The offset is wrong in bitmap_storage_alloc, we should
set it like below in bitmap_init_from_disk().

node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));

Because 'offset' is only assigned to 'page->index' and
that is usually over-written by read_sb_page. So it does
not cause problem in general, but it still need to be fixed.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

If the node received RESYNCING message which means
another node will perform resync with the area, then
we don't want to do it again in another node.

Let's set RESYNC_MASK and clear NEEDED_MASK for the
region from old-low to new-low which has finished
syncing, and the region from old-hi to new-hi is about
to syncing, bitmap_sync_with_cluste is introduced for
the purpose.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

The in-memory bitmap for raid is allocated on demand,
then for cluster scenario, it is possible that slave
node which received RESYNCING message doesn't have the
in-memory bitmap when master node is perform resyncing,
so we can't make bitmap is match up well among each
nodes.

So for cluster scenario, we need always preserve the
bitmap, and ensure the page will not be freed. And a
no_hijack flag is introduced to both bitmap_checkpage
and bitmap_get_counter, which makes cluster raid returns
fail once allocate failed.

And the next patch is relied on this change since it
keeps sync bitmap among each nodes during resyncing
stage.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

When a device is re-added, it will ultimately need
to be activated and that happens in md_check_recovery,
so we need to set MD_RECOVERY_NEEDED right after
remove_and_add_spares.

A specifical issue without the change is that when
one node perform fail/remove/readd on a disk, but
slave nodes could not add the disk back to array as
expected (added as missed instead of in sync). So
give slave nodes a chance to do resync.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

Currently, some features are not supported yet,
such as change array_sectors and update size, so
return EINVAL for them and listed it in document.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

If a node joins the cluster while a message broadcast
is under way, a lock issue could happen as follows.

For a cluster which included two nodes, if node A is
calling __sendmsg before up-convert CR to EX on ack,
and node B released CR on ack. But if a new node C
joins the cluster and it doesn't receive the message
which A sent before, so it could hold CR on ack before
A up-convert CR to EX on ack.

So a node joining the cluster should get an EX lock on
the "token" first to ensure no broadcast is ongoing,
then release it after held CR on ack.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

The two threads need to be unregistered if a node
can't join cluster successfully.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

In recovery case, we need to set MD_RECOVERY_NEEDED
and wake up thread only if recover is not finished.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

It is not reasonable that cluster raid to release resync
lock before the last pers->sync_request has finished.

As the metadata will be changed when node performs resync,
we need to inform other nodes to update metadata, so the
MD_CHANGE_PENDING flag is set before finish resync.

Then metadata_update_finish is move ahead to ensure that
METADATA_UPDATED msg is sent before finish resync, and
metadata_update_start need to be run after "repeat:" label
accordingly.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

If multiple nodes choose to attempt do resync at the same time
they need to be serialized so they don't duplicate effort. This
serialization is done by locking the 'resync' DLM lock.

Currently if a node cannot get the lock immediately it doesn't
request notification when the lock becomes available (i.e.
DLM_LKF_NOQUEUE is set), so it may not reliably find out when it
is safe to try again.

Rather than trying to arrange an async wake-up when the lock
becomes available, switch to using synchronous locking - this is
a lot easier to think about.  As it is not permitted to block in
the 'raid1d' thread, move the locking to the resync thread.  So
the rsync thread is forked immediately, but it blocks until the
resync lock is available. Once the lock is locked it checks again
if any resync action is needed.

A particular symptom of the current problem is that a node can
get stuck with "resync=pending" indefinitely.
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: NShaohua Li <shli@fb.com>

Pull IMA fix from James Morris.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima: fix the string representation of the LSM/IMA hook enumeration ordering

Pull xen regression fixes from David Vrabel:

 - Fix two regressions causing crashes in 32-bit PV guests

 - Fix a regression in the evtchn driver

* tag 'for-linus-4.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/evtchn: fix ring resize when binding new events
  xen/balloon: Fix crash when ballooning on x86 32 bit PAE
  xen: Fix page <-> pfn conversion on 32 bit systems

The copying of ring data was wrong for two cases: For a full ring
nothing got copied at all (as in that case the canonicalized producer
and consumer indexes are identical). And in case one or both of the
canonicalized (after the resize) indexes would point into the second
half of the buffer, the copied data ended up in the wrong (free) part
of the new buffer. In both cases uninitialized data would get passed
back to the caller.

