Commit dc9edc44 ("block: Fix a blk_exit_rl() regression") merged on
v4.12 moved the work behind blk_release_queue() into a workqueue after a
splat floated around which indicated some work on blk_release_queue()
could sleep in blk_exit_rl(). This splat would be possible when a driver
called blk_put_queue() or blk_cleanup_queue() (which calls blk_put_queue()
as its final call) from an atomic context.

blk_put_queue() decrements the refcount for the request_queue kobject, and
upon reaching 0 blk_release_queue() is called. Although blk_exit_rl() is
now removed through commit db6d9952 ("block: remove request_list code")
on v5.0, we reserve the right to be able to sleep within
blk_release_queue() context.

The last reference for the request_queue must not be called from atomic
context. *When* the last reference to the request_queue reaches 0 varies,
and so let's take the opportunity to document when that is expected to
happen and also document the context of the related calls as best as
possible so we can avoid future issues, and with the hopes that the
synchronous request_queue removal sticks.

We revert back to synchronous request_queue removal because asynchronous
removal creates a regression with expected userspace interaction with
several drivers. An example is when removing the loopback driver, one
uses ioctls from userspace to do so, but upon return and if successful,
one expects the device to be removed. Likewise if one races to add another
device the new one may not be added as it is still being removed. This was
expected behavior before and it now fails as the device is still present
and busy still. Moving to asynchronous request_queue removal could have
broken many scripts which relied on the removal to have been completed if
there was no error. Document this expectation as well so that this
doesn't regress userspace again.

Using asynchronous request_queue removal however has helped us find
other bugs. In the future we can test what could break with this
arrangement by enabling CONFIG_DEBUG_KOBJECT_RELEASE.

While at it, update the docs with the context expectations for the
request_queue / gendisk refcount decrement, and make these
expectations explicit by using might_sleep().

Fixes: dc9edc44 ("block: Fix a blk_exit_rl() regression")
Suggested-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: yu kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Let us clarify the context under which the helpers to increment the
refcount for the gendisk and request_queue can be called under. We
make this explicit on the places where we may sleep with might_sleep().

We don't address the decrement context yet, as that needs some extra
work and fixes, but will be addressed in the next patch.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This adds documentation for the gendisk / request_queue refcount
helpers.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Use the new blk_mq_complete_request_remote helper to avoid an indirect
function call in the completion fast path.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Factor a small sniplet of duplicated code into a new helper in
preparation for making this sniplet a little bit less trivial.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This is a variant of blk_mq_complete_request_remote that only completes
the request if it needs to be bounced to another CPU or a softirq.  If
the request can be completed locally the function returns false and lets
the driver complete it without requring and indirect function call.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add a helper to decide if we can complete locally or need an IPI.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We don't really care if we get migrated during the I/O completion.
In the worth case we either perform an IPI that wasn't required, or
complete the request on a CPU which we just migrated off.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Move the call to blk_should_fake_timeout out of blk_mq_complete_request
and into the drivers, skipping call sites that are obvious error
handlers, and remove the now superflous blk_mq_force_complete_rq helper.
This ensures we don't keep injecting errors into completions that just
terminate the Linux request after the hardware has been reset or the
command has been aborted.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Both the softirq path for single queue devices and the multi-queue
completion handler share the same logic to figure out if we need an
IPI for the completion and eventually issue it.  Merge the two
versions into a single unified code path.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Let the compile optimize out the entire IPI path, given that we are
obviously not going to use it.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Even for single queue devices there is no point in offloading a polled
completion to the softirq, given that blk_mq_force_complete_rq is called
from the polling thread in that case and thus there are no starvation
issues.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

By open coding raise_blk_irq in the only caller, and replacing the
ifdef CONFIG_SMP with an IS_ENABLED check the flow in the caller
can be significantly simplified.
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add a helper to deduplicate the logic that raises the block softirq.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

__blk_complete_request is only called from the blk-mq code, and
duplicates a lot of code from blk-mq.c.  Move it there to prepare
for better code sharing and simplifications.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull SELinux fixes from Paul Moore:
 "Three small patches to fix problems in the SELinux code, all found via
  clang.

