrals to handle the case when i2C
adapters appear late in the game, and not handling device unbinding all
that well, let's switch to using I2C bus notifier to get told when a new
I2C adapter appears in the system, and attempt to add appropriate devices
at that time.

In case when we have 2 Designware adapters in the system (Acer C720),
instead of counting and hoping they get enumerate din the right order,
let's switch to using their PCI devids (slot/function) that should be
stable.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

Instead of trying to parse DMI IRQ data every time we try to instantiate a
device, let's do it once, when we identify the device we are working with.
This allows us to mark chromeos_laptop_get_irq_from_dmi() as __init and
discard it once module is initialized.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

Instead of having separate setup() functions responsible for instantiating
i2c client for each peripheral, let's generalize the behavior and use
common code for instantiating all i2c peripherals.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

This will make code instantiating I2C device a bit clearer.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

Define pr_fmt() to standardize driver messages.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

Atmel touch controller driver no longer respects suspend mode specified in
platform data, so let's stop setting it.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

Replace the original license statement with the SPDX identifier.
Add also one line of description as recommended by the COPYING file.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

Move older ChromeOS devices describing Atmel controllers in ACPI, but not
providing enough details to configure the controllers properly, from
platform data over to generic device properties. This will allow us
remove support for platform data later on, leaving only generic device
properties in place.
Acked-by: Nick Dyer <nick@shmanahar.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

Instead of using OF-specific APIs to fecth device properties, let's switch
to generic device properties API. This will allow us to use device
properties on legacy ChromeOS devices and get rid of platform data down
the road.
Acked-by: Nick Dyer <nick@shmanahar.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

The way we are supposed to put controller to sleep and wake it up does not
depend on the platform, but rather on controller itself, so we want to get
rid of suspend mode in platform data (and eventually get rid of platform
data completely). Unfortunately some early chromebooks (the original Pixel,
Acer C720) were shipped with config that requires manually re-enabling
touch reporting in T9. We will sort it out, but in the meantime let's
switch to a simple DMI quirk.

We'll keep pdata->suspend_mode for now and remove it when we rework
chromeos-laptop driver.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

Pull dmaengine fix from Vinod Koul:
 "One small fix for stm32-dmamux fixing buffer overflow"

* tag 'dmaengine-fix-4.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/slave-dma:
  dmaengine: stm32-dmamux: fix a potential buffer overflow

Pull x86 and PTI fixes from Ingo Molnar:
 "Misc fixes:

   - fix EFI pagetables freeing

   - fix vsyscall pagetable setting on Xen PV guests

   - remove ancient CONFIG_X86_PPRO_FENCE=y - x86 is TSO again

   - fix two binutils (ld) development version related incompatibilities

   - clean up breakpoint handling

   - fix an x86 self-test"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Don't use IST entry for #BP stack
  x86/efi: Free efi_pgd with free_pages()
  x86/vsyscall/64: Use proper accessor to update P4D entry
  x86/cpu: Remove the CONFIG_X86_PPRO_FENCE=y quirk
  x86/boot/64: Verify alignment of the LOAD segment
  x86/build/64: Force the linker to use 2MB page size
  selftests/x86/ptrace_syscall: Fix for yet more glibc interference

Pull timer fix from Ingo Molnar:
 "Make posix clock ID usage Spectre-safe"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-timers: Protect posix clock array access against speculation

Pull scheduler fixes from Ingo Molnar:
 "Two sched debug output related fixes: a console output fix and
  formatting fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Adjust newlines for better alignment
  sched/debug: Fix per-task line continuation for console output

Pull perf fixes from Ingo Molnar:
 "Misc kernel side fixes.

  Generic:
   - cgroup events counting fix

  x86:
   - Intel PMU truncated-parameter fix

   - RDPMC fix

   - API naming fix/rename

   - uncore driver big-hardware PCI enumeration fix

   - uncore driver filter constraint fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/cgroup: Fix child event counting bug
  perf/x86/intel/uncore: Fix multi-domain PCI CHA enumeration bug on Skylake servers
  perf/x86/intel: Rename confusing 'freerunning PEBS' API and implementation to 'large PEBS'
  perf/x86/intel/uncore: Add missing filter constraint for SKX CHA event
  perf/x86/intel: Don't accidentally clear high bits in bdw_limit_period()
  perf/x86/intel: Disable userspace RDPMC usage for large PEBS

Pull locking fixes from Ingo Molnar:
 "Two fixes: tighten up a jump-labels warning to not trigger on certain
  modules and fix confusing (and non-existent) mutex API documentation"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  jump_label: Disable jump labels in __exit code
  locking/mutex: Improve documentation

Tabs on a console with long lines do not wrap properly, so correctly
account for the line length when computing the tab placement location.
Reported-by: James Holderness <j4_james@hotmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull mqueuefs revert from Eric Biederman:
 "This fixes a regression that came in the merge window for v4.16.

