This patch adds support to compute context invoke method on the
remote processor (DSP).
This involves setting up the functions input and output arguments,
input and output handles and mapping the dmabuf fd for the
argument/handle buffers.

The below diagram depicts invocation of a single method where the
client and objects reside on different processors. An object could
expose multiple methods which can be grouped together and referred
to as an interface.

,--------,        ,------,  ,-----------,  ,------,        ,--------,
|        | method |      |  |           |  |      | method |        |
| Client |------->| Stub |->| Transport |->| Skel |------->| Object |
|        |        |      |  |           |  |      |        |        |
`--------`        `------`  `-----------`  `------`        `--------`

Client:    Linux user mode process that initiates the remote invocation
Stub:      Auto generated code linked in with the user mode process that
           takes care of marshaling parameters
Transport: Involved in carrying an invocation from a client to an
           object. This involves two portions: 1) FastRPC Linux
           kernel driver that receives the remote invocation, queues
           them up and then waits for the response after signaling the
           remote side. 2) Service running on the remote side that
           dequeues the messages from the queue and dispatches them for
           processing.
Skel:      Auto generated code that takes care of un-marshaling
           parameters
Object:    Method implementation

Most of the work is derived from various downstream Qualcomm kernels.
Credits to various Qualcomm authors who have contributed to this code.
Specially Tharun Kumar Merugu <mtharu@codeaurora.org>

Co-developed-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds basic driver model for Qualcomm FastRPC driver which
implements an IPC (Inter-Processor Communication) mechanism that
allows for clients to transparently make remote method invocations
across processor boundaries.

Each DSP rpmsg channel is represented as fastrpc channel context and
is exposed as a character device for userspace interface.
Each compute context bank is represented as fastrpc-session-context,
which are dynamically managed by the channel context char device.

Co-developed-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The FastRPC driver implements an IPC (Inter-Processor Communication)
mechanism that allows for clients to transparently make remote method
invocations across DSP and APPS boundaries. This enables developers
to offload tasks to the DSP and free up the application processor for
other tasks.

Co-developed-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We added some locking to this function but forgot to drop the lock on
these two error paths.  This bug would lead to an immediate deadlock.

Fixes: c7b3690f

 ("vmw_balloon: stats rework")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Reviewed-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Export to_mei_cl_device macro, as it is needed also
in the mei client drivers.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In the original code before 181bf1e8 the loop was continuing until
it finds the first matching superios[i].io and p->base.
But after 181bf1e8 the logic changed and the loop now returns the
pointer to the first mismatched array element which is then used in
get_superio_dma() and get_superio_irq() and thus returning the wrong
value.
Fix the condition so that it now returns the correct pointer.

Fixes: 181bf1e8

 ("parport_pc: clean up the modified while loops using for")
Cc: Alan Cox <alan@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: QiaoChong <qiaochong@loongson.cn>
[rewrite the commit message]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge tag 'extcon-next-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon into char-misc-next

Chanwoo writes:

Update extcon for 5.1

Detailed description for this pull request:
1. Add new extcon-ptn5150.c extcon provider driver
- NXP PTN5150 supports the detection of USB connectors through
USB Type-C port and controls it. It is interfaced to the host
controller using an I2C interface.

* tag 'extcon-next-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon:
  extcon: ptn5150: Fix return value check in ptn5150_i2c_probe()
  extcon: Add support for ptn5150 extcon driver

In case of error, the function devm_gpiod_get() returns ERR_PTR() and
never returns NULL. The NULL test in the return value check should be
replaced with IS_ERR().

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PTN5150 is a small thin low power CC (Configurationn Channel)
Logic chip supporting the USB Type-C connector application with
CC control logic detection and indication functions.