  Two patches fix potential double-free conditions and one fixes an
  undefined return value"

* tag 'selinux-pr-20200621' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: fix undefined return of cond_evaluate_expr
  selinux: fix a double free in cond_read_node()/cond_read_list()
  selinux: fix double free

Pull pin control fixes from Linus Walleij:
 "Some early fixes collected during the first week after the merge
  window, all pretty self-evident, with the details below. The revert is
  the crucial thing.

   - Fix a warning on the Qualcomm SPMI GPIO chip being instatiated
     twice without a unique irqchip struct

   - Use the noirq variants of the suspend and resume callbacks in the
     Tegra driver

   - Clean up the errorpath on the MCP23s08 driver

   - Revert the use of devm_of_iomap() in the Freescale driver as it was
     regressing the platform

   - Add some missing pins in the Qualcomm IPQ6018 driver

   - Fix a simple documentation bug in the pinctrl-single driver"

* tag 'pinctrl-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: single: fix function name in documentation
  pinctrl: qcom: ipq6018 Add missing pins in qpic pin group
  Revert "pinctrl: freescale: imx: Use 'devm_of_iomap()' to avoid a resource leak in case of error in 'imx_pinctrl_probe()'"
  pinctrl: mcp23s08: Split to three parts: fix ptr_ret.cocci warnings
  pinctrl: tegra: Use noirq suspend/resume callbacks
  pinctrl: qcom: spmi-gpio: fix warning about irq chip reusage

Merge tag 'kbuild-fixes-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - fix -gz=zlib compiler option test for CONFIG_DEBUG_INFO_COMPRESSED

 - improve cc-option in scripts/Kbuild.include to clean up temp files

 - improve cc-option in scripts/Kconfig.include for more reliable
   compile option test

 - do not copy modules.builtin by 'make install' because it would break
   existing systems

 - use 'userprogs' syntax for watch_queue sample

* tag 'kbuild-fixes-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  samples: watch_queue: build sample program for target architecture
  Revert "Makefile: install modules.builtin even if CONFIG_MODULES=n"
  scripts: Fix typo in headers_install.sh
  kconfig: unify cc-option and as-option
  kbuild: improve cc-option to clean up all temporary files
  Makefile: Improve compressed debug info support detection

Pull powerpc fixes from Michael Ellerman:

 - One fix for the interrupt rework we did last release which broke
   KVM-PR

 - Three commits fixing some fallout from the READ_ONCE() changes
   interacting badly with our 8xx 16K pages support, which uses a pte_t
   that is a structure of 4 actual PTEs

 - A cleanup of the 8xx pte_update() to use the newly added pmd_off()

 - A fix for a crash when handling an oops if CONFIG_DEBUG_VIRTUAL is
   enabled

 - A minor fix for the SPU syscall generation

Thanks to Aneesh Kumar K.V, Christian Zigotzky, Christophe Leroy, Mike
Rapoport, Nicholas Piggin.

* tag 'powerpc-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/8xx: Provide ptep_get() with 16k pages
  mm: Allow arches to provide ptep_get()
  mm/gup: Use huge_ptep_get() in gup_hugepte()
  powerpc/syscalls: Use the number when building SPU syscall table
  powerpc/8xx: use pmd_off() to access a PMD entry in pte_update()
  powerpc/64s: Fix KVM interrupt using wrong save area
  powerpc: Fix kernel crash in show_instructions() w/DEBUG_VIRTUAL

Pull crypto fixes from Herbert Xu:

 - NULL dereference in octeontx

 - PM reference imbalance in ks-sa

 - deadlock in crypto manager

 - memory leak in drbg

 - missing socket limit check on receive SG list size in algif_skcipher

 - typos in caam

 - warnings in ccp and hisilicon

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: drbg - always try to free Jitter RNG instance
  crypto: marvell/octeontx - Fix a potential NULL dereference
  crypto: algboss - don't wait during notifier callback
  crypto: caam - fix typos
  crypto: ccp - Fix sparse warnings in sev-dev
  crypto: hisilicon - Cap block size at 2^31
  crypto: algif_skcipher - Cap recv SG list at ctx->used
  hwrng: ks-sa - Fix runtime PM imbalance on error

This userspace program includes UAPI headers exported to usr/include/.
'make headers' always works for the target architecture (i.e. the same
architecture as the kernel), so the sample program should be built for
the target as well. Kbuild now supports 'userprogs' for that.

I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because
$(CC) may not provide libc.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This reverts commit e0b250b5,
which broke build systems that need to install files to a certain
path, but do not set INSTALL_MOD_PATH when invoking 'make install'.

  $ make INSTALL_PATH=/tmp/destdir install
  mkdir: cannot create directory ‘/lib/modules/5.8.0-rc1+/’: Permission denied
  Makefile:1342: recipe for target '_builtin_inst_' failed
  make: *** [_builtin_inst_] Error 1

While modules.builtin is useful also for CONFIG_MODULES=n, this change
in the behavior is quite unexpected. Maybe "make modules_install"
can install modules.builtin irrespective of CONFIG_MODULES as Jonas
originally suggested.

Anyway, that commit should be reverted ASAP.
Reported-by: Douglas Anderson <dianders@chromium.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>

Pull SCSI fixes from James Bottomley:
 "One minor fix and two patches reworking the ata dma drain for the
  !CONFIG_LIBATA case. The latter is a 5.7 regression fix"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: Wire up ata_scsi_dma_need_drain for SAS HBA drivers
  scsi: libata: Provide an ata_scsi_dma_need_drain stub for !CONFIG_ATA
  scsi: ufs-bsg: Fix runtime PM imbalance on error

Pull i2c fixes from Wolfram Sang:

 - a small collection of remaining API conversion patches (all acked)
   which allow to finally remove the deprecated API

 - some documentation fixes and a MAINTAINERS addition

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  MAINTAINERS: Add robert and myself as qcom i2c cci maintainers
  i2c: smbus: Fix spelling mistake in the comments
  Documentation/i2c: SMBus start signal is S not A
  i2c: remove deprecated i2c_new_device API
  Documentation: media: convert to use i2c_new_client_device()
  video: backlight: tosa_lcd: convert to use i2c_new_client_device()
  x86/platform/intel-mid: convert to use i2c_new_client_device()
  drm: encoder_slave: use new I2C API
  drm: encoder_slave: fix refcouting error for modules

Use the correct the function name in the documentation for
"pcs_parse_one_pinctrl_entry()".

"smux_parse_one_pinctrl_entry()" appears to be an artifact from the
development of a prior patch series ("simple pinmux driver") which
transformed into pinctrl-single.
Signed-off-by: Drew Fustini <drew@beagleboard.org>
Link: https://lore.kernel.org/r/20200612112758.GA3407886@x1Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Pull tracing fixes from Steven Rostedt:

 - Have recordmcount work with > 64K sections (to support LTO)

 - kprobe RCU fixes

 - Correct a kprobe critical section with missing mutex

 - Remove redundant arch_disarm_kprobe() call

 - Fix lockup when kretprobe triggers within kprobe_flush_task()

 - Fix memory leak in fetch_op_data operations

 - Fix sleep in atomic in ftrace trace array sample code

 - Free up memory on failure in sample trace array code

 - Fix incorrect reporting of function_graph fields in format file

 - Fix quote within quote parsing in bootconfig

 - Fix return value of bootconfig tool

 - Add testcases for bootconfig tool

 - Fix maybe uninitialized warning in ftrace pid file code

 - Remove unused variable in tracing_iter_reset()

