An attempt to establish a connection can always fail and then be
retried. GFP_KERNEL allocation is not necessary here.

Like MR allocation, establishing a connection is always done in a
worker thread. The new GFP flags align with the flags that would
be returned by rpc_task_gfp_mask() in this case.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprtrdma always drives a retry of MR allocation if it should fail.
It should be safe to not use GFP_KERNEL for this purpose rather
than sleeping in the memory allocator.

In theory, if these weaker allocations are attempted first, memory
exhaustion is likely to cause xprtrdma to fail fast and not then
invoke the RDMA core APIs, which still might use GFP_KERNEL.

Also note that rpc_task_gfp_mask() always sets __GFP_NORETRY and
__GFP_NOWARN when an RPC-related allocation is being done in a
worker thread. MR allocation is already always done in worker
threads.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Currently all rpcrdma_regbuf_alloc() call sites pass the same value
as their third argument. That argument can therefore be eliminated.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Commit 1769e6a8 ("xprtrdma: Clean up rpcrdma_create_req()")
added rpcrdma_req_create() with a GFP flags argument in case a
caller might want to avoid waiting for memory.

There has never been a caller that does not pass GFP_KERNEL as
the third argument. That argument can therefore be eliminated.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

xprt_rdma_bc_allocate() is now the only user of RPCRDMA_DEF_GFP.
Replace that macro with the raw flags.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

While setting up a new lab, I accidentally misconfigured the
Ethernet port for a system that tried an NFS mount using RoCE.
This made the NFS server unreachable. The following WARNING
popped on the NFS client while waiting for the mount attempt to
time out:

kernel: workqueue: WQ_MEM_RECLAIM xprtiod:xprt_rdma_connect_worker [rpcrdma] is flushing !WQ_MEM_RECLAI>
kernel: WARNING: CPU: 0 PID: 100 at kernel/workqueue.c:2628 check_flush_dependency+0xbf/0xca
kernel: Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs 8021q garp stp mrp llc rfkill rpcrdma>
kernel: CPU: 0 PID: 100 Comm: kworker/u8:8 Not tainted 6.0.0-rc1-00002-g6229f8c054e5 #13
kernel: Hardware name: Supermicro X10SRA-F/X10SRA-F, BIOS 2.0b 06/12/2017
kernel: Workqueue: xprtiod xprt_rdma_connect_worker [rpcrdma]
kernel: RIP: 0010:check_flush_dependency+0xbf/0xca
kernel: Code: 75 2a 48 8b 55 18 48 8d 8b b0 00 00 00 4d 89 e0 48 81 c6 b0 00 00 00 48 c7 c7 65 33 2e be>
kernel: RSP: 0018:ffffb562806cfcf8 EFLAGS: 00010092
kernel: RAX: 0000000000000082 RBX: ffff97894f8c3c00 RCX: 0000000000000027
kernel: RDX: 0000000000000002 RSI: ffffffffbe3447d1 RDI: 00000000ffffffff
kernel: RBP: ffff978941315840 R08: 0000000000000000 R09: 0000000000000000
kernel: R10: 00000000000008b0 R11: 0000000000000001 R12: ffffffffc0ce3731
kernel: R13: ffff978950c00500 R14: ffff97894341f0c0 R15: ffff978951112eb0
kernel: FS:  0000000000000000(0000) GS:ffff97987fc00000(0000) knlGS:0000000000000000
kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 00007f807535eae8 CR3: 000000010b8e4002 CR4: 00000000003706f0
kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kernel: Call Trace:
kernel:  <TASK>
kernel:  __flush_work.isra.0+0xaf/0x188
kernel:  ? _raw_spin_lock_irqsave+0x2c/0x37
kernel:  ? lock_timer_base+0x38/0x5f
kernel:  __cancel_work_timer+0xea/0x13d
kernel:  ? preempt_latency_start+0x2b/0x46
kernel:  rdma_addr_cancel+0x70/0x81 [ib_core]
kernel:  _destroy_id+0x1a/0x246 [rdma_cm]
kernel:  rpcrdma_xprt_connect+0x115/0x5ae [rpcrdma]
kernel:  ? _raw_spin_unlock+0x14/0x29
kernel:  ? raw_spin_rq_unlock_irq+0x5/0x10
kernel:  ? finish_task_switch.isra.0+0x171/0x249
kernel:  xprt_rdma_connect_worker+0x3b/0xc7 [rpcrdma]
kernel:  process_one_work+0x1d8/0x2d4
kernel:  worker_thread+0x18b/0x24f
kernel:  ? rescuer_thread+0x280/0x280
kernel:  kthread+0xf4/0xfc
kernel:  ? kthread_complete_and_exit+0x1b/0x1b
kernel:  ret_from_fork+0x22/0x30
kernel:  </TASK>

