Merge tag 'v5.4-rc5' into rdma.git for-next

Linux 5.4-rc5

For dependencies in the next patches

Conflict resolved by keeping the delete of the unlock.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.

Merge tag 'v5.4-rc5' into rdma.git for-next

Linux 5.4-rc5

For dependencies in the next patches

Conflict resolved by keeping the delete of the unlock.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

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Merge branch 'perf/urgent' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge 5.4-rc5 into tty-next

We want the tty/serial fix in here as well.

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

Merge 5.4-rc5 into usb-next

We want the USB fixes in here as well.

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

Merge tag 'v5.4-rc5' into next

Sync up with mainline.

Merge 5.4-rc5 into staging-next

We want the staging fixes in here for testing and building on.

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

Merge 5.4-rc5 into driver-core-next

We want the sysfs fix in here as well to build on top of.

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

Merge 5.4-rc5 into char-misc-next

We want the binder fix in here as well for testing and to work on top
of.

Also handles a merge issue in binder.c to help linux-next out

Signed-off-by: Greg Kroah-

Merge 5.4-rc5 into char-misc-next

We want the binder fix in here as well for testing and to work on top
of.

Also handles a merge issue in binder.c to help linux-next out

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

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Merge drm/drm-next into drm-misc-next

Parroting Daniel's backmerge justification from
2e79e22e092acd55da0b2db066e4826d7d152c41:

Thierry needs fd70c7755bf0 ("drm/bridge: tc358767: fix max_tu_symbol

Merge drm/drm-next into drm-misc-next

Parroting Daniel's backmerge justification from
2e79e22e092acd55da0b2db066e4826d7d152c41:

Thierry needs fd70c7755bf0 ("drm/bridge: tc358767: fix max_tu_symbol
value") to be able to merge his dp_link patch series.

Signed-off-by: Sean Paul <seanpaul@chromium.org>

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Merge v5.4-rc4 into drm-next

Thierry needs fd70c7755bf0 ("drm/bridge: tc358767: fix max_tu_symbol
value") to be able to merge his dp_link patch series.

Some adjacent changes conflicts, plus some cl

Merge v5.4-rc4 into drm-next

Thierry needs fd70c7755bf0 ("drm/bridge: tc358767: fix max_tu_symbol
value") to be able to merge his dp_link patch series.

Some adjacent changes conflicts, plus some clashes in i915 due to
cherry-picking and git trying to be helpful and leaving both versions
in.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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Merge tag 'v5.4-rc4' into devel

Linux 5.4-rc4

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Several cases of overlapping changes which were for the most
part trivially resolvable.

Signed-off-by: David S. Miller <davem@davemlof

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Several cases of overlapping changes which were for the most
part trivially resolvable.

Signed-off-by: David S. Miller <davem@davemloft.net>

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Merge tag 'for-5.4/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

- Fix DM snapshot deadlock that can occur due to CO

Merge tag 'for-5.4/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

- Fix DM snapshot deadlock that can occur due to COW throttling
preventing locks from being released.

- Fix DM cache's GFP_NOWAIT allocation failure error paths by switching
to GFP_NOIO.

- Make __hash_find() static in the DM clone target.

* tag 'for-5.4/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm cache: fix bugs when a GFP_NOWAIT allocation fails
dm snapshot: rework COW throttling to fix deadlock
dm snapshot: introduce account_start_copy() and account_end_copy()
dm clone: Make __hash_find static

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dm snapshot: rework COW throttling to fix deadlock

Commit 721b1d98fb517a ("dm snapshot: Fix excessive memory usage and
workqueue stalls") introduced a semaphore to limit the maximum number of
in-fli

dm snapshot: rework COW throttling to fix deadlock

Commit 721b1d98fb517a ("dm snapshot: Fix excessive memory usage and
workqueue stalls") introduced a semaphore to limit the maximum number of
in-flight kcopyd (COW) jobs.

