Function demote_incompat_holders iterates over the list of glock holders
with list_for_each_entry, and it then sometimes removes the current
holder from the list.  This will get the loop stuck; we must use
list_for_each_entry_safe instead.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Fix the length of holes reported at the end of a file: the length is
relative to the beginning of the extent, not the seek position which is
rounded down to the filesystem block size.

This bug went unnoticed for some time, but is now caught by the
following assertion in iomap_iter_done():

  WARN_ON_ONCE(iter->iomap.offset + iter->iomap.length <= iter->pos)

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Before this patch, evict would clear the iopen glock's gl_object after
releasing the inode glock.  In the meantime, another process could reuse
the same block and thus glocks for a new inode.  It would lock the inode
glock (exclusively), and then the iopen glock (shared).  The shared
locking mode doesn't provide any ordering against the evict, so by the
time the iopen glock is reused, evict may not have gotten to setting
gl_object to NULL.

Fix that by releasing the iopen glock before the inode glock in
gfs2_evict_inode.

Signed-off-by: Bob Peterson <rpeterso@redhat.com&gt;gl_object>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Replace test_bit() + set_bit() with test_and_set_bit() where we need an atomic
operation.  Use clear_and_wake_up_bit() instead of open coding it.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Only dereference i->iov after establishing that i is of type ITER_IOVEC.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Pull gfs2 updates from Andreas Gruenbacher:

 - Fix a locking order inversion between the inode and iopen glocks in
   gfs2_inode_lookup.

 - Implement proper queuing of glock holders for glocks that require
   instantiation (like reading an inode or bitmap blocks from disk).
   Before, multiple glock holders could race with each other and
   half-initialized objects could be exposed; the GL_SKIP flag further
   exacerbated this problem.

 - Fix a rare deadlock between inode lookup / creation and remote delete
   work.

 - Fix a rare scheduling-while-atomic bug in dlm during glock hash table
   walks.

 - Various other minor fixes and cleanups.

* tag 'gfs2-v5.15-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: (21 commits)
  gfs2: Fix unused value warning in do_gfs2_set_flags()
  gfs2: check context in gfs2_glock_put
  gfs2: Fix glock_hash_walk bugs
  gfs2: Cancel remote delete work asynchronously
  gfs2: set glock object after nq
  gfs2: remove RDF_UPTODATE flag
  gfs2: Eliminate GIF_INVALID flag
  gfs2: fix GL_SKIP node_scope problems
  gfs2: split glock instantiation off from do_promote
  gfs2: further simplify do_promote
  gfs2: re-factor function do_promote
  gfs2: Remove 'first' trace_gfs2_promote argument
  gfs2: change go_lock to go_instantiate
  gfs2: dump glocks from gfs2_consist_OBJ_i
  gfs2: dequeue iopen holder in gfs2_inode_lookup error
  gfs2: Save ip from gfs2_glock_nq_init
  gfs2: Allow append and immutable bits to coexist
  gfs2: Switch some BUG_ON to GLOCK_BUG_ON for debug
  gfs2: move GL_SKIP check from glops to do_promote
  gfs2: Add GL_SKIP holder flag to dump_holder
  ...

Merge tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

Pull gfs2 mmap + page fault deadlocks fixes from Andreas Gruenbacher:
 "Functions gfs2_file_read_iter and gfs2_file_write_iter are both
  accessing the user buffer to write to or read from while holding the
  inode glock.

  In the most basic deadlock scenario, that buffer will not be resident
  and it will be mapped to the same file. Accessing the buffer will
  trigger a page fault, and gfs2 will deadlock trying to take the same
  inode glock again while trying to handle that fault.

  Fix that and similar, more complex scenarios by disabling page faults
  while accessing user buffers. To make this work, introduce a small
  amount of new infrastructure and fix some bugs that didn't trigger so
  far, with page faults enabled"

* tag 'gfs2-v5.15-rc5-mmap-fault' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Fix mmap + page fault deadlocks for direct I/O
  iov_iter: Introduce nofault flag to disable page faults
  gup: Introduce FOLL_NOFAULT flag to disable page faults
  iomap: Add done_before argument to iomap_dio_rw
  iomap: Support partial direct I/O on user copy failures
  iomap: Fix iomap_dio_rw return value for user copies
  gfs2: Fix mmap + page fault deadlocks for buffered I/O
  gfs2: Eliminate ip->i_gh
  gfs2: Move the inode glock locking to gfs2_file_buffered_write
  gfs2: Introduce flag for glock holder auto-demotion
  gfs2: Clean up function may_grant
  gfs2: Add wrapper for iomap_file_buffered_write
  iov_iter: Introduce fault_in_iov_iter_writeable
  iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable
  gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable}
  powerpc/kvm: Fix kvm_use_magic_page
  iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value

Pull ARM updates from Russell King:

 - Rejig task/thread info to place thread info in task struct

 - Amba bus cleanups (removing unused functions)

