Many throughput-sensitive workloads are made of several parallel I/O
flows, with all flows generated by the same application, or more
generically by the same task (e.g., system boot). The most
counterproductive action with these workloads is plugging I/O dispatch
when one of the bfq_queues associated with these flows remains
temporarily empty.

To avoid this plugging, BFQ has been using a burst-handling mechanism
for years now. This mechanism has proven effective for throughput, and
not detrimental for service guarantees. This commit pushes this
mechanism a little bit further, basing on the following two facts.

First, all the I/O flows of a the same application or task contribute
to the execution/completion of that common application or task. So the
performance figures that matter are total throughput of the flows and
task-wide I/O latency.  In particular, these flows do not need to be
protected from each other, in terms of individual bandwidth or
latency.

Second, the above fact holds regardless of the number of flows.

Putting these two facts together, this commits merges stably the
bfq_queues associated with these I/O flows, i.e., with the processes
that generate these IO/ flows, regardless of how many the involved
processes are.

To decide whether a set of bfq_queues is actually associated with the
I/O flows of a common application or task, and to merge these queues
stably, this commit operates as follows: given a bfq_queue, say Q2,
currently being created, and the last bfq_queue, say Q1, created
before Q2, Q2 is merged stably with Q1 if
- very little time has elapsed since when Q1 was created
- Q2 has the same ioprio as Q1
- Q2 belongs to the same group as Q1

Merging bfq_queues also reduces scheduling overhead. A fio test with
ten random readers on /dev/nullb shows a throughput boost of 40%, with
a quadcore. Since BFQ's execution time amounts to ~50% of the total
per-request processing time, the above throughput boost implies that
BFQ's overhead is reduced by more than 50%.
Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/r/20210304174627.161-7-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Shared queues are likely to receive I/O at a high rate. This may
deceptively let them be considered as wakers of other queues. But a
false waker will unjustly steal bandwidth to its supposedly woken
queue. So considering also shared queues in the waking mechanism may
cause more control troubles than throughput benefits. This commit
keeps shared queues out of the waker-detection mechanism.
Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/r/20210304174627.161-6-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

When the io_latency heuristic is off, bfq_queues must not start to be
weight-raised. Unfortunately, by mistake, this may happen when the
state of a previously weight-raised bfq_queue is resumed after a queue
split. This commit fixes this error.
Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/r/20210304174627.161-5-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Consider a bfq_queue bfqq that is about to be merged with another
bfq_queue new_bfqq. The processes associated with bfqq are cooperators
of the processes associated with new_bfqq. So, if bfqq has a waker,
then it is reasonable (and beneficial for throughput) to assume that
all these processes will be happy to let bfqq's waker freely inject
I/O when they have no I/O. So this commit makes new_bfqq inherit
bfqq's waker.
Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/r/20210304174627.161-4-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Consider a new I/O request that arrives for a bfq_queue bfqq. If, when
this happens, the only active bfq_queues are bfqq and either its waker
bfq_queue or one of its woken bfq_queues, then there is no point in
queueing this new I/O request in bfqq for service. In fact, the
in-service queue and bfqq agree on serving this new I/O request as
soon as possible. So this commit puts this new I/O request directly
into the dispatch list.
Tested-by: Jan Kara <jack@suse.cz>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/r/20210304174627.161-3-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Suppose that I/O dispatch is plugged, to wait for new I/O for the
in-service bfq-queue, say bfqq.  Suppose then that there is a further
bfq_queue woken by bfqq, and that this woken queue has pending I/O. A
woken queue does not steal bandwidth from bfqq, because it remains
soon without I/O if bfqq is not served. So there is virtually no risk
of loss of bandwidth for bfqq if this woken queue has I/O dispatched
while bfqq is waiting for new I/O. In contrast, this extra I/O
injection boosts throughput. This commit performs this extra
injection.
Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/r/20210304174627.161-2-paolo.valente@linaro.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

