If the number of dirty pages to be written back is large,
then writeback_inodes_sb will block waiting for a long time,
causing hung task detection alarm. Therefore, we should limit
the maximum number of pages written back this time, which let
the budget be completed faster. The remaining dirty pages
tend to rely on the writeback mechanism to complete the
synchronization.

Fixes: b6e51316 ("writeback: separate starting of sync vs opportunistic writeback")
Signed-off-by: NLiu Song <liu.song11@zte.com.cn>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Currently on a freshly mounted UBIFS, c->min_log_bytes is 0.
This can lead to a log overrun and make commits fail.

Recent kernels will report the following assert:
UBIFS assert failed: c->lhead_lnum != c->ltail_lnum, in fs/ubifs/log.c:412

c->min_log_bytes can have two states, 0 and c->leb_size.
It controls how much bytes of the log area are reserved for non-bud
nodes such as commit nodes.

After a commit it has to be set to c->leb_size such that we have always
enough space for a commit. While a commit runs it can be 0 to make the
remaining bytes of the log available to writers.

Having it set to 0 right after mount is wrong since no space for commits
is reserved.

Fixes: 1e51764a ("UBIFS: add new flash file system")
Reported-and-tested-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>

We unlock after orphan_delete(), so no need to unlock
in the function too.
Reported-by: NHan Xu <han.xu@nxp.com>
Fixes: 8009ce95 ("ubifs: Don't leak orphans on memory during commit")
Signed-off-by: NRichard Weinberger <richard@nod.at>

Linux kernel tolerates C++ style comments these days. Actually, the
SPDX License tags for .c files start with //.

On the other hand, uapi headers are written in more strict C, where
the C++ comment style is forbidden.

I simply dropped these lines instead of fixing the comment style.

This code has been always commented out since it was added around
Linux 2.4.9 (i.e. commented out for more than 17 years).

'Maybe later...' will never happen.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Pull MTD fix from Richard Weinberger:
 "A single fix for MTD to correctly set the spi-nor WP pin"

* tag 'fixes-for-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: spi-nor: Fix the disabling of write protection at init

Pull btrfs fixes from David Sterba:
 "Two fixes that popped up during testing:

   - fix for sysfs-related code that adds/removes block groups, warnings
     appear during several fstests in connection with sysfs updates in
     5.3, the fix essentially replaces a workaround with scope NOFS and
     applies to 5.2-based branch too

   - add sanity check of trim range"

* tag 'for-5.3-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: trim: Check the range passed into to prevent overflow
  Btrfs: fix sysfs warning and missing raid sysfs directories

Pull x86 fixes from Thomas Gleixner:
 "A set of fixes for x86:

   - Fix the inconsistent error handling in the umwait init code

   - Rework the boot param zeroing so gcc9 stops complaining about out
     of bound memset. The resulting source code is actually more sane to
     read than the smart solution we had

   - Maintainers update so Tony gets involved when Intel models are
     added

   - Some more fallthrough fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Save fields explicitly, zero out everything else
  MAINTAINERS, x86/CPU: Tony Luck will maintain asm/intel-family.h
  x86/fpu/math-emu: Address fallthrough warnings
  x86/apic/32: Fix yet another implicit fallthrough warning
  x86/umwait: Fix error handling in umwait_init()

Pull EFI fix from Thomas Gleixner:
 "A single fix for a EFI mixed mode regression caused by recent rework
  which did not take the firmware bitwidth into account"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi-stub: Fix get_efi_config_table on mixed-mode setups

Pull SPDX fixes from Greg KH:
 "Here are four small SPDX fixes for 5.3-rc5.

  A few style fixes for some SPDX comments, added an SPDX tag for one
  file, and fix up some GPL boilerplate for another file.

  All of these have been in linux-next for a few weeks with no reported
  issues (they are comment changes only, so that's to be expected...)"

* tag 'spdx-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
  i2c: stm32: Use the correct style for SPDX License Identifier
  intel_th: Use the correct style for SPDX License Identifier
  coccinelle: api/atomic_as_refcounter: add SPDX License Identifier
  kernel/configs: Replace GPL boilerplate code with SPDX identifier

Pull char/misc driver fixes from Greg KH:
 "Here are some small char and misc driver fixes for 5.3-rc5.

  These are two different subsystems needing some fixes, the habanalabs
  driver which is has some more big endian fixes for problems found. The
  other are some small soundwire fixes, including some Kconfig
  dependencies needed to resolve reported build errors.

