Generic skb_vlan_push/skb_vlan_pop functions don't properly handle the
case where the input skb data pointer does not point at the mac header:

- They're doing push/pop, but fail to properly unwind data back to its
  original location.
  For example, in the skb_vlan_push case, any subsequent
  'skb_push(skb, skb->mac_len)' calls make the skb->data point 4 bytes
  BEFORE start of frame, leading to bogus frames that may be transmitted.

- They update rcsum per the added/removed 4 bytes tag.
  Alas if data is originally after the vlan/eth headers, then these
  bytes were already pulled out of the csum.

OTOH calling skb_vlan_push/skb_vlan_pop with skb->data at mac_header
present no issues.

act_vlan is the only caller to skb_vlan_*() that has skb->data pointing
at network header (upon ingress).
Other calles (ovs, bpf) already adjust skb->data at mac_header.

This patch fixes act_vlan to point to the mac_header prior calling
skb_vlan_*() functions, as other callers do.
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Pravin Shelar <pshelar@ovn.org>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is no need to clk_disable_unprepare(dev->clk)
before it was initialized.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'rxrpc-rewrite-20160930' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: More fixes and adjustments

This set of patches contains some more fixes and adjustments:

 (1) Actually display the retransmission indication previously added to the
     tx_data trace.

 (2) Switch to Congestion Avoidance mode properly at cwnd==ssthresh rather
     than relying on detection during an overshoot and correction.

 (3) Reduce ssthresh to the peer's declared receive window.

 (4) The offset field in rxrpc_skb_priv can be dispensed with and the error
     field is no longer used.  Get rid of them.

 (5) Keep the call timeouts as ktimes rather than jiffies to make it easier
     to deal with RTT-based timeout values in future.  Rounding to jiffies
     is still necessary when the system timer is set.

 (6) Fix the call timer handling to avoid retriggering of expired timeout
     actions.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Jiri Benc says:

====================
openvswitch: mpls fix and clean up

Convert to the new mpls skb layout the last remaining place in openvswitch,
forgotten on the mpls GSO rework. The GSO rework also allows for some
cleanup in the third patch.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

skb_mpls_header is equivalent to mpls_hdr now. Use the existing helper
instead.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This will be also used by openvswitch.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

After the 48d2ab60 ("net: mpls: Fixups for GSO"), MPLS handling in
openvswitch was changed to have network header pointing to the start of the
MPLS headers and inner_network_header pointing after the MPLS headers.

However, key_extract was missed by the mentioned commit, causing incorrect
headers to be set when a MPLS packet just enters the bridge or after it is
recirculated.

Fixes: 48d2ab60 ("net: mpls: Fixups for GSO")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

If fi->fib_nhs is zero, the router interface pointer is uninitialized, as shown by
this warning:

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_router_fib_event':
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:1674:21: error: 'r' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:1643:23: note: 'r' was declared here

This changes the loop so we handle the case the same way as finding no router
interface pointer attached to one of the nexthops to ensure we always
trap here instead of using uninitialized data.

Fixes: b45f64d1 ("mlxsw: spectrum_router: Use FIB notifications instead of switchdev calls")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Build-testing this driver with -Wmaybe-uninitialized gives a new false-positive
warning that I can't really explain:

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c: In function 'mlx5e_configure_flower':
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:509:3: error: 'old_attr' may be used uninitialized in this function [-Werror=maybe-uninitialized]

It's obvious from the code that 'old_attr' is initialized whenever 'old'
is non-NULL here. The warning appears with all versions I tested from gcc-4.7
through gcc-6.1, and I could not come up with a way to rewrite the function
in a more readable way that avoids the warning, so I'm adding another
initialization to shut it up.

Fixes: 8b32580d ("net/mlx5e: Add TC vlan action for SRIOV offloads")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A recent cleanup marked cxgb4_dcb_enabled as 'static', which is correct, but this ignored
how the symbol is also exported. In addition, the export can be compiled out when modules
are disabled, causing a harmless compiler warning in configurations for which it is not
used at all:

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:282:12: error: 'cxgb4_dcb_enabled' defined but not used [-Werror=unused-function]

This removes the export and moves the function into the correct #ifdef so we only build
it when there are users.

Fixes: 50935857 ("cxgb4: mark symbols static where possible")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

With the newly added support for IFLA_VF_VLAN_LIST netlink messages,
we get a warning about potential uninitialized variable use in
the parsing of the user input when enabling the -Wmaybe-uninitialized
warning:

net/core/rtnetlink.c: In function 'do_setvfinfo':
net/core/rtnetlink.c:1756:9: error: 'ivvl$' may be used uninitialized in this function [-Werror=maybe-uninitialized]

I have not been able to prove whether it is possible to arrive in
this code with an empty IFLA_VF_VLAN_LIST block, but if we do,
then ndo_set_vf_vlan gets called with uninitialized arguments.