Sentence reconstruction for better readability.
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull ext4 fixes from Ted Ts'o:
 "Miscellaneous ext4 bug fixes for v5.12"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: initialize ret to suppress smatch warning
  ext4: stop inode update before return
  ext4: fix rename whiteout with fast commit
  ext4: fix timer use-after-free on failed mount
  ext4: fix potential error in ext4_do_update_inode
  ext4: do not try to set xattr into ea_inode if value is empty
  ext4: do not iput inode under running transaction in ext4_rename()
  ext4: find old entry again if failed to rename whiteout
  ext4: fix error handling in ext4_end_enable_verity()
  ext4: fix bh ref count on error paths
  fs/ext4: fix integer overflow in s_log_groups_per_flex
  ext4: add reclaim checks to xattr code
  ext4: shrink race window in ext4_should_retry_alloc()

Pull io_uring followup fixes from Jens Axboe:

 - The SIGSTOP change from Eric, so we properly ignore that for
   PF_IO_WORKER threads.

 - Disallow sending signals to PF_IO_WORKER threads in general, we're
   not interested in having them funnel back to the io_uring owning
   task.

 - Stable fix from Stefan, ensuring we properly break links for short
   send/sendmsg recv/recvmsg if MSG_WAITALL is set.

 - Catch and loop when needing to run task_work before a PF_IO_WORKER
   threads goes to sleep.

* tag 'io_uring-5.12-2021-03-21' of git://git.kernel.dk/linux-block:
  io_uring: call req_set_fail_links() on short send[msg]()/recv[msg]() with MSG_WAITALL
  io-wq: ensure task is running before processing task_work
  signal: don't allow STOP on PF_IO_WORKER threads
  signal: don't allow sending any signals to PF_IO_WORKER threads

Pull staging and IIO driver fixes from Greg KH:
 "Some small staging and IIO driver fixes:

   - MAINTAINERS changes for the move of the staging mailing list

   - comedi driver fixes to get request_irq() to work correctly

   - counter driver fixes for reported issues with iio devices

   - tiny iio driver fixes for reported issues.

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

* tag 'staging-5.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: vt665x: fix alignment constraints
  staging: comedi: cb_pcidas64: fix request_irq() warn
  staging: comedi: cb_pcidas: fix request_irq() warn
  MAINTAINERS: move the staging subsystem to lists.linux.dev
  MAINTAINERS: move some real subsystems off of the staging mailing list
  iio: gyro: mpu3050: Fix error handling in mpu3050_trigger_handler
  iio: hid-sensor-temperature: Fix issues of timestamp channel
  iio: hid-sensor-humidity: Fix alignment issue of timestamp channel
  counter: stm32-timer-cnt: fix ceiling miss-alignment with reload register
  counter: stm32-timer-cnt: fix ceiling write max value
  counter: stm32-timer-cnt: Report count function when SLAVE_MODE_DISABLED
  iio: adc: ab8500-gpadc: Fix off by 10 to 3
  iio:adc:stm32-adc: Add HAS_IOMEM dependency
  iio: adis16400: Fix an error code in adis16400_initial_setup()
  iio: adc: adi-axi-adc: add proper Kconfig dependencies
  iio: adc: ad7949: fix wrong ADC result due to incorrect bit mask
  iio: hid-sensor-prox: Fix scale not correct issue
  iio:adc:qcom-spmi-vadc: add default scale to LR_MUX2_BAT_ID channel

Pull USB and Thunderbolt driver fixes from Greg KH:
 "Here are some small Thunderbolt and USB driver fixes for some reported
  issues:

   - thunderbolt fixes for minor problems

   - typec fixes for power issues

   - usb-storage quirk addition

   - usbip bugfix

   - dwc3 bugfix when stopping transfers

   - cdnsp bugfix for isoc transfers

   - gadget use-after-free fix

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

* tag 'usb-5.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: typec: tcpm: Skip sink_cap query only when VDM sm is busy
  usb: dwc3: gadget: Prevent EP queuing while stopping transfers
  usb: typec: tcpm: Invoke power_supply_changed for tcpm-source-psy-
  usb: typec: Remove vdo[3] part of tps6598x_rx_identity_reg struct
  usb-storage: Add quirk to defeat Kindle's automatic unload
  usb: gadget: configfs: Fix KASAN use-after-free
  usbip: Fix incorrect double assignment to udc->ud.tcp_rx
  usb: cdnsp: Fixes incorrect value in ISOC TRB
  thunderbolt: Increase runtime PM reference count on DP tunnel discovery
  thunderbolt: Initialize HopID IDAs in tb_switch_alloc()

Pull irq fix from Ingo Molnar:
 "A change to robustify force-threaded IRQ handlers to always disable
  interrupts, plus a DocBook fix.