SUNRPC's xprtiod workqueue is WQ_MEM_RECLAIM, so any workqueue that
one of its work items tries to cancel has to be WQ_MEM_RECLAIM to
prevent a priority inversion. The internal workqueues in the
RDMA/core are currently non-MEM_RECLAIM.

Jason Gunthorpe says this about the current state of RDMA/core:
> If you attempt to do a reconnection/etc from within a RECLAIM
> context it will deadlock on one of the many allocations that are
> made to support opening the connection.
>
> The general idea of reclaim is that the entire task context
> working under the reclaim is marked with an override of the gfp
> flags to make all allocations under that call chain reclaim safe.
>
> But rdmacm does allocations outside this, eg in the WQs processing
> the CM packets. So this doesn't work and we will deadlock.
>
> Fixing it is a big deal and needs more than poking WQ_MEM_RECLAIM
> here and there.

So we will change the ULP in this case to avoid the use of
WQ_MEM_RECLAIM where possible. Deadlocks that were possible before
are not fixed, but at least we no longer have a false sense of
confidence that the stack won't allocate memory during memory
reclaim.
Suggested-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

This can be defined as simply an NFS4_INODE_EVENT() since we don't have
the name of a specific xattr to list. This roughly matches readdir,
which also uses an NFS4_INODE_EVENT() tracepoint.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

These functions take similar arguments, and can share a tracepoint class
for common formatting.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS4_CONTENT_DATA and NFS4_CONTENT_HOLE both only exist under NFS v4.2.
Move their corresponding TRACE_DEFINE_ENUM calls under this Kconfig
option.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

We can translate this into an empty response list instead of passing an
error up to userspace.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs_write_prepare() has been removed since
commit a4cdda59 ("NFS: Create a common pgio_rpc_prepare
function"), so remove it.

nfs_wait_atomic_killable() has been removed since
commit 723c921e ("sched/wait, fs/nfs: Convert wait_on_atomic_t()
usage to the new wait_var_event() API"), so remove it.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs4_renewd_prepare_shutdown() has been removed since
commit 3050141b ("NFSv4: Kill nfs4_renewd_prepare_shutdown()"),
so remove it.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Fix spelling typo and syntax error in comment.
Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

We want to ensure that the server never misses the layout stats when
we're closing the file, so that it knows whether or not to update its
internal state. Otherwise, if we were racing with a layout stat, we
might cause the server to invalidate its layout before the layout stat
got processed.

Fixes: 06946c6a ("pNFS/flexfiles: Only send layoutstats updates for mirrors that were updated")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Commit 064109db ("NFS: remove redundant code in nfs_file_write()")
identifies that filemap_fdatawait_range() will always return 0 and removes
a dead error-handling case in nfs_file_write(). With this change however,
assigning the return of filemap_fdatawait_range() to the result variable is
a dead store.

Remove this needless assignment.

No functional change. No change in object code.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

remove unnecessary void* type castings.
Signed-off-by: yuzhe <yuzhe@nfschina.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Use max_t() to simplify open code which uses "if...else" to get maximum of
two values.