  All of these have been in linux-next this week with no reported
  issues"

* tag 'char-misc-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc: xilinx-sdfec: fix dependency and build error
  habanalabs: fix device IRQ unmasking for BE host
  habanalabs: fix endianness handling for internal QMAN submission
  habanalabs: fix completion queue handling when host is BE
  habanalabs: fix endianness handling for packets from user
  habanalabs: fix DRAM usage accounting on context tear down
  habanalabs: Avoid double free in error flow
  soundwire: fix regmap dependencies and align with other serial links
  soundwire: cadence_master: fix definitions for INTSTAT0/1
  soundwire: cadence_master: fix register definition for SLAVE_STATE

Pull staging/IIO fixes from Greg KH:
 "Here are four small staging and iio driver fixes for 5.3-rc5

  Two are for the dt3000 comedi driver for some reported problems found
  in that codebase, and two are some small iio fixes.

  All of these have been in linux-next this week with no reported
  issues"

* tag 'staging-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: comedi: dt3000: Fix rounding up of timer divisor
  staging: comedi: dt3000: Fix signed integer overflow 'divider * base'
  iio: adc: max9611: Fix temperature reading in probe
  iio: frequency: adf4371: Fix output frequency setting

Pull USB fixes from Greg KH:
 "Here are number of small USB fixes for 5.3-rc5.

  Syzbot has been on a tear recently now that it has some good USB
  debugging hooks integrated, so there's a number of fixes in here found
  by those tools for some _very_ old bugs. Also a handful of gadget
  driver fixes for reported issues, some hopefully-final dma fixes for
  host controller drivers, and some new USB serial gadget driver ids.

  All of these have been in linux-next this week with no reported issues
  (the usb-serial ones were in linux-next in its own branch, but merged
  into mine on Friday)"

* tag 'usb-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: add a hcd_uses_dma helper
  usb: don't create dma pools for HCDs with a localmem_pool
  usb: chipidea: imx: fix EPROBE_DEFER support during driver probe
  usb: host: fotg2: restart hcd after port reset
  USB: CDC: fix sanity checks in CDC union parser
  usb: cdc-acm: make sure a refcount is taken early enough
  USB: serial: option: add the BroadMobi BM818 card
  USB: serial: option: Add Motorola modem UARTs
  USB: core: Fix races in character device registration and deregistraion
  usb: gadget: mass_storage: Fix races between fsg_disable and fsg_set_alt
  usb: gadget: composite: Clear "suspended" on reset/disconnect
  usb: gadget: udc: renesas_usb3: Fix sysfs interface of "role"
  USB: serial: option: add D-Link DWM-222 device ID
  USB: serial: option: Add support for ZTE MF871A

Pull block fixes from Jens Axboe:
 "A collection of fixes that should go into this series. This contains:

   - Revert of the REQ_NOWAIT_INLINE and associated dio changes. There
     were still corner cases there, and even though I had a solution for
     it, it's too involved for this stage. (me)

   - Set of NVMe fixes (via Sagi)

   - io_uring fix for fixed buffers (Anthony)

   - io_uring defer issue fix (Jackie)

   - Regression fix for queue sync at exit time (zhengbin)

   - xen blk-back memory leak fix (Wenwen)"

* tag 'for-linus-2019-08-17' of git://git.kernel.dk/linux-block:
  io_uring: fix an issue when IOSQE_IO_LINK is inserted into defer list
  block: remove REQ_NOWAIT_INLINE
  io_uring: fix manual setup of iov_iter for fixed buffers
  xen/blkback: fix memory leaks
  blk-mq: move cancel of requeue_work to the front of blk_exit_queue
  nvme-pci: Fix async probe remove race
  nvme: fix controller removal race with scan work
  nvme-rdma: fix possible use-after-free in connect error flow
  nvme: fix a possible deadlock when passthru commands sent to a multipath device
  nvme-core: Fix extra device_put() call on error path
  nvmet-file: fix nvmet_file_flush() always returning an error
  nvmet-loop: Flush nvme_delete_wq when removing the port
  nvmet: Fix use-after-free bug when a port is removed
  nvme-multipath: revalidate nvme_ns_head gendisk in nvme_validate_ns

Pull Hyper-V fixes from Sasha Levin:

 - A few fixes for the userspace hyper-v tools from Adrian Vladu.

 - A fix for the hyper-v MAINTAINERs entry from Lan Tianyu.

 - Fix for SPDX license identifier in the userspace tools from Nishad
   Kamdar.