  The force-threaded IRQ handler change has been accelerated from the
  normal schedule of such a change to keep the bad pattern/workaround of
  spin_lock_irqsave() in handlers or IRQF_NOTHREAD as a kludge from
  spreading"

* tag 'irq-urgent-2021-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Disable interrupts for force threaded handlers
  genirq/irq_sim: Fix typos in kernel doc (fnode -> fwnode)

Pull perf fixes from Ingo Molnar:
 "Boundary condition fixes for bugs unearthed by the perf fuzzer"

* tag 'perf-urgent-2021-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix unchecked MSR access error caused by VLBR_EVENT
  perf/x86/intel: Fix a crash caused by zero PEBS status

Pull locking fixes from Ingo Molnar:

 - Get static calls & modules right. Hopefully.

 - WW mutex fixes

* tag 'locking-urgent-2021-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  static_call: Fix static_call_update() sanity check
  static_call: Align static_call_is_init() patching condition
  static_call: Fix static_call_set_init()
  locking/ww_mutex: Fix acquire/release imbalance in ww_acquire_init()/ww_acquire_fini()
  locking/ww_mutex: Simplify use_ww_ctx & ww_ctx handling

Pull EFI fixes from Ingo Molnar:

 - another missing RT_PROP table related fix, to ensure that the
   efivarfs pseudo filesystem fails gracefully if variable services
   are unsupported

 - use the correct alignment for literal EFI GUIDs

 - fix a use after unmap issue in the memreserve code

* tag 'efi-urgent-2021-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: use 32-bit alignment for efi_guid_t literals
  firmware/efi: Fix a use after bug in efi_mem_reserve_persistent
  efivars: respect EFI_UNSUPPORTED return from firmware

Pull x86 fixes from Borislav Petkov:
 "The freshest pile of shiny x86 fixes for 5.12:

   - Add the arch-specific mapping between physical and logical CPUs to
     fix devicetree-node lookups

   - Restore the IRQ2 ignore logic

   - Fix get_nr_restart_syscall() to return the correct restart syscall
     number. Split in a 4-patches set to avoid kABI breakage when
     backporting to dead kernels"

* tag 'x86_urgent_for_v5.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic/of: Fix CPU devicetree-node lookups
  x86/ioapic: Ignore IRQ2 again
  x86: Introduce restart_block->arch_data to remove TS_COMPAT_RESTART
  x86: Introduce TS_COMPAT_RESTART to fix get_nr_restart_syscall()
  x86: Move TS_COMPAT back to asm/thread_info.h
  kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data()

Pull powerpc fixes from Michael Ellerman:

 - Fix a possible stack corruption and subsequent DLPAR failure in the
   rpadlpar_io PCI hotplug driver

 - Two build fixes for uncommon configurations

Thanks to Christophe Leroy and Tyrel Datwyler.

* tag 'powerpc-5.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  PCI: rpadlpar: Fix potential drc_name corruption in store functions
  powerpc: Force inlining of cpu_has_feature() to avoid build failure
  powerpc/vdso32: Add missing _restgpr_31_x to fix build failure

Without that it's not safe to use them in a linked combination with
others.

Now combinations like IORING_OP_SENDMSG followed by IORING_OP_SPLICE
should be possible.

We already handle short reads and writes for the following opcodes:

- IORING_OP_READV
- IORING_OP_READ_FIXED
- IORING_OP_READ
- IORING_OP_WRITEV
- IORING_OP_WRITE_FIXED
- IORING_OP_WRITE
- IORING_OP_SPLICE
- IORING_OP_TEE

Now we have it for these as well:

- IORING_OP_SENDMSG
- IORING_OP_SEND
- IORING_OP_RECVMSG
- IORING_OP_RECV

For IORING_OP_RECVMSG we also check for the MSG_TRUNC and MSG_CTRUNC
flags in order to call req_set_fail_links().