Fix this by simply copying the old ring contents twice: Once to the
low half of the new buffer, and a second time to the high half.

This addresses the inability to boot a HVM guest with 64 or more
vCPUs.  This regression was caused by 86200154 (xen/evtchn:
dynamically grow pending event channel ring).
Reported-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Cc: <stable@vger.kernel.org> # 4.4+
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

This patch fixes the string representation of the LSM/IMA hook enumeration
ordering used for displaying the IMA policy.

Fixes: d9ddf077 ("ima: support for kexec image and initramfs")
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Tested-by: NEric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

Merge tag 'trace-fixes-v4.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Chunyu Hu noticed that if one writes into the trigger files within the
  ftrace subsystem of events that it can cause an oops.  This file is
  only writable by root, but still is a bug that needs to be fixed"

* tag 'trace-fixes-v4.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Don't display trigger file for events that can't be enabled

Pull networking fixes from David Miller:
 "Some straggler bug fixes:

   1) Batman-adv DAT must consider VLAN IDs when choosing candidate
      nodes, from Antonio Quartulli.

   2) Fix botched reference counting of vlan objects and neigh nodes in
      batman-adv, from Sven Eckelmann.

   3) netem can crash when it sees GSO packets, the fix is to segment
      then upon ->enqueue.  Fix from Neil Horman with help from Eric
      Dumazet.

   4) Fix VXLAN dependencies in mlx5 driver Kconfig, from Matthew
      Finlay.

   5) Handle VXLAN ops outside of rcu lock, via a workqueue, in mlx5,
      since it can sleep.  Fix also from Matthew Finlay.

   6) Check mdiobus_scan() return values properly in pxa168_eth and macb
      drivers.  From Sergei Shtylyov.

   7) If the netdevice doesn't support checksumming, disable
      segmentation.  From Alexandery Duyck.

   8) Fix races between RDS tcp accept and sending, from Sowmini
      Varadhan.

   9) In macb driver, probe MDIO bus before we register the netdev,
      otherwise we can try to open the device before it is really ready
      for that.  Fix from Florian Fainelli.

  10) Netlink attribute size for ILA "tunnels" not calculated properly,
      fix from Nicolas Dichtel"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  ipv6/ila: fix nlsize calculation for lwtunnel
  net: macb: Probe MDIO bus before registering netdev
  RDS: TCP: Synchronize accept() and connect() paths on t_conn_lock.
  RDS:TCP: Synchronize rds_tcp_accept_one with rds_send_xmit when resetting t_sock
  vxlan: Add checksum check to the features check function
  net: Disable segmentation if checksumming is not supported
  net: mvneta: Remove superfluous SMP function call
  macb: fix mdiobus_scan() error check
  pxa168_eth: fix mdiobus_scan() error check
  net/mlx5e: Use workqueue for vxlan ops
  net/mlx5e: Implement a mlx5e workqueue
  net/mlx5: Kconfig: Fix MLX5_EN/VXLAN build issue
  net/mlx5: Unmap only the relevant IO memory mapping
  netem: Segment GSO packets on enqueue
  batman-adv: Fix reference counting of hardif_neigh_node object for neigh_node
  batman-adv: Fix reference counting of vlan object for tt_local_entry
  batman-adv: B.A.T.M.A.N V - make sure iface is reactivated upon NETDEV_UP event
  batman-adv: fix DAT candidate selection (must use vid)

Pull fuse fixes from Miklos Szeredi:
 "Fix a regression and update the MAINTAINERS entry for fuse"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: update mailing list in MAINTAINERS
  fuse: Fix return value from fuse_get_user_pages()

The handler 'ila_fill_encap_info' adds one attribute: ILA_ATTR_LOCATOR.