 - Fix some typos

* tag 'trace-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix maybe-uninitialized compiler warning
  tools/bootconfig: Add testcase for show-command and quotes test
  tools/bootconfig: Fix to return 0 if succeeded to show the bootconfig
  tools/bootconfig: Fix to use correct quotes for value
  proc/bootconfig: Fix to use correct quotes for value
  tracing: Remove unused event variable in tracing_iter_reset
  tracing/probe: Fix memleak in fetch_op_data operations
  trace: Fix typo in allocate_ftrace_ops()'s comment
  tracing: Make ftrace packed events have align of 1
  sample-trace-array: Remove trace_array 'sample-instance'
  sample-trace-array: Fix sleeping function called from invalid context
  kretprobe: Prevent triggering kretprobe from within kprobe_flush_task
  kprobes: Remove redundant arch_disarm_kprobe() call
  kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex
  kprobes: Use non RCU traversal APIs on kprobe_tables if possible
  kprobes: Suppress the suspicious RCU warning on kprobes
  recordmcount: support >64k sections

Pull libnvdimm updates from Dan Williams:
 "A feature (papr_scm health retrieval) and a fix (sysfs attribute
  visibility) for v5.8.

  Vaibhav explains in the merge commit below why missing v5.8 would be
  painful and I agreed to try a -rc2 pull because only cosmetics kept
  this out of -rc1 and his initial versions were posted in more than
  enough time for v5.8 consideration:

   'These patches are tied to specific features that were committed to
    customers in upcoming distros releases (RHEL and SLES) whose
    time-lines are tied to 5.8 kernel release.

    Being able to track the health of an nvdimm is critical for our
    customers that are running workloads leveraging papr-scm nvdimms.
    Missing the 5.8 kernel would mean missing the distro timelines and
    shifting forward the availability of this feature in distro kernels
    by at least 6 months'

  Summary:

   - Fix the visibility of the region 'align' attribute.

     The new unit tests for region alignment handling caught a corner
     case where the alignment cannot be specified if the region is
     converted from static to dynamic provisioning at runtime.

   - Add support for device health retrieval for the persistent memory
     supported by the papr_scm driver.

     This includes both the standard sysfs "health flags" that the nfit
     persistent memory driver publishes and a mechanism for the ndctl
     tool to retrieve a health-command payload"

* tag 'libnvdimm-for-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  nvdimm/region: always show the 'align' attribute
  powerpc/papr_scm: Implement support for PAPR_PDSM_HEALTH
  ndctl/papr_scm,uapi: Add support for PAPR nvdimm specific methods
  powerpc/papr_scm: Improve error logging and handling papr_scm_ndctl()
  powerpc/papr_scm: Fetch nvdimm health information from PHYP
  seq_buf: Export seq_buf_printf
  powerpc: Document details on H_SCM_HEALTH hcall

The patch adds missing qpic data pins to qpic pingroup. These pins are
necessary for the qpic nand to work.

Fixes: ef1ea54e ("pinctrl: qcom: Add ipq6018 pinctrl driver")
Signed-off-by: Sivaprakash Murugesan <sivaprak@codeaurora.org>
Link: https://lore.kernel.org/r/1592541089-17700-1-git-send-email-sivaprak@codeaurora.orgSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Revert "pinctrl: freescale: imx: Use 'devm_of_iomap()' to avoid a resource leak in case of error in 'imx_pinctrl_probe()'"

This reverts commit ba403242.

After commit 26d8cde5 ("pinctrl: freescale: imx: add shared
input select reg support"). i.MX7D has two iomux controllers
iomuxc and iomuxc-lpsr which share select_input register for
daisy chain settings.
If use 'devm_of_iomap()', when probe the iomuxc-lpsr, will call
devm_request_mem_region() for the region <0x30330000-0x3033ffff>
for the first time. Then, next time when probe the iomuxc, API
devm_platform_ioremap_resource() will also use the API
devm_request_mem_region() for the share region <0x30330000-0x3033ffff>
again, then cause issue, log like below:

[    0.179561] imx7d-pinctrl 302c0000.iomuxc-lpsr: initialized IMX pinctrl driver
[    0.191742] imx7d-pinctrl 30330000.pinctrl: can't request region for resource [mem 0x30330000-0x3033ffff]
[    0.191842] imx7d-pinctrl: probe of 30330000.pinctrl failed with error -16

Fixes: ba403242 ("pinctrl: freescale: imx: Use 'devm_of_iomap()' to avoid a resource leak in case of error in 'imx_pinctrl_probe()'")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Link: https://lore.kernel.org/r/1591673223-1680-1-git-send-email-haibo.chen@nxp.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Pull s390 fixes from Vasily Gorbik:

 - a few ptrace fixes mostly for strace and seccomp_bpf kernel tests
   findings

 - cleanup unused pm callbacks in virtio ccw

 - replace kmalloc + memset with kzalloc in crypto

 - use $(LD) for vDSO linkage to make clang happy

 - fix vDSO clock_getres() to preserve the same behaviour as
   posix_get_hrtimer_res()

 - fix workqueue cpumask warning when NUMA=n and nr_node_ids=2

 - reduce SLSB writes during input processing, improve warnings and
   cleanup qdio_data usage in qdio

 - a few fixes to use scnprintf() instead of snprintf()

* tag 's390-5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: fix syscall_get_error for compat processes
  s390/qdio: warn about unexpected SLSB states
  s390/qdio: clean up usage of qdio_data
  s390/numa: let NODES_SHIFT depend on NEED_MULTIPLE_NODES
  s390/vdso: fix vDSO clock_getres()
  s390/vdso: Use $(LD) instead of $(CC) to link vDSO
  s390/protvirt: use scnprintf() instead of snprintf()
  s390: use scnprintf() in sys_##_prefix##_##_name##_show
  s390/crypto: use scnprintf() instead of snprintf()
  s390/zcrypt: use kzalloc
  s390/virtio: remove unused pm callbacks
  s390/qdio: reduce SLSB writes during Input Queue processing
  selftests/seccomp: s390 shares the syscall and return value register
  s390/ptrace: fix setting syscall number
  s390/ptrace: pass invalid syscall numbers to tracing
  s390/ptrace: return -ENOSYS when invalid syscall is supplied
  s390/seccomp: pass syscall arguments via seccomp_data
  s390/qdio: fine-tune SLSB update

Pull RISC-V fixes from Palmer Dabbelt:

 - a workaround for a compiler surprise related to the "r" inline
   assembly that allows LLVM to boot.

 - a fix to avoid WX-only mappings, which the ISA does not allow. While
   this probably manifests in many ways, the bug was found in stress-ng.

 - a missing lock in set_direct_map_*(), which due to a recent lockdep
   change started asserting.

* tag 'riscv-for-linus-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: Acquire mmap lock before invoking walk_page_range
  RISC-V: Don't allow write+exec only page mapping request in mmap
  riscv/atomic: Fix sign extension for RV64I

Merge tag 'linux-kselftest-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest cleanups from Shuah Khan:

 - ftrace "requires:" list for simplifying and unifying requirement
   checks for each test case, adding "requires:" line instead of
   checking required ftrace interfaces in each test case.

 - a minor spelling correction patch

* tag 'linux-kselftest-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/ftrace: Support ":README" suffix for requires
  selftests/ftrace: Support ":tracer" suffix for requires
  selftests/ftrace: Convert check_filter_file() with requires list
  selftests/ftrace: Convert required interface checks into requires list
  selftests/ftrace: Add "requires:" list support
  selftests/ftrace: Return unsupported for the unconfigured features
  selftests/ftrace: Allow ":" in description
  tools: testing: ftrace: trigger: fix spelling mistake

The fileserver probe timer, net->fs_probe_timer, isn't cancelled when
the kafs module is being removed and so the count it holds on
net->servers_outstanding doesn't get dropped..

