If the shared_info PFN cache has already been initialized then the content
of the shared_info page needs to be re-initialized whenever the guest
mode is (re)set.
Setting the guest mode is either done explicitly by the VMM via the
KVM_XEN_ATTR_TYPE_LONG_MODE attribute, or implicitly when the guest writes
the MSR to set up the hypercall page.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-12-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

A subsequent patch will allow shared_info to be initialized using either a
GPA or a user-space (i.e. VMM) HVA. To make that patch cleaner, separate
the initialization of the shared_info content from the activation of the
pfncache.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-11-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

Some pfncache pages may actually be overlays on guest memory that have a
fixed HVA within the VMM. It's pointless to invalidate such cached
mappings if the overlay is moved so allow a cache to be activated directly
with the HVA to cater for such cases. A subsequent patch will make use
of this facility.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-10-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

Rename kvm_is_error_gpa() to kvm_is_gpa_in_memslot() and invert the
polarity accordingly in order to (a) free up kvm_is_error_gpa() to match
with kvm_is_error_{hva,page}(), and (b) to make it more obvious that the
helper is doing a memslot lookup, i.e. not simply checking for INVALID_GPA.

No functional change intended.

Link: https://lore.kernel.org/r/20240215152916.1158-9-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

Currently the pfncache page offset is sometimes determined using the gpa
and sometimes the khva, whilst the uhva is always page-aligned. After a
subsequent patch is applied the gpa will not always be valid so adjust
the code to include the page offset in the uhva and use it consistently
as the source of truth.

Also, where a page-aligned address is required, use PAGE_ALIGN_DOWN()
for clarity.

No functional change intended.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-8-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

Some code in pfncache uses offset_in_page() but in other places it is open-
coded. Use offset_in_page() consistently everywhere.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-7-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

As noted in [1] the KVM_GUEST_USES_PFN usage flag is never set by any
callers of kvm_gpc_init(), and for good reason: the implementation is
incomplete/broken.  And it's not clear that there will ever be a user of
KVM_GUEST_USES_PFN, as coordinating vCPUs with mmu_notifier events is
non-trivial.

Remove KVM_GUEST_USES_PFN and all related code, e.g. dropping
KVM_GUEST_USES_PFN also makes the 'vcpu' argument redundant, to avoid
having to reason about broken code as __kvm_gpc_refresh() evolves.

Moreover, all existing callers specify KVM_HOST_USES_PFN so the usage
check in hva_to_pfn_retry() and hence the 'usage' argument to
kvm_gpc_init() are also redundant.

[1] https://lore.kernel.org/all/ZQiR8IpqOZrOpzHC@google.comSigned-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-6-paul@xen.org
[sean: explicitly call out that guest usage is incomplete]
Signed-off-by: Sean Christopherson <seanjc@google.com>

At the moment pages are marked dirty by open-coded calls to
mark_page_dirty_in_slot(), directly deferefencing the gpa and memslot
from the cache. After a subsequent patch these may not always be set
so add a helper now so that caller will protected from the need to know
about this detail.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-5-paul@xen.org
[sean: decrease indentation, use gpa_to_gfn()]
Signed-off-by: Sean Christopherson <seanjc@google.com>

Sampling gpa and memslot from an unlocked pfncache may yield inconsistent
values so, since there is no problem with calling mark_page_dirty_in_slot()
with the pfncache lock held, relocate the calls in
kvm_xen_update_runstate_guest() and kvm_xen_inject_pending_events()
accordingly.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-4-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

There is no need for the existing kvm_gpc_XXX() functions to be exported.
Clean up now before additional functions are added in subsequent patches.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-3-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

There is a pfncache unmap helper but mapping is open-coded. Arguably this
is fine because mapping is done in only one place, hva_to_pfn_retry(), but
adding the helper does make that function more readable.

No functional change intended.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-2-paul@xen.orgSigned-off-by: Sean Christopherson <seanjc@google.com>

KVM_CAP_IRQ_ROUTING is always defined, so there is no need to check if it is.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Since all architectures (for historical reasons) have to define
struct kvm_guest_debug_arch, and since userspace has to check
KVM_CHECK_EXTENSION(KVM_CAP_SET_GUEST_DEBUG) anyway, there is
no advantage in masking the capability #define itself.  Remove
the #define __KVM_HAVE_GUEST_DEBUG from architecture-specific
headers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM uses __KVM_HAVE_* symbols in the architecture-dependent uapi/asm/kvm.h to mask
unused definitions in include/uapi/linux/kvm.h.  __KVM_HAVE_READONLY_MEM however
was nothing but a misguided attempt to define KVM_CAP_READONLY_MEM only on
architectures where KVM_CHECK_EXTENSION(KVM_CAP_READONLY_MEM) could possibly
return nonzero.  This however does not make sense, and it prevented userspace
from supporting this architecture-independent feature without recompilation.