 - Handle Amba device probe without IRQ domains

 - Parse linux,usable-memory-range in decompressor

 - Mark OCRAM as read-only after initialisation

 - Refactor page fault handling

 - Fix PXN handling with LPAE kernels

 - Warning and build fixes from Arnd

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (32 commits)
  ARM: 9151/1: Thumb2: avoid __builtin_thread_pointer() on Clang
  ARM: 9150/1: Fix PID_IN_CONTEXTIDR regression when THREAD_INFO_IN_TASK=y
  ARM: 9147/1: add printf format attribute to early_print()
  ARM: 9146/1: RiscPC needs older gcc version
  ARM: 9145/1: patch: fix BE32 compilation
  ARM: 9144/1: forbid ftrace with clang and thumb2_kernel
  ARM: 9143/1: add CONFIG_PHYS_OFFSET default values
  ARM: 9142/1: kasan: work around LPAE build warning
  ARM: 9140/1: ...

Pull KVM updates from Paolo Bonzini:
 "ARM:

   - More progress on the protected VM front, now with the full fixed
     feature set as well as the limitation of some hypercalls after
     initialisation.

   - Cleanup of the RAZ/WI sysreg handling, which was pointlessly
     complicated

   - Fixes for the vgic placement in the IPA space, together with a
     bunch of selftests

   - More memcg accounting of the memory allocated on behalf of a guest

   - Timer and vgic selftests

   - Workarounds for the Apple M1 broken vgic implementation

   - KConfig cleanups

   - New kvmarm.mode=none option, for those who really dislike us

  RISC-V:

   - New KVM port.

  x86:

   - New API to control TSC offset from userspace

   - TSC scaling for nested hypervisors on SVM

   - Switch masterclock protection from raw_spin_lock to seqcount

   - Clean up function prototypes in the page fault code and avoid
     repeated memslot lookups

   - Convey ...

Merge tag 'hyperv-next-signed-20211102' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Initial patch set for Hyper-V isolation VM support (Tianyu Lan)

 - Fix a warning on preemption (Vitaly Kuznetsov)

 - A bunch of misc cleanup patches

* tag 'hyperv-next-signed-20211102' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Protect set_hv_tscchange_cb() against getting preempted
  Drivers: hv : vmbus: Adding NULL pointer check
  x86/hyperv: Remove duplicate include
  x86/hyperv: Remove duplicated include in hv_init
  Drivers: hv: vmbus: Remove unused code to check for subchannels
  Drivers: hv: vmbus: Initialize VMbus ring buffer for Isolation VM
  Drivers: hv: vmbus: Add SNP support for VMbus channel initiate message
  x86/hyperv: Add ghcb hvcall support for SNP VM
  x86/hyperv: Add Write/Read MSR registers via ghcb page
  Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in Isolation VM
  x86/hyperv: Add new hvcall guest address host visibility support
  x86/hyperv: Initialize shared memory boundary in the Isolation VM.
  x86/hyperv: Initialize GHCB page in Isolation VM

Pull printk updates from Petr Mladek:

 - Extend %pGp print format to print hex value of the page flags

 - Use kvmalloc instead of kmalloc to allocate devkmsg buffers

 - Misc cleanup and warning fixes

* tag 'printk-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  vsprintf: Update %pGp documentation about that it prints hex value
  lib/vsprintf.c: Amend static asserts for format specifier flags
  vsprintf: Make %pGp print the hex value
  test_printf: Append strings more efficiently
  test_printf: Remove custom appending of '|'
  test_printf: Remove separate page_flags variable
  test_printf: Make pft array const
  ia64: don't do IA64_CMPXCHG_DEBUG without CONFIG_PRINTK
  printk: use gnu_printf format attribute for printk_sprint()
  printk: avoid -Wsometimes-uninitialized warning
  printk: use kvmalloc instead of kmalloc for devkmsg_user

Pull integrity subsystem updates from Mimi Zohar:
 "Other than the new gid IMA policy rule support and the RCU locking
  fix, the couple of remaining changes are minor/trivial (e.g.
  __ro_after_init, replacing strscpy)"

* tag 'integrity-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  evm: mark evm_fixmode as __ro_after_init
  ima: Use strscpy instead of strlcpy
  ima_policy: Remove duplicate 'the' in docs comment
  ima: add gid support
  ima: fix uid code style problems
  ima: fix deadlock when traversing "ima_default_rules".

Pull libata updates from Damien Le Moal:

 - Remove duplicated AHCI adapter PCI device IDs (from Krzysztof)

 - Cleanup of device DMA state checking to consistantly use
   ata_dma_enabled() (from Reimar)

* tag 'libata-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  pata_radisys: fix checking of DMA state
  pata_optidma: fix checking of DMA state
  pata_amd: fix checking of DMA state
  pata_ali: fix checking of DMA state
  libata-scsi: fix checking of DMA state
  libata: fix checking of DMA state
  Add AHCI support for ASM1062+JBM575 cards
  ahci: remove duplicated PCI device IDs

Pull x86 core updates from Borislav Petkov:

 - Do not #GP on userspace use of CLI/STI but pretend it was a NOP to
   keep old userspace from breaking. Adjust the corresponding iopl
   selftest to that.