The implementation of this throttling mechanism is prone to a deadlock:

1. One or more threads write to the origin device causing COW, which is
performed by kcopyd.

2. At some point some of these threads might reach the s->cow_count
semaphore limit and block in down(&s->cow_count), holding a read lock
on _origins_lock.

3. Someone tries to acquire a write lock on _origins_lock, e.g.,
snapshot_ctr(), which blocks because the threads at step (2) already
hold a read lock on it.

4. A COW operation completes and kcopyd runs dm-snapshot's completion
callback, which ends up calling pending_complete().
pending_complete() tries to resubmit any deferred origin bios. This
requires acquiring a read lock on _origins_lock, which blocks.

This happens because the read-write semaphore implementation gives
priority to writers, meaning that as soon as a writer tries to enter
the critical section, no readers will be allowed in, until all
writers have completed their work.

So, pending_complete() waits for the writer at step (3) to acquire
and release the lock. This writer waits for the readers at step (2)
to release the read lock and those readers wait for
pending_complete() (the kcopyd thread) to signal the s->cow_count
semaphore: DEADLOCK.

The above was thoroughly analyzed and documented by Nikos Tsironis as
part of his initial proposal for fixing this deadlock, see:
https://www.redhat.com/archives/dm-devel/2019-October/msg00001.html

Fix this deadlock by reworking COW throttling so that it waits without
holding any locks. Add a variable 'in_progress' that counts how many
kcopyd jobs are running. A function wait_for_in_progress() will sleep if
'in_progress' is over the limit. It drops _origins_lock in order to
avoid the deadlock.

Reported-by: Guruswamy Basavaiah <guru2018@gmail.com>
Reported-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
Tested-by: Nikos Tsironis <ntsironis@arrikto.com>
Fixes: 721b1d98fb51 ("dm snapshot: Fix excessive memory usage and workqueue stalls")
Cc: stable@vger.kernel.org # v5.0+
Depends-on: 4a3f111a73a8c ("dm snapshot: introduce account_start_copy() and account_end_copy()")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

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dm snapshot: introduce account_start_copy() and account_end_copy()

This simple refactoring moves code for modifying the semaphore cow_count
into separate functions to prepare for changes that will e

dm snapshot: introduce account_start_copy() and account_end_copy()

This simple refactoring moves code for modifying the semaphore cow_count
into separate functions to prepare for changes that will extend these
methods to provide for a more sophisticated mechanism for COW
throttling.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

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Merge branch 'next' into for-linus

Prepare input updates for 5.4 merge window.

Merge branch 'for-next' into for-linus

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Merge branch 'master' into for-5.4/logitech

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next

This merges in fixes for the XIVE interrupt controller which touch both
generic powerpc and PPC KVM code. To avoid mer

Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next

This merges in fixes for the XIVE interrupt controller which touch both
generic powerpc and PPC KVM code. To avoid merge conflicts, these
commits will go upstream via the powerpc tree as well as the KVM tree.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

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Merge branch 'ti-sysc-fixes' into fixes

Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/urgent

Pull a single EFI fix for v5.3 from Ard:

- Fix mixed mode breakage in EFI config table handling for

Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/urgent

Pull a single EFI fix for v5.3 from Ard:

- Fix mixed mode breakage in EFI config table handling for TPM.

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Merge tag 'v5.3-rc4' into next

Sync up with mainline to bring in device_property_count_u32 andother
newer APIs.

Merge tag 'v5.3-rc3' into drm-next-5.4

Linux 5.3-rc3

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Merge tag 'kvmarm-fixes-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm fixes for 5.3

- A bunch of switch/case fall-through annotation, fixing one actual b

Merge tag 'kvmarm-fixes-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm fixes for 5.3

- A bunch of switch/case fall-through annotation, fixing one actual bug
- Fix PMU reset bug
- Add missing exception class debug strings

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Merge drm/drm-next into drm-intel-next-queued

Catching up with 5.3-rc*

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>