Therefore, these days __KVM_HAVE_READONLY_MEM does not mask anything and
is only used in virt/kvm/kvm_main.c.  Userspace does not need to test it
and there should be no need for it to exist.  Remove it and replace it
with a Kconfig symbol within Linux source code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

While this in principle breaks userspace code that mentions KVM_ARM_DEV_*
on architectures other than aarch64, this seems unlikely to be
a problem considering that run->s.regs.device_irq_level is only
defined on that architecture.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

While this in principle breaks the appearance of KVM_S390_* ioctls on architectures
other than s390, this seems unlikely to be a problem considering that there are
already many "struct kvm_s390_*" definitions in arch/s390/include/uapi.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

While this in principle breaks the appearance of KVM_PPC_* ioctls on architectures
other than powerpc, this seems unlikely to be a problem considering that there are
already many "struct kvm_ppc_*" definitions in arch/powerpc/include/uapi.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Several capabilities that exist only on x86 nevertheless have their
structs defined in include/uapi/linux/kvm.h.  Move them to
arch/x86/include/uapi/asm/kvm.h for cleanliness.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Change uapi header uses of GENMASK to instead use the uapi/linux/bits.h bit
macros, since GENMASK is not defined in uapi headers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Change uapi header uses of BIT to instead use the uapi/linux/const.h bit
macros, since BIT is not defined in uapi headers.

The PMU mask uses _BITUL since it targets a 32 bit flag field, whereas
the longmode definition is meant for a 64 bit flag field.

Cc: Sean Christophersen <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
Message-Id: <20231207001142.3617856-1-dionnaglaze@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Move __GENMASK and __GENMASK_ULL from include/ to include/uapi/ so that they can
be used to define masks in userspace API headers.  Compared to what is already
in include/linux/bits.h, the definitions need to use the uglified versions of
UL(), ULL(), BITS_PER_LONG and BITS_PER_LONG_LONG (which did not even exist),
but otherwise expand to the same content.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull crypto fixes from Herbert Xu:
 "Fix regressions in cbc and algif_hash, as well as an older
  NULL-pointer dereference in ccp"

* tag 'v6.8-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: algif_hash - Remove bogus SGL free on zero-length error path
  crypto: cbc - Ensure statesize is zero
  crypto: ccp - Fix null pointer dereference in __sev_platform_shutdown_locked

Pull percpu fix from Dennis Zhou:

 - fix riscv wrong size passed to local_flush_tlb_range_asid()

* tag 'percpu-for-6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  riscv: Fix wrong size passed to local_flush_tlb_range_asid()

Merge tag 'loongarch-fixes-6.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Fix acpi_core_pic[] array overflow, fix earlycon parameter if KASAN
  enabled, disable UBSAN instrumentation for vDSO build, and two Kconfig
  cleanups"

* tag 'loongarch-fixes-6.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: vDSO: Disable UBSAN instrumentation
  LoongArch: Fix earlycon parameter if KASAN enabled
  LoongArch: Change acpi_core_pic[NR_CPUS] to acpi_core_pic[MAX_CORE_PIC]
  LoongArch: Select HAVE_ARCH_SECCOMP to use the common SECCOMP menu
  LoongArch: Select ARCH_ENABLE_THP_MIGRATION instead of redefining it

Pull kvm fixes from Paolo Bonzini:
 "x86 guest:

   - Avoid false positive for check that only matters on AMD processors

  x86:

   - Give a hint when Win2016 might fail to boot due to XSAVES &&
     !XSAVEC configuration

   - Do not allow creating an in-kernel PIT unless an IOAPIC already
     exists

  RISC-V:

   - Allow ISA extensions that were enabled for bare metal in 6.8 (Zbc,
     scalar and vector crypto, Zfh[min], Zihintntl, Zvfh[min], Zfa)

  S390:

   - fix CC for successful PQAP instruction

   - fix a race when creating a shadow page"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  x86/coco: Define cc_vendor without CONFIG_ARCH_HAS_CC_PLATFORM
  x86/kvm: Fix SEV check in sev_map_percpu_data()
  KVM: x86: Give a hint when Win2016 might fail to boot due to XSAVES erratum
  KVM: x86: Check irqchip mode before create PIT
  KVM: riscv: selftests: Add Zfa extension to get-reg-list test
  RISC-V: KVM: Allow Zfa extension for Guest/VM
  KVM: riscv: selftests: Add Zvfh[min] extensions to get-reg-list test
  RISC-V: KVM: Allow Zvfh[min] extensions for Guest/VM
  KVM: riscv: selftests: Add Zihintntl extension to get-reg-list test
  RISC-V: KVM: Allow Zihintntl extension for Guest/VM
  KVM: riscv: selftests: Add Zfh[min] extensions to get-reg-list test
  RISC-V: KVM: Allow Zfh[min] extensions for Guest/VM
  KVM: riscv: selftests: Add vector crypto extensions to get-reg-list test
  RISC-V: KVM: Allow vector crypto extensions for Guest/VM
  KVM: riscv: selftests: Add scaler crypto extensions to get-reg-list test
  RISC-V: KVM: Allow scalar crypto extensions for Guest/VM
  KVM: riscv: selftests: Add Zbc extension to get-reg-list test
  RISC-V: KVM: Allow Zbc extension for Guest/VM
  KVM: s390: fix cc for successful PQAP
  KVM: s390: vsie: fix race during shadow creation

Pull nfsd fix from Chuck Lever:

 - Address a deadlock regression in RELEASE_LOCKOWNER

* tag 'nfsd-6.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: don't take fi_lock in nfsd_break_deleg_cb()

Pull btrfs fixes from David Sterba:

 - two fixes preventing deletion and manual creation of subvolume qgroup

 - unify error code returned for unknown send flags

 - fix assertion during subvolume creation when anonymous device could
   be allocated by other thread (e.g. due to backref walk)

* tag 'for-6.8-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: do not ASSERT() if the newly created subvolume already got read
  btrfs: forbid deleting live subvol qgroup
  btrfs: forbid creating subvol qgroups
  btrfs: send: return EOPNOTSUPP on unknown flags

After commit a9ef2774 ("x86/kvm: Fix SEV check in
sev_map_percpu_data()"), there is a build error when building
x86_64_defconfig with GCOV using LLVM:

  ld.lld: error: undefined symbol: cc_vendor
  >>> referenced by kvm.c
  >>>               arch/x86/kernel/kvm.o:(kvm_smp_prepare_boot_cpu) in archive vmlinux.a

which corresponds to

  if (cc_vendor != CC_VENDOR_AMD ||
      !cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
            return;

Without GCOV, clang is able to eliminate the use of cc_vendor because
cc_platform_has() evaluates to false when CONFIG_ARCH_HAS_CC_PLATFORM is
not set, meaning that if statement will be true no matter what value
cc_vendor has.

With GCOV, the instrumentation keeps the use of cc_vendor around for
code coverage purposes but cc_vendor is only declared, not defined,
without CONFIG_ARCH_HAS_CC_PLATFORM, leading to the build error above.

Provide a macro definition of cc_vendor when CONFIG_ARCH_HAS_CC_PLATFORM
is not set with a value of CC_VENDOR_NONE, so that the first condition
can always be evaluated/eliminated at compile time, avoiding the build
error altogether. This is very similar to the situation prior to
commit da86eb96 ("x86/coco: Get rid of accessor functions").
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Message-Id: <20240202-provide-cc_vendor-without-arch_has_cc_platform-v1-1-09ad5f2a3099@kernel.org>
Fixes: a9ef2774 ("x86/kvm: Fix SEV check in sev_map_percpu_data()", 2024-01-31)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull bcachefs fixes from Kent Overstreet:
 "Two serious ones here that we'll want to backport to stable: a fix for
  a race in the thread_with_file code, and another locking fixup in the
  subvolume deletion path"

* tag 'bcachefs-2024-02-05' of https://evilpiepirate.org/git/bcachefs:
  bcachefs: time_stats: Check for last_event == 0 when updating freq stats
  bcachefs: install fd later to avoid race with close
  bcachefs: unlock parent dir if entry is not found in subvolume deletion
  bcachefs: Fix build on parisc by avoiding __multi3()

The vDSO executes in userspace, so the kernel's UBSAN should not
instrument it. Solves these kind of build errors:

  loongarch64-linux-ld: arch/loongarch/vdso/vgettimeofday.o: in function `vdso_shift_ns':
  lib/vdso/gettimeofday.c:23:(.text+0x3f8): undefined reference to `__ubsan_handle_shift_out_of_bounds'
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401310530.lZHCj1Zl-lkp@intel.com/
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Fangrui Song <maskray@google.com>
Cc: loongarch@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

The earlycon parameter is based on fixmap, and fixmap addresses are not
supposed to be shadowed by KASAN. So return the kasan_early_shadow_page
in kasan_mem_to_shadow() if the input address is above FIXADDR_START.
Otherwise earlycon cannot work after kasan_init().