 - Improve stack overflow warnings to say which stack got overflowed and
   raise the exception stack sizes to 2 pages since overflowing the
   single page of exception stack is very easy to do nowadays with all
   the tracing machinery enabled. With that, rip out the custom mapping
   of AMD SEV's too.

 - A bunch of changes in preparation for FGKASLR like supporting more
   than 64K section headers in the relocs tool, correct ORC lookup table
   size to cover the whole kernel .text and other adjustments.

* tag 'x86_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests/x86/iopl: Adjust to the faked iopl CLI/STI usage
  vmlinux.lds.h: Have ORC lookup cover entire _etext - _stext
  x86/boot/compressed: Avoid duplicate malloc() implementations
  x86/boot: Allow a "silent" kaslr random byte fetch
  x86/tools/relocs: Support >64K section headers
  x86/sev: Make the #VC exception stacks part of the default stacks storage
  x86: Increase exception stack sizes
  x86/mm/64: Improve stack overflow warnings
  x86/iopl: Fake iopl(3) CLI/STI usage

Pull networking updates from Jakub Kicinski:
 "Core:

   - Remove socket skb caches

   - Add a SO_RESERVE_MEM socket op to forward allocate buffer space and
     avoid memory accounting overhead on each message sent

   - Introduce managed neighbor entries - added by control plane and
     resolved by the kernel for use in acceleration paths (BPF / XDP
     right now, HW offload users will benefit as well)

   - Make neighbor eviction on link down controllable by userspace to
     work around WiFi networks with bad roaming implementations

   - vrf: Rework interaction with netfilter/conntrack

   - fq_codel: implement L4S style ce_threshold_ect1 marking

   - sch: Eliminate unnecessary RCU waits in mini_qdisc_pair_swap()

  BPF:

   - Add support for new btf kind BTF_KIND_TAG, arbitrary type tagging
     as implemented in LLVM14

   - Introduce bpf_get_branch_snapshot() to capture Last Branch Records

   - Impl...

Minor cocci warning fixes:
1) Bool return warning fix
2) Unnedded semicolon warning fix

This reverts commit f1a456f8

.

  WARNING: CPU: 1 PID: 6819 at net/core/skbuff.c:5429 skb_try_coalesce+0x78b/0x7e0
  CPU: 1 PID: 6819 Comm: xxxxxxx Kdump: loaded Tainted: G S                5.15.0-04194-gd852503f7711 #16
  RIP: 0010:skb_try_coalesce+0x78b/0x7e0
  Code: e8 2a bf 41 ff 44 8b b3 bc 00 00 00 48 8b 7c 24 30 e8 19 c0 41 ff 44 89 f0 48 03 83 c0 00 00 00 48 89 44 24 40 e9 47 fb ff ff <0f> 0b e9 ca fc ff ff 4c 8d 70 ff 48 83 c0 07 48 89 44 24 38 e9 61
  RSP: 0018:ffff88881f449688 EFLAGS: 00010282
  RAX: 00000000fffffe96 RBX: ffff8881566e4460 RCX: ffffffff82079f7e
  RDX: 0000000000000003 RSI: dffffc0000000000 RDI: ffff8881566e47b0
  RBP: ffff8881566e46e0 R08: ffffed102619235d R09: ffffed102619235d
  R10: ffff888130c91ae3 R11: ffffed102619235c R12: ffff88881f4498a0
  R13: 0000000000000056 R14: 0000000000000009 R15: ffff888130c91ac0
  FS:  00007fec2cbb9700(0000) GS:ffff88881f440000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fec1b060d80 CR3: 00000003acf94005 CR4: 00000000003706e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <IRQ>
   tcp_try_coalesce+0xeb/0x290
   ? tcp_parse_options+0x610/0x610
   ? mark_held_locks+0x79/0xa0
   tcp_queue_rcv+0x69/0x2f0
   tcp_rcv_established+0xa49/0xd40
   ? tcp_data_queue+0x18a0/0x18a0
   tcp_v6_do_rcv+0x1c9/0x880
   ? rt6_mtu_change_route+0x100/0x100
   tcp_v6_rcv+0x1624/0x1830

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull crypto updates from Herbert Xu:
 "API:

   - Delay boot-up self-test for built-in algorithms

  Algorithms:

   - Remove fallback path on arm64 as SIMD now runs with softirq off

  Drivers:

   - Add Keem Bay OCS ECC Driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (61 commits)
  crypto: testmgr - fix wrong key length for pkcs1pad
  crypto: pcrypt - Delay write to padata->info
  crypto: ccp - Make use of the helper macro kthread_run()
  crypto: sa2ul - Use the defined variable to clean code
  crypto: s5p-sss - Add error handling in s5p_aes_probe()
  crypto: keembay-ocs-ecc - Add Keem Bay OCS ECC Driver
  dt-bindings: crypto: Add Keem Bay ECC bindings
  crypto: ecc - Export additional helper functions
  crypto: ecc - Move ecc.h to include/crypto/internal
  crypto: engine - Add KPP Support to Crypto Engine
  crypto: api - Do not create test larvals if manager is disabled
  crypto: tcrypt - fix skcipher multi-buffer tests for 1420B blocks
  hwrng: s390 - replace snprintf in show functions with sysfs_emit
  crypto: octeontx2 - set assoclen in aead_do_fallback()
  crypto: ccp - Fix whitespace in sev_cmd_buffer_len()
  hwrng: mtk - Force runtime pm ops for sleep ops
  crypto: testmgr - Only disable migration in crypto_disable_simd_for_test()
  crypto: qat - share adf_enable_pf2vf_comms() from adf_pf2vf_msg.c
  crypto: qat - extract send and wait from adf_vf2pf_request_version()
  crypto: qat - add VF and PF wrappers to common send function
  ...

Pull audit updates from Paul Moore:
 "Add some additional audit logging to capture the openat2() syscall
  open_how struct info.

  Previous variations of the open()/openat() syscalls allowed audit
  admins to inspect the syscall args to get the information contained in
  the new open_how struct used in openat2()"

* tag 'audit-pr-20211101' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: return early if the filter rule has a lower priority
  audit: add OPENAT2 record to list "how" info
  audit: add support for the openat2 syscall
  audit: replace magic audit syscall class numbers with macros
  lsm_audit: avoid overloading the "key" audit field
  audit: Convert to SPDX identifier
  audit: rename struct node to struct audit_node to prevent future name collisions

Pull selinux updates from Paul Moore:

 - Add LSM/SELinux/Smack controls and auditing for io-uring.

   As usual, the individual commit descriptions have more detail, but we
   were basically missing two things which we're adding here:

      + establishment of a proper audit context so that auditing of
        io-uring ops works similarly to how it does for syscalls (with
        some io-uring additions because io-uring ops are *not* syscalls)

      + additional LSM hooks to enable access control points for some of
        the more unusual io-uring features, e.g. credential overrides.

   The additional audit callouts and LSM hooks were done in conjunction
   with the io-uring folks, based on conversations and RFC patches
   earlier in the year.

 - Fixup the binder credential handling so that the proper credentials
   are used in the LSM hooks; the commit description and the code
   comment which is removed...

Pull RCU updates from Paul McKenney:

 - Miscellaneous fixes

 - Torture-test updates for smp_call_function(), most notably improved
   checking of module parameters.

 - Tasks-trace RCU updates that fix a number of rare but important
   race-condition bugs.

 - Other torture-test updates, most notably better checking of module
   parameters. In addition, rcutorture may once again be run on
   CONFIG_PREEMPT_RT kernels.

 - Torture-test scripting updates, most notably specifying the new
   CONFIG_KCSAN_STRICT kconfig option rather than maintaining an
   ever-changing list of individual KCSAN kconfig options.

* tag 'rcu.2021.11.01a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (46 commits)
  rcu: Fix rcu_dynticks_curr_cpu_in_eqs() vs noinstr
  rcu: Always inline rcu_dynticks_task*_{enter,exit}()
  torture: Make kvm-remote.sh print size of downloaded tarball
  torture: Allot 1G of memory fo...

Pull tracing updates from Steven Rostedt:

 - kprobes: Restructured stack unwinder to show properly on x86 when a
   stack dump happens from a kretprobe callback.

 - Fix to bootconfig parsing

 - Have tracefs allow owner and group permissions by default (only
   denying others). There's been pressure to allow non root to tracefs
   in a controlled fashion, and using groups is probably the safest.

 - Bootconfig memory managament updates.

 - Bootconfig clean up to have the tools directory be less dependent on
   changes in the kernel tree.

 - Allow perf to be traced by function tracer.

 - Rewrite of function graph tracer to be a callback from the function
   tracer instead of having its own trampoline (this change will happen
   on an arch by arch basis, and currently only x86_64 implements it).

 - Allow multiple direct trampolines (bpf hooks to functions) be batched
   together in one synchronization.

 - Allow histogram triggers to add variables that can perform
   calculations against the event's fields.

 - Use the linker to determine architecture callbacks from the ftrace
   trampoline to allow for proper parameter prototypes and prevent
   warnings from the compiler.

 - Extend histogram triggers to key off of variables.

 - Have trace recursion use bit magic to determine preempt context over
   if branches.

 - Have trace recursion disable preemption as all use cases do anyway.

 - Added testing for verification of tracing utilities.

 - Various small clean ups and fixes.

* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
  tracing/histogram: Fix semicolon.cocci warnings
  tracing/histogram: Fix documentation inline emphasis warning
  tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
  tracing: Show size of requested perf buffer
  bootconfig: Initialize ret in xbc_parse_tree()
  ftrace: do CPU checking after preemption disabled
  ftrace: disable preemption when recursion locked
  tracing/histogram: Document expression arithmetic and constants
  tracing/histogram: Optimize division by a power of 2
  tracing/histogram: Covert expr to const if both operands are constants
  tracing/histogram: Simplify handling of .sym-offset in expressions
  tracing: Fix operator precedence for hist triggers expression
  tracing: Add division and multiplication support for hist triggers
  tracing: Add support for creating hist trigger variables from literal
  selftests/ftrace: Stop tracing while reading the trace file by default
  MAINTAINERS: Update KPROBES and TRACING entries
  test_kprobes: Move it from kernel/ to lib/
  docs, kprobes: Remove invalid URL and add new reference
  samples/kretprobes: Fix return value if register_kretprobe() failed
  lib/bootconfig: Fix the xbc_get_info kerneldoc
  ...

Merge in the fixes we had queued in case there was another -rc.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-11-01

We've added 181 non-merge commits during the last 28 day(s) which contain
a total of 280 files changed, 11791 insertions(+), 5879 deletions(-).

The main changes are:

1) Fix bpf verifier propagation of 64-bit bounds, from Alexei.

2) Parallelize bpf test_progs, from Yucong and Andrii.

3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus.

4) Improve bpf selftests on s390, from Ilya.

5) bloomfilter bpf map type, from Joanne.

6) Big improvements to JIT tests especially on Mips, from Johan.

7) Support kernel module function calls from bpf, from Kumar.

8) Support typeless and weak ksym in light skeleton, from Kumar.

9) Disallow unprivileged bpf by default, from Pawan.

10) BTF_KIND_DECL_TAG support, from Yonghong.

11) Various bpftool cleanups, from Quentin.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 com...

James Prestwood says:

====================
Make neighbor eviction controllable by userspace
====================

Link: https://lore.kernel.org/r/20211101173630.300969-1-prestwoj@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This tests the sysctl options for ARP/ND:

/net/ipv4/conf/<iface>/arp_evict_nocarrier
/net/ipv4/conf/all/arp_evict_nocarrier
/net/ipv6/conf/<iface>/ndisc_evict_nocarrier
/net/ipv6/conf/all/ndisc_evict_nocarrier

Signed-off-by: James Prestwood <prestwoj@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In most situations the neighbor discovery cache should be cleared on a
NOCARRIER event which is currently done unconditionally. But for wireless
roams the neighbor discovery cache can and should remain intact since
the underlying network has not changed.

This patch introduces a sysctl option ndisc_evict_nocarrier which can
be disabled by a wireless supplicant during a roam. This allows packets
to be sent after a roam immediately without having to wait for
neighbor discovery.

A user reported roughly a 1 second delay after a roam before packets
could be sent out (note, on IPv4). This delay was due to the ARP
cache being cleared. During testing of this same scenario using IPv6
no delay was noticed, but regardless there is no reason to clear
the ndisc cache for wireless roams.

Signed-off-by: James Prestwood <prestwoj@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This change introduces a new sysctl parameter, arp_evict_nocarrier.
When set (default) the ARP cache will be cleared on a NOCARRIER event.
This new option has been defaulted to '1' which maintains existing
behavior.

Clearing the ARP cache on NOCARRIER is relatively new, introduced by:

commit 859bd2ef
Author: David Ahern <dsahern@gmail.com>
Date:   Thu Oct 11 20:33:49 2018 -0700

    net: Evict neighbor entries on carrier down

The reason for this changes is to prevent the ARP cache from being
cleared when a wireless device roams. Specifically for wireless roams
the ARP cache should not be cleared because the underlying network has not
changed. Clearing the ARP cache in this case can introduce significant
delays sending out packets after a roam.

A user reported such a situation here:

https://lore.kernel.org/linux-wireless/CACsRnHWa47zpx3D1oDq9JYnZWniS8yBwW1h0WAVZ6vrbwL_S0w@mail.gmail.com/



After some investigation it was found that the kernel was holding onto
packets until ARP finished which resulted in this 1 second delay. It
was also found that the first ARP who-has was never responded to,
which is actually what caues the delay. This change is more or less
working around this behavior, but again, there is no reason to clear
the cache on a roam anyways.

As for the unanswered who-has, we know the packet made it OTA since
it was seen while monitoring. Why it never received a response is
unknown. In any case, since this is a problem on the AP side of things
all that can be done is to work around it until it is solved.

Some background on testing/reproducing the packet delay:

Hardware:
 - 2 access points configured for Fast BSS Transition (Though I don't
   see why regular reassociation wouldn't have the same behavior)
 - Wireless station running IWD as supplicant
 - A device on network able to respond to pings (I used one of the APs)

Procedure:
 - Connect to first AP
 - Ping once to establish an ARP entry
 - Start a tcpdump
 - Roam to second AP
 - Wait for operstate UP event, and note the timestamp
 - Start pinging

Results:

Below is the tcpdump after UP. It was recorded the interface went UP at
10:42:01.432875.