There might be applications arround depending on the behavior
that even short send[msg]()/recv[msg]() retuns continue an
IOSQE_IO_LINK chain.

It's very unlikely that such applications pass in MSG_WAITALL,
which is only defined in 'man 2 recvmsg', but not in 'man 2 sendmsg'.

It's expected that the low level sock_sendmsg() call just ignores
MSG_WAITALL, as MSG_ZEROCOPY is also ignored without explicitly set
SO_ZEROCOPY.

We also expect the caller to know about the implicit truncation to
MAX_RW_COUNT, which we don't detect.

cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/c4e1a4cc0d905314f4d5dc567e65a7b09621aab3.1615908477.git.metze@samba.orgSigned-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Mark the current task as running if we need to run task_work from the
io-wq threads as part of work handling. If that is the case, then return
as such so that the caller can appropriately loop back and reset if it
was part of a going-to-sleep flush.

Fixes: 3bfe6106 ("io-wq: fork worker threads from original task")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Just like we don't allow normal signals to IO threads, don't deliver a
STOP to a task that has PF_IO_WORKER set. The IO threads don't take
signals in general, and have no means of flushing out a stop either.

Longer term, we may want to look into allowing stop of these threads,
as it relates to eg process freezing. For now, this prevents a spin
issue if a SIGSTOP is delivered to the parent task.
Reported-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

They don't take signals individually, and even if they share signals with
the parent task, don't allow them to be delivered through the worker
thread. Linux does allow this kind of behavior for regular threads, but
it's really a compatability thing that we need not care about for the IO
threads.
Reported-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

The inode update should be stopped before returing the error code.
Signed-off-by: Pan Bian <bianpan2016@163.com>
Link: https://lore.kernel.org/r/20210117085732.93788-1-bianpan2016@163.com
Fixes: 8016e29f ("ext4: fast commit recovery path")
Cc: stable@kernel.org
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

This patch adds rename whiteout support in fast commits. Note that the
whiteout object that gets created is actually char device. Which
imples, the function ext4_inode_journal_mode(struct inode *inode)
would return "JOURNAL_DATA" for this inode. This has a consequence in
fast commit code that it will make creation of the whiteout object a
fast-commit ineligible behavior and thus will fall back to full
commits. With this patch, this can be observed by running fast commits
with rename whiteout and seeing the stats generated by ext4_fc_stats
tracepoint as follows:

ext4_fc_stats: dev 254:32 fc ineligible reasons:
XATTR:0, CROSS_RENAME:0, JOURNAL_FLAG_CHANGE:0, NO_MEM:0, SWAP_BOOT:0,
RESIZE:0, RENAME_DIR:0, FALLOC_RANGE:0, INODE_JOURNAL_DATA:16;
num_commits:6, ineligible: 6, numblks: 3

So in short, this patch guarantees that in case of rename whiteout, we
fall back to full commits.

Amir mentioned that instead of creating a new whiteout object for
every rename, we can create a static whiteout object with irrelevant
nlink. That will make fast commits to not fall back to full
commit. But until this happens, this patch will ensure correctness by
falling back to full commits.

Fixes: 8016e29f ("ext4: fast commit recovery path")
Cc: stable@kernel.org
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20210316221921.1124955-1-harshadshirwadkar@gmail.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

When filesystem mount fails because of corrupted filesystem we first
cancel the s_err_report timer reminding fs errors every day and only
then we flush s_error_work. However s_error_work may report another fs
error and re-arm timer thus resulting in timer use-after-free. Fix the
problem by first flushing the work and only after that canceling the
s_err_report timer.

Reported-by: syzbot+628472a2aac693ab0fcd@syzkaller.appspotmail.com
Fixes: 2d01ddc8 ("ext4: save error info to sb through journal if available")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210315165906.2175-1-jack@suse.czSigned-off-by: Theodore Ts'o <tytso@mit.edu>

If set_large_file = 1 and errors occur in ext4_handle_dirty_metadata(),
the error code will be overridden, go to out_brelse to avoid this
situation.
Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Link: https://lore.kernel.org/r/20210312065051.36314-1-luoshijie1@huawei.com
Cc: stable@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Syzbot report a warning that ext4 may create an empty ea_inode if set
an empty extent attribute to a file on the file system which is no free
blocks left.