Signed-off-by: Vijai Kumar K <vijaikumar.kanagarajan@gmail.com>
[cw00.choi: Fix bulid dependency and clean-up code]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

We need the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull dmaengine fixes from Vinod Koul:
 - Fix in at_xdmac fr wrongful channel state
 - Fix for imx driver for wrong callback invocation
 - Fix to bcm driver for interrupt race & transaction abort.
 - Fix in dmatest to abort in mapping error

* tag 'dmaengine-fix-5.0-rc6' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dmatest: Abort test in case of mapping error
  dmaengine: bcm2835: Fix abort of transactions
  dmaengine: bcm2835: Fix interrupt race on RT
  dmaengine: imx-dma: fix wrong callback invoke
  dmaengine: at_xdmac: Fix wrongfull report of a channel as in use

Pull x86 fixes from Ingo Molnar:
 "A handful of fixes:

   - Fix an MCE corner case bug/crash found via MCE injection testing

   - Fix 5-level paging boot crash

   - Fix MCE recovery cache invalidation bug

   - Fix regression on Xen guests caused by a recent PMD level mremap
     speedup optimization"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Make set_pmd_at() paravirt aware
  x86/mm/cpa: Fix set_mce_nospec()
  x86/boot/compressed/64: Do not corrupt EDX on EFER.LME=1 setting
  x86/MCE: Initialize mce.bank in the case of a fatal error in mce_no_way_out()

Pull irq fixes from Ingo Molnar:
 "irqchip driver fixes: most of them are race fixes for ARM GIC (General
  Interrupt Controller) variants, but also a fix for the ARM MMP
  (Marvell PXA168 et al) irqchip affecting OLPC keyboards"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Fix ITT_entry_size accessor
  irqchip/mmp: Only touch the PJ4 IRQ & FIQ bits on enable/disable
  irqchip/gic-v3-its: Gracefully fail on LPI exhaustion
  irqchip/gic-v3-its: Plug allocation race for devices sharing a DevID
  irqchip/gic-v4: Fix occasional VLPI drop

Pull perf fixes from Ingo Molnar:
 "A couple of kernel side fixes:

   - Fix the Intel uncore driver on certain hardware configurations

   - Fix a CPU hotplug related memory allocation bug

   - Remove a spurious WARN()

  ... plus also a handful of perf tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf script python: Add Python3 support to tests/attr.py
  perf trace: Support multiple "vfs_getname" probes
  perf symbols: Filter out hidden symbols from labels
  perf symbols: Add fallback definitions for GELF_ST_VISIBILITY()
  tools headers uapi: Sync linux/in.h copy from the kernel sources
  perf clang: Do not use 'return std::move(something)'
  perf mem/c2c: Fix perf_mem_events to support powerpc
  perf tests evsel-tp-sched: Fix bitwise operator
  perf/core: Don't WARN() for impossible ring-buffer sizes
  perf/x86/intel: Delay memory deallocation until x86_pmu_dead_cpu()
  perf/x86/intel/uncore: Add Node ID mask

Pull locking fixes from Ingo Molnar:
 "An rtmutex (PI-futex) deadlock scenario fix, plus a locking
  documentation fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Handle early deadlock return correctly
  futex: Fix barrier comment

set_pmd_at() calls native_set_pmd() unconditionally on x86. This was
fine as long as only huge page entries were written via set_pmd_at(),
as Xen pv guests don't support those.

Commit 2c91bd4a ("mm: speed up mremap by 20x on large regions")
introduced a usage of set_pmd_at() possible on pv guests, leading to
failures like:

BUG: unable to handle kernel paging request at ffff888023e26778
#PF error: [PROT] [WRITE]
RIP: e030:move_page_tables+0x7c1/0xae0
move_vma.isra.3+0xd1/0x2d0
__se_sys_mremap+0x3c6/0x5b0
 do_syscall_64+0x49/0x100
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Make set_pmd_at() paravirt aware by just letting it use set_pmd().

Fixes: 2c91bd4a

 ("mm: speed up mremap by 20x on large regions")
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Cc: sstabellini@kernel.org
Cc: hpa@zytor.com
Cc: bp@alien8.de
Cc: torvalds@linux-foundation.org
Link: https://lkml.kernel.org/r/20190210074056.11842-1-jgross@suse.com

Pull i2c fixes from Wolfram Sang:
 "One PM related driver bugfix and a MAINTAINERS update"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  MAINTAINERS: Update the ocores i2c bus driver maintainer, etc
  i2c: omap: Use noirq system sleep pm ops to idle device for suspend

Pull MIPS fixes from Paul Burton:
 "A batch of MIPS fixes for 5.0, nothing too scary.

