To simplify the code, pull in checking the fatal signals into
ep_send_events().  ep_send_events() is called only from ep_poll().

Note that, previously, we were always checking fatal events, but it is
checked only if eavail is true.  This should be fine because the goal of
that check is to quickly return from epoll_wait() when there is a pending
fatal signal.

Link: https://lkml.kernel.org/r/20201106231635.3528496-4-soheil.kdev@gmail.comSigned-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Suggested-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Khazhismel Kumykov <khazhy@google.com>
Cc: Guantao Liu <guantaol@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Check signals before locking ep->lock, and immediately return -EINTR if
there is any signal pending.

This saves a few loads, stores, and branches from the hot path and
simplifies the loop structure for follow up patches.

Link: https://lkml.kernel.org/r/20201106231635.3528496-3-soheil.kdev@gmail.comSigned-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Khazhismel Kumykov <khazhy@google.com>
Cc: Guantao Liu <guantaol@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "simplify ep_poll".

This patch series is a followup based on the suggestions and feedback by
Linus:
https://lkml.kernel.org/r/CAHk-=wizk=OxUyQPbO8MS41w2Pag1kniUV5WdD5qWL-gq1kjDA@mail.gmail.com

The first patch in the series is a fix for the epoll race in presence of
timeouts, so that it can be cleanly backported to all affected stable
kernels.

The rest of the patch series simplify the ep_poll() implementation.  Some
of these simplifications result in minor performance enhancements as well.
We have kept these changes under self tests and internal benchmarks for a
few days, and there are minor (1-2%) performance enhancements as a result.

This patch (of 8):

After abc610e0 ("fs/epoll: avoid barrier after an epoll_wait(2)
timeout"), we break out of the ep_poll loop upon timeout, without checking
whether there is any new events available.  Prior to that patch-series we
always called ep_events_available() after exiting the loop.

This can cause races and missed wakeups.  For example, consider the
following scenario reported by Guantao Liu:

Suppose we have an eventfd added using EPOLLET to an epollfd.

Thread 1: Sleeps for just below 5ms and then writes to an eventfd.
Thread 2: Calls epoll_wait with a timeout of 5 ms. If it sees an
          event of the eventfd, it will write back on that fd.
Thread 3: Calls epoll_wait with a negative timeout.

Prior to abc610e0, it is guaranteed that Thread 3 will wake up either
by Thread 1 or Thread 2.  After abc610e0, Thread 3 can be blocked
indefinitely if Thread 2 sees a timeout right before the write to the
eventfd by Thread 1.  Thread 2 will be woken up from
schedule_hrtimeout_range and, with evail 0, it will not call
ep_send_events().

To fix this issue:
1) Simplify the timed_out case as suggested by Linus.
2) while holding the lock, recheck whether the thread was woken up
   after its time out has reached.

Note that (2) is different from Linus' original suggestion: It do not set
"eavail = ep_events_available(ep)" to avoid unnecessary contention (when
there are too many timed-out threads and a small number of events), as
well as races mentioned in the discussion thread.

This is the first patch in the series so that the backport to stable
releases is straightforward.

Link: https://lkml.kernel.org/r/20201106231635.3528496-1-soheil.kdev@gmail.com
Link: https://lkml.kernel.org/r/CAHk-=wizk=OxUyQPbO8MS41w2Pag1kniUV5WdD5qWL-gq1kjDA@mail.gmail.com
Link: https://lkml.kernel.org/r/20201106231635.3528496-2-soheil.kdev@gmail.com
Fixes: abc610e0 ("fs/epoll: avoid barrier after an epoll_wait(2) timeout")
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Tested-by: Guantao Liu <guantaol@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Guantao Liu <guantaol@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mem_cgroup_page_lruvec() in memcontrol.c and mem_cgroup_lruvec() in
memcontrol.h is very similar except for the param(page and memcg) which
also can be convert to each other.

So rewrite mem_cgroup_page_lruvec() with mem_cgroup_lruvec().

[alex.shi@linux.alibaba.com: add missed warning in mem_cgroup_lruvec]
  Link: https://lkml.kernel.org/r/94f17bb7-ec61-5b72-3555-fabeb5a4d73b@linux.alibaba.com
[lstoakes@gmail.com: warn on missing memcg on mem_cgroup_page_lruvec()]
  Link: https://lkml.kernel.org/r/20201125112202.387009-1-lstoakes@gmail.com

Link: https://lkml.kernel.org/r/20201108143731.GA74138@rlkSigned-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A VCPU of a VM can allocate couple of pages which can be mmap'ed by the
user space application. At the moment this memory is not charged to the
memcg of the VMM. On a large machine running large number of VMs or
small number of VMs having large number of VCPUs, this unaccounted
memory can be very significant. So, charge this memory to the memcg of
the VMM. Please note that lifetime of these allocations corresponds to
the lifetime of the VMM.

Link: https://lkml.kernel.org/r/20201106202923.2087414-1-shakeelb@google.comSigned-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Some definitions are left unused, just clean them.

Link: https://lkml.kernel.org/r/20201108003834.12669-1-richard.weiyang@gmail.comSigned-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add VM_WARN_ON_ONCE_PAGE() macro.

Since readahead page is charged on memcg too, in theory we don't have to
check this exception now.  Before safely remove them all, add a warning
for the unexpected !memcg.