This adds an explicit check for an empty list, making it obvious
to the reader and the compiler that this cannot happen.

Fixes: 79aab093 ("net: Update API for VF vlan protocol 802.1ad support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The commit 879c7220 ("net: pktgen: Observe needed_headroom
of the device") increased the 'pkt_overhead' field value by
LL_RESERVED_SPACE.
As a side effect the generated packet size, computed as:

	/* Eth + IPh + UDPh + mpls */
	datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 -
		  pkt_dev->pkt_overhead;

is decreased by the same value.
The above changed slightly the behavior of existing pktgen users,
and made the procfs interface somewhat inconsistent.
Fix it by restoring the previous pkt_overhead value and using
LL_RESERVED_SPACE as extralen in skb allocation.
Also, change pktgen_alloc_skb() to only partially reserve
the headroom to allow the caller to prefetch from ll header
start.

v1 -> v2:
 - fixed some typos in the comments

Fixes: 879c7220 ("net: pktgen: Observe needed_headroom of the device")
Suggested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the mac address origin is not dt, you can only safely assign a mac
address after "link up" of the device. If the link is off the clocks are
disabled and because of issues assigning registers when clocks are off the
new mac address cannot be written in .ndo_set_mac_address() on some soc's.
This fix sets the mac address unconditionally in fec_restart(...) and
ensures consistency between fec registers and the network layer.
Signed-off-by: Gavin Schenk <g.schenk@eckelmann.de>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: 9638d19e ("net: fec: add netif status check before set mac address")
Signed-off-by: David S. Miller <davem@davemloft.net>

We get 2 warnings when building kernel with W=1:
drivers/net/ethernet/mediatek/mtk_eth_soc.c:2041:5: warning: no previous prototype for 'mtk_get_link_ksettings' [-Wmissing-prototypes]
drivers/net/ethernet/mediatek/mtk_eth_soc.c:2052:5: warning: no previous prototype for 'mtk_set_link_ksettings' [-Wmissing-prototypes]

In fact, these functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
So this patch marks these functions with 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

We get 1 warning when building kernel with W=1:
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:2715:5: warning: no previous prototype for 'cxgb_setup_tc' [-Wmissing-prototypes]

In fact, this function is only used in the file in which it is
declared and don't need a declaration, but can be made static.
so this patch marks this function with 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is an effective no-op in terms of user observable behaviour.

By preventing the overwrite of non-null extra1/extra2 fields
in addrconf_sysctl() we can enable the use of proc_dointvec_minmax().

This allows us to eliminate the constant min/max (1..255) trampoline
function that is addrconf_sysctl_hop_limit().

This is nice because it simplifies the code, and allows future
sysctls with constant min/max limits to also not require trampolines.

We still can't eliminate the trampoline for mtu because it isn't
actually a constant (it depends on other tunables of the device)
and thus requires at-write-time logic to enforce range.
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Erik Kline <ek@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When using bridge without bridge netfilter enabled the message
displayed is rather confusing and leads to belive that a deprecated
feature is in use. Use IS_MODULE to be explicit that the message only
affects users which use bridge netfilter as module and reword the
message.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Three sets of overlapping changes.  Nothing serious.
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull ARM fixes from Russell King:
 "Three relatively small fixes for ARM:

   - Roger noticed that dma_max_pfn() was calculating the upper limit
     wrongly, by adding the PFN offset of memory twice.

   - A fix from Robin to correct parsing of MPIDR values when the
     address size is larger than one BE32 unit.

   - A fix from Srinivas to ensure that we do not rely on the boot
     loader (or previous Linux kernel) setting the translation table
     base register a certain way in the decompressor, which can lead to
     crashes"

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7
  ARM: 8617/1: dma: fix dma_max_pfn()
  ARM: 8616/1: dt: Respect property size when parsing CPUs

If the bootloader uses the long descriptor format and jumps to
kernel decompressor code, TTBCR may not be in a right state.
Before enabling the MMU, it is required to clear the TTBCR.PD0
field to use TTBR0 for translation table walks.

The commit dbece458 ("ARM: 7501/1: decompressor:
reset ttbcr for VMSA ARMv7 cores") does the reset of TTBCR.N, but
doesn't consider all the bits for the size of TTBCR.N.

Clear TTBCR.PD0 field and reset all the three bits of TTBCR.N to
indicate the use of TTBR0 and the correct base address width.