   - A workaround for a Loongson 3 CPU bug is the biggest change, but
     still fairly straightforward. It adds extra memory barriers (sync
     instructions) around atomics to avoid a CPU bug that can break
     atomicity.

   - Loongson64 also sees a fix for powering off some systems which
     would incorrectly reboot rather than waiting for the power down
     sequence to complete.

   - We have DT fixes for the Ingenic JZ4740 SoC & the JZ4780-based Ci20
     board, and a DT warning fix for the Nexsys4/MIPSfpga board.

   - The Cavium Octeon platform sees a further fix to the behaviour of
     the pcie_disable command line argument that was introduced in v3.3.

   - The VDSO, introduced in v4.4, sees build fixes for configurations
     of GCC that were built using the --with-fp-32= flag to specify a
     default 32-bit floating point ABI.

   - get_frame_info() sees a fix for configurations with
     CONFIG_KALLSYMS=n, for which it previously always returned an
     error.

   - If the MIPS Coherence Manager (CM) reports an error then we'll now
     clear that error correctly so that the GCR_ERROR_CAUSE register
     will be updated with information about any future errors"

* tag 'mips_fixes_5.0_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  mips: cm: reprime error cause
  mips: loongson64: remove unreachable(), fix loongson_poweroff().
  MIPS: Remove function size check in get_frame_info()
  MIPS: Use lower case for addresses in nexys4ddr.dts
  MIPS: Loongson: Introduce and use loongson_llsc_mb()
  MIPS: VDSO: Include $(ccflags-vdso) in o32,n32 .lds builds
  MIPS: VDSO: Use same -m%-float cflag as the kernel proper
  MIPS: OCTEON: don't set octeon_dma_bar_type if PCI is disabled
  DTS: CI20: Fix bugs in ci20's device tree.
  MIPS: DTS: jz4740: Correct interrupt number of DMA core

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph, fixing namespace locking when
   dealing with the effects log, and a rapid add/remove issue (Keith)

 - blktrace tweak, ensuring requests with -1 sectors are shown (Jan)

 - link power management quirk for a Smasung SSD (Hans)

 - m68k nfblock dynamic major number fix (Chengguang)

 - series fixing blk-iolatency inflight counter issue (Liu)

 - ensure that we clear ->private when setting up the aio kiocb (Mike)

 - __find_get_block_slow() rate limit print (Tetsuo)

* tag 'for-linus-20190209' of git://git.kernel.dk/linux-block:
  blk-mq: remove duplicated definition of blk_mq_freeze_queue
  Blk-iolatency: warn on negative inflight IO counter
  blk-iolatency: fix IO hang due to negative inflight counter
  blktrace: Show requests without sector
  fs: ratelimit __find_get_block_slow() failure message.
  m68k: set proper major_num when specifying module param major_num
  libata: Add NOLPM quirk for SAMSUNG MZ7TE512HMHP-000L1 SSD
  nvme-pci: fix rapid add remove sequence
  nvme: lock NS list changes while handling command effects
  aio: initialize kiocb private in case any filesystems expect it.

Pull mtd fixes from Boris Brezillon:

 - Fix a problem with the imx28 ECC engine

 - Remove a debug trace introduced in 2b6f0090 ("mtd: Check
   add_mtd_device() ret code")

 - Make sure partitions of size 0 can be registered

 - Fix kernel-doc warning in the rawnand core

 - Fix the error path of spinand_init() (missing manufacturer cleanup in
   a few places)

 - Address a problem with the SPI NAND PROGRAM LOAD operation which does
   not work as expected on some parts.