Generated by coccinelle script:
	scripts/coccinelle/misc/minmax.cocci
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Use ida_alloc()/ida_free() instead of
ida_simple_get()/ida_simple_remove().
The latter is deprecated and more verbose.
Signed-off-by: Bo Liu <liubo03@inspur.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Use ida_alloc()/ida_free() instead of
ida_simple_get()/ida_simple_remove().
The latter is deprecated and more verbose.
Signed-off-by: Bo Liu <liubo03@inspur.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Pull ext4 fixes from Ted Ts'o:
 "Regression and bug fixes:

   - Performance regression fix from 5.18 on a Rasberry Pi

   - Fix extent parsing bug which triggers a BUG_ON when a (corrupted)
     extent tree has has a non-root node when zero entries.

   - Fix a livelock where in the right (wrong) circumstances a large
     number of nfsd threads can try to write to a nearly full file
     system, and retry for hours(!)"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: limit the number of retries after discarding preallocations blocks
  ext4: fix bug in extents parsing when eh_entries == 0 and eh_depth > 0
  ext4: use buckets for cr 1 block scan instead of rbtree
  ext4: use locality group preallocation for small closed files
  ext4: make directory inode spreading reflect flexbg size
  ext4: avoid unnecessary spreading of allocations among groups
  ext4: make mballoc try target group first even with mb_optimize_scan

Merge tag 'dax-and-nvdimm-fixes-v6.0-final' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull NVDIMM and DAX fixes from Dan Williams:
 "A recently discovered one-line fix for devdax that further addresses a
  v5.5 regression, and (a bit embarrassing) a small batch of fixes that
  have been sitting in my fixes tree for weeks.

  The older fixes have soaked in linux-next during that time and address
  an fsdax infinite loop and some other minor fixups.

   - Fix a infinite loop bug in fsdax

   - Fix memory-type detection for devdax (EINJ regression)

   - Small cleanups"

* tag 'dax-and-nvdimm-fixes-v6.0-final' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  devdax: Fix soft-reservation memory description
  fsdax: Fix infinite loop in dax_iomap_rw()
  nvdimm/namespace: drop nested variable in create_namespace_pmem()
  ndtest: Cleanup all of blk namespace specific code
  pmem: fix a name collision

Pull i2c fixes from Wolfram Sang:
 "I2C driver bugfixes for mlxbf and imx, a few documentation fixes after
  the rework this cycle, and one hardening for the i2c-mux core"

* tag 'i2c-for-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: mux: harden i2c_mux_alloc() against integer overflows
  i2c: mlxbf: Fix frequency calculation
  i2c: mlxbf: prevent stack overflow in mlxbf_i2c_smbus_start_transaction()
  i2c: mlxbf: incorrect base address passed during io write
  Documentation: i2c: fix references to other documents
  MAINTAINERS: remove Nehal Shah from AMD MP2 I2C DRIVER
  i2c: imx: If pm_runtime_get_sync() returned 1 device access is possible

Pick up another "Soft Reservation" fix for v6.0-final on top of some
straggling nvdimm fixes that missed v5.19.

The "hmem" platform-devices that are created to represent the
platform-advertised "Soft Reserved" memory ranges end up inserting a
resource that causes the iomem_resource tree to look like this:

340000000-43fffffff : hmem.0
  340000000-43fffffff : Soft Reserved
    340000000-43fffffff : dax0.0

This is because insert_resource() reparents ranges when they completely
intersect an existing range.

This matters because code that uses region_intersects() to scan for a
given IORES_DESC will only check that top-level 'hmem.0' resource and
not the 'Soft Reserved' descendant.

So, to support EINJ (via einj_error_inject()) to inject errors into
memory hosted by a dax-device, be sure to describe the memory as
IORES_DESC_SOFT_RESERVED. This is a follow-on to:

commit b13a3e5f ("ACPI: APEI: Fix _EINJ vs EFI_MEMORY_SP")

...that fixed EINJ support for "Soft Reserved" ranges in the first
instance.

