percpu-refcount currently reserves two lowest bits of its percpu
pointer to indicate its state; however, only one bit is used for
PCPU_REF_DEAD.

Simplify it by removing PCPU_STATUS_BITS/MASK and testing
PCPU_REF_DEAD directly.  This also allows the compiler to choose a
more efficient instruction depending on the architecture.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Christoph Lameter <cl@linux-foundation.org>

ioctx_alloc() reaches inside percpu_ref and directly frees
->pcpu_count in its failure path, which is quite gross.  percpu_ref
has been providing a proper interface to do this,
percpu_ref_cancel_init(), for quite some time now.  Let's use that
instead.

This patch doesn't introduce any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Kent Overstreet <kmo@daterainc.com>

After the recent changes, when POOL_DISASSOCIATED is cleared, the
running worker's local CPU should be the same as pool->cpu without any
exception even during cpu-hotplug.  Update the sanity check in
process_one_work() accordingly.

This patch changes "(proposition_A && proposition_B && proposition_C)"
to "(proposition_B && proposition_C)", so if the old compound
proposition is true, the new one must be true too. so this will not
hide any possible bug which can be caught by the old test.

tj: Minor updates to the description.

CC: Jason J. Herne <jjherne@linux.vnet.ibm.com>
CC: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

The commit a9ab775b ("workqueue: directly restore CPU affinity of
workers from CPU_ONLINE") moved the pool->lock into rebind_workers()
without also moving "pool->flags &= ~POOL_DISASSOCIATED".

There is nothing wrong with "pool->flags &= ~POOL_DISASSOCIATED" not
being moved together, but there isn't any benefit either. We move it
into rebind_workers() and achieve these benefits:

1) Better readability.  POOL_DISASSOCIATED is cleared in
   rebind_workers() as expected.

2) When POOL_DISASSOCIATED is cleared, we can ensure that all the
   running workers of the pool are on the local CPU (pool->cpu).

tj: Cosmetic updates to the code and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

__verify_pcpu_ptr() is used to verify that a specified parameter is
actually an percpu pointer by percpu accessor and operation
implementations.  Currently, where it's called isn't clearly defined
and we just ensure that it's invoked at least once for all accessors
and operations.

The lack of clarity on when it should be called isn't nice and given
that this is a completely generic issue, there's no reason to make
archs worry about it.

This patch updates __verify_pcpu_ptr() invocations such that it's
always invoked from the final generic wrapper once per access or
operation.  As this is already the case for {raw|this}_cpu_*()
definitions through __pcpu_size_*(), only the {raw|per|this}_cpu_ptr()
accessors need to be updated.

This change makes it unnecessary for archs to worry about
__verify_pcpu_ptr().  x86's arch_raw_cpu_ptr() is updated accordingly.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>

percpu macros are difficult to read.  It's partly because they're
fairly complex but also because they simply lack visual and
conventional consistency to an unusual degree.  The preceding patches
tried to organize macro definitions consistently by their roles.  This
patch makes the following cosmetic changes to improve overall
readability.

* Use consistent convention for multi-line macro definitions - "do {"
  or "({" are now put on their own lines and the line continuing '\'
  are all put on the same column.

* Temp variables used inside macro are consistently given "__" prefix.

* When a macro argument is passed to another macro or a function,
  putting extra parenthses around it doesn't help anything.  Don't put
  them.

* _this_cpu_generic_*() are renamed to this_cpu_generic_*() so that
  they're consistent with raw_cpu_generic_*().

* Reorganize raw_cpu_*() and this_cpu_*() definitions so that trivial
  wrappers are collected in one place after actual operation
  definitions.

* Other misc cleanups including reorganizing comments.

All changes in this patch are cosmetic and cause no functional
difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

__this_cpu_*() operations are the same as raw_cpu_*() operations
except for the added __this_cpu_preempt_check().  Curiously, these
were defined using __pcu_size_call_*() instead of being layered on top
of raw_cpu_*().

Let's layer them so that __this_cpu_*() are defined in terms of
raw_cpu_*().  It's simpler and less error-prone this way.

This patch doesn't introduce any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

* In include/asm-generic/percpu.h, collect {raw|_this}_cpu_generic*()
  macros into one place.  They were dispersed through
  {raw|this}_cpu_*_N() definitions and the visiual inconsistency was
  making following the code unnecessarily difficult.

* In include/linux/percpu-defs.h, move __verify_pcpu_ptr() later in
  the file so that it's right above accessor definitions where it's
  actually used.