Link: https://lkml.kernel.org/r/1604283436-18880-3-git-send-email-alex.shi@linux.alibaba.comSigned-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "bail out early for memcg disable".

These 2 patches are indepenedent from per memcg lru lock, and may
encounter unexpected warning, so let's move out them from per memcg
lru locking patchset.

This patch (of 2):

We could bail out early when memcg wasn't enabled.

Link: https://lkml.kernel.org/r/1604283436-18880-1-git-send-email-alex.shi@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604283436-18880-2-git-send-email-alex.shi@linux.alibaba.comSigned-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull GPIO updates from Linus Walleij:
 "This is the bulk of the GPIO changes for the v5.11 kernel cycle:

  Core changes:

   - Retired the old set-up function for GPIO IRQ chips. All chips now
     use the template struct gpio_irq_chip and pass that to the core to
     be set up alongside the gpio_chip. We can finally get rid of the
     old cruft.

   - Some refactoring and clean up of the core code.

   - Support edge event timestamps to be stamped using REALTIME (wall
     clock) timestamps. We have found solid use cases for this, so we
     support it.

  New drivers:

   - MStar MSC313 GPIO driver.

   - HiSilicon GPIO driver.

  Driver improvements:

   - The PCA953x driver now also supports the NXP PCAL9554B/C chips.

   - The mockup driver can now be probed from the device tree which is
     pretty useful for virtual prototyping of devices.

   - The Rcar driver now supports .get_multiple()

   - The MXC driver dropped some legacy and became a pure device tree
     client.

   - The Exar driver was moved over to the IDA interface for
     enumerating, and also switched over to using regmap for register
     access"

* tag 'gpio-v5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (87 commits)
  MAINTAINERS: Remove reference to non-existing file
  gpio: hisi: Do not require ACPI for COMPILE_TEST
  MAINTAINERS: Add maintainer for HiSilicon GPIO driver
  gpio: gpio-hisi: Add HiSilicon GPIO support
  gpio: cs5535: Simplify the return expression of cs5535_gpio_probe()
  gpiolib: irq hooks: fix recursion in gpiochip_irq_unmask
  dt-bindings: mt7621-gpio: convert bindings to YAML format
  gpiolib: cdev: Flag invalid GPIOs as used
  gpio: put virtual gpio device into their own submenu
  drivers: gpio: amd8111: use SPDX-License-Identifier
  drivers: gpio: amd8111: prefer dev_err()/dev_info() over raw printk
  drivers: gpio: bt8xx: prefer dev_err()/dev_warn() over of raw printk
  gpio: Add TODO item for debugfs interface
  gpio: just plain warning when nonexisting gpio requested
  tools: gpio: add option to report wall-clock time to gpio-event-mon
  tools: gpio: add support for reporting realtime event clock to lsgpio
  gpiolib: cdev: allow edge event timestamps to be configured as REALTIME
  gpio: msc313: MStar MSC313 GPIO driver
  dt-bindings: gpio: Binding for MStar MSC313 GPIO controller
  dt-bindings: gpio: Add a binding header for the MSC313 GPIO driver
  ...

Pull UML updates from Richard Weinberger:

 - IRQ handling cleanups

 - Support for suspend

 - Various fixes for UML specific drivers: ubd, vector, xterm

* tag 'for-linus-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (32 commits)
  um: Fix build w/o CONFIG_PM_SLEEP
  um: time-travel: Correct time event IRQ delivery
  um: irq/sigio: Support suspend/resume handling of workaround IRQs
  um: time-travel: Actually apply "free-until" optimisation
  um: chan_xterm: Fix fd leak
  um: tty: Fix handling of close in tty lines
  um: Monitor error events in IRQ controller
  um: allocate a guard page to helper threads
  um: support some of ARCH_HAS_SET_MEMORY
  um: time-travel: avoid multiple identical propagations
  um: Fetch registers only for signals which need them
  um: Support suspend to RAM
  um: Allow PM with suspend-to-idle
  um: time: Fix read_persistent_clock64() in time-travel
  um: Simplify os_idle_sleep() and sleep longer
  um: Simplify IRQ handling code
  um: Remove IRQ_NONE type
  um: irq: Reduce irq_reg allocation
  um: irq: Clean up and rename struct irq_fd
  um: Clean up alarm IRQ chip name
  ...

Pull jffs2, ubi and ubifs updates from Richard Weinberger:
 "JFFS2:
   - Fix for a remount regression
   - Fix for an abnormal GC exit
   - Fix for a possible NULL pointer issue while mounting

  UBI:
   - Add support ECC-ed NOR flash
   - Removal of dead code

  UBIFS:
   - Make node dumping debug code more reliable
   - Various cleanups: less ifdefs, less typos
   - Fix for an info leak"