Fixes: dbece458 ("ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores")
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull x86 fixes from Thomas Gleixner:
 "The last regression fixes for 4.8 final:

   - Two patches addressing the fallout of the CR4 optimizations which
     caused CR4-less machines to fail.

   - Fix the VDSO build on big endian machines

   - Take care of FPU initialization if no CPUID is available otherwise
     task struct size ends up being zero

   - Fix up context tracking in case load_gs_index fails"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Fix context tracking state warning when load_gs_index fails
  x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
  x86/vdso: Fix building on big endian host
  x86/boot: Fix another __read_cr4() case on 486
  x86/init: Fix cr4_init_shadow() on CR4-less machines

Pull MIPS fixes from Ralf Baechle:
 "Another round of fixes:

   - CM: Fix mips_cm_max_vp_width for non-MT kernels on MT systems
   - CPS: Avoid BUG() when offlining pre-r6 CPUs
   - DEC: Avoid gas warnings due to suspicious instruction scheduling by
     manually expanding assembler macros.
   - FTLB: Fix configuration by moving confiuguratoin after probing
   - FTLB: clear execution hazard after changing FTLB enable
   - Highmem: Fix detection of unsupported highmem with cache aliases
   - I6400: Don't touch FTLBP chicken bits
   - microMIPS: Fix BUILD_ROLLBACK_PROLOGUE
   - Malta: Fix IOCU disable switch read for MIPS64
   - Octeon: Fix probing of devices attached to GPIO lines
   - uprobes: Misc small fixes"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: CM: Fix mips_cm_max_vp_width for non-MT kernels on MT systems
  MIPS: Fix detection of unsupported highmem with cache aliases
  MIPS: Malta: Fix IOCU disable switch read for MIPS64
  MIPS: Fix BUILD_ROLLBACK_PROLOGUE for microMIPS
  MIPS: clear execution hazard after changing FTLB enable
  MIPS: Configure FTLB after probing TLB sizes from config4
  MIPS: Stop setting I6400 FTLBP
  MIPS: DEC: Avoid la pseudo-instruction in delay slots
  MIPS: Octeon: mark GPIO controller node not populated after IRQ init.
  MIPS: uprobes: fix use of uninitialised variable
  MIPS: uprobes: remove incorrect set_orig_insn
  MIPS: fix uretprobe implementation
  MIPS: smp-cps: Avoid BUG() when offlining pre-r6 CPUs

Pull sparc fixes from David Miller:

 1) Fix section mismatches in some builds, from Paul Gortmaker.

 2) Need to count huge zero page mappings when doing TSB sizing, from
    Mike Kravetz.

 3) Fix handing of cpu_possible_mask when nr_cpus module option is
    specified, from Atish Patra.

 4) Don't allocate irq stacks until nr_irqs has been processed, also
    from Atish Patra.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix non-SMP build.
  sparc64: Fix irq stack bootmem allocation.
  sparc64: Fix cpu_possible_mask if nr_cpus is set
  sparc64 mm: Fix more TSB sizing issues
  sparc64: fix section mismatch in find_numa_latencies_for_group

Pull networking fixes from David Miller:

 1) Fix wrong TCP checksums on MTU probing when checksum offloading is
    disabled, from Douglas Caetano dos Santos.

 2) Fix qdisc backlog updates in qfq and sfb schedulers, from Cong Wang.

 3) Route lookup flow key protocol value is wrong in ip6gre_xmit_other(),
    fix from Lance Richardson.

 4) Scheduling while atomic in multicast routing code of ipv4 and ipv6,
    fix from Nikolay Aleksandrov.

 5) Fix packet alignment in fec driver, from Eric Nelson.

 6) Fix perf regression in sctp due to struct layout and cache misses,
    from Xin Long.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock
  sctp: change to check peer prsctp_capable when using prsctp polices
  sctp: remove prsctp_param from sctp_chunk
  sctp: move sent_count to the memory hole in sctp_chunk
  tg3: Avoid NULL pointer dereference in tg3_io_error_detected()
  act_ife: Fix false encoding
  act_ife: Fix external mac header on encode
  VSOCK: Don't dec ack backlog twice for rejected connections
  Revert "net: ethernet: bcmgenet: use phydev from struct net_device"
  net: fec: align IP header in hardware
  net: fec: remove QUIRK_HAS_RACC from i.mx27
  net: fec: remove QUIRK_HAS_RACC from i.mx25
  ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route
  ip6_gre: fix flowi6_proto value in ip6gre_xmit_other()
  tcp: fix a compile error in DBGUNDO()
  tcp: fix wrong checksum calculation on MTU probing
  sch_sfb: keep backlog updated with qlen
  sch_qfq: keep backlog updated with qlen
  can: dev: fix deadlock reported after bus-off

When discovering the number of VPEs per core, smp_num_siblings will be
incorrect for kernels built without support for the MIPS MultiThreading
(MT) ASE running on systems which implement said ASE. This leads to
accesses to VPEs in secondary cores being performed incorrectly since
mips_cm_vp_id calculates the wrong ID to write to the local "other"
registers. Fix this by examining the number of VPEs in the core as
reported by the CM.