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  MAINTAINERS: Fix Hyperv vIOMMU driver file name
  tools: hv: Use the correct style for SPDX License Identifier
  tools: hv: fix typos in toolchain
  tools: hv: fix KVP and VSS daemons exit code
  tools: hv: fixed Python pep8/flake8 warnings for lsvmbus

The Hyperv vIOMMU file name should be "hyperv-iommu.c" rather
than "hyperv_iommu.c". This patch is to fix it.
Signed-off-by: NLan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

This patch corrects the SPDX License Identifier style
in the trace header file related to Microsoft Hyper-V
client drivers.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46Suggested-by: NJoe Perches <joe@perches.com>
Signed-off-by: NNishad Kamdar <nishadkamdar@gmail.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

Fix typos in the HyperV toolchain.
Signed-off-by: NAdrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Alessandro Pilotti <apilotti@cloudbasesolutions.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

HyperV KVP and VSS daemons should exit with 0 when the '--help'
or '-h' flags are used.
Signed-off-by: NAdrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Alessandro Pilotti <apilotti@cloudbasesolutions.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

Fixed pep8/flake8 python style code for lsvmbus tool.

The TAB indentation was on purpose ignored (pep8 rule W191) to make
sure the code is complying with the Linux code guideline.
The following command doe not show any warnings now:
pep8 --ignore=W191 lsvmbus
flake8 --ignore=W191 lsvmbus
Signed-off-by: NAdrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Alessandro Pilotti <apilotti@cloudbasesolutions.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

Pull i2c fixes from Wolfram Sang:
 "I2C has one revert because of a regression, two fixes for tiny race
  windows (which we were not able to trigger), a MAINTAINERS addition,
  and a SPDX fix"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: stm32: Use the correct style for SPDX License Identifier
  i2c: emev2: avoid race when unregistering slave client
  i2c: rcar: avoid race when unregistering slave client
  MAINTAINERS: i2c-imx: take over maintainership
  Revert "i2c: imx: improve the error handling in i2c_imx_dma_request()"

Pull RISC-V fixes from Paul Walmsley:

 - Two patches to fix significant bugs in floating point register
   context handling

 - A minor fix in RISC-V flush_tlb_page(), to supply a valid end address
   to flush_tlb_range()

 - Two minor defconfig additions: to build the virtio hwrng driver by
   default (for QEMU targets), and to partially synchronize the 32-bit
   defconfig with the 64-bit defconfig

* tag 'riscv/for-v5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Make __fstate_clean() work correctly.
  riscv: Correct the initialized flow of FP register
  riscv: defconfig: Update the defconfig
  riscv: rv32_defconfig: Update the defconfig
  riscv: fix flush_tlb_range() end address for flush_tlb_page()

Merge tag 'usb-serial-5.3-rc5' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus

Johan writes:

USB-serial fixes for 5.3-rc5

Here are some new modem device ids.

All have been in linux-next with no reported issues.
Signed-off-by: NJohan Hovold <johan@kernel.org>

* tag 'usb-serial-5.3-rc5' of https://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial:
  USB: serial: option: add the BroadMobi BM818 card
  USB: serial: option: Add Motorola modem UARTs
  USB: serial: option: add D-Link DWM-222 device ID
  USB: serial: option: Add support for ZTE MF871A

Pull Xtensa fix from Max Filippov:
 "Add missing isync into cpu_reset to make sure ITLB changes are
  effective"

* tag 'xtensa-20190816' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: add missing isync to the cpu_reset TLB code

Pull arm64 fixes from Catalin Marinas:

 - Don't taint the kernel if CPUs have different sets of page sizes
   supported (other than the one in use).

 - Issue I-cache maintenance for module ftrace trampoline.

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: ftrace: Ensure module ftrace trampoline is coherent with I-side
  arm64: cpufeature: Don't treat granule sizes as strict

The initial support for dynamic ftrace trampolines in modules made use
of an indirect branch which loaded its target from the beginning of
a special section (e71a4e1b ("arm64: ftrace: add support for far
branches to dynamic ftrace")). Since no instructions were being patched,
no cache maintenance was needed. However, later in be0f272b ("arm64:
ftrace: emit ftrace-mod.o contents through code") this code was reworked
to output the trampoline instructions directly into the PLT entry but,
unfortunately, the necessary cache maintenance was overlooked.