* tag 'mtd/fixes-for-5.0-rc6' of git://git.infradead.org/linux-mtd:
  mtd: rawnand: gpmi: fix MX28 bus master lockup problem
  mtd: Make sure mtd->erasesize is valid even if the partition is of size 0
  mtd: Remove a debug trace in mtdpart.c
  mtd: rawnand: fix kernel-doc warnings
  mtd: spinand: Fix the error/cleanup path in spinand_init()
  mtd: spinand: Handle the case where PROGRAM LOAD does not reset the cache

Pull xen fixes from Juergen Gross:
 "Two very minor fixes: one remove of a #include for an unused header
  and a fix of the xen ML address in MAINTAINERS"

* tag 'for-linus-5.0-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  MAINTAINERS: unify reference to xen-devel list
  arch/arm/xen: Remove duplicate header

Merge tag 'perf-urgent-for-mingo-5.0-20190205' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

 into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

perf trace:

  Arnaldo Carvalho de Melo:

    Fix handling of probe:vfs_getname when the probed routine is
    inlined in multiple places, fixing the collection of the 'filename'
    parameter in open syscalls.

perf test:

  Gustavo A. R. Silva:

    Fix bitwise operator usage in evsel-tp-sched test, which made tat
    test always detect fields as signed.

  Jiri Olsa:

    Filter out hidden symbols from labels, added in systems where the
    annobin plugin is used, such as RHEL8, which, if left in place make
    the DWARF unwind 'perf test' to fail on PPC.

  Tony Jones:

    Fix 'perf_event_attr' tests when building with python3.

perf mem/c2c:

  Ravi Bangoria:

    Fix perf_mem_events on PowerPC.

tools headers UAPI:

  Arnaldo Carvalho de Melo:

    Sync linux/in.h copy from the kernel sources, silencing a perf build warning.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull ARM SoC fixes from Arnd Bergmann:
 "This is a bit larger than normal, as we had not managed to send out a
  pull request before traveling for a week without my signing key.

  There are multiple code fixes for older bugs, all of which should get
  backported into stable kernels:

   - tango: one fix for multiplatform configurations broken on other
     platforms when tango is enabled

   - arm_scmi: device unregistration fix

   - iop32x: fix kernel oops from extraneous __init annotation

   - pxa: remove a double kfree

   - fsl qbman: close an interrupt clearing race

  The rest is the usual collection of smaller fixes for device tree
  files, on the renesas, allwinner, meson, omap, davinci, qualcomm and
  imx platforms.

  Some of these are for compile-time warnings, most are for board
  specific functionality that fails to work because of incorrect
  settings"

* tag 'armsoc-fixes-5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (30 commits)
  ARM: tango: Improve ARCH_MULTIPLATFORM compatibility
  firmware: arm_scmi: provide the mandatory device release callback
  ARM: iop32x/n2100: fix PCI IRQ mapping
  arm64: dts: add msm8996 compatible to gicv3
  ARM: dts: am335x-shc.dts: fix wrong cd pin level
  ARM: dts: n900: fix mmc1 card detect gpio polarity
  ARM: dts: omap3-gta04: Fix graph_port warning
  ARM: pxa: ssp: unneeded to free devm_ allocated data
  ARM: dts: r8a7743: Convert to new LVDS DT bindings
  soc: fsl: qbman: avoid race in clearing QMan interrupt
  arm64: dts: renesas: r8a77965: Enable DMA for SCIF2
  arm64: dts: renesas: r8a7796: Enable DMA for SCIF2
  arm64: dts: renesas: r8a774a1: Enable DMA for SCIF2
  ARM: dts: da850: fix interrupt numbers for clocksource
  dt-bindings: imx8mq: Number clocks consecutively
  arm64: dts: meson: Fix mmc cd-gpios polarity
  ARM: dts: imx6sx: correct backward compatible of gpt
  ARM: dts: imx: replace gpio-key,wakeup with wakeup-source property
  ARM: dts: vf610-bk4: fix incorrect #address-cells for dspi3
  ARM: dts: meson8m2: mxiii-plus: mark the SD card detection GPIO active-low
  ...