10:42:01.461871 ARP, Request who-has 192.168.254.1 tell 192.168.254.71, length 28
10:42:02.497976 ARP, Request who-has 192.168.254.1 tell 192.168.254.71, length 28
10:42:02.507162 ARP, Reply 192.168.254.1 is-at ac:86:74:55:b0:20, length 46
10:42:02.507185 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 1, length 64
10:42:02.507205 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 2, length 64
10:42:02.507212 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 3, length 64
10:42:02.507219 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 4, length 64
10:42:02.507225 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 5, length 64
10:42:02.507232 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 6, length 64
10:42:02.515373 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 1, length 64
10:42:02.521399 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 2, length 64
10:42:02.521612 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 3, length 64
10:42:02.521941 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 4, length 64
10:42:02.522419 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 5, length 64
10:42:02.523085 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 6, length 64

You can see the first ARP who-has went out very quickly after UP, but
was never responded to. Nearly a second later the kernel retries and
gets a response. Only then do the ping packets go out. If an ARP entry
is manually added prior to UP (after the cache is cleared) it is seen
that the first ping is never responded to, so its not only an issue with
ARP but with data packets in general.

As mentioned prior, the wireless interface was also monitored to verify
the ping/ARP packet made it OTA which was observed to be true.

Signed-off-by: James Prestwood <prestwoj@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull hwmon updates from Guenter Roeck:
 "New driver:

   - Maxim MAX6620

  Notable functional enhancements:

   - Add Asus WMI support to nct6775 driver, and list boards supporting
     it

   - Move TMP461 support from tm401 driver to lm90 driver

   - Add support for fanX_min, fanX_max and fanX_target to dell-smm
     driver, and clean it up while doing so

   - Extend mlxreg-fan driver to support multiple cooling devices and
     multiple PWM channels. Also increase number of supported fan
     tachometers.

   - Add a new customer ID (for ASRock) to nct6683 driver

   - Make temperature/voltage sensors on nct7802 configurable

   - Add mfg_id debugfs entry to pmbus/ibm-cffps driver

   - Support configurable sense resistor values in pmbus/lm25066, and
     fix various coefficients

   - Use generic notification mechanism in raspberrypi driver

  Notable cleanups:

   - Convert various devicetree bindings to dtschema, and add missing
     bindings

   - Convert i5500_temp and tmp103 drivers to
     devm_hwmon_device_register_with_info

   - Clean up non-bool "valid" data fields

   - Improve devicetree configurability for tmp421 driver"

* tag 'hwmon-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: (73 commits)
  hwmon: (nct7802) Add of_node_put() before return
  hwmon: (tmp401) Drop support for TMP461
  hwmon: (lm90) Add basic support for TI TMP461
  hwmon: (lm90) Introduce flag indicating extended temperature support
  hwmon: (nct6775) add ProArt X570-CREATOR WIFI.
  hwmon: (nct7802) Make temperature/voltage sensors configurable
  dt-bindings: hwmon: Add nct7802 bindings
  hwmon: (dell-smm) Speed up setting of fan speed
  hwmon: (dell-smm) Add comment explaining usage of i8k_config_data[]
  hwmon: (dell-smm) Return -ENOIOCTLCMD instead of -EINVAL
  hwmon: (dell-smm) Use strscpy_pad()
  hwmon: (dell-smm) Sort includes in alphabetical order
  hwmon: (tmp421) Add of_node_put() before return
  hwmon: (max31722) Warn about failure to put device in stand-by in .remove()
  hwmon: (acpi_power_meter) Use acpi_bus_get_acpi_device()
  hwmon: (dell-smm) Add support for fanX_min, fanX_max and fanX_target
  dt-bindings: hwmon: allow specifying channels for tmp421
  hwmon: (tmp421) ignore non-channel related DT nodes
  hwmon: (tmp421) update documentation
  hwmon: (tmp421) support HWMON_T_ENABLE
  ...

Pull spi updates from Mark Brown:
 "This is quite a quiet release for SPI, there's been a bit of cleanup
  to the core from Uwe but nothing functionality wise.

  We have added several new drivers, Cadence XSPI, Ingenic JZ47xx,
  Qualcomm SC7280 and SC7180 and Xilinx Versal OSPI"

* tag 'spi-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (41 commits)
  spi: Convert NXP flexspi to json schema
  spi: spi-geni-qcom: Add support for GPI dma
  spi: fsi: Fix contention in the FSI2SPI engine
  spi: spi-rpc-if: Check return value of rpcif_sw_init()
  spi: tegra210-quad: Put device into suspend on driver removal
  spi: tegra20-slink: Put device into suspend on driver removal
  spi: bcm-qspi: Fix missing clk_disable_unprepare() on error in bcm_qspi_probe()
  spi: at91-usart: replacing legacy gpio interface for gpiod
  spi: replace snprintf in show functions with sysfs_emit
  spi: cadence: Add of_node_put() befor...

Pull regulator updates from Mark Brown:
 "Thanks to the removal of the unused TPS80021 driver the regulator
  updates for this cycle actually have a negative diffstat.