Add a call to __flush_icache_range() after writing the new trampoline
instructions but before patching in the branch to the trampoline.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: James Morse <james.morse@arm.com>
Cc: <stable@vger.kernel.org>
Fixes: be0f272b ("arm64: ftrace: emit ftrace-mod.o contents through code")
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Pull power management fixes from Rafael Wysocki:
 "These add a check to avoid recent suspend-to-idle power regression on
  systems with NVMe drives where the PCIe ASPM policy is "performance"
  (or when the kernel is built without ASPM support), fix an issue
  related to frequency limits in the schedutil cpufreq governor and fix
  a mistake related to the PM QoS usage in the cpufreq core introduced
  recently.

  Specifics:

   - Disable NVMe power optimization related to suspend-to-idle added
     recently on systems where PCIe ASPM is not able to put PCIe links
     into low-power states to prevent excess power from being drawn by
     the system while suspended (Rafael Wysocki).

   - Make the schedutil governor handle frequency limits changes
     properly in all cases (Viresh Kumar).

   - Prevent the cpufreq core from treating positive values returned by
     dev_pm_qos_update_request() as errors (Viresh Kumar)"

* tag 'pm-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled
  PCI/ASPM: Add pcie_aspm_enabled()
  cpufreq: schedutil: Don't skip freq update when limits change
  cpufreq: dev_pm_qos_update_request() can return 1 on success

Pull dmaengine fixes from Vinod Koul:
 "Fixes in dmaengine drivers for:

   - dw-edma: endianess, _iomem type and stack usages

   - ste_dma40: unneeded variable and null-pointer dereference

   - tegra210-adma: unused function

   - omap-dma: off-by-one fix"

* tag 'dmaengine-fix-5.3-rc5' of git://git.infradead.org/users/vkoul/slave-dma:
  omap-dma/omap_vout_vrfb: fix off-by-one fi value
  dmaengine: stm32-mdma: Fix a possible null-pointer dereference in stm32_mdma_irq_handler()
  dmaengine: tegra210-adma: Fix unused function warnings
  dmaengine: ste_dma40: fix unneeded variable warning
  dmaengine: dw-edma: fix endianess confusion
  dmaengine: dw-edma: fix __iomem type confusion
  dmaengine: dw-edma: fix unnecessary stack usage

Pull sound fixes from Takashi Iwai:
 "All small fixes targeted for stable:

   - Two fixes for USB-audio with malformed descriptor, spotted by
     fuzzers

   - Two fixes Conexant HD-audio codec wrt power management

   - Quirks for HD-audio AMD platform and HP laptop

   - HD-audio memory leak fix"

* tag 'sound-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: usb-audio: Fix a stack buffer overflow bug in check_input_term
  ALSA: usb-audio: Fix an OOB bug in parse_audio_mixer_unit
  ALSA: hda - Add a generic reboot_notify
  ALSA: hda - Let all conexant codec enter D3 when rebooting
  ALSA: hda/realtek - Add quirk for HP Envy x360
  ALSA: hda - Fix a memory leak bug
  ALSA: hda - Apply workaround for another AMD chip 1022:1487

Pull drm fixes from Dave Airlie:
 "Nothing too crazy this week, one amdgpu fix to use vmalloc for a
  struct that grew in size, and another MST fix for nouveau, and some
  other misc fixes:

  i915:
   - single GVT use after free fix

  scheduler:
   - entity destruction race fix

  amdgpu:
   - struct allocation fix
   - gfx9 soft recovery fix

  nouveau:
   - followup MST fix

  ast:
   - vga register race fix"

* tag 'drm-fixes-2019-08-16' of git://anongit.freedesktop.org/drm/drm:
  drm/nouveau: Only recalculate PBN/VCPI on mode/connector changes
  drm/ast: Fixed reboot test may cause system hanged
  drm/scheduler: use job count instead of peek
  drm/amd/display: use kvmalloc for dc_state (v2)
  drm/amdgpu: fix gfx9 soft recovery
  drm/i915: Use after free in error path in intel_vgpu_create_workload()

* pm-cpufreq:
  cpufreq: schedutil: Don't skip freq update when limits change
  cpufreq: dev_pm_qos_update_request() can return 1 on success

Recent gcc compilers (gcc 9.1) generate warnings about an out of bounds
memset, if the memset goes accross several fields of a struct. This
generated a couple of warnings on x86_64 builds in sanitize_boot_params().

Fix this by explicitly saving the fields in struct boot_params
that are intended to be preserved, and zeroing all the rest.