Fixes: 262b45ae ("x86/efi: EFI soft reservation to E820 enumeration")
Reported-by: Ricardo Sandoval Torres <ricardo.sandoval.torres@intel.com>
Tested-by: Ricardo Sandoval Torres <ricardo.sandoval.torres@intel.com>
Cc: <stable@vger.kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Omar Avelar <omar.avelar@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mark Gross <markgross@kernel.org>
Link: https://lore.kernel.org/r/166397075670.389916.7435722208896316387.stgit@dwillia2-xfh.jf.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

Merge tag 'kbuild-fixes-v6.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix build error for the combination of SYSTEM_TRUSTED_KEYRING=y and
   X509_CERTIFICATE_PARSER=m

 - Fix DEBUG_INFO_SPLIT to generate debug info for GCC 11+ and Clang 12+

 - Revive debug info for assembly files

 - Remove unused code

* tag 'kbuild-fixes-v6.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Makefile.debug: re-enable debug info for .S files
  Makefile.debug: set -g unconditional on CONFIG_DEBUG_INFO_SPLIT
  certs: make system keyring depend on built-in x509 parser
  Kconfig: remove unused function 'menu_get_root_menu'
  scripts/clang-tools: remove unused module

Pull s390 fix from Vasily Gorbik:

 - Fix potential hangs in VFIO AP driver

* tag 's390-6.0-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/vfio-ap: bypass unnecessary processing of AP resources

Pull power management fixes from Rafael Wysocki:
 "These fix an uninitialized variable usage in the operating performance
  points code and add missing DT bindings for it.

  Specifics:

   - Fix uninitialized variable usage in dev_pm_opp_config_clks_simple()
     (Christophe JAILLET)

   - Add missing OPP DT properties (Rob Herring)"

* tag 'pm-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  dt-bindings: opp: Add missing (unevaluated|additional)Properties on child nodes
  OPP: Fix an un-initialized variable usage

Pull char/misc driver fixes from Greg KH:
 "Here are three tiny driver fixes for 6.0-rc7.  They include:

   - phy driver reset bugfix

   - fpga memleak bugfix

   - counter irq config bugfix

  The first two have been in linux-next for a while, the last one has
  only been added to my tree in the past few days, but was in linux-next
  under a different commit id. I couldn't pull directly from the counter
  tree due to some gpg key propagation issue, so I took the commit
  directly from email instead"

* tag 'char-misc-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  counter: 104-quad-8: Fix skipped IRQ lines during events configuration
  fpga: m10bmc-sec: Fix possible memory leak of flash_buf
  phy: marvell: phy-mvebu-a3700-comphy: Remove broken reset support

Pull tty/serial driver fixes from Greg KH:
 "Here are some small, and late, serial driver fixes for 6.0-rc7 to
  resolve some reported problems.

  Included in here are:

   - tegra icount accounting fixes, including a framework function that
     other drivers will be converted over to using in 6.1-rc1.

   - fsl_lpuart reset bugfix

   - 8250 omap 485 bugfix

   - sifive serial clock bugfix

  The last three patches have not shown up in linux-next due to them
  being added to my tree only 2 days ago, but they are tiny and
  self-contained and the developers say they resolve issues that they
  have with 6.0-rc. The other three have been in linux-next for a while
  with no reported issues"

* tag 'tty-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: sifive: enable clocks for UART when probed
  serial: 8250: omap: Use serial8250_em485_supported
  serial: fsl_lpuart: Reset prior to registration
  serial: tegra-tcu: Use uart_xmit_advance(), fixes icount.tx accounting
  serial: tegra: Use uart_xmit_advance(), fixes icount.tx accounting
  serial: Create uart_xmit_advance()

Pull cgroup fixes from Tejun Heo:

 - Add Waiman Long as a cpuset maintainer

 - cgroup_get_from_id() could be fed a kernfs ID which doesn't point to
   a cgroup directory but a knob file and then crash. Error out if the
   lookup kernfs_node isn't a directory.

* tag 'cgroup-for-6.0-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: cgroup_get_from_id() must check the looked-up kn is a directory
  cpuset: Add Waiman Long as a cpuset maintainer

Pull workqueue fix from Tejun Heo:
 "Just one patch to improve flush lockdep coverage"

* tag 'wq-for-6.0-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: don't skip lockdep work dependency in cancel_work_sync()

Pull io_uring fix from Jens Axboe:
 "Just a single fix for an issue with un-reaped IOPOLL requests on ring
  exit"

* tag 'io_uring-6.0-2022-09-23' of git://git.kernel.dk/linux:
  io_uring: ensure that cached task references are always put on exit

Pull block fixes from Jens Axboe:
 "Fix a regression that's been plaguing us by reverting the offending
  commit, as attempts to both reproduce the issue and fix it in a saner
  fashion have failed.