  The problem is that the permissions for mounting and using the
  mqueuefs filesystem are broken. The necessary permission check is
  missing letting people who should not be able to mount mqueuefs mount
  mqueuefs. The field sb->s_user_ns is set incorrectly not allowing the
  mounter of mqueuefs to remount and otherwise have proper control over
  the filesystem.

  Al Viro and I see the path to the necessary fixes differently and I am
  not even certain at this point he actually sees all of the necessary
  fixes. Given a couple weeks we can probably work something out but I
  don't see the review being resolved in time for the final v4.16. I
  don't want v4.16 shipping with a nasty regression. So unfortunately I
  am sending a revert"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  Revert "mqueue: switch to on-demand creation of internal mount"

This reverts commit 36735a6a.

Aleksa Sarai <asarai@suse.de> writes:
> [REGRESSION v4.16-rc6] [PATCH] mqueue: forbid unprivileged user access to internal mount
>
> Felix reported weird behaviour on 4.16.0-rc6 with regards to mqueue[1],
> which was introduced by 36735a6a ("mqueue: switch to on-demand
> creation of internal mount").
>
> Basically, the reproducer boils down to being able to mount mqueue if
> you create a new user namespace, even if you don't unshare the IPC
> namespace.
>
> Previously this was not possible, and you would get an -EPERM. The mount
> is the *host* mqueue mount, which is being cached and just returned from
> mqueue_mount(). To be honest, I'm not sure if this is safe or not (or if
> it was intentional -- since I'm not familiar with mqueue).
>
> To me it looks like there is a missing permission check. I've included a
> patch below that I've compile-tested, and should block the above case.
> Can someone please tell me if I'm missing something? Is this actually
> safe?
>
> [1]: https://github.com/docker/docker/issues/36674

The issue is a lot deeper than a missing permission check.  sb->s_user_ns
was is improperly set as well.  So in addition to the filesystem being
mounted when it should not be mounted, so things are not allow that should
be.

We are practically to the release of 4.16 and there is no agreement between
Al Viro and myself on what the code should looks like to fix things properly.
So revert the code to what it was before so that we can take our time
and discuss this properly.

Fixes: 36735a6a ("mqueue: switch to on-demand creation of internal mount")
Reported-by: Felix Abecassis <fabecassis@nvidia.com>
Reported-by: Aleksa Sarai <asarai@suse.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Pull pin control fixes from Linus Walleij:
 "Two fixes for pin control for v4.16:

   - Renesas SH-PFC: remove a duplicate clkout pin which was causing
     crashes

   - fix Samsung out of bounds exceptions"

* tag 'pinctrl-v4.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: samsung: Validate alias coming from DT
  pinctrl: sh-pfc: r8a7795: remove duplicate of CLKOUT pin in pinmux_pins[]

Pull kprobe fixes from Steven Rostedt:
 "The documentation for kprobe events says that symbol offets can take
  both a + and - sign to get to befor and after the symbol address.

  But in actuality, the code does not support the minus. This fixes that
  issue, and adds a few more selftests to kprobe events"

* tag 'trace-v4.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests: ftrace: Add a testcase for probepoint
  selftests: ftrace: Add a testcase for string type with kprobe_event
  selftests: ftrace: Add probe event argument syntax testcase
  tracing: probeevent: Fix to support minus offset from symbol

There's nothing IST-worthy about #BP/int3.  We don't allow kprobes
in the small handful of places in the kernel that run at CPL0 with
an invalid stack, and 32-bit kernels have used normal interrupt
gates for #BP forever.

Furthermore, we don't allow kprobes in places that have usergs while
in kernel mode, so "paranoid" is also unnecessary.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org

The efi_pgd is allocated as PGD_ALLOCATION_ORDER pages and therefore must
also be freed as PGD_ALLOCATION_ORDER pages with free_pages().