This is pure reorganization.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

We're in the process of moving all percpu accessors and operations to
include/linux/percpu-defs.h so that they're available to arch headers
without having to include full include/linux/percpu.h which may cause
cyclic inclusion dependency.

This patch moves {raw|this}_cpu_*() definitions from
include/linux/percpu.h to include/linux/percpu-defs.h.  The code is
moved mostly verbatim; however, raw_cpu_*() are placed above
this_cpu_*() which is more conventional as the raw operations may be
used to defined other variants.

This is pure reorganization.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

{raw|this}_cpu_*_N() operations are expected to be provided by archs
and the generic definitions are provided as fallbacks.  As such, these
firmly belong to include/asm-generic/percpu.h.

Move the generic definitions to include/asm-generic/percpu.h.  The
code is moved mostly verbatim; however, raw_cpu_*_N() are placed above
this_cpu_*_N() which is more conventional as the raw operations may be
used to defined other variants.

This is pure reorganization.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

Currently, percpu allows two separate methods for overriding
{raw|this}_cpu_*() ops - for a given operation, an arch can provide
whole replacement or sized sub operations to override specific parts
of it.  e.g. arch either can provide this_cpu_add() or
this_cpu_add_4() to override only the 4 byte operation.

While quite flexible on a glance, the dual-overriding scheme
complicates the code path for no actual gain.  It compilcates the
already complex operation definitions and if an arch wants to override
all sizes, it can easily provide all variants anyway.  In fact, no
arch is actually making use of whole operation override.

Another oddity is that __this_cpu_*() operations are defined in the
same way as raw_cpu_*() but ignores full overrides of the raw_cpu_*()
and doesn't allow full operation override, so if an arch provides
whole overrides for raw_cpu_*() operations __this_cpu_*() ends up
using the generic implementations.

More importantly, it takes away the layering between arch-specific and
generic parts making it impossible for the generic part to implement
arch-independent features on top of arch-specific overrides.

This patch removes the support for whole operation overrides.  As no
arch is using it, this doesn't cause any actual difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

Reorganize for better readability.

* Accessor definitions are collected into one place and SMP and UP now
  define them in the same order.

* Definitions are layered when possible - e.g. per_cpu() is now
  defined in terms of this_cpu_ptr().

* Rather pointless comment dropped.

* per_cpu(), __raw_get_cpu_var() and __get_cpu_var() are defined in a
  way which can be shared between SMP and UP and moved out of
  CONFIG_SMP blocks.

This patch doesn't introduce any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>

include/linux/percpu-defs.h is gonna host all accessors and operations
so that arch headers can make use of them too without worrying about
circular dependency through include/linux/percpu.h.

This patch moves the following accessors from include/linux/percpu.h
to include/linux/percpu-defs.h.

* get/put_cpu_var()
* get/put_cpu_ptr()
* per_cpu_ptr()

This is pure reorgniazation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

The roles of the various percpu header files has become unclear.
There are four header files involved.

 include/linux/percpu-defs.h
 include/linux/percpu.h
 include/asm-generic/percpu.h
 arch/*/include/asm/percpu.h

The original intention for include/asm-generic/percpu.h is providing
generic definitions for arch-overridable parts; however, it now hosts
various stuff which can't be overridden by archs.

Also, include/linux/percpu-defs.h was initially added to contain
section and percpu variable definition macros so that arch header
files can make use of them without worrying about introducing cyclic
inclusion dependency by including include/linux/percpu.h; however,
arch headers sometimes need to access percpu variables too and this is
one of the reasons why some accessors were implemented in
include/linux/asm-generic/percpu.h.

Let's clear up the situation by making include/asm-generic/percpu.h
contain only arch-overridable parts and moving accessors and
operations into include/linux/percpu-defs.  Note that this patch only
moves things from include/asm-generic/percpu.h.
include/linux/percpu.h will be taken care of by later patches.

This patch moves the followings.

* SHIFT_PERCPU_PTR() / VERIFY_PERCPU_PTR()
* per_cpu()
* raw_cpu_ptr()
* this_cpu_ptr()
* __get_cpu_var()
* __raw_get_cpu_var()
* __this_cpu_ptr()
* PER_CPU_[SHARED_]ALIGNED_SECTION
* PER_CPU_[SHARED_]ALIGNED_SECTION
* PER_CPU_FIRST_SECTION

This patch is pure reorganization.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

Currently, archs can override raw_cpu_ptr() directly; however, we
wanna build a layer of indirection in the generic part of percpu so
that we can implement generic features there without affecting archs.