* tag 'for-linus-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubifs: ubifs_dump_node: Dump all branches of the index node
  ubifs: ubifs_dump_sleb: Remove unused function
  ubifs: Pass node length in all node dumping callers
  Revert "ubifs: Fix out-of-bounds memory access caused by abnormal value of node_len"
  ubifs: Limit dumping length by size of memory which is allocated for the node
  ubifs: Remove the redundant return in dbg_check_nondata_nodes_order
  jffs2: Fix NULL pointer dereference in rp_size fs option parsing
  ubifs: Fixed print foramt mismatch in ubifs
  ubi: Do not zero out EC and VID on ECC-ed NOR flashes
  jffs2: remove trailing semicolon in macro definition
  ubifs: Fix error return code in ubifs_init_authentication()
  ubifs: wbuf: Don't leak kernel memory to flash
  ubi: Remove useless code in bytes_str_to_int
  ubifs: Fix the printing type of c->big_lpt
  jffs2: Allow setting rp_size to zero during remounting
  jffs2: Fix ignoring mounting options problem during remounting
  jffs2: Fix GC exit abnormally
  ubifs: Code cleanup by removing ifdef macro surrounding
  jffs2: Fix if/else empty body warnings
  ubifs: Delete duplicated words + other fixes

Pull cifs updates from Steve French:
 "The largest part are for support of the newer mount API which has been
  needed for cifs/smb3 mounts for a long time due to the new API's
  better handling of remount, and better error reporting. There are
  three additional small cleanup patches for this being tested, that are
  not included yet.

  This series also includes addition of support for the SMB3 witness
  protocol which can provide important notifications from the server to
  client on server address or export or network changes. This can be
  useful for example in order to be notified before the failure - when a
  server's IP address changes (in the future it will allow us to support
  server notifications of when a share is moved).

  It also includes three patches for stable e.g. some that better handle
  some confusing error messages during session establishment"

* tag '5.11-rc-smb3' of git://git.samba.org/sfrench/cifs-2.6: (55 commits)
  cifs: update internal module version number
  cifs: Fix support for remount when not changing rsize/wsize
  cifs: handle "guest" mount parameter
  cifs: correct four aliased mount parms to allow use of previous names
  cifs: Tracepoints and logs for tracing credit changes.
  cifs: fix use after free in cifs_smb3_do_mount()
  cifs: fix rsize/wsize to be negotiated values
  cifs: Fix some error pointers handling detected by static checker
  smb3: remind users that witness protocol is experimental
  cifs: update super_operations to show_devname
  cifs: fix uninitialized variable in smb3_fs_context_parse_param
  cifs: update mnt_cifs_flags during reconfigure
  cifs: move update of flags into a separate function
  cifs: remove ctx argument from cifs_setup_cifs_sb
  cifs: do not allow changing posix_paths during remount
  cifs: uncomplicate printing the iocharset parameter
  cifs: don't create a temp nls in cifs_setup_ipc
  cifs: simplify handling of cifs_sb/ctx->local_nls
  cifs: we do not allow changing username/password/unc/... during remount
  cifs: add initial reconfigure support
  ...

Pull networking fixes from Jakub Kicinski:
 "Current release - always broken:

   - net/smc: fix access to parent of an ib device

   - devlink: use _BITUL() macro instead of BIT() in the UAPI header

   - handful of mptcp fixes

  Previous release - regressions:

   - intel: AF_XDP: clear the status bits for the next_to_use descriptor

   - dpaa2-eth: fix the size of the mapped SGT buffer

  Previous release - always broken:

   - mptcp: fix security context on server socket

   - ethtool: fix string set id check

   - ethtool: fix error paths in ethnl_set_channels()

   - lan743x: fix rx_napi_poll/interrupt ping-pong

   - qca: ar9331: fix sleeping function called from invalid context bug"

* tag 'net-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (32 commits)
  net/sched: sch_taprio: reset child qdiscs before freeing them
  nfp: move indirect block cleanup to flower app stop callback
  octeontx2-af: Fix undetected unmap PF error check
  net: nixge: fix spelling mistake in Kconfig: "Instuments" -> "Instruments"
  qlcnic: Fix error code in probe
  mptcp: fix pending data accounting
  mptcp: push pending frames when subflow has free space
  mptcp: properly annotate nested lock
  mptcp: fix security context on server socket
  net/mlx5: Fix compilation warning for 32-bit platform
  mptcp: clear use_ack and use_map when dropping other suboptions
  devlink: use _BITUL() macro instead of BIT() in the UAPI header
  net: korina: fix return value
  net/smc: fix access to parent of an ib device
  ethtool: fix error paths in ethnl_set_channels()
  nfc: s3fwrn5: Remove unused NCI prop commands
  nfc: s3fwrn5: Remove the delay for NFC sleep
  phy: fix kdoc warning
  tipc: do sanity check payload of a netlink message
  use __netdev_notify_peers in hyperv
  ...

Pull OpenRISC updates from Stafford Horne:

 - New drivers and OpenRISC support for the LiteX platform

 - A bug fix to support userspace gdb debugging

 - Fixes one compile issue with blk-iocost

* tag 'for-linus' of git://github.com/openrisc/linux:
  openrisc: add local64.h to fix blk-iocost build
  openrisc: fix trap for debugger breakpoint signalling
  openrisc: add support for LiteX
  drivers/tty/serial: add LiteUART driver
  dt-bindings: serial: document LiteUART bindings
  drivers/soc/litex: add LiteX SoC Controller driver
  dt-bindings: soc: document LiteX SoC Controller bindings
  dt-bindings: vendor: add vendor prefix for LiteX

Pull powerpc updates from Michael Ellerman:

 - Switch to the generic C VDSO, as well as some cleanups of our VDSO
   setup/handling code.

 - Support for KUAP (Kernel User Access Prevention) on systems using the
   hashed page table MMU, using memory protection keys.