Pull arm64 fixes from Will Deacon:
 "Two arm64 fixes for -rc6. They resolve a kernel NULL dereference in
  kexec and bogus kernel page table dumping when userspace is configured
  for 52-bit virtual addressing.

  Summary:

   - Fix kernel oops when attemping kexec_file() with a NULL cmdline

   - Fix page table output in debugfs when ARM64_USER_VA_BITS_52=y"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: kexec_file: handle empty command-line
  arm64: ptdump: Don't iterate kernel page tables using PTRS_PER_PXX

Pull powerpc fixes from Michael Ellerman:
 "Just two fixes, both going to stable.

   - Our support for split pmd page table lock had a bug which could
     lead to a crash on mremap() when using the Radix MMU (Power9 only).

   - A fix for the PAPR SCM driver (nvdimm) we added last release, which
     had a bug where we might mis-handle a hypervisor response leading
     to us failing to attach the memory region.

  Thanks to: Aneesh Kumar K.V, Oliver O'Halloran"

* tag 'powerpc-5.0-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/papr_scm: Use the correct bind address
  powerpc/radix: Fix kernel crash with mremap()

Pull signal fixes from Eric Biederman:
 "This contains four small fixes for signal handling. A missing range
  check, a regression fix, prioritizing signals we have already started
  a signal group exit for, and better detection of synchronous signals.

  The confused decision of which signals to handle failed spectacularly
  when a timer was pointed at SIGBUS and the stack overflowed. Resulting
  in an unkillable process in an infinite loop instead of a SIGSEGV and
  core dump"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Better detection of synchronous signals
  signal: Always notice exiting tasks
  signal: Always attempt to allocate siginfo for SIGSTOP
  signal: Make siginmask safe when passed a signal of 0

Pull SCSI fixes from James Bottomley:
 "This is a set of five minor fixes (although, tecnhincally, the aicxxx
  fix is for a major problem in that the driver won't load without it,
  but I think the fact it's taken us since 4.10 to discover this
  indicates that the user base for these things has declined)"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: cxlflash: Prevent deadlock when adapter probe fails
  Revert "scsi: libfc: Add WARN_ON() when deleting rports"
  scsi: sd_zbc: Fix zone information messages
  scsi: target: make the pi_prot_format ConfigFS path readable
  scsi: aic94xx: fix module loading

Pull IOMMU fix from Joerg Roedel:
 "Intel decided to leave the newly added Scalable Mode Feature
  default-disabled for now. The patch here accomplishes that"

* tag 'iommu-fixes-v5.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Leave scalable mode default off

Pull PCI fix from Bjorn Helgaas:
 "Work around Synopsys duplicate Device ID (HAPS USB3, NXP i.MX) that
  breaks PCIe on I.MX SoCs (Thinh Nguyen)"

* tag 'pci-v5.0-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Work around Synopsys duplicate Device ID (HAPS USB3, NXP i.MX)

Pull ACPI fix from Rafael Wysocki:
 "This prevents excessive ACPI debug messages from being printed to the
  kernel log, which has started to happen after one of the recent ACPICA
  commits (Erik Schmauss)"

* tag 'acpi-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: Set debug output flags independent of ACPICA

The listed maintainer has not been responding to emails for a while.
Add myself as a second maintainer.

Add the platform data include file, which was not listed.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

As the prototype has been defined in "include/linux/blk-mq.h", the one
in "block/blk-mq.h" can be removed then.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This is to catch any unexpected negative value of inflight IO counter.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Our test reported the following stack, and vmcore showed that
->inflight counter is -1.