  Otherwise it's been quite a quiet release, lots of fixes and small
  improvements with the biggest individual changes being several
  conversions of DT bindings to YAML format"

* tag 'regulator-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (34 commits)
  regulator: Don't error out fixed regulator in regulator_sync_voltage()
  regulator: tps80031: Remove driver
  regulator: Fix SY7636A breakage
  regulator: uniphier: Add binding for NX1 SoC
  regulator: uniphier: Add USB-VBUS compatible string for NX1 SoC
  regulator: qcom,rpmh: Add compatible for PM6350
  regulator: qcom-rpmh: Add PM6350 regulators
  regulator: sy7636a: Remove requirement on sy7636a mfd
  regulator: tps62360: replacing legacy gpio interface for gpiod
  regulator: lp872x: Remove lp872x_dvs_state
  regulator: lp872x: replacing legacy gpio interface for gpiod
  regulator: dt-bindings: samsung,s5m8767: convert to dtschema
  regulator: dt-bindings: samsung,s2mpa01: convert to dtschema
  regulator: dt-bindings: samsung,s2m: convert to dtschema
  dt-bindings: clock: samsung,s2mps11: convert to dtschema
  regulator: dt-bindings: samsung,s5m8767: correct s5m8767,pmic-buck-default-dvs-idx property
  regulator: s5m8767: do not use reset value as DVS voltage if GPIO DVS is disabled
  regulator: dt-bindings: maxim,max8973: convert to dtschema
  regulator: dt-bindings: maxim,max8997: convert to dtschema
  regulator: dt-bindings: maxim,max8952: convert to dtschema
  ...

Pull regmap update from Mark Brown:
 "A single change to use the maximum transfer and message sizes
  advertised by SPI controllers to configure limits within the
  regmap core, ensuring better interoperation"

* tag 'regmap-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: spi: Set regmap max raw r/w from max_transfer_size

Pull mailbox updates from Jassi Brar:
 "qcom:
   - add support for qcm2290
   - consolidate msm8994 type apcs_data

  mtk:
   - fix clock id usage

  apple:
   - add driver for ASC/M3 controllers

  pcc:
   - reorganise PCC pcc_mbox_request_channel
   - add support for PCCT extended PCC subspaces

  misc:
   - make use of devm_platform_ioremap_resource()
   - change Altera, PCC and Apple mailbox maintainers"

* tag 'mailbox-v5.16' of git://git.linaro.org/landing-teams/working/fujitsu/integration: (38 commits)
  mailbox: imx: support i.MX8ULP S4 MU
  dt-bindings: mailbox: imx-mu: add i.MX8ULP S400 MU support
  ACPI/PCC: Add maintainer for PCC mailbox driver
  mailbox: pcc: Move bulk of PCCT parsing into pcc_mbox_probe
  mailbox: pcc: Add support for PCCT extended PCC subspaces(type 3/4)
  mailbox: pcc: Drop handling invalid bit-width in {read,write}_register
  mailbox: pcc: Avoid accessing PCCT table in pcc_send_data and pcc_mbox_irq
  mailbox: pcc: Add PCC register bundle and associated accessor functions
  mailbox: pcc: Rename doorbell ack to platform interrupt ack register
  mailbox: pcc: Use PCC mailbox channel pointer instead of standard
  mailbox: pcc: Add pcc_mbox_chan structure to hold shared memory region info
  mailbox: pcc: Consolidate subspace doorbell register parsing
  mailbox: pcc: Consolidate subspace interrupt information parsing
  mailbox: pcc: Refactor all PCC channel information into a structure
  mailbox: pcc: Fix kernel doc warnings
  mailbox: apple: Add driver for Apple mailboxes
  dt-bindings: mailbox: Add Apple mailbox bindings
  MAINTAINERS: Add Apple mailbox files
  mailbox: mtk-cmdq: Fix local clock ID usage
  mailbox: mtk-cmdq: Validate alias_id on probe
  ...

Pull MMC and MEMSTICK updates from Ulf Hansson:
 "MMC core:
   - Update maintainer and URL for the mmc-utils
   - Set default label for slot-gpio in case of no con-id
   - Convert MMC card DT bindings to a schema
   - Add optional host specific tuning support for eMMC HS400
   - Add error handling of add_disk()

  MMC host:
   - mtk-sd: Add host specific tuning support for eMMC HS400
   - mtk-sd: Make DMA handling more robust
   - dw_mmc: Prevent hangs for some data writes
   - dw_mmc: Move away from using the ->init_card() callback
   - mxs-mmc: Manage the regulator in the error path and in ->remove()
   - sdhci-cadence: Add support for the Microchip MPFS variant
   - sdhci-esdhc-imx: Add support for the NXP S32G2 variant
   - sdhci-of-arasan: Add support for the Intel Thunder Bay variant
   - sdhci-omap: Prepare to support more SoCs
   - sdhci-omap: Add support for omap3 and omap4 variants
   - sdhci-omap: Add support for power management
   - sdhci-omap: Add support for system wakeups
   - sdhci-msm: Add support for the msm8226 variant
   - sdhci-sprd: Verify that the DLL locks according to spec