This patch presumes that the number of VPEs will be the same in each
core of the system. As this path only applies to systems with CM version
2.5 or lower, and this property is true of all such known systems, this
is likely to be fine but is described in a comment for good measure.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14338/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Pull SCSI fix from James Bottomley:
 "One final fix before 4.8.

  There was a memory leak triggered by turning scsi mq off due to the
  fact that we assume on host release that the already running hosts
  weren't mq based because that's the state of the global flag (even
  though they were).

  Fix it by tracking this on a per host host basis"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: Avoid that toggling use_blk_mq triggers a memory leak

The capability check should not be audited since it is only being used
to determine the inode permissions. A failed check does not indicate a
violation of security policy but, when an LSM is enabled, a denial audit
message was being generated.

The denial audit message caused confusion for some application authors
because root-running Go applications always triggered the denial. To
prevent this confusion, the capability check in net_ctl_permissions() is
switched to the noaudit variant.

BugLink: https://launchpad.net/bugs/1465724Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
[dtor: reapplied after e79c6a4f ("net: make net namespace sysctls
belong to container's owner") accidentally reverted the change.]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull input fix from Dmitry Torokhov:
 "One small change to make joydev (which is used by older games) to bind
  to devices that export Z axis but not X or Y (such as TRC rudder)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: joydev - recognize devices with Z axis as joysticks

Merge more fixes from Andrew Morton:
 "Three fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  include/linux/property.h: fix typo/compile error
  ocfs2: fix deadlock on mmapped page in ocfs2_write_begin_nolock()
  mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()

This fixes commit d76eebfa ("include/linux/property.h: fix build
issues with gcc-4.4.4").

With that commit we get the following compile error when using the
PROPERTY_ENTRY_INTEGER_ARRAY macro.

 include/linux/property.h:201:39: error: `u32_data' undeclared (first
                 use in this function)
  PROPERTY_ENTRY_INTEGER_ARRAY(_name_, u32, _val_)
                                       ^
 include/linux/property.h:193:17: note: in definition of macro
                 `PROPERTY_ENTRY_INTEGER_ARRAY'
  { .pointer = { _type_##_data = _val_ } },  \
                 ^

This needs a '.' to reference the union member.  It seems this was just
overlooked here since it is done correctly in similar constructs in
other parts of the original commit.

This fix is in preparation of upcoming commits that will use this macro.

Fixes: commit d76eebfa ("include/linux/property.h: fix build issues with gcc-4.4.4")
Link: http://lkml.kernel.org/r/2de3b929290d88a723ed829a3e3cbd02044714df.1475114627.git.johnyoun@synopsys.comSigned-off-by: John Youn <johnyoun@synopsys.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The testcase "mmaptruncate" of ocfs2-test deadlocks occasionally.

In this testcase, we create a 2*CLUSTER_SIZE file and mmap() on it;
there are 2 process repeatedly performing the following operations
respectively: one is doing memset(mmaped_addr + 2*CLUSTER_SIZE - 1, 'a',
1), while the another is playing ftruncate(fd, 2*CLUSTER_SIZE) and then
ftruncate(fd, CLUSTER_SIZE) again and again.

This is the backtrace when the deadlock happens:

   __wait_on_bit_lock+0x50/0xa0
   __lock_page+0xb7/0xc0
   ocfs2_write_begin_nolock+0x163f/0x1790 [ocfs2]
   ocfs2_page_mkwrite+0x1c7/0x2a0 [ocfs2]
   do_page_mkwrite+0x66/0xc0
   handle_mm_fault+0x685/0x1350
   __do_page_fault+0x1d8/0x4d0
   trace_do_page_fault+0x37/0xf0
   do_async_page_fault+0x19/0x70
   async_page_fault+0x28/0x30

In ocfs2_write_begin_nolock(), we first grab the pages and then allocate
disk space for this write; ocfs2_try_to_free_truncate_log() will be
called if -ENOSPC is returned; if we're lucky to get enough clusters,
which is usually the case, we start over again.

But in ocfs2_free_write_ctxt() the target page isn't unlocked, so we
will deadlock when trying to grab the target page again.