Introduce arch_raw_cpu_ptr() which is used to define raw_cpu_ptr() by
generic percpu code.  The two are identical for now.  x86 is currently
the only arch which overrides raw_cpu_ptr() and is converted to
define arch_raw_cpu_ptr() instead.

This doesn't introduce any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>

It has been about half a decade since all archs started using the
dynamic percpu allocator and thus the same SHIFT_PERCPU_PTR()
implementation.  There's no benefit in overriding SHIFT_PERCPU_PTR()
anymore.

Remove #ifndef around it to clarify that this is identical regardless
of the arch.

This patch doesn't cause any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>

This fixes use-after-free of epi->fllink.next inside list loop macro.
This loop actually releases elements in the body.  The list is
rcu-protected but here we cannot hold rcu_read_lock because we need to
lock mutex inside.

The obvious solution is to use list_for_each_entry_safe().  RCU-ness
isn't essential because nobody can change this list under us, it's final
fput for this file.

The bug was introduced by ae10b2b4 ("epoll: optimize EPOLL_CTL_DEL
using rcu")
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Reported-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Stable <stable@vger.kernel.org> # 3.13+
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit e1edf18b.

This patch was a misguided attempt at fixing offb for LE ppc64
kernels on BE qemu but is just wrong ... it breaks real LE/LE
setups, LE with real HW, and existing mixed endian systems
that did the fight thing with the appropriate device-tree
property. Bad reviewing on my part, sorry.

The right fix is to either make qemu change its endian when
the guest changes endian (working on that) or to use the
existing foreign endian support.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.13+]
---

Pull networking fixes from David Miller:

 1) Fix checksumming regressions, from Tom Herbert.

 2) Undo unintentional permissions changes for SCTP rto_alpha and
    rto_beta sysfs knobs, from Denial Borkmann.

 3) VXLAN, like other IP tunnels, should advertize it's encapsulation
    size using dev->needed_headroom instead of dev->hard_header_len.
    From Cong Wang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: sctp: fix permissions for rto_alpha and rto_beta knobs
  vxlan: Checksum fixes
  net: add skb_pop_rcv_encapsulation
  udp: call __skb_checksum_complete when doing full checksum
  net: Fix save software checksum complete
  net: Fix GSO constants to match NETIF flags
  udp: ipv4: do not waste time in __udp4_lib_mcast_demux_lookup
  vxlan: use dev->needed_headroom instead of dev->hard_header_len
  MAINTAINERS: update cxgb4 maintainer

Pull more clock framework updates from Mike Turquette:
 "This contains the second half the of the clk changes for 3.16.

  They are simply fixes and code refactoring for the OMAP clock drivers.
  The sunxi clock driver changes include splitting out the one
  mega-driver into several smaller pieces and adding support for the A31
  SoC clocks"

* tag 'clk-for-linus-3.16-part2' of git://git.linaro.org/people/mike.turquette/linux: (25 commits)
  clk: sunxi: document PRCM clock compatible strings
  clk: sunxi: add PRCM (Power/Reset/Clock Management) clks support
  clk: sun6i: Protect SDRAM gating bit
  clk: sun6i: Protect CPU clock
  clk: sunxi: Rework clock protection code
  clk: sunxi: Move the GMAC clock to a file of its own
  clk: sunxi: Move the 24M oscillator to a file of its own
  clk: sunxi: Remove calls to clk_put
  clk: sunxi: document new A31 USB clock compatible
  clk: sunxi: Implement A31 USB clock
  ARM: dts: OMAP5/DRA7: use omap5-mpu-dpll-clock capable of dealing with higher frequencies
  CLK: TI: dpll: support OMAP5 MPU DPLL that need special handling for higher frequencies
  ARM: OMAP5+: dpll: support Duty Cycle Correction(DCC)
  CLK: TI: clk-54xx: Set the rate for dpll_abe_m2x2_ck
  CLK: TI: Driver for DRA7 ATL (Audio Tracking Logic)
  dt:/bindings: DRA7 ATL (Audio Tracking Logic) clock bindings
  ARM: dts: dra7xx-clocks: Correct name for atl clkin3 clock
  CLK: TI: gate: add composite interface clock to OMAP2 only build
  ARM: OMAP2: clock: add DT boot support for cpufreq_ck
  CLK: TI: OMAP2: add clock init support
  ...