Fixes: d9e9a641 ("x86/mm/pti: Allocate a separate user PGD")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1521746333-19593-1-git-send-email-longman@redhat.com

Pull MIPS fixes from James Hogan:
 "Another miscellaneous pile of MIPS fixes for 4.16:

   - lantiq: fixes for clocks and Amazon SE (4.14)

   - ralink: fix booting on MT7621 (4.5)

   - ralink: fix halt (3.9)"

* tag 'mips_fixes_4.16_5' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MIPS: ralink: Fix booting on MT7621
  MIPS: ralink: Remove ralink_halt()
  MIPS: lantiq: ase: Enable MFD_SYSCON
  MIPS: lantiq: Enable AHB Bus for USB
  MIPS: lantiq: Fix Danube USB clock

Pull VFIO fix from Alex Williamson:
 "Revert masking INTx where it cannot be enabled - it plays poorly with
  SR-IOV VFs and presumes DisINTx support"

* tag 'vfio-v4.16-rc7' of git://github.com/awilliam/linux-vfio:
  Revert: "vfio-pci: Mask INTx if a device is not capabable of enabling it"

Pull MTD fixes from Boris Brezillon:

 - Fix several problems in the fsl_ifc NAND controller driver

 - Fix misuse of mtd_ooblayout_ecc() in mtdchar.c

* tag 'mtd/fixes-for-4.16-rc7' of git://git.infradead.org/linux-mtd:
  mtd: nand: fsl_ifc: Read ECCSTAT0 and ECCSTAT1 registers for IFC 2.0
  mtd: nand: fsl_ifc: Fix eccstat array overflow for IFC ver >= 2.0.0
  mtd: nand: fsl_ifc: Fix nand waitfunc return value
  mtdchar: fix usage of mtd_ooblayout_ecc()

Pull staging/IIO fixes from Greg KH:
 "Here are a few small staging and IIO fixes for various reported
  issues.

  All of them are tiny, the majority being iio driver fixes for small
  issues, and one staging driver fix for a memory corruption issue.

  All have been in linux-next with no reported issues"

* tag 'staging-4.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: ncpfs: memory corruption in ncp_read_kernel()
  iio: st_pressure: st_accel: pass correct platform data to init
  Revert "iio: accel: st_accel: remove redundant pointer pdata"
  iio: adc: meson-saradc: unlock on error in meson_sar_adc_lock()
  dt-bindings: iio: adc: sd-modulator: fix io-channel-cells
  iio: adc: stm32-dfsdm: fix multiple channel initialization
  iio: adc: stm32-dfsdm: fix clock source selection
  iio: adc: stm32-dfsdm: fix call to stop channel
  iio: adc: stm32-dfsdm: fix compatible data use
  iio: chemical: ccs811: Corrected firmware boot/application mode transition

Pull hyperv fix from Greg KH:
 "This is a single hyperv bugfix for 4.16-rc7.

  It resolves an issue with the ring-buffer signaling to resolve
  reported problems.

  It's been in linux-next for a while now with no reported issues"

* tag 'char-misc-4.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Drivers: hv: vmbus: Fix ring buffer signaling

Pull media fixes from Mauro Carvalho Chehab:
 "Three fixes:

   - dvb: fix a Kconfig typo on a help text

   - tegra-cec: reset rx_buf_cnt when start bit detected

   - rc: lirc does not use LIRC_CAN_SEND_SCANCODE feature"

* tag 'media/v4.16-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: dvb: fix a Kconfig typo
  media: tegra-cec: reset rx_buf_cnt when start bit detected
  media: rc: lirc does not use LIRC_CAN_SEND_SCANCODE feature

Pull sound fixes from Takashi Iwai:
 "Things look calming down, but people were still busy to plaster over
  small holes:

   - Two fixes to harden against races in aloop driver

   - A correction of a long-standing bug in USB-audio UAC2 processing
     unit parser

   - As usual suspects, HD-audio: a workaround for Coffee Lake
     controller and a few other device-specific fixes

  All small and for stable"

* tag 'sound-4.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: aloop: Fix access to not-yet-ready substream via cable
  ALSA: aloop: Sync stale timer before release
  ALSA: hda/realtek - Fix speaker no sound after system resume
  ALSA: hda/realtek - Fix Dell headset Mic can't record
  ALSA: hda - Force polling mode on CFL for fixing codec communication
  ALSA: usb-audio: Fix parsing descriptor of UAC2 processing unit
  ALSA: hda/realtek - Always immediately update mute LED with pin VREF

Add a testcase for probe point definition. This tests
symbol, address and symbol+offset syntax. The offset
must be positive and smaller than UINT_MAX.