This causes rmmod to wait forever.  The hung process shows a stack like:

	afs_purge_servers+0x1b5/0x23c [kafs]
	afs_net_exit+0x44/0x6e [kafs]
	ops_exit_list+0x72/0x93
	unregister_pernet_operations+0x14c/0x1ba
	unregister_pernet_subsys+0x1d/0x2a
	afs_exit+0x29/0x6f [kafs]
	__do_sys_delete_module.isra.0+0x1a2/0x24b
	do_syscall_64+0x51/0x95
	entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by:

 (1) Attempting to cancel the probe timer and, if successful, drop the
     count that the timer was holding.

 (2) Make the timer function just drop the count and not schedule the
     prober if the afs portion of net namespace is being destroyed.

Also, whilst we're at it, make the following changes:

 (3) Initialise net->servers_outstanding to 1 and decrement it before
     waiting on it so that it doesn't generate wake up events by being
     decremented to 0 until we're cleaning up.

 (4) Switch the atomic_dec() on ->servers_outstanding for ->fs_timer in
     afs_purge_servers() to use the helper function for that.

Fixes: f6cbb368 ("afs: Actively poll fileservers to maintain NAT or firewall openings")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix afs_do_lookup()'s fallback case for when FS.InlineBulkStatus isn't
supported by the server.

In the fallback, it calls FS.FetchStatus for the specific vnode it's
meant to be looking up.  Commit b6489a49 broke this by renaming one
of the two identically-named afs_fetch_status_operation descriptors to
something else so that one of them could be made non-static.  The site
that used the renamed one, however, wasn't renamed and didn't produce
any warning because the other was declared in a header.

Fix this by making afs_do_lookup() use the renamed variant.

Note that there are two variants of the success method because one is
called from ->lookup() where we may or may not have an inode, but can't
call iget until after we've talked to the server - whereas the other is
called from within iget where we have an inode, but it may or may not be
initialised.

The latter variant expects there to be an inode, but because it's being
called from there former case, there might not be - resulting in an oops
like the following:

  BUG: kernel NULL pointer dereference, address: 00000000000000b0
  ...
  RIP: 0010:afs_fetch_status_success+0x27/0x7e
  ...
  Call Trace:
    afs_wait_for_operation+0xda/0x234
    afs_do_lookup+0x2fe/0x3c1
    afs_lookup+0x3c5/0x4bd
    __lookup_slow+0xcd/0x10f
    walk_component+0xa2/0x10c
    path_lookupat.isra.0+0x80/0x110
    filename_lookup+0x81/0x104
    vfs_statx+0x76/0x109
    __do_sys_newlstat+0x39/0x6b
    do_syscall_64+0x4c/0x78
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: b6489a49 ("afs: Fix silly rename")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

READ_ONCE() now enforces atomic read, which leads to:

  CC      mm/gup.o
In file included from ./include/linux/kernel.h:11:0,
                 from mm/gup.c:2:
In function 'gup_hugepte.constprop',
    inlined from 'gup_huge_pd.isra.79' at mm/gup.c:2465:8:
./include/linux/compiler.h:392:38: error: call to '__compiletime_assert_222' declared with attribute error: Unsupported access size for {READ,WRITE}_ONCE().
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
                                      ^
./include/linux/compiler.h:373:4: note: in definition of macro '__compiletime_assert'
    prefix ## suffix();    \
    ^
./include/linux/compiler.h:392:2: note: in expansion of macro '_compiletime_assert'
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
  ^
./include/linux/compiler.h:405:2: note: in expansion of macro 'compiletime_assert'
  compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
  ^
./include/linux/compiler.h:291:2: note: in expansion of macro 'compiletime_assert_rwonce_type'
  compiletime_assert_rwonce_type(x);    \
  ^
mm/gup.c:2428:8: note: in expansion of macro 'READ_ONCE'
  pte = READ_ONCE(*ptep);
        ^
In function 'gup_get_pte',
    inlined from 'gup_pte_range' at mm/gup.c:2228:9,
    inlined from 'gup_pmd_range' at mm/gup.c:2613:15,
    inlined from 'gup_pud_range' at mm/gup.c:2641:15,
    inlined from 'gup_p4d_range' at mm/gup.c:2666:15,
    inlined from 'gup_pgd_range' at mm/gup.c:2694:15,
    inlined from 'internal_get_user_pages_fast' at mm/gup.c:2795:3:
./include/linux/compiler.h:392:38: error: call to '__compiletime_assert_219' declared with attribute error: Unsupported access size for {READ,WRITE}_ONCE().
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
                                      ^
./include/linux/compiler.h:373:4: note: in definition of macro '__compiletime_assert'
    prefix ## suffix();    \
    ^
./include/linux/compiler.h:392:2: note: in expansion of macro '_compiletime_assert'
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
  ^
./include/linux/compiler.h:405:2: note: in expansion of macro 'compiletime_assert'
  compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
  ^
./include/linux/compiler.h:291:2: note: in expansion of macro 'compiletime_assert_rwonce_type'
  compiletime_assert_rwonce_type(x);    \
  ^
mm/gup.c:2199:9: note: in expansion of macro 'READ_ONCE'
  return READ_ONCE(*ptep);
         ^
make[2]: *** [mm/gup.o] Error 1