 - Better handling of PowerVM SMT8 systems where all threads of a core
   do not share an L2, allowing the scheduler to make better scheduling
   decisions.

 - Further improvements to our machine check handling.

 - Show registers when unwinding interrupt frames during stack traces.

 - Improvements to our pseries (PowerVM) partition migration code.

 - Several series from Christophe refactoring and cleaning up various
   parts of the 32-bit code.

 - Other smaller features, fixes & cleanups.

Thanks to: Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh
Kumar K.V, Ard Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling,
Cédric Le Goater, Christophe Leroy, Christophe Lombard, Colin Ian King,
Daniel Axtens, David Hildenbrand, Frederic Barrat, Ganesh Goudar,
Gautham R. Shenoy, Geert Uytterhoeven, Giuseppe Sacco, Greg Kurz,
Harish, Jan Kratochvil, Jordan Niethe, Kaixu Xia, Laurent Dufour,
Leonardo Bras, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu
Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov, Oliver
O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej
Siewior , Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe
Kleine-König, Vincent Stehlé, Youling Tang, and Zhang Xiaoxu.

* tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (304 commits)
  powerpc/32s: Fix cleanup_cpu_mmu_context() compile bug
  powerpc: Add config fragment for disabling -Werror
  powerpc/configs: Add ppc64le_allnoconfig target
  powerpc/powernv: Rate limit opal-elog read failure message
  powerpc/pseries/memhotplug: Quieten some DLPAR operations
  powerpc/ps3: use dma_mapping_error()
  powerpc: force inlining of csum_partial() to avoid multiple csum_partial() with GCC10
  powerpc/perf: Fix Threshold Event Counter Multiplier width for P10
  powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range()
  KVM: PPC: Book3S HV: Fix mask size for emulated msgsndp
  KVM: PPC: fix comparison to bool warning
  KVM: PPC: Book3S: Assign boolean values to a bool variable
  powerpc: Inline setup_kup()
  powerpc/64s: Mark the kuap/kuep functions non __init
  KVM: PPC: Book3S HV: XIVE: Add a comment regarding VP numbering
  powerpc/xive: Improve error reporting of OPAL calls
  powerpc/xive: Simplify xive_do_source_eoi()
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_EOI_FW
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_MASK_FW
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_SHIFT_BUG
  ...

Pull tracing updates from Steven Rostedt:
 "The major update to this release is that there's a new arch config
  option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS.

  Currently, only x86_64 enables it. All the ftrace callbacks now take a
  struct ftrace_regs instead of a struct pt_regs. If the architecture
  has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will
  have enough information to read the arguments of the function being
  traced, as well as access to the stack pointer.

  This way, if a user (like live kernel patching) only cares about the
  arguments, then it can avoid using the heavier weight "regs" callback,
  that puts in enough information in the struct ftrace_regs to simulate
  a breakpoint exception (needed for kprobes).

  A new config option that audits the timestamps of the ftrace ring
  buffer at most every event recorded.

  Ftrace recursion protection has been cleaned up to move the protection
  to the callback itself (this saves on an extra function call for those
  callbacks).

  Perf now handles its own RCU protection and does not depend on ftrace
  to do it for it (saving on that extra function call).

  New debug option to add "recursed_functions" file to tracefs that
  lists all the places that triggered the recursion protection of the
  function tracer. This will show where things need to be fixed as
  recursion slows down the function tracer.

  The eval enum mapping updates done at boot up are now offloaded to a
  work queue, as it caused a noticeable pause on slow embedded boards.

  Various clean ups and last minute fixes"

* tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  tracing: Offload eval map updates to a work queue
  Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
  ring-buffer: Add rb_check_bpage in __rb_allocate_pages
  ring-buffer: Fix two typos in comments
  tracing: Drop unneeded assignment in ring_buffer_resize()
  tracing: Disable ftrace selftests when any tracer is running
  seq_buf: Avoid type mismatch for seq_buf_init
  ring-buffer: Fix a typo in function description
  ring-buffer: Remove obsolete rb_event_is_commit()
  ring-buffer: Add test to validate the time stamp deltas
  ftrace/documentation: Fix RST C code blocks
  tracing: Clean up after filter logic rewriting
  tracing: Remove the useless value assignment in test_create_synth_event()
  livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
  ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default
  ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs
  MAINTAINERS: assign ./fs/tracefs to TRACING
  tracing: Fix some typos in comments
  ftrace: Remove unused varible 'ret'
  ring-buffer: Add recording of ring buffer recursion into recursed_functions
  ...

Pull modules updates from Jessica Yu:
 "Summary of modules changes for the 5.11 merge window:

   - Fix a race condition between systemd/udev and the module loader.

     The module loader was sending a uevent before the module was fully
     initialized (i.e., before its init function has been called). This
     means udev can start processing the module uevent before the module
     has finished initializing, and some udev rules expect that the
     module has initialized already upon receiving the uevent.

     This resulted in some systemd mount units failing if udev processes
     the event faster than the module can finish init. This is fixed by
     delaying the uevent until after the module has called its init
     routine.

   - Make the linker array sections for kernel params and module version
     attributes more robust by switching to use the alignment of the
     type in question.