Link: http://lkml.kernel.org/r/152129043097.31874.14273580606301767394.stgit@devboxSigned-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add a testcase for string type with kprobe event.
This tests good/bad syntax combinations and also
the traced data is correct in several way.

Link: http://lkml.kernel.org/r/152129038381.31874.9201387794548737554.stgit@devboxSigned-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Add a testcase for probe event argument syntax which
ensures the kprobe_events interface correctly parses
given event arguments.

Link: http://lkml.kernel.org/r/152129033679.31874.12705519603869152799.stgit@devboxSigned-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

In Documentation/trace/kprobetrace.txt, it says

 @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)

However, the parser doesn't parse minus offset correctly, since
commit 2fba0c88 ("tracing/kprobes: Fix probe offset to be
unsigned") drops minus ("-") offset support for kprobe probe
address usage.

This fixes the traceprobe_split_symbol_offset() to parse minus
offset again with checking the offset range, and add a minus
offset check in kprobe probe address usage.

Link: http://lkml.kernel.org/r/152129028983.31874.13419301530285775521.stgit@devbox

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 2fba0c88 ("tracing/kprobes: Fix probe offset to be unsigned")
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Merge misc fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, thp: do not cause memcg oom for thp
  mm/vmscan: wake up flushers for legacy cgroups too
  Revert "mm: page_alloc: skip over regions of invalid pfns where possible"
  mm/shmem: do not wait for lock_page() in shmem_unused_huge_shrink()
  mm/thp: do not wait for lock_page() in deferred_split_scan()
  mm/khugepaged.c: convert VM_BUG_ON() to collapse fail
  x86/mm: implement free pmd/pte page interfaces
  mm/vmalloc: add interfaces to free unmapped page table
  h8300: remove extraneous __BIG_ENDIAN definition
  hugetlbfs: check for pgoff value overflow
  lockdep: fix fs_reclaim warning
  MAINTAINERS: update Mark Fasheh's e-mail
  mm/mempolicy.c: avoid use uninitialized preferred_node

Pull libnvdimm fixes from Dan Williams:
 "Two regression fixes, two bug fixes for older issues, two fixes for
  new functionality added this cycle that have userspace ABI concerns,
  and a small cleanup. These have appeared in a linux-next release and
  have a build success report from the 0day robot.

   * The 4.16 rework of altmap handling led to some configurations
     leaking page table allocations due to freeing from the altmap
     reservation rather than the page allocator.

     The impact without the fix is leaked memory and a WARN() message
     when tearing down libnvdimm namespaces. The rework also missed a
     place where error handling code needed to be removed that can lead
     to a crash if devm_memremap_pages() fails.

   * acpi_map_pxm_to_node() had a latent bug whereby it could
     misidentify the closest online node to a given proximity domain.

   * Block integrity handling was reworked several kernels back to allow
     calling add_disk() after setting up the integrity profile.

     The nd_btt and nd_blk drivers are just now catching up to fix
     automatic partition detection at driver load time.

   * The new peristence_domain attribute, a platform indicator of
     whether cpu caches are powerfail protected for example, is meant to
     be a single value enum and not a set of flags.

     This oversight was caught while reviewing new userspace code in
     libndctl to communicate the attribute.

     Fix this new enabling up so that we are not stuck with an unwanted
     userspace ABI"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, nfit: fix persistence domain reporting
  libnvdimm, region: hide persistence_domain when unknown
  acpi, numa: fix pxm to online numa node associations
  x86, memremap: fix altmap accounting at free
  libnvdimm: remove redundant assignment to pointer 'dev'
  libnvdimm, {btt, blk}: do integrity setup before add_disk()
  kernel/memremap: Remove stale devres_free() call

Pull drm fixes from Dave Airlie:
 "A bunch of fixes all over the place (core, i915, amdgpu, imx, sun4i,
  ast, tegra, vmwgfx), nothing too serious or worrying at this stage.