Pull NVMe update from Matthew Wilcox:
 "Mostly bugfixes again for the NVMe driver.  I'd like to call out the
  exported tracepoint in the block layer; I believe Keith has cleared
  this with Jens.

  We've had a few reports from people who're really pounding on NVMe
  devices at scale, hence the timeout changes (and new module
  parameters), hotplug cpu deadlock, tracepoints, and minor performance
  tweaks"

[ Jens hadn't seen that tracepoint thing, but is ok with it - it will
  end up going away when mq conversion happens ]

* git://git.infradead.org/users/willy/linux-nvme: (22 commits)
  NVMe: Fix START_STOP_UNIT Scsi->NVMe translation.
  NVMe: Use Log Page constants in SCSI emulation
  NVMe: Define Log Page constants
  NVMe: Fix hot cpu notification dead lock
  NVMe: Rename io_timeout to nvme_io_timeout
  NVMe: Use last bytes of f/w rev SCSI Inquiry
  NVMe: Adhere to request queue block accounting enable/disable
  NVMe: Fix nvme get/put queue semantics
  NVMe: Delete NVME_GET_FEAT_TEMP_THRESH
  NVMe: Make admin timeout a module parameter
  NVMe: Make iod bio timeout a parameter
  NVMe: Prevent possible NULL pointer dereference
  NVMe: Fix the buffer size passed in GetLogPage(CDW10.NUMD)
  NVMe: Update data structures for NVMe 1.2
  NVMe: Enable BUILD_BUG_ON checks
  NVMe: Update namespace and controller identify structures to the 1.1a spec
  NVMe: Flush with data support
  NVMe: Configure support for block flush
  NVMe: Add tracepoints
  NVMe: Protect against badly formatted CQEs
  ...

Commit 3fd091e7 ("[SCTP]: Remove multiple levels of msecs
to jiffies conversions.") has silently changed permissions for
rto_alpha and rto_beta knobs from 0644 to 0444. The purpose of
this was to discourage users from tweaking rto_alpha and
rto_beta knobs in production environments since they are key
to correctly compute rtt/srtt.

RFC4960 under section 6.3.1. RTO Calculation says regarding
rto_alpha and rto_beta under rule C3 and C4:

  [...]
  C3)  When a new RTT measurement R' is made, set

       RTTVAR <- (1 - RTO.Beta) * RTTVAR + RTO.Beta * |SRTT - R'|

       and

       SRTT <- (1 - RTO.Alpha) * SRTT + RTO.Alpha * R'

       Note: The value of SRTT used in the update to RTTVAR
       is its value before updating SRTT itself using the
       second assignment. After the computation, update
       RTO <- SRTT + 4 * RTTVAR.

  C4)  When data is in flight and when allowed by rule C5
       below, a new RTT measurement MUST be made each round
       trip. Furthermore, new RTT measurements SHOULD be
       made no more than once per round trip for a given
       destination transport address. There are two reasons
       for this recommendation: First, it appears that
       measuring more frequently often does not in practice
       yield any significant benefit [ALLMAN99]; second,
       if measurements are made more often, then the values
       of RTO.Alpha and RTO.Beta in rule C3 above should be
       adjusted so that SRTT and RTTVAR still adjust to
       changes at roughly the same rate (in terms of how many
       round trips it takes them to reflect new values) as
       they would if making only one measurement per
       round-trip and using RTO.Alpha and RTO.Beta as given
       in rule C3. However, the exact nature of these
       adjustments remains a research issue.
  [...]

While it is discouraged to adjust rto_alpha and rto_beta
and not further specified how to adjust them, the RFC also
doesn't explicitly forbid it, but rather gives a RECOMMENDED
default value (rto_alpha=3, rto_beta=2). We have a couple
of users relying on the old permissions before they got
changed. That said, if someone really has the urge to adjust
them, we could allow it with a warning in the log.

Fixes: 3fd091e7 ("[SCTP]: Remove multiple levels of msecs to jiffies conversions.")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tom Herbert says:

====================
Fixes related to some recent checksum modifications.