[ffffc9003fcc38d0] __schedule at ffffffff8173d95d
[ffffc9003fcc3958] schedule at ffffffff8173de26
[ffffc9003fcc3970] io_schedule at ffffffff810bb6b6
[ffffc9003fcc3988] blkcg_iolatency_throttle at ffffffff813911cb
[ffffc9003fcc3a20] rq_qos_throttle at ffffffff813847f3
[ffffc9003fcc3a48] blk_mq_make_request at ffffffff8137468a
[ffffc9003fcc3b08] generic_make_request at ffffffff81368b49
[ffffc9003fcc3b68] submit_bio at ffffffff81368d7d
[ffffc9003fcc3bb8] ext4_io_submit at ffffffffa031be00 [ext4]
[ffffc9003fcc3c00] ext4_writepages at ffffffffa03163de [ext4]
[ffffc9003fcc3d68] do_writepages at ffffffff811c49ae
[ffffc9003fcc3d78] __filemap_fdatawrite_range at ffffffff811b6188
[ffffc9003fcc3e30] filemap_write_and_wait_range at ffffffff811b6301
[ffffc9003fcc3e60] ext4_sync_file at ffffffffa030cee8 [ext4]
[ffffc9003fcc3ea8] vfs_fsync_range at ffffffff8128594b
[ffffc9003fcc3ee8] do_fsync at ffffffff81285abd
[ffffc9003fcc3f18] sys_fsync at ffffffff81285d50
[ffffc9003fcc3f28] do_syscall_64 at ffffffff81003c04
[ffffc9003fcc3f50] entry_SYSCALL_64_after_swapgs at ffffffff81742b8e

The ->inflight counter may be negative (-1) if

1) blk-iolatency was disabled when the IO was issued,

2) blk-iolatency was enabled before this IO reached its endio,

3) the ->inflight counter is decreased from 0 to -1 in endio()

In fact the hang can be easily reproduced by the below script,

H=/sys/fs/cgroup/unified/
P=/sys/fs/cgroup/unified/test

echo "+io" > $H/cgroup.subtree_control
mkdir -p $P

echo $$ > $P/cgroup.procs

xfs_io -f -d -c "pwrite 0 4k" /dev/sdg

echo "`cat /sys/block/sdg/dev` target=1000000" > $P/io.latency

xfs_io -f -d -c "pwrite 0 4k" /dev/sdg

This fixes the problem by freezing the queue so that while
enabling/disabling iolatency, there is no inflight rq running.

Note that quiesce_queue is not needed as this only updating iolatency
configuration about which dispatching request_queue doesn't care.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull networking fixes from David Miller:
 "This pull request is dedicated to the upcoming snowpocalypse parts 2
  and 3 in the Pacific Northwest:

   1) Drop profiles are broken because some drivers use dev_kfree_skb*
      instead of dev_consume_skb*, from Yang Wei.

   2) Fix IWLWIFI kconfig deps, from Luca Coelho.

   3) Fix percpu maps updating in bpftool, from Paolo Abeni.

   4) Missing station release in batman-adv, from Felix Fietkau.

   5) Fix some networking compat ioctl bugs, from Johannes Berg.

   6) ucc_geth must reset the BQL queue state when stopping the device,
      from Mathias Thore.

   7) Several XDP bug fixes in virtio_net from Toshiaki Makita.

   8) TSO packets must be sent always on queue 0 in stmmac, from Jose
      Abreu.

   9) Fix socket refcounting bug in RDS, from Eric Dumazet.

  10) Handle sparse cpu allocations in bpf selftests, from Martynas
      Pumputis.

  11) Make sure mgmt frames have enough tailroom in mac80211, from Felix
      Feitkau.

  12) Use safe list walking in sctp_sendmsg() asoc list traversal, from
      Greg Kroah-Hartman.

  13) Make DCCP's ccid_hc_[rt]x_parse_options always check for NULL
      ccid, from Eric Dumazet.

  14) Need to reload WoL password into bcmsysport device after deep
      sleeps, from Florian Fainelli.

  15) Remove filter from mask before freeing in cls_flower, from Petr
      Machata.

  16) Missing release and use after free in error paths of s390 qeth
      code, from Julian Wiedmann.

  17) Fix lockdep false positive in dsa code, from Marc Zyngier.

  18) Fix counting of ATU violations in mv88e6xxx, from Andrew Lunn.

  19) Fix EQ firmware assert in qed driver, from Manish Chopra.