  WARNING: CPU: 6 PID: 10667 at fs/ext4/xattr.c:1640 ext4_xattr_set_entry+0x10f8/0x1114 fs/ext4/xattr.c:1640
  ...
  Call trace:
   ext4_xattr_set_entry+0x10f8/0x1114 fs/ext4/xattr.c:1640
   ext4_xattr_block_set+0x1d0/0x1b1c fs/ext4/xattr.c:1942
   ext4_xattr_set_handle+0x8a0/0xf1c fs/ext4/xattr.c:2390
   ext4_xattr_set+0x120/0x1f0 fs/ext4/xattr.c:2491
   ext4_xattr_trusted_set+0x48/0x5c fs/ext4/xattr_trusted.c:37
   __vfs_setxattr+0x208/0x23c fs/xattr.c:177
  ...

Now, ext4 try to store extent attribute into an external inode if
ext4_xattr_block_set() return -ENOSPC, but for the case of store an
empty extent attribute, store the extent entry into the extent
attribute block is enough. A simple reproduce below.

  fallocate test.img -l 1M
  mkfs.ext4 -F -b 2048 -O ea_inode test.img
  mount test.img /mnt
  dd if=/dev/zero of=/mnt/foo bs=2048 count=500
  setfattr -n "user.test" /mnt/foo

Reported-by: syzbot+98b881fdd8ebf45ab4ae@syzkaller.appspotmail.com
Fixes: 9c6e7853 ("ext4: reserve space for xattr entries/names")
Cc: stable@kernel.org
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210305120508.298465-1-yi.zhang@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

In ext4_rename(), when RENAME_WHITEOUT failed to add new entry into
directory, it ends up dropping new created whiteout inode under the
running transaction. After commit <9b88f9fb> ("ext4: Do not iput inode
under running transaction"), we follow the assumptions that evict() does
not get called from a transaction context but in ext4_rename() it breaks
this suggestion. Although it's not a real problem, better to obey it, so
this patch add inode to orphan list and stop transaction before final
iput().
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210303131703.330415-2-yi.zhang@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

If we failed to add new entry on rename whiteout, we cannot reset the
old->de entry directly, because the old->de could have moved from under
us during make indexed dir. So find the old entry again before reset is
needed, otherwise it may corrupt the filesystem as below.

  /dev/sda: Entry '00000001' in ??? (12) has deleted/unused inode 15. CLEARED.
  /dev/sda: Unattached inode 75
  /dev/sda: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.

Fixes: 6b4b8e6b ("ext4: fix bug for rename with RENAME_WHITEOUT")
Cc: stable@vger.kernel.org
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210303131703.330415-1-yi.zhang@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

With interrupt force threading all device interrupt handlers are invoked
from kernel threads. Contrary to hard interrupt context the invocation only
disables bottom halfs, but not interrupts. This was an oversight back then
because any code like this will have an issue:

thread(irq_A)
  irq_handler(A)
    spin_lock(&foo->lock);

interrupt(irq_B)
  irq_handler(B)
    spin_lock(&foo->lock);

This has been triggered with networking (NAPI vs. hrtimers) and console
drivers where printk() happens from an interrupt which interrupted the
force threaded handler.

Now people noticed and started to change the spin_lock() in the handler to
spin_lock_irqsave() which affects performance or add IRQF_NOTHREAD to the
interrupt request which in turn breaks RT.

Fix the root cause and not the symptom and disable interrupts before
invoking the force threaded handler which preserves the regular semantics
and the usefulness of the interrupt force threading as a general debugging
tool.

For not RT this is not changing much, except that during the execution of
the threaded handler interrupts are delayed until the handler
returns. Vs. scheduling and softirq processing there is no difference.

For RT kernels there is no issue.

Fixes: 8d32a307 ("genirq: Provide forced interrupt threading")
Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Johan Hovold <johan@kernel.org>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20210317143859.513307808@linutronix.de

Pull RISC-V fixes from Palmer Dabbelt:
 "A handful of fixes for 5.12:

   - fix the SBI remote fence numbers for hypervisor fences, which had
     been transcribed in the wrong order in Linux. These fences are only
     used with the KVM patches applied.