     Namely, linker section arrays will be constructed using the
     alignment required by the struct (using __alignof__()) as opposed
     to a specific value such as sizeof(void *) or sizeof(long). This is
     less likely to cause breakages should the size of the type ever
     change (Johan Hovold)

   - Fix module state inconsistency by setting it back to GOING when a
     module fails to load and is on its way out (Miroslav Benes)

   - Some comment and code cleanups (Sergey Shtylyov)"

* tag 'modules-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: delay kobject uevent until after module init call
  module: drop semicolon from version macro
  init: use type alignment for kernel parameters
  params: clean up module-param macros
  params: use type alignment for kernel parameters
  params: drop redundant "unused" attributes
  module: simplify version-attribute handling
  module: drop version-attribute alignment
  module: fix comment style
  module: add more 'kernel-doc' comments
  module: fix up 'kernel-doc' comments
  module: only handle errors with the *switch* statement in module_sig_check()
  module: avoid *goto*s in module_sig_check()
  module: merge repetitive strings in module_sig_check()
  module: set MODULE_STATE_GOING state when a module fails to load

Pull dmaengine updates from Vinod Koul:
 "The last dmaengine updates for this year :)

  This contains couple of new drivers, new device support and updates to
  bunch of drivers.

  New drivers/devices:
   - Qualcomm ADM driver
   - Qualcomm GPI driver
   - Allwinner A100 DMA support
   - Microchip Sama7g5 support
   - Mediatek MT8516 apdma

  Updates:
   - more updates to idxd driver and support for IAX config
   - runtime PM support for dw driver
   - TI drivers"

* tag 'dmaengine-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (75 commits)
  soc: ti: k3-ringacc: Use correct error casting in k3_ringacc_dmarings_init
  dmaengine: ti: k3-udma-glue: Add support for K3 PKTDMA
  dmaengine: ti: k3-udma: Initial support for K3 PKTDMA
  dmaengine: ti: k3-udma: Add support for BCDMA channel TPL handling
  dmaengine: ti: k3-udma: Initial support for K3 BCDMA
  soc: ti: k3-ringacc: add AM64 DMA rings support.
  dmaengine: ti: Add support for k3 event routers
  dmaengine: ti: k3-psil: Add initial map for AM64
  dmaengine: ti: k3-psil: Extend psil_endpoint_config for K3 PKTDMA
  dt-bindings: dma: ti: Add document for K3 PKTDMA
  dt-bindings: dma: ti: Add document for K3 BCDMA
  dmaengine: dmatest: Use dmaengine_get_dma_device
  dmaengine: doc: client: Update for dmaengine_get_dma_device() usage
  dmaengine: Add support for per channel coherency handling
  dmaengine: of-dma: Add support for optional router configuration callback
  dmaengine: ti: k3-udma-glue: Configure the dma_dev for rings
  dmaengine: ti: k3-udma-glue: Get the ringacc from udma_dev
  dmaengine: ti: k3-udma-glue: Add function to get device pointer for DMA API
  dmaengine: ti: k3-udma: Add support for second resource range from sysfw
  dmaengine: ti: k3-udma: Wait for peer teardown completion if supported
  ...

Pull mailbox updates from Jassi Brar:

 - arm: added mhu-v2 controller driver

 - arm_mhu_db: fix kfree by using devm_ variant

 - stm32-ipcc: misc cleanup

* tag 'mailbox-v5.11' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: arm_mhuv2: Add driver
  dt-bindings: mailbox : arm,mhuv2: Add bindings
  mailbox: stm32-ipcc: cast void pointers to unsigned long
  mailbox: stm32-ipcc: remove duplicate error message
  mailbox: stm32-ipcc: add COMPILE_TEST dependency
  mailbox: arm_mhu_db: Fix mhu_db_shutdown by replacing kfree with devm_kfree

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Features:

   - NFSv3: Add emulation of lookupp() to improve open_by_filehandle()
     support

   - A series of patches to improve readdir performance, particularly
     with large directories

   - Basic support for using NFS/RDMA with the pNFS files and flexfiles
     drivers

   - Micro-optimisations for RDMA

   - RDMA tracing improvements

  Bugfixes:

   - Fix a long standing bug with xs_read_xdr_buf() when receiving
     partial pages (Dan Aloni)

   - Various fixes for getxattr and listxattr, when used over non-TCP
     transports

   - Fixes for containerised NFS from Sargun Dhillon

   - switch nfsiod to be an UNBOUND workqueue (Neil Brown)

   - READDIR should not ask for security label information if there is
     no LSM policy (Olga Kornievskaia)

   - Avoid using interval-based rebinding with TCP in lockd (Calum
     Mackay)

   - A series of RPC and NFS layer fixes to support the NFSv4.2
     READ_PLUS code

   - A couple of fixes for pnfs/flexfiles read failover

  Cleanups:

   - Various cleanups for the SUNRPC xdr code in conjunction with the
     READ_PLUS fixes"