Fixes: 65d7ab8d ("net: Identifier Locator Addressing module")
CC: Tom Herbert <tom@herbertland.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current sequence makes us register for a network device prior to
registering and probing the MDIO bus which could lead to some unwanted
consequences, like a thread of execution calling into ndo_open before
register_netdev() returns, while the MDIO bus is not ready yet.

Rework the sequence to register for the MDIO bus, and therefore attach
to a PHY prior to calling register_netdev(), which implies reworking the
error path a bit.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sowmini Varadhan says:

====================
RDS: TCP: sychronization during connection startup

This patch series ensures that the passive (accept) side of the
TCP connection used for RDS-TCP is correctly synchronized with
any concurrent active (connect) attempts for a given pair of peers.

Patch 1 in the series makes sure that the t_sock in struct
rds_tcp_connection is only reset after any threads in rds_tcp_xmit
have completed (otherwise a null-ptr deref may be encountered).
Patch 2 synchronizes rds_tcp_accept_one() with the rds_tcp*connect()
path.

v2: review comments from Santosh Shilimkar, other spelling corrections
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

An arbitration scheme for duelling SYNs is implemented as part of
commit 241b2719 ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()") which ensures that both nodes
involved will arrive at the same arbitration decision. However, this
needs to be synchronized with an outgoing SYN to be generated by
rds_tcp_conn_connect(). This commit achieves the synchronization
through the t_conn_lock mutex in struct rds_tcp_connection.

The rds_conn_state is checked in rds_tcp_conn_connect() after acquiring
the t_conn_lock mutex.  A SYN is sent out only if the RDS connection is
not already UP (an UP would indicate that rds_tcp_accept_one() has
completed 3WH, so no SYN needs to be generated).

Similarly, the rds_conn_state is checked in rds_tcp_accept_one() after
acquiring the t_conn_lock mutex. The only acceptable states (to
allow continuation of the arbitration logic) are UP (i.e., outgoing SYN
was SYN-ACKed by peer after it sent us the SYN) or CONNECTING (we sent
outgoing SYN before we saw incoming SYN).
Signed-off-by: NSowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a race condition between rds_send_xmit -> rds_tcp_xmit
and the code that deals with resolution of duelling syns added
by commit 241b2719 ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()").

Specifically, we may end up derefencing a null pointer in rds_send_xmit
if we have the interleaving sequence:
           rds_tcp_accept_one                  rds_send_xmit

                                             conn is RDS_CONN_UP, so
    					 invoke rds_tcp_xmit

                                             tc = conn->c_transport_data
        rds_tcp_restore_callbacks
            /* reset t_sock */
    					 null ptr deref from tc->t_sock

The race condition can be avoided without adding the overhead of
additional locking in the xmit path: have rds_tcp_accept_one wait
for rds_tcp_xmit threads to complete before resetting callbacks.
The synchronization can be done in the same manner as rds_conn_shutdown().
First set the rds_conn_state to something other than RDS_CONN_UP
(so that new threads cannot get into rds_tcp_xmit()), then wait for
RDS_IN_XMIT to be cleared in the conn->c_flags indicating that any
threads in rds_tcp_xmit are done.

Fixes: 241b2719 ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()")
Signed-off-by: NSowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Alexander Duyck says:

====================
Fixes for tunnel checksum and segmentation offloads

This patch series is a subset of patches I had submitted for net-next.  I
plan to drop these two patches from the v3 of "Fix Tunnel features and
enable GSO partial for several drivers" and I am instead submitting them
for net since these are truly fixes and likely will need to be backported
to stable branches.