Cc: stable@vger.kernel.org
Fixes: 5aa4ac64 ("LoongArch: Add KASAN (Kernel Address Sanitizer) support")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

With default config, the value of NR_CPUS is 64. When HW platform has
more then 64 cpus, system will crash on these platforms. MAX_CORE_PIC
is the maximum cpu number in MADT table (max physical number) which can
exceed the supported maximum cpu number (NR_CPUS, max logical number),
but kernel should not crash. Kernel should boot cpus with NR_CPUS, let
the remainder cpus stay in BIOS.

The potential crash reason is that the array acpi_core_pic[NR_CPUS] can
be overflowed when parsing MADT table, and it is obvious that CORE_PIC
should be corresponding to physical core rather than logical core, so it
is better to define the array as acpi_core_pic[MAX_CORE_PIC].

With the patch, system can boot up 64 vcpus with qemu parameter -smp 128,
otherwise system will crash with the following message.

[    0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000420000004259, era == 90000000037a5f0c, ra == 90000000037a46ec
[    0.000000] Oops[#1]:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-rc2+ #192
[    0.000000] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
[    0.000000] pc 90000000037a5f0c ra 90000000037a46ec tp 9000000003c90000 sp 9000000003c93d60
[    0.000000] a0 0000000000000019 a1 9000000003d93bc0 a2 0000000000000000 a3 9000000003c93bd8
[    0.000000] a4 9000000003c93a74 a5 9000000083c93a67 a6 9000000003c938f0 a7 0000000000000005
[    0.000000] t0 0000420000004201 t1 0000000000000000 t2 0000000000000001 t3 0000000000000001
[    0.000000] t4 0000000000000003 t5 0000000000000000 t6 0000000000000030 t7 0000000000000063
[    0.000000] t8 0000000000000014 u0 ffffffffffffffff s9 0000000000000000 s0 9000000003caee98
[    0.000000] s1 90000000041b0480 s2 9000000003c93da0 s3 9000000003c93d98 s4 9000000003c93d90
[    0.000000] s5 9000000003caa000 s6 000000000a7fd000 s7 000000000f556b60 s8 000000000e0a4330
[    0.000000]    ra: 90000000037a46ec platform_init+0x214/0x250
[    0.000000]   ERA: 90000000037a5f0c efi_runtime_init+0x30/0x94
[    0.000000]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
[    0.000000]  PRMD: 00000000 (PPLV0 -PIE -PWE)
[    0.000000]  EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
[    0.000000]  ECFG: 00070800 (LIE=11 VS=7)
[    0.000000] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)
[    0.000000]  BADV: 0000420000004259
[    0.000000]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
[    0.000000] Modules linked in:
[    0.000000] Process swapper (pid: 0, threadinfo=(____ptrval____), task=(____ptrval____))
[    0.000000] Stack : 9000000003c93a14 9000000003800898 90000000041844f8 90000000037a46ec
[    0.000000]         000000000a7fd000 0000000008290000 0000000000000000 0000000000000000
[    0.000000]         0000000000000000 0000000000000000 00000000019d8000 000000000f556b60
[    0.000000]         000000000a7fd000 000000000f556b08 9000000003ca7700 9000000003800000
[    0.000000]         9000000003c93e50 9000000003800898 9000000003800108 90000000037a484c
[    0.000000]         000000000e0a4330 000000000f556b60 000000000a7fd000 000000000f556b08
[    0.000000]         9000000003ca7700 9000000004184000 0000000000200000 000000000e02b018
[    0.000000]         000000000a7fd000 90000000037a0790 9000000003800108 0000000000000000
[    0.000000]         0000000000000000 000000000e0a4330 000000000f556b60 000000000a7fd000
[    0.000000]         000000000f556b08 000000000eaae298 000000000eaa5040 0000000000200000
[    0.000000]         ...
[    0.000000] Call Trace:
[    0.000000] [<90000000037a5f0c>] efi_runtime_init+0x30/0x94
[    0.000000] [<90000000037a46ec>] platform_init+0x214/0x250
[    0.000000] [<90000000037a484c>] setup_arch+0x124/0x45c
[    0.000000] [<90000000037a0790>] start_kernel+0x90/0x670
[    0.000000] [<900000000378b0d8>] kernel_entry+0xd8/0xdc
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

LoongArch missed the refactoring made by commit 282a181b ("seccomp:
Move config option SECCOMP to arch/Kconfig") because LoongArch was not
mainlined at that time.