- Fix GSO constants to match NETIF flags
- Fix logic in saving checksum complete in __skb_checksum_complete
- Call __skb_checksum_complete from UDP if we are checksumming over
  whole packet in order to save checksum.
- Fixes to VXLAN to work correctly with checksum complete
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Call skb_pop_rcv_encapsulation and postpull_rcsum for the Ethernet
header to work properly with checksum complete.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This function is used by UDP encapsulation protocols in RX when
crossing encapsulation boundary. If ip_summed is set to
CHECKSUM_UNNECESSARY and encapsulation is not set, change to
CHECKSUM_NONE since the checksum has not been validated within the
encapsulation. Clears csum_valid by the same rationale.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In __udp_lib_checksum_complete check if checksum is being done over all
the data (len is equal to skb->len) and if it is call
__skb_checksum_complete instead of __skb_checksum_complete_head. This
allows checksum to be saved in checksum complete.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Geert reported issues regarding checksum complete and UDP.
The logic introduced in commit 7e3cead5
("net: Save software checksum complete") is not correct.

This patch:
1) Restores code in __skb_checksum_complete_header except for setting
   CHECKSUM_UNNECESSARY. This function may be calculating checksum on
   something less than skb->len.
2) Adds saving checksum to __skb_checksum_complete. The full packet
   checksum 0..skb->len is calculated without adding in pseudo header.
   This value is saved in skb->csum and then the pseudo header is added
   to that to derive the checksum for validation.
3) In both __skb_checksum_complete_header and __skb_checksum_complete,
   set skb->csum_valid to whether checksum of zero was computed. This
   allows skb_csum_unnecessary to return true without changing to
   CHECKSUM_UNNECESSARY which was done previously.
4) Copy new csum related bits in __copy_skb_header.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Joseph Gasparakis reported that VXLAN GSO offload stopped working with
i40e device after recent UDP changes. The problem is that the
SKB_GSO_* bits are out of sync with the corresponding NETIF flags. This
patch fixes that. Also, we add BUILD_BUG_ONs in net_gso_ok for several
GSO constants that were missing to avoid the problem in the future.
Reported-by: Joseph Gasparakis <joseph.gasparakis@intel.com>
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull more SCSI updates from James Bottomley:
 "This is just a couple of drivers (hpsa and lpfc) that got left out for
  further testing in linux-next.  We also have one fix to a prior
  submission (qla2xxx sparse)"

* tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (36 commits)
  qla2xxx: fix sparse warnings introduced by previous target mode t10-dif patch
  lpfc: Update lpfc version to driver version 10.2.8001.0
  lpfc: Fix ExpressLane priority setup
  lpfc: mark old devices as obsolete
  lpfc: Fix for initializing RRQ bitmap
  lpfc: Fix for cleaning up stale ring flag and sp_queue_event entries
  lpfc: Update lpfc version to driver version 10.2.8000.0
  lpfc: Update Copyright on changed files from 8.3.45 patches
  lpfc: Update Copyright on changed files
  lpfc: Fixed locking for scsi task management commands
  lpfc: Convert runtime references to old xlane cfg param to fof cfg param
  lpfc: Fix FW dump using sysfs
  lpfc: Fix SLI4 s abort loop to process all FCP rings and under ring_lock
  lpfc: Fixed kernel panic in lpfc_abort_handler
  lpfc: Fix locking for postbufq when freeing
  lpfc: Fix locking for lpfc_hba_down_post
  lpfc: Fix dynamic transitions of FirstBurst from on to off
  hpsa: fix handling of hpsa_volume_offline return value
  hpsa: return -ENOMEM not -1 on kzalloc failure in hpsa_get_device_id
  hpsa: remove messages about volume status VPD inquiry page not supported
  ...

Pull more btrfs updates from Chris Mason:
 "This has a few fixes since our last pull and a new ioctl for doing
  btree searches from userland.  It's very similar to the existing
  ioctl, but lets us return larger items back down to the app"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix error handling in create_pending_snapshot
  btrfs: fix use of uninit "ret" in end_extent_writepage()
  btrfs: free ulist in qgroup_shared_accounting() error path
  Btrfs: fix qgroups sanity test crash or hang
  btrfs: prevent RCU warning when dereferencing radix tree slot
  Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting
  btrfs: new ioctl TREE_SEARCH_V2
  btrfs: tree_search, search_ioctl: direct copy to userspace
  btrfs: new function read_extent_buffer_to_user
  btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW
  btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer
  btrfs: tree_search, search_ioctl: accept varying buffer
  btrfs: tree_search: eliminate redundant nr_items check

Pull aio fix and cleanups from Ben LaHaise:
 "This consists of a couple of code cleanups plus a minor bug fix"

* git://git.kvack.org/~bcrl/aio-next:
  aio: cleanup: flatten kill_ioctx()
  aio: report error from io_destroy() when threads race in io_destroy()
  fs/aio.c: Remove ctx parameter in kiocb_cancel