* tag 'nfs-for-5.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (90 commits)
  NFS/pNFS: Fix a typo in ff_layout_resend_pnfs_read()
  pNFS/flexfiles: Avoid spurious layout returns in ff_layout_choose_ds_for_read
  NFSv4/pnfs: Add tracing for the deviceid cache
  fs/lockd: convert comma to semicolon
  NFSv4.2: fix error return on memory allocation failure
  NFSv4.2/pnfs: Don't use READ_PLUS with pNFS yet
  NFSv4.2: Deal with potential READ_PLUS data extent buffer overflow
  NFSv4.2: Don't error when exiting early on a READ_PLUS buffer overflow
  NFSv4.2: Handle hole lengths that exceed the READ_PLUS read buffer
  NFSv4.2: decode_read_plus_hole() needs to check the extent offset
  NFSv4.2: decode_read_plus_data() must skip padding after data segment
  NFSv4.2: Ensure we always reset the result->count in decode_read_plus()
  SUNRPC: When expanding the buffer, we may need grow the sparse pages
  SUNRPC: Cleanup - constify a number of xdr_buf helpers
  SUNRPC: Clean up open coded setting of the xdr_stream 'nwords' field
  SUNRPC: _copy_to/from_pages() now check for zero length
  SUNRPC: Cleanup xdr_shrink_bufhead()
  SUNRPC: Fix xdr_expand_hole()
  SUNRPC: Fixes for xdr_align_data()
  SUNRPC: _shift_data_left/right_pages should check the shift length
  ...

Pull ceph updates from Ilya Dryomov:
 "The big ticket item here is support for msgr2 on-wire protocol, which
  adds the option of full in-transit encryption using AES-GCM algorithm
  (myself).

  On top of that we have a series to avoid intermittent errors during
  recovery with recover_session=clean and some MDS request encoding work
  from Jeff, a cap handling fix and assorted observability improvements
  from Luis and Xiubo and a good number of cleanups.

  Luis also ran into a corner case with quotas which sadly means that we
  are back to denying cross-quota-realm renames"

* tag 'ceph-for-5.11-rc1' of git://github.com/ceph/ceph-client: (59 commits)
  libceph: drop ceph_auth_{create,update}_authorizer()
  libceph, ceph: make use of __ceph_auth_get_authorizer() in msgr1
  libceph, ceph: implement msgr2.1 protocol (crc and secure modes)
  libceph: introduce connection modes and ms_mode option
  libceph, rbd: ignore addr->type while comparing in some cases
  libceph, ceph: get and handle cluster maps with addrvecs
  libceph: factor out finish_auth()
  libceph: drop ac->ops->name field
  libceph: amend cephx init_protocol() and build_request()
  libceph, ceph: incorporate nautilus cephx changes
  libceph: safer en/decoding of cephx requests and replies
  libceph: more insight into ticket expiry and invalidation
  libceph: move msgr1 protocol specific fields to its own struct
  libceph: move msgr1 protocol implementation to its own file
  libceph: separate msgr1 protocol implementation
  libceph: export remaining protocol independent infrastructure
  libceph: export zero_page
  libceph: rename and export con->flags bits
  libceph: rename and export con->state states
  libceph: make con->state an int
  ...

Pull overlayfs updates from Miklos Szeredi:

 - Allow unprivileged mounting in a user namespace.

   For quite some time the security model of overlayfs has been that
   operations on underlying layers shall be performed with the
   privileges of the mounting task.

   This way an unprvileged user cannot gain privileges by the act of
   mounting an overlayfs instance. A full audit of all function calls
   made by the overlayfs code has been performed to see whether they
   conform to this model, and this branch contains some fixes in this
   regard.

 - Support running on copied filesystem images by optionally disabling
   UUID verification.

 - Bug fixes as well as documentation updates.

* tag 'ovl-update-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: unprivieged mounts
  ovl: do not get metacopy for userxattr
  ovl: do not fail because of O_NOATIME
  ovl: do not fail when setting origin xattr
  ovl: user xattr
  ovl: simplify file splice
  ovl: make ioctl() safe
  ovl: check privs before decoding file handle
  vfs: verify source area in vfs_dedupe_file_range_one()
  vfs: move cap_convert_nscap() call into vfs_setxattr()
  ovl: fix incorrect extent info in metacopy case
  ovl: expand warning in ovl_d_real()
  ovl: document lower modification caveats
  ovl: warn about orphan metacopy
  ovl: doc clarification
  ovl: introduce new "uuid=off" option for inodes index feature
  ovl: propagate ovl_fs to ovl_decode_real_fh and ovl_encode_real_fh

Pull fuse updates from Miklos Szeredi:

 - Improve performance of virtio-fs in mixed read/write workloads

 - Try to revalidate cache before returning EEXIST on exclusive create

 - Add a couple of miscellaneous bug fixes as well as some code cleanups

* tag 'fuse-update-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: fix bad inode
  fuse: support SB_NOSEC flag to improve write performance
  fuse: add a flag FUSE_OPEN_KILL_SUIDGID for open() request
  fuse: don't send ATTR_MODE to kill suid/sgid for handle_killpriv_v2
  fuse: setattr should set FATTR_KILL_SUIDGID
  fuse: set FUSE_WRITE_KILL_SUIDGID in cached write path
  fuse: rename FUSE_WRITE_KILL_PRIV to FUSE_WRITE_KILL_SUIDGID
  fuse: introduce the notion of FUSE_HANDLE_KILLPRIV_V2
  fuse: always revalidate if exclusive create
  virtiofs: clean up error handling in virtio_fs_get_tree()
  fuse: add fuse_sb_destroy() helper
  fuse: simplify get_fuse_conn*()
  fuse: get rid of fuse_mount refcount
  virtiofs: simplify sb setup
  virtiofs fix leak in setup
  fuse: launder page should wait for page writeback

Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've made more work into per-file compression support.