  20) Don't default Caivum PTP to Y in kconfig, from Bjorn Helgaas"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (116 commits)
  net: dsa: b53: Fix for failure when irq is not defined in dt
  sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach()
  geneve: should not call rt6_lookup() when ipv6 was disabled
  net: Don't default Cavium PTP driver to 'y'
  net: broadcom: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: via-velocity: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: tehuti: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: sun: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: fsl_ucc_hdlc: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: fec_mpc52xx: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: smsc: epic100: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: dscc4: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: tulip: de2104x: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net: defxx: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles
  net/mlx5e: Don't overwrite pedit action when multiple pedit used
  net/mlx5e: Update hw flows when encap source mac changed
  qed*: Advance drivers version to 8.37.0.20
  qed: Change verbosity for coalescing message.
  qede: Fix system crash on configuring channels.
  qed: Consider TX tcs while deriving the max num_queues for PF.
  ...

Pull char/misc fixes from Greg KH:
 "Here are some small char and misc driver fixes for 5.0-rc6.

  Nothing huge here, some more binderfs fixups found as people use it,
  and there is a "large" selftest added to validate the binderfs code,
  which makes up the majority of this pull request.

  There's also some small mei and mic fixes to resolve some reported
  issues.

  All of these have been in linux-next for over a week with no reported
  issues"

* tag 'char-misc-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  mic: vop: Fix crash on remove
  mic: vop: Fix use-after-free on remove
  binderfs: remove separate device_initcall()
  fpga: stratix10-soc: fix wrong of_node_put() in init function
  mic: vop: Fix broken virtqueues
  mei: free read cb on ctrl_wr list flush
  samples: mei: use /dev/mei0 instead of /dev/mei
  mei: me: add ice lake point device id.
  binderfs: respect limit on binder control creation
  binder: fix CONFIG_ANDROID_BINDER_DEVICES
  selftests: add binderfs selftests

Pull driver core fixes from Greg KH:
 "Here are some driver core fixes for 5.0-rc6.

  Well, not so much "driver core" as "debugfs". There's a lot of
  outstanding debugfs cleanup patches coming in through different
  subsystem trees, and in that process the debugfs core was found that
  it really should return errors when something bad happens, to prevent
  random files from showing up in the root of debugfs afterward. So
  debugfs was fixed up to handle this properly, and then two fixes for
  the relay and blk-mq code was needed as it was making invalid
  assumptions about debugfs return values.

  There's also a cacheinfo fix in here that resolves a tiny issue.

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

* tag 'driver-core-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  blk-mq: protect debugfs_create_files() from failures
  relay: check return of create_buf_file() properly
  debugfs: debugfs_lookup() should return NULL if not found
  debugfs: return error values, not NULL
  debugfs: fix debugfs_rename parameter checking
  cacheinfo: Keep the old value if of_property_read_u32 fails

Pull staging/IIO driver fixes from Greg KH:
 "Here are some small iio and staging driver fixes for 5.0-rc6.

  Nothing big, just resolve some reported IIO driver issues, and one
  staging driver bug. One staging driver patch was added and then
  reverted as well.

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

* tag 'staging-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  Revert "staging: erofs: keep corrupted fs from crashing kernel in erofs_namei()"
  staging: erofs: keep corrupted fs from crashing kernel in erofs_namei()
  staging: octeon: fix broken phylib usage
  iio: ti-ads8688: Update buffer allocation for timestamps
  tools: iio: iio_generic_buffer: make num_loops signed
  iio: adc: axp288: Fix TS-pin handling
  iio: chemical: atlas-ph-sensor: correct IIO_TEMP values to millicelsius

Pull tty/serial fixes from Greg KH:
 "Here are some small tty and serial fixes for 5.0-rc6.

  Nothing huge, just a few small fixes for reported issues. The speakup
  fix is in here as it is a tty operation issue.

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

* tag 'tty-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: fix race between flush_to_ldisc and tty_open
  staging: speakup: fix tty-operation NULL derefs
  serial: sh-sci: Do not free irqs that have already been freed
  serial: 8250_pci: Make PCI class test non fatal
  tty: serial: 8250_mtk: Fix potential NULL pointer dereference