   - one uapi fix to stop multi-planar images with getfb

   - Sun4i error path and clock fixes

   - udl driver mmap offset fix

   - i915 DP MST and GPU reset fixes

   - vmwgfx mutex and black screen fixes

   - imx array underflow fix and vblank fix

   - amdgpu: display fixes

   - exynos devicetree fix

   - ast mode fix"

* tag 'drm-fixes-for-v4.16-rc7' of git://people.freedesktop.org/~airlied/linux: (29 commits)
  drm/ast: Fixed 1280x800 Display Issue
  drm: udl: Properly check framebuffer mmap offsets
  drm/i915: Specify which engines to reset following semaphore/event lockups
  drm/vmwgfx: Fix a destoy-while-held mutex problem.
  drm/vmwgfx: Fix black screen and device errors when running without fbdev
  drm: Reject getfb for multi-plane framebuffers
  drm/amd/display: Add one to EDID's audio channel count when passing to DC
  drm/amd/display: We shouldn't set format_default on plane as atomic driver
  drm/amd/display: Fix FMT truncation programming
  drm/amd/display: Allow truncation to 10 bits
  drm/sun4i: hdmi: Fix another error handling path in 'sun4i_hdmi_bind()'
  drm/sun4i: hdmi: Fix an error handling path in 'sun4i_hdmi_bind()'
  drm/i915/dp: Write to SET_POWER dpcd to enable MST hub.
  drm/amd/display: fix dereferencing possible ERR_PTR()
  drm/amd/display: Refine disable VGA
  drm/tegra: Shutdown on driver unbind
  drm/tegra: dsi: Don't disable regulator on ->exit()
  drm/tegra: dc: Detach IOMMU group from domain only once
  dt-bindings: exynos: Document #sound-dai-cells property of the HDMI node
  drm/imx: move arming of the vblank event to atomic_flush
  ...

Commit 25160354 ("mm, thp: remove __GFP_NORETRY from khugepaged and
madvised allocations") changed the page allocator to no longer detect
thp allocations based on __GFP_NORETRY.

It did not, however, modify the mem cgroup try_charge() path to avoid
oom kill for either khugepaged collapsing or thp faulting.  It is never
expected to oom kill a process to allocate a hugepage for thp; reclaim
is governed by the thp defrag mode and MADV_HUGEPAGE, but allocations
(and charging) should fallback instead of oom killing processes.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803191409420.124411@chino.kir.corp.google.com
Fixes: 25160354 ("mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations")
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 726d061f ("mm: vmscan: kick flushers when we encounter dirty
pages on the LRU") added flusher invocation to shrink_inactive_list()
when many dirty pages on the LRU are encountered.

However, shrink_inactive_list() doesn't wake up flushers for legacy
cgroup reclaim, so the next commit bbef9384 ("mm: vmscan: remove old
flusher wakeup from direct reclaim path") removed the only source of
flusher's wake up in legacy mem cgroup reclaim path.

This leads to premature OOM if there is too many dirty pages in cgroup:
    # mkdir /sys/fs/cgroup/memory/test
    # echo $$ > /sys/fs/cgroup/memory/test/tasks
    # echo 50M > /sys/fs/cgroup/memory/test/memory.limit_in_bytes
    # dd if=/dev/zero of=tmp_file bs=1M count=100
    Killed

    dd invoked oom-killer: gfp_mask=0x14000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=0

    Call Trace:
     dump_stack+0x46/0x65
     dump_header+0x6b/0x2ac
     oom_kill_process+0x21c/0x4a0
     out_of_memory+0x2a5/0x4b0
     mem_cgroup_out_of_memory+0x3b/0x60
     mem_cgroup_oom_synchronize+0x2ed/0x330
     pagefault_out_of_memory+0x24/0x54
     __do_page_fault+0x521/0x540
     page_fault+0x45/0x50

    Task in /test killed as a result of limit of /test
    memory: usage 51200kB, limit 51200kB, failcnt 73
    memory+swap: usage 51200kB, limit 9007199254740988kB, failcnt 0
    kmem: usage 296kB, limit 9007199254740988kB, failcnt 0
    Memory cgroup stats for /test: cache:49632KB rss:1056KB rss_huge:0KB shmem:0KB
            mapped_file:0KB dirty:49500KB writeback:0KB swap:0KB inactive_anon:0KB
	    active_anon:1168KB inactive_file:24760KB active_file:24960KB unevictable:0KB
    Memory cgroup out of memory: Kill process 3861 (bash) score 88 or sacrifice child
    Killed process 3876 (dd) total-vm:8484kB, anon-rss:1052kB, file-rss:1720kB, shmem-rss:0kB
    oom_reaper: reaped process 3876 (dd), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB

Wake up flushers in legacy cgroup reclaim too.

Link: http://lkml.kernel.org/r/20180315164553.17856-1-aryabinin@virtuozzo.com
Fixes: bbef9384 ("mm: vmscan: remove old flusher wakeup from direct reclaim path")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>