[ tglx: Tagged for stable as it breaks the warning free build there as well ]
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Suggested-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190731054627.5627-2-jhubbard@nvidia.com

Merge tag 'soundwire-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire into char-misc-linus

Vinod writes:

soundwire fixes for v5.3-rc5

Pierre sent fixes which are queued now for v5.3-rc5 are:
 - regmap dependecy
 - cadence register definitions

* tag 'soundwire-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire:
  soundwire: fix regmap dependencies and align with other serial links
  soundwire: cadence_master: fix definitions for INTSTAT0/1
  soundwire: cadence_master: fix register definition for SLAVE_STATE

Merge tag 'drm-intel-fixes-2019-08-15' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

drm/i915 fixes for v5.4-rc5:
- GVT use-after-free fix
Signed-off-by: NDave Airlie <airlied@redhat.com>
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/87zhkag9ic.fsf@intel.com

`check_input_term` recursively calls itself with input from
device side (e.g., uac_input_terminal_descriptor.bCSourceID)
as argument (id). In `check_input_term`, if `check_input_term`
is called with the same `id` argument as the caller, it triggers
endless recursive call, resulting kernel space stack overflow.

This patch fixes the bug by adding a bitmap to `struct mixer_build`
to keep track of the checked ids and stop the execution if some id
has been checked (similar to how parse_audio_unit handles unitid
argument).
Reported-by: NHui Peng <benquike@gmail.com>
Reported-by: NMathias Payer <mathias.payer@nebelwelt.net>
Signed-off-by: NHui Peng <benquike@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Pull xfs fixes from Darrick Wong:

 - Fix crashes when the attr fork isn't present due to errors but inode
   inactivation tries to zap the attr data anyway.

 - Convert more directory corruption debugging asserts to actual
   EFSCORRUPTED returns instead of blowing up later on.

 - Don't fail writeback just because we ran out of memory allocating
   metadata log data.

* tag 'xfs-5.3-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: don't crash on null attr fork xfs_bmapi_read
  xfs: remove more ondisk directory corruption asserts
  fs: xfs: xfs_log: Don't use KM_MAYFAIL at xfs_log_reserve().

Pull iomap fixlet from Darrick Wong:
 "A single update to the MAINTAINERS entry for iomap now that we've
  removed fs/iomap.c"

* tag 'iomap-5.3-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  MAINTAINERS: iomap: Remove fs/iomap.c record

This patch may fix two issues:

First, when IOSQE_IO_DRAIN set, the next IOs need to be inserted into
defer list to delay execution, but link io will be actively scheduled to
run by calling io_queue_sqe.

Second, when multiple LINK_IOs are inserted together with defer_list,
the LINK_IO is no longer keep order.

   |-------------|
   |   LINK_IO   |      ----> insert to defer_list  -----------
   |-------------|                                            |
   |   LINK_IO   |      ----> insert to defer_list  ----------|
   |-------------|                                            |
   |   LINK_IO   |      ----> insert to defer_list  ----------|
   |-------------|                                            |
   |   NORMAL_IO |      ----> insert to defer_list  ----------|
   |-------------|                                            |
                                                              |
                              queue_work at same time   <-----|

Fixes: 9e645e11 ("io_uring: add support for sqe links")
Signed-off-by: NJackie Liu <liuyun01@kylinos.cn>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We had a few issues with this code, and there's still a problem around
how we deal with error handling for chained/split bios. For now, just
revert the code and we'll try again with a thoroug solution. This
reverts commits:

e15c2ffa ("block: fix O_DIRECT error handling for bio fragments")
0eb6ddfb ("block: Fix __blkdev_direct_IO() for bio fragments")
6a43074e ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
893a1c97 ("blk-mq: allow REQ_NOWAIT to return an error inline")
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Commit bd11b3a3 ("io_uring: don't use iov_iter_advance() for fixed
buffers") introduced an optimization to avoid using the slow
iov_iter_advance by manually populating the iov_iter iterator in some
cases.

However, the computation of the iterator count field was erroneous: The
first bvec was always accounted for an extent of page size even if the
bvec length was smaller.

In consequence, some I/O operations on fixed buffers were unable to
operate on the full extent of the buffer, consistently skipping some
bytes at the end of it.

Fixes: bd11b3a3 ("io_uring: don't use iov_iter_advance() for fixed buffers")
Cc: stable@vger.kernel.org
Signed-off-by: NAleix Roca Nonell <aleix.rocanonell@bsc.es>
Signed-off-by: NJens Axboe <axboe@kernel.dk>