   - fix a whole host of build warnings, these should have no functional
     change.

   - fix init_resources() to prevent an off-by-one error from causing an
     out-of-bounds array reference. This was manifesting during boot on
     vexriscv.

   - ensure the KASAN mappings are visible before proceeding to use
     them"

* tag 'riscv-for-linus-5.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Correct SPARSEMEM configuration
  RISC-V: kasan: Declare kasan_shallow_populate() static
  riscv: Ensure page table writes are flushed when initializing KASAN vmalloc
  RISC-V: Fix out-of-bounds accesses in init_resources()
  riscv: Fix compilation error with Canaan SoC
  ftrace: Fix spelling mistake "disabed" -> "disabled"
  riscv: fix bugon.cocci warnings
  riscv: process: Fix no prototype for arch_dup_task_struct
  riscv: ftrace: Use ftrace_get_regs helper
  riscv: process: Fix no prototype for show_regs
  riscv: syscall_table: Reduce W=1 compilation warnings noise
  riscv: time: Fix no prototype for time_init
  riscv: ptrace: Fix no prototype warnings
  riscv: sbi: Fix comment of __sbi_set_timer_v01
  riscv: irq: Fix no prototype warning
  riscv: traps: Fix no prototype warnings
  RISC-V: correct enum sbi_ext_rfence_fid

Pull cifs fixes from Steve French:
 "Five cifs/smb3 fixes - three for stable, including an important ACL
  fix and security signature fix"

* tag '5.12-rc3-smb3' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix allocation size on newly created files
  cifs: warn and fail if trying to use rootfs without the config option
  fs/cifs/: fix misspellings using codespell tool
  cifs: Fix preauth hash corruption
  cifs: update new ACE pointer after populate_new_aces.

Pull SCSI fixes from James Bottomley:
 "Eight fixes, all in drivers, all fairly minor either being fixes in
  error legs, memory leaks on teardown, context errors or semantic
  problems"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: mpt3sas: Do not use GFP_KERNEL in atomic context
  scsi: ufs: ufs-mediatek: Correct operator & -> &&
  scsi: sd_zbc: Update write pointer offset cache
  scsi: lpfc: Fix some error codes in debugfs
  scsi: qla2xxx: Fix broken #endif placement
  scsi: st: Fix a use after free in st_open()
  scsi: myrs: Fix a double free in myrs_cleanup()
  scsi: ibmvfc: Free channel_setup_buf during device tear down

Pull zonefs fixes from Damien Le Moal:

 - fix inode write open reference count (Chao)

 - Fix wrong write offset for asynchronous O_APPEND writes (me)

 - Prevent use of sequential zone file as swap files (me)

* tag 'zonefs-5.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
  zonefs: fix to update .i_wr_refcnt correctly in zonefs_open_zone()
  zonefs: Fix O_APPEND async write handling
  zonefs: prevent use of seq files as swap file

Pull block fixes from Jens Axboe:
 "Just an NVMe pull request this week:

   - fix tag allocation for keep alive

   - fix a unit mismatch for the Write Zeroes limits

   - various TCP transport fixes (Sagi Grimberg, Elad Grupi)

   - fix iosqes and iocqes validation for discovery controllers (Sagi Grimberg)"

* tag 'block-5.12-2021-03-19' of git://git.kernel.dk/linux-block:
  nvmet-tcp: fix kmap leak when data digest in use
  nvmet: don't check iosqes,iocqes for discovery controllers
  nvme-rdma: fix possible hang when failing to set io queues
  nvme-tcp: fix possible hang when failing to set io queues
  nvme-tcp: fix misuse of __smp_processor_id with preemption enabled
  nvme-tcp: fix a NULL deref when receiving a 0-length r2t PDU
  nvme: fix Write Zeroes limitations
  nvme: allocate the keep alive request using BLK_MQ_REQ_NOWAIT
  nvme: merge nvme_keep_alive into nvme_keep_alive_work
  nvme-fabrics: only reserve a single tag

Pull io_uring fixes from Jens Axboe:
 "Quieter week this time, which was both expected and desired. About
  half of the below is fixes for this release, the other half are just
  fixes in general. In detail:

   - Fix the freezing of IO threads, by making the freezer not send them
     fake signals. Make them freezable by default.