  For example, F2FS_IOC_GET | SET_COMPRESS_OPTION provides a way to
  change the algorithm or cluster size per file. F2FS_IOC_COMPRESS |
  DECOMPRESS_FILE provides a way to compress and decompress the existing
  normal files manually.

  There is also a new mount option, compress_mode=fs|user, which can
  control who compresses the data.

  Chao also added a checksum feature with a mount option so that
  we are able to detect any corrupted cluster.

  In addition, Daniel contributed casefolding with encryption patch,
  which will be used for Android devices.

  Summary:

  Enhancements:
   - add ioctls and mount option to manage per-file compression feature
   - support casefolding with encryption
   - support checksum for compressed cluster
   - avoid IO starvation by replacing mutex with rwsem
   - add sysfs, max_io_bytes, to control max bio size

  Bug fixes:
   - fix use-after-free issue when compression and fsverity are enabled
   - fix consistency corruption during fault injection test
   - fix data offset for lseek
   - get rid of buffer_head which has 32bits limit in fiemap
   - fix some bugs in multi-partitions support
   - fix nat entry count calculation in shrinker
   - fix some stat information

  And, we've refactored some logics and fix minor bugs as well"

* tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (36 commits)
  f2fs: compress: fix compression chksum
  f2fs: fix shift-out-of-bounds in sanity_check_raw_super()
  f2fs: fix race of pending_pages in decompression
  f2fs: fix to account inline xattr correctly during recovery
  f2fs: inline: fix wrong inline inode stat
  f2fs: inline: correct comment in f2fs_recover_inline_data
  f2fs: don't check PAGE_SIZE again in sanity_check_raw_super()
  f2fs: convert to F2FS_*_INO macro
  f2fs: introduce max_io_bytes, a sysfs entry, to limit bio size
  f2fs: don't allow any writes on readonly mount
  f2fs: avoid race condition for shrinker count
  f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE
  f2fs: add compress_mode mount option
  f2fs: Remove unnecessary unlikely()
  f2fs: init dirty_secmap incorrectly
  f2fs: remove buffer_head which has 32bits limit
  f2fs: fix wrong block count instead of bytes
  f2fs: use new conversion functions between blks and bytes
  f2fs: rename logical_to_blk and blk_to_logical
  f2fs: fix kbytes written stat for multi-device case
  ...

Pull ext2, reiserfs, quota and writeback updates from Jan Kara:

 - a couple of quota fixes (mostly for problems found by syzbot)

 - several ext2 cleanups

 - one fix for reiserfs crash on corrupted image

 - a fix for spurious warning in writeback code

* tag 'for_v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  writeback: don't warn on an unregistered BDI in __mark_inode_dirty
  fs: quota: fix array-index-out-of-bounds bug by passing correct argument to vfs_cleanup_quota_inode()
  reiserfs: add check for an invalid ih_entry_count
  ext2: Fix fall-through warnings for Clang
  fs/ext2: Use ext2_put_page
  docs: filesystems: Reduce ext2.rst to one top-level heading
  quota: Sanity-check quota file headers on load
  quota: Don't overflow quota file offsets
  ext2: Remove unnecessary blank
  fs/quota: update quota state flags scheme with project quota flags

syzkaller shows that packets can still be dequeued while taprio_destroy()
is running. Let sch_taprio use the reset() function to cancel the advance
timer and drop all skbs from the child qdiscs.

Fixes: 5a781ccb ("tc: Add support for configuring the taprio scheduler")
Link: https://syzkaller.appspot.com/bug?id=f362872379bf8f0017fb667c1ab158f2d1e764ae
Reported-by: syzbot+8971da381fb5a31f542d@syzkaller.appspotmail.com
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Link: https://lore.kernel.org/r/63b6d79b0e830ebb0283e020db4df3cdfdfb2b94.1608142843.git.dcaratti@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The indirect block cleanup may cause control messages to be sent
if offloaded flows are present. However, by the time the flower app
cleanup callback is called txbufs are no longer available and attempts
to send control messages result in a NULL-pointer dereference in
nfp_ctrl_tx_one().

This problem may be resolved by moving the indirect block cleanup
to the stop callback, where txbufs are still available.

As suggested by Jakub Kicinski and Louis Peens.

Fixes: a1db2178 ("net: flow_offload: fix flow_indr_dev_unregister path")
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Louis Peens <louis.peens@netronome.com>
Link: https://lore.kernel.org/r/20201216145701.30005-1-simon.horman@netronome.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Currently the check for an unmap PF error is always going to be false
because intr_val is a 32 bit int and is being bit-mask checked against
1ULL << 32.  Fix this by making intr_val a u64 to match the type at it
is copied from, namely npa_event_context->npa_af_rvu_ge.

Addresses-Coverity: ("Operands don't affect result")
Fixes: f1168d1e ("octeontx2-af: Add devlink health reporters for NPA")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: George Cherian <george.cherian@marvell.com>
Link: https://lore.kernel.org/r/20201216123604.15369-1-colin.king@canonical.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pull fsnotify updates from Jan Kara:
 "A few fsnotify fixes from Amir fixing fallout from big fsnotify
  overhaul a few months back and an improvement of defaults limiting
  maximum number of inotify watches from Waiman"

* tag 'fsnotify_for_v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fsnotify: fix events reported to watching parent and child
  inotify: convert to handle_inode_event() interface
  fsnotify: generalize handle_inode_event()
  inotify: Increase default inotify.max_user_watches limit to 1048576

There is a spelling mistake in the Kconfig. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20201216120020.13149-1-colin.king@canonical.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Return -EINVAL if we can't find the correct device.  Currently it
returns success.