The 'depends on PROC_FS' statement is stale as described in that commit.
Select HAVE_ARCH_SECCOMP, and remove the duplicated config entry.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

ARCH_ENABLE_THP_MIGRATION is supposed to be selected by arch Kconfig.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

A recent change to check_for_locks() changed it to take ->flc_lock while
holding ->fi_lock.  This creates a lock inversion (reported by lockdep)
because there is a case where ->fi_lock is taken while holding
->flc_lock.

->flc_lock is held across ->fl_lmops callbacks, and
nfsd_break_deleg_cb() is one of those and does take ->fi_lock.  However
it doesn't need to.

Prior to v4.17-rc1~110^2~22 ("nfsd: create a separate lease for each
delegation") nfsd_break_deleg_cb() would walk the ->fi_delegations list
and so needed the lock.  Since then it doesn't walk the list and doesn't
need the lock.

Two actions are performed under the lock.  One is to call
nfsd_break_one_deleg which calls nfsd4_run_cb().  These doesn't act on
the nfs4_file at all, so don't need the lock.

The other is to set ->fi_had_conflict which is in the nfs4_file.
This field is only ever set here (except when initialised to false)
so there is no possible problem will multiple threads racing when
setting it.

The field is tested twice in nfs4_set_delegation().  The first test does
not hold a lock and is documented as an opportunistic optimisation, so
it doesn't impose any need to hold ->fi_lock while setting
->fi_had_conflict.

The second test in nfs4_set_delegation() *is* make under ->fi_lock, so
removing the locking when ->fi_had_conflict is set could make a change.
The change could only be interesting if ->fi_had_conflict tested as
false even though nfsd_break_one_deleg() ran before ->fi_lock was
unlocked.  i.e. while hash_delegation_locked() was running.
As hash_delegation_lock() doesn't interact in any way with nfs4_run_cb()
there can be no importance to this interaction.

So this patch removes the locking from nfsd_break_one_deleg() and moves
the final test on ->fi_had_conflict out of the locked region to make it
clear that locking isn't important to the test.  It is still tested
*after* vfs_setlease() has succeeded.  This might be significant and as
vfs_setlease() takes ->flc_lock, and nfsd_break_one_deleg() is called
under ->flc_lock this "after" is a true ordering provided by a spinlock.

Fixes: edcf9725 ("nfsd: fix RELEASE_LOCKOWNER")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

This fixes spurious outliers in the frequency stats.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Calling fd_install() makes a file reachable for userland, including the
possibility to close the file descriptor, which leads to calling its
'release' hook. If that happens before the code had a chance to bump the
reference of the newly created task struct, the release callback will
call put_task_struct() too early, leading to the premature destruction
of the kernel thread.

Avoid that race by calling fd_install() later, after all the setup is
done.

Fixes: 1c6fdbd8 ("bcachefs: Initial commit")
Signed-off-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Pull ext4 fixes from Ted Ts'o:
 "Miscellaneous bug fixes and cleanups in ext4's multi-block allocator
  and extent handling code"

* tag 'for-linus-6.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (23 commits)
  ext4: make ext4_set_iomap() recognize IOMAP_DELALLOC map type
  ext4: make ext4_map_blocks() distinguish delalloc only extent
  ext4: add a hole extent entry in cache after punch
  ext4: correct the hole length returned by ext4_map_blocks()
  ext4: convert to exclusive lock while inserting delalloc extents
  ext4: refactor ext4_da_map_blocks()
  ext4: remove 'needed' in trace_ext4_discard_preallocations
  ext4: remove unnecessary parameter "needed" in ext4_discard_preallocations
  ext4: remove unused return value of ext4_mb_release_group_pa
  ext4: remove unused return value of ext4_mb_release_inode_pa
  ext4: remove unused return value of ext4_mb_release
  ext4: remove unused ext4_allocation_context::ac_groups_considered
  ext4: remove unneeded return value of ext4_mb_release_context
  ext4: remove unused parameter ngroup in ext4_mb_choose_next_group_*()
  ext4: remove unused return value of __mb_check_buddy
  ext4: mark the group block bitmap as corrupted before reporting an error
  ext4: avoid allocating blocks from corrupted group in ext4_mb_find_by_goal()
  ext4: avoid allocating blocks from corrupted group in ext4_mb_try_best_found()
  ext4: avoid dividing by 0 in mb_update_avg_fragment_size() when block bitmap corrupt
  ext4: avoid bb_free and bb_fragments inconsistency in mb_free_blocks()
  ...