Tetsuo Handa wrote:
 "Commit 62a8067a ("bio_vec-backed iov_iter") introduced an unnamed
  union inside a struct which gcc-4.4.7 cannot handle.  Name the unnamed
   union as u in order to fix build failure"

Let's do this instead: there is only one place in the entire tree that
steps into this breakage.  Anon structs and unions work in older gcc
versions; as the matter of fact, we have those in the tree - see e.g.
struct ieee80211_tx_info in include/net/mac80211.h

What doesn't work is handling their initializers:

struct {
	int a;
	union {
		int b;
		char c;
	};
} x[2] = {{.a = 1, .c = 'a'}, {.a = 0, .b = 1}};

is the obvious syntax for initializer, perfectly fine for C11 and
handled correctly by gcc-4.7 or later.

Earlier versions, though, break on it - declaration is fine and so's
access to fields (i.e.  x[0].c = 'a'; would produce the right code), but
members of the anon structs and unions are not inserted into the right
namespace.  Tellingly, those older versions will not barf on struct {int
a; struct {int a;};}; - looks like they just have it hacked up somewhere
around the handling of .  and -> instead of doing the right thing.

The easiest way to deal with that crap is to turn initialization of
those fields (in the only place where we have such initializer of
iov_iter) into plain assignment.
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull HSI build fixes from Sebastian Reichel:
 - tighten dependency between ssi-protocol and omap-ssi to fix build
   failures with randconfig.
 - use normal module refcounting in omap driver to fix build with
   disabled module support

* tag 'hsi-for-3.16-fixes1' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-hsi:
  hsi: omap_ssi_port: use normal module refcounting
  HSI: fix omap ssi driver dependency

Pull GPIO fix from Linus Walleij:
 "A first GPIO fix for the v3.16 series, this was serious since it
  blocks the OMAP boot.

  Sending you this vital fix before leaving for a short vacation so it
  does not sit collecting dust in my tree for no good reason.

  Apart from this, our v3.16 cycle looks like a good start"

* tag 'gpio-v3.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: of: Fix handling for deferred probe for -gpio suffix

Pull x86 vdso fixes from Peter Anvin:
 "Fixes for x86/vdso.

  One is a simple build fix for bigendian hosts, one is to make "make
  vdso_install" work again, and the rest is about working around a bug
  in Google's Go language -- two are documentation patches that improves
  the sample code that the Go coders took, modified, and broke; the
  other two implements a workaround that keeps existing Go binaries from
  segfaulting at least"

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso: Fix vdso_install
  x86/vdso: Hack to keep 64-bit Go programs working
  x86/vdso: Add PUT_LE to store little-endian values
  x86/vdso/doc: Make vDSO examples more portable
  x86/vdso/doc: Rename vdso_test.c to vdso_standalone_test_x86.c
  x86, vdso: Remove one final use of htole16()

Pull hwmon updates from Guenter Roeck:
 - new driver for Sensirion SHTC1 humidity / temperature sensor
 - convert ltc4151 and vexpress drivers to use devm functions
 - drop generic chip detection from lm85 driver
 - avoid forward declarations in atxp1 driver
 - fix sign extensions in ina2xx driver

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: vexpress: Use devm helper for hwmon device registration
  hwmon: (atxp1) Avoid forward declaration
  hwmon: add support for Sensirion SHTC1 sensor
  hwmon: (ltc4151) Convert to devm_hwmon_device_register_with_groups
  hwmon: (lm85) Drop generic detection
  hwmon: (ina2xx) Cast to s16 on shunt and current regs

Its too easy to add thousand of UDP sockets on a particular bucket,
and slow down an innocent multicast receiver.

Early demux is supposed to be an optimization, we should avoid spending
too much time in it.

It is interesting to note __udp4_lib_demux_lookup() only tries to
match first socket in the chain.

10 is the threshold we already have in __udp4_lib_lookup() to switch
to secondary hash.

Fixes: 421b3885 ("udp: ipv4: Add udp early demux")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: David Held <drheld@google.com>
Cc: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When we mirror packets from a vxlan tunnel to other device,
the mirror device should see the same packets (that is, without
outer header). Because vxlan tunnel sets dev->hard_header_len,
tcf_mirred() resets mac header back to outer mac, the mirror device
actually sees packets with outer headers

Vxlan tunnel should set dev->needed_headroom instead of
dev->hard_header_len, like what other ip tunnels do. This fixes
the above problem.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: stephen hemminger <stephen@networkplumber.org>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>