  MEMSTICK:
   - Add error handling of add_disk()
   - A couple of small fixes and improvements"

* tag 'mmc-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (60 commits)
  docs: mmc: update maintainer name and URL
  mmc: dw_mmc: exynos: Fix spelling mistake "candiates" -> candidates
  MAINTAINERS: drop obsolete file pattern in SDHCI DRIVER section
  mmc: sdhci-esdhc-imx: add NXP S32G2 support
  dt-bindings: mmc: fsl-imx-esdhc: add NXP S32G2 support
  mmc: dw_mmc: Drop use of ->init_card() callback
  mmc: sdhci-omap: Fix build if CONFIG_PM_SLEEP is not set
  mmc: sdhci-omap: Remove forward declaration of sdhci_omap_context_save()
  memstick: r592: Fix a UAF bug when removing the driver
  mmc: mxs-mmc: disable regulator on error and in the remove function
  mmc: sdhci-omap: Configure optional wakeirq
  mmc: sdhci-omap: Allow SDIO card power off and enable aggressive PM
  mmc: sdhci-omap: Implement PM runtime functions
  mmc: sdhci-omap: Add omap_offset to support omap3 and earlier
  mmc: sdhci-omap: Handle voltages to add support omap4
  dt-bindings: sdhci-omap: Update binding for legacy SoCs
  mmc: sdhci-pci: Remove dead code (rst_n_gpio et al)
  mmc: sdhci-pci: Remove dead code (cd_gpio, cd_irq et al)
  mmc: sdhci-pci: Remove dead code (struct sdhci_pci_data et al)
  mmc: sdhci: Remove unused prototype declaration in the header
  ...

Pull IPMI driver updates from Corey Minyard:
 "A new type of low-level IPMI driver is added for direct communication
  over the IPMI message bus without a BMC between the driver and the
  bus.

  Other than that, lots of little bug fixes and enhancements"

* tag 'for-linus-5.16-1' of https://github.com/cminyard/linux-ipmi:
  ipmi: kcs_bmc: Fix a memory leak in the error handling path of 'kcs_bmc_serio_add_device()'
  char: ipmi: replace snprintf in show functions with sysfs_emit
  ipmi: ipmb: fix dependencies to eliminate build error
  ipmi:ipmb: Add OF support
  ipmi: bt: Add ast2600 compatible string
  ipmi: bt-bmc: Use registers directly
  ipmi: ipmb: Fix off-by-one size check on rcvlen
  ipmi:ssif: Use depends on, not select, for I2C
  ipmi: Add docs for the IPMI IPMB driver
  ipmi: Add docs for IPMB direct addressing
  ipmi:ipmb: Add initial support for IPMI over IPMB
  ipmi: Add support for IPMB direct messages
  ipmi: Export ipmb_checksum()
  ipmi: Fix a typo
  ipmi: Check error code before processing BMC response
  ipmi:devintf: Return a proper error when recv buffer too small
  ipmi: Disable some operations during a panic
  ipmi:watchdog: Set panic count to proper value on a panic

Pull LED updates from Pavel Machek:
 "Johannes pointed out that locking is still problematic with triggers
  list, attempt to solve that by using RCU"

* tag 'leds-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds:
  leds: trigger: Disable CPU trigger on PREEMPT_RT
  leds: trigger: use RCU to protect the led_cdevs list
  led-class-flash: fix -Wrestrict warning

Pull media updates from Mauro Carvalho Chehab:

 - New driver for SK Hynix Hi-846 8M pixel camera

 - New driver for the ov13b10 camera

 - New driver for Renesas R-Car ISP

 - mtk-vcodec gained support for version 2 of decoder firmware ABI

 - The legacy sir_ir driver got removed

 - videobuf2: the vb2_mem_ops kAPI had some improvements

 - lots of cleanups, fixes and new features at device drivers

* tag 'media/v5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (328 commits)
  media: venus: core: Add sdm660 DT compatible and resource struct
  media: dt-bindings: media: venus: Add sdm660 dt schema
  media: venus: vdec: decoded picture buffer handling during reconfig sequence
  media: venus: Handle fatal errors during encoding and decoding
  media: venus: helpers: Add helper to mark fatal vb2 error
  media: venus: hfi: Check for sys error on session hfi functions
  media: venus: Make ...

Deprecate AF_XDP support in libbpf ([0]). This has been moved to
libxdp as it is a better fit for that library. The AF_XDP support only
uses the public libbpf functions and can therefore just use libbpf as
a library from libxdp. The libxdp APIs are exactly the same so it
should just be linking with libxdp instead of libbpf for the AF_XDP
functionality. If not, please submit a bug report. Linking with both
libraries is supported but make sure you link in the correct order so
that the new functions in libxdp are used instead of the deprecated
ones in libbpf.

Libxdp can be found at https://github.com/xdp-project/xdp-tools.

  [0] Closes: https://github.com/libbpf/libbpf/issues/270



Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20211029090111.4733-1-magnus.karlsson@gmail.com