   - Like we did for personalities, move the buffer IDR to xarray. Kills
     some code and avoids a use-after-free on teardown.

   - SQPOLL cleanups and fixes (Pavel)

   - Fix linked timeout race (Pavel)

   - Fix potential completion post use-after-free (Pavel)

   - Cleanup and move internal structures outside of general kernel view
     (Stefan)

   - Use MSG_SIGNAL for send/recv from io_uring (Stefan)"

* tag 'io_uring-5.12-2021-03-19' of git://git.kernel.dk/linux-block:
  io_uring: don't leak creds on SQO attach error
  io_uring: use typesafe pointers in io_uring_task
  io_uring: remove structures from include/linux/io_uring.h
  io_uring: imply MSG_NOSIGNAL for send[msg]()/recv[msg]() calls
  io_uring: fix sqpoll cancellation via task_work
  io_uring: add generic callback_head helpers
  io_uring: fix concurrent parking
  io_uring: halt SQO submission on ctx exit
  io_uring: replace sqd rw_semaphore with mutex
  io_uring: fix complete_post use ctx after free
  io_uring: fix ->flags races by linked timeouts
  io_uring: convert io_buffer_idr to XArray
  io_uring: allow IO worker threads to be frozen
  kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing

Architectures that describe the CPU topology in devicetree and do not have
an identity mapping between physical and logical CPU ids must override the
default implementation of arch_match_cpu_phys_id().

Failing to do so breaks CPU devicetree-node lookups using of_get_cpu_node()
and of_cpu_device_node_get() which several drivers rely on. It also causes
the CPU struct devices exported through sysfs to point to the wrong
devicetree nodes.

On x86, CPUs are described in devicetree using their APIC ids and those
do not generally coincide with the logical ids, even if CPU0 typically
uses APIC id 0.

Add the missing implementation of arch_match_cpu_phys_id() so that CPU-node
lookups work also with SMP.

Apart from fixing the broken sysfs devicetree-node links this likely does
not affect current users of mainline kernels on x86.

Fixes: 4e07db9c ("x86/devicetree: Use CPU description from Device Tree")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210312092033.26317-1-johan@kernel.org

Pull kvm fixes from Paolo Bonzini:
 "Fixes for kvm on x86:

   - new selftests

   - fixes for migration with HyperV re-enlightenment enabled

   - fix RCU/SRCU usage

   - fixes for local_irq_restore misuse false positive"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  documentation/kvm: additional explanations on KVM_SET_BOOT_CPU_ID
  x86/kvm: Fix broken irq restoration in kvm_wait
  KVM: X86: Fix missing local pCPU when executing wbinvd on all dirty pCPUs
  KVM: x86: Protect userspace MSR filter with SRCU, and set atomically-ish
  selftests: kvm: add set_boot_cpu_id test
  selftests: kvm: add _vm_ioctl
  selftests: kvm: add get_msr_index_features
  selftests: kvm: Add basic Hyper-V clocksources tests
  KVM: x86: hyper-v: Don't touch TSC page values when guest opted for re-enlightenment
  KVM: x86: hyper-v: Track Hyper-V TSC page status
  KVM: x86: hyper-v: Prevent using not-yet-updated TSC page by secondary CPUs
  KVM: x86: hyper-v: Limit guest to writing zero to HV_X64_MSR_TSC_EMULATION_STATUS
  KVM: x86/mmu: Store the address space ID in the TDP iterator
  KVM: x86/mmu: Factor out tdp_iter_return_to_root
  KVM: x86/mmu: Fix RCU usage when atomically zapping SPTEs
  KVM: x86/mmu: Fix RCU usage in handle_removed_tdp_mmu_page

Pull gpio fixes from Bartosz Golaszewski:
 "Two fixes for the GPIO subsystem. Both address issues in the core GPIO
  code:

   - fix the return value in error path in gpiolib_dev_init()

   - fix the 'gpio-line-names' property handling correctly this time"

* tag 'gpio-fixes-for-v5.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpiolib: Assign fwnode to parent's if no primary one provided
  gpiolib: Fix error return code in gpiolib_dev_init()