  Fix for a potential oops condition in the s390 dasd block driver"

* tag 'block-6.0-2022-09-22' of git://git.kernel.dk/linux:
  Revert "block: freeze the queue earlier in del_gendisk"
  s390/dasd: fix Oops in dasd_alias_get_start_dev due to missing pavgroup

Alexey reported that the fraction of unknown filename instances in
kallsyms grew from ~0.3% to ~10% recently; Bill and Greg tracked it down
to assembler defined symbols, which regressed as a result of:

commit b8a90923 ("Kbuild: do not emit debug info for assembly with LLVM_IAS=1")

In that commit, I allude to restoring debug info for assembler defined
symbols in a follow up patch, but it seems I forgot to do so in

commit a66049e2 ("Kbuild: make DWARF version a choice")

Link: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=31bf18645d98b4d3d7357353be840e320649a67d
Fixes: b8a90923 ("Kbuild: do not emit debug info for assembly with LLVM_IAS=1")
Reported-by: Alexey Alexandrov <aalexand@google.com>
Reported-by: Bill Wendling <morbo@google.com>
Reported-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Dmitrii, Fangrui, and Mashahiro note:

  Before GCC 11 and Clang 12 -gsplit-dwarf implicitly uses -g2.

Fix CONFIG_DEBUG_INFO_SPLIT for gcc-11+ & clang-12+ which now need -g
specified in order for -gsplit-dwarf to work at all.

-gsplit-dwarf has been mutually exclusive with -g since support for
CONFIG_DEBUG_INFO_SPLIT was introduced in
commit 866ced95 ("kbuild: Support split debug info v4")
I don't think it ever needed to be.

Link: https://lore.kernel.org/lkml/20220815013317.26121-1-dmitrii.bundin.a@gmail.com/
Link: https://lore.kernel.org/lkml/CAK7LNARPAmsJD5XKAw7m_X2g7Fi-CAAsWDQiP7+ANBjkg7R7ng@mail.gmail.com/
Link: https://reviews.llvm.org/D80391
Cc: Andi Kleen <ak@linux.intel.com>
Reported-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
Reported-by: Fangrui Song <maskray@google.com>
Reported-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

io_uring caches task references to avoid doing atomics for each of them
per request. If a request is put from the same task that allocated it,
then we can maintain a per-ctx cache of them. This obviously relies
on io_uring always pruning caches in a reliable way, and there's
currently a case off io_uring fd release where we can miss that.

One example is a ring setup with IOPOLL, which relies on the task
polling for completions, which will free them. However, if such a task
submits a request and then exits or closes the ring without reaping
the completion, then ring release will reap and put. If release happens
from that very same task, the completed request task refs will get
put back into the cache pool. This is problematic, as we're now beyond
the point of pruning caches.

Manually drop these caches after doing an IOPOLL reap. This releases
references from the current task, which is enough. If another task
happens to be doing the release, then the caching will not be
triggered and there's no issue.

Cc: stable@vger.kernel.org
Fixes: e98e49b2 ("io_uring: extend task put optimisations")
Reported-by: Homin Rhee <hominlab@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull arm64 fixes from Will Deacon:
 "These are all very simple and self-contained, although the CFI
  jump-table fix touches the generic linker script as that's where the
  problematic macro lives.

   - Fix false positive "sleeping while atomic" warning resulting from
     the kPTI rework taking a mutex too early.

   - Fix possible overflow in AMU frequency calculation

   - Fix incorrect shift in CMN PMU driver which causes problems with
     newer versions of the IP

   - Reduce alignment of the CFI jump table to avoid huge kernel images
     and link errors with !4KiB page size configurations"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  vmlinux.lds.h: CFI: Reduce alignment of jump-table to function alignment
  perf/arm-cmn: Add more bits to child node address offset field
  arm64: topology: fix possible overflow in amu_fie_setup()
  arm64: mm: don't acquire mutex when rewriting swapper