Fixes: 13159183 ("qlcnic: 83xx base driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/X9nHbMqEyI/xPfGd@mwandaSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Paolo Abeni says:

====================
mptcp: a bunch of assorted fixes

This series pulls a few fixes for the MPTCP datapath.
Most issues addressed here has been recently introduced
with the recent reworks, with the notable exception of
the first patch, which addresses an issue present since
the early days
====================

Link: https://lore.kernel.org/r/cover.1608114076.git.pabeni@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

When sendmsg() needs to wait for memory, the pending data
is not updated. That causes a drift in forward memory allocation,
leading to stall and/or warnings at socket close time.

This change addresses the above issue moving the pending data
counter update inside the sendmsg() main loop.

Fixes: 6e628cd3 ("mptcp: use mptcp release_cb for delayed tasks")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When multiple subflows are active, we can receive a
window update on subflow with no write space available.
MPTCP will try to push frames on such subflow and will
fail. Pending frames will be pushed only after receiving
a window update on a subflow with some wspace available.

Overall the above could lead to suboptimal aggregate
bandwidth usage.

Instead, we should try to push pending frames as soon as
the subflow reaches both conditions mentioned above.

We can finally enable self-tests with asymmetric links,
as the above makes them finally pass.

Fixes: 6f8a612a ("mptcp: keep track of advertised windows right edge")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

MPTCP closes the subflows while holding the msk-level lock.
While acquiring the subflow socket lock we need to use the
correct nested annotation, or we can hit a lockdep splat
at runtime.
Reported-and-tested-by: Geliang Tang <geliangtang@gmail.com>
Fixes: e16163b6 ("mptcp: refactor shutdown and close")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Currently MPTCP is not propagating the security context
from the ingress request socket to newly created msk
at clone time.

Address the issue invoking the missing security helper.

Fixes: cf7da0d6 ("mptcp: Create SUBFLOW socket for incoming connections")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

MLX5_GENERAL_OBJECT_TYPES types bitfield is 64-bit field.

Defining an enum for such bit fields on 32-bit platform results in below
warning.

./include/vdso/bits.h:7:26: warning: left shift count >= width of type [-Wshift-count-overflow]
                         ^
./include/linux/mlx5/mlx5_ifc.h:10716:46: note: in expansion of macro ‘BIT’
 MLX5_HCA_CAP_GENERAL_OBJECT_TYPES_SAMPLER = BIT(0x20),
                                             ^~~

Use 32-bit friendly BIT_ULL macro.

Fixes: 2a297089 ("net/mlx5: Add sample offload hardware bits and structures")
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20201213120641.216032-1-leon@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Commit 991fcb77 ("drm/edid: Fix uninitialized variable in
drm_cvt_modes()") just replaced one warning with another.

The original warning about a possibly uninitialized variable was due to
the compiler not being smart enough to see that the case statement
actually enumerated all possible cases.  And the initial fix was just to
add a "default" case that had a single "unreachable()", just to tell the
compiler that that situation cannot happen.

However, that doesn't actually fix the fundamental reason for the
problem: the compiler still doesn't see that the existing case
statements enumerate all possibilities, so the compiler will still
generate code to jump to that unreachable case statement.  It just won't
complain about an uninitialized variable any more.

So now the compiler generates code to our inline asm marker that we told
it would not fall through, and end end result is basically random.  We
have created a bridge to nowhere.

And then, depending on the random details of just exactly what the
compiler ends up doing, 'objtool' might end up complaining about the
conditional branches (for conditions that cannot happen, and that thus
will never be taken - but if the compiler was not smart enough to figure
that out, we can't expect objtool to do so) going off in the weeds.

So depending on how the compiler has laid out the result, you might see
something like this:

    drivers/gpu/drm/drm_edid.o: warning: objtool: do_cvt_mode() falls through to next function drm_mode_detailed.isra.0()

and now you have a truly inscrutable warning that makes no sense at all
unless you start looking at whatever random code the compiler happened
to generate for our bare "unreachable()" statement.

IOW, don't use "unreachable()" unless you have an _active_ operation
that generates code that actually makes it obvious that something is not
reachable (ie an UD instruction or similar).

Solve the "compiler isn't smart enough" problem by just marking one of
the cases as "default", so that even when the compiler doesn't otherwise
see that we've enumerated all cases, the compiler will feel happy and
safe about there always being a valid case that initializes the 'width'
variable.

This also generates better code, since now the compiler doesn't generate
comparisons for five different possibilities (the four real ones and the
one that can't happen), but just for the three real ones and "the rest"
(which is that last one).

A smart enough compiler that sees that we cover all the cases won't care.

Cc: Lyude Paul <lyude@redhat.com>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

To 2.30
Signed-off-by: Steve French <stfrench@microsoft.com>

When remounting with the new mount API, we need to set
rsize and wsize to the previous values if they are not passed
in on the remount. Otherwise they get set to zero which breaks
xfstest 452 for example.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>