Define ptep_get() on 8xx when using 16k pages.

Fixes: 9e343b46 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/341688399c1b102756046d19ea6ce39db1ae4742.1592225558.git.christophe.leroy@csgroup.eu

Since commit 9e343b46 ("READ_ONCE: Enforce atomicity for
{READ,WRITE}_ONCE() memory accesses") it is not possible anymore to
use READ_ONCE() to access complex page table entries like the one
defined for powerpc 8xx with 16k size pages.

Define a ptep_get() helper that architectures can override instead
of performing a READ_ONCE() on the page table entry pointer.

Fixes: 9e343b46 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/087fa12b6e920e32315136b998aa834f99242695.1592225558.git.christophe.leroy@csgroup.eu

gup_hugepte() reads hugepage table entries, it can't read
them directly, huge_ptep_get() must be used.

Fixes: 9e343b46 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ffc3714334c3bfaca6f13788ad039e8759ae413f.1592225558.git.christophe.leroy@csgroup.eu

Include the papr_scm health retrieval feature for v5.8-rc2. The
functionality was initially posted well in advance of the merge window,
but review comments and a late build-bot warning kept them out of the
v5.8-rc1 libnvdimm pull request.

Vaibhav notes:
These patches are tied to specific features that were committed to
customers in upcoming distros releases (RHEL and SLES) whose time-lines
are tied to 5.8 kernel release.

Being able to track the health of an nvdimm is critical for our
customers that are running workloads leveraging papr-scm nvdimms.
Missing the 5.8 kernel would mean missing the distro timelines and
shifting forward the availability of this feature in distro kernels by
at least 6 months.

Pull io_uring fixes from Jens Axboe:

 - Catch a case where io_sq_thread() didn't do proper mm acquire

 - Ensure poll completions are reaped on shutdown

 - Async cancelation and run fixes (Pavel)

 - io-poll race fixes (Xiaoguang)

 - Request cleanup race fix (Xiaoguang)

* tag 'io_uring-5.8-2020-06-19' of git://git.kernel.dk/linux-block:
  io_uring: fix possible race condition against REQ_F_NEED_CLEANUP
  io_uring: reap poll completions while waiting for refs to drop on exit
  io_uring: acquire 'mm' for task_work for SQPOLL
  io_uring: add memory barrier to synchronize io_kiocb's result and iopoll_completed
  io_uring: don't fail links for EAGAIN error in IOPOLL mode
  io_uring: cancel by ->task not pid
  io_uring: lazy get task
  io_uring: batch cancel in io_uring_cancel_files()
  io_uring: cancel all task's requests on exit
  io-wq: add an option to cancel all matched reqs
  io-wq: reorder cancellation pending -> running
  io_uring: fix lazy work init