Also, -ENOMEM might be returned in ocfs2_grab_pages_for_write().
Another deadlock will happen in __do_page_mkwrite() if
ocfs2_page_mkwrite() returns non-VM_FAULT_LOCKED, and along with a
locked target page.

These two errors fail on the same path, so fix them by unlocking the
target page manually before ocfs2_free_write_ctxt().

Jan Kara helps me clear out the JBD2 part, and suggest the hint for root
cause.

Changes since v1:
1. Also put ENOMEM error case into consideration.

Link: http://lkml.kernel.org/r/1474173902-32075-1-git-send-email-zren@suse.comSigned-off-by: Eric Ren <zren@suse.com>
Reviewed-by: He Gang <ghe@suse.com>
Acked-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Antonio reports the following crash when using fuse under memory pressure:

  kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: all of them
  CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000
  RIP: shadow_lru_isolate+0x181/0x190
  Call Trace:
    __list_lru_walk_one.isra.3+0x8f/0x130
    list_lru_walk_one+0x23/0x30
    scan_shadow_nodes+0x34/0x50
    shrink_slab.part.40+0x1ed/0x3d0
    shrink_zone+0x2ca/0x2e0
    kswapd+0x51e/0x990
    kthread+0xd8/0xf0
    ret_from_fork+0x3f/0x70

which corresponds to the following sanity check in the shadow node
tracking:

  BUG_ON(node->count & RADIX_TREE_COUNT_MASK);

The workingset code tracks radix tree nodes that exclusively contain
shadow entries of evicted pages in them, and this (somewhat obscure)
line checks whether there are real pages left that would interfere with
reclaim of the radix tree node under memory pressure.

While discussing ways how fuse might sneak pages into the radix tree
past the workingset code, Miklos pointed to replace_page_cache_page(),
and indeed there is a problem there: it properly accounts for the old
page being removed - __delete_from_page_cache() does that - but then
does a raw raw radix_tree_insert(), not accounting for the replacement
page.  Eventually the page count bits in node->count underflow while
leaving the node incorrectly linked to the shadow node LRU.

To address this, make sure replace_page_cache_page() uses the tracked
page insertion code, page_cache_tree_insert().  This fixes the page
accounting and makes sure page-containing nodes are properly unlinked
from the shadow node LRU again.

Also, make the sanity checks a bit less obscure by using the helpers for
checking the number of pages and shadows in a radix tree node.

Fixes: 449dd698 ("mm: keep page cache radix tree nodes in check")
Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.orgSigned-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Antonio SJ Musumeci <trapexit@spawn.link>
Debugged-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>	[3.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Change my email address to my kernel.org account instead of the ARM one.
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The call timer's concept of a call timeout (of which there are three) that
is inactive is that it is the timeout has the same expiration time as the
call expiration timeout (the expiration timer is never inactive).  However,
I'm not resetting the timeouts when they expire, leading to repeated
processing of expired timeouts when other timeout events occur.

Fix this by:

 (1) Move the timer expiry detection into rxrpc_set_timer() inside the
     locked section.  This means that if a timeout is set that will expire
     immediately, we deal with it immediately.

 (2) If a timeout is at or before now then it has expired.  When an expiry
     is detected, an event is raised, the timeout is automatically
     inactivated and the event processor is queued.

 (3) If a timeout is at or after the expiry timeout then it is inactive.
     Inactive timeouts do not contribute to the timer setting.

 (4) The call timer callback can now just call rxrpc_set_timer() to handle
     things.

 (5) The call processor work function now checks the event flags rather
     than checking the timeouts directly.
Signed-off-by: David Howells <dhowells@redhat.com>

Keep that call timeouts as ktimes rather than jiffies so that they can be
expressed as functions of RTT.
Signed-off-by: David Howells <dhowells@redhat.com>

Remove error from struct rxrpc_skb_priv as it is no longer used.
Signed-off-by: David Howells <dhowells@redhat.com>

The offset field in struct rxrpc_skb_priv is unnecessary as the value can
always be calculated.
Signed-off-by: David Howells <dhowells@redhat.com>

When we receive an ACK from the peer that tells us what the peer's receive
window (rwind) is, we should reduce ssthresh to rwind if rwind is smaller
than ssthresh.
Signed-off-by: David Howells <dhowells@redhat.com>

Switch to Congestion Avoidance mode at cwnd == ssthresh rather than relying
on cwnd getting incremented beyond ssthresh and the window size, the mode
being shifted and then cwnd being corrected.

We need to make sure we switch into CA mode so that we stop marking every
packet for ACK.
Signed-off-by: David Howells <dhowells@redhat.com>