This series addresses 2 specific issues.  The first is that we could
request TSO on a v4 inner header while not supporting checksum offload of
the outer IPv6 header.  The second is that we could request an IPv6 inner
checksum offload without validating that we could actually support an inner
IPv6 checksum offload.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need to perform an additional check on the inner headers to determine if
we can offload the checksum for them.  Previously this check didn't occur
so we would generate an invalid frame in the case of an IPv6 header
encapsulated inside of an IPv4 tunnel.  To fix this I added a secondary
check to vxlan_features_check so that we can verify that we can offload the
inner checksum.
Signed-off-by: NAlexander Duyck <aduyck@mirantis.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the case of the mlx4 and mlx5 driver they do not support IPv6 checksum
offload for tunnels.  With this being the case we should disable GSO in
addition to the checksum offload features when we find that a device cannot
perform a checksum on a given packet type.
Signed-off-by: NAlexander Duyck <aduyck@mirantis.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 3b9d6da6 ("cpu/hotplug: Fix rollback during error-out
in __cpu_disable()") it is ensured that callbacks of CPU_ONLINE and
CPU_DOWN_PREPARE are processed on the hotplugged CPU. Due to this SMP
function calls are no longer required.

Replace smp_call_function_single() with a direct call to
mvneta_percpu_enable() or mvneta_percpu_disable(). The functions do
not require to be called with interrupts disabled, therefore the
smp_call_function_single() calling convention is not preserved.

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: netdev@vger.kernel.org
Signed-off-by: NAnna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now mdiobus_scan() returns ERR_PTR(-ENODEV) instead of NULL if the PHY
device ID was read as all ones. As this was not  an error before, this
value  should be filtered out now in this driver.

Fixes: b74766a0 ("phylib: don't return NULL from get_phy_device()")
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since mdiobus_scan() returns either an error code or NULL on error, the
driver should check  for both,  not only for NULL, otherwise a crash is
imminent...
Reported-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull HID fixes from Jiri Kosina:
 "Fixes for the HID subsystem:

   - regression fix for Wacom driver; commit introduced in 4.6-rc1
     mistakenly removed line that should be kept.  Fix by Ping Cheng

   - two device-specific quirks, by Ping Cheng and Nazar Mokrynskyi"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: wacom: add missed stylus_in_proximity line back
  HID: Fix boot delay for Creative SB Omni Surround 5.1 with quirk
  HID: wacom: Add support for DTK-1651

Pull clk fix from Stephen Boyd:
 "One small bug fix for the imx6qp CAN clk definition that was causing
  failures and division by zeros in the kernel on those devices"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: imx6q: fix typo in CAN clock definition

Saeed Mahameed says:

====================
Mellanox 100G mlx5 fixes for 4.6-rc

This small series provides some bug fixes for mlx5 driver.

A small bug fix for iounmap of a null pointer, which dumps a warning on some archs.

One patch to fix the VXLAN/MLX5_EN dependency issue reported by Arnd.

Two patches to fix the scheduling while atomic issue for ndo_add/del_vxlan_port
NDOs.  The first will add an internal mlx5e workqueue and the second will
delegate vxlan ports add/del requests to that workqueue.

Note: ('net/mlx5: Kconfig: Fix MLX5_EN/VXLAN build issue') is only needed for net
and not net-next as the issue was globally fixed for all device drivers by:
b7aade15 ('vxlan: break dependency with netdev drivers') in net-next.

Applied on top: f27337e1 ('ip_tunnel: fix preempt warning in ip tunnel creation/updating')
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The vxlan add/delete port NDOs are called under rcu lock.
The current mlx5e implementation can potentially block in these
calls, which is not allowed.  Move to using the mlx5e workqueue
to handle these NDOs.

Fixes: b3f63c3d ('net/mlx5e: Add netdev support for VXLAN tunneling')
Signed-off-by: NMatthew Finlay <matt@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement a mlx5e workqueue to handle all mlx5e specific tasks.  Move
all tasks currently using the system workqueue to the new workqueue.
This is in preparation for vxlan using the mlx5e workqueue in order to
schedule port add/remove operations.
Signed-off-by: NMatthew Finlay <matt@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When MLX5_EN=y MLX5_CORE=y and VXLAN=m there is a linker error for
vxlan_get_rx_port() due to the fact that VXLAN is a module. Change Kconfig
to select VXLAN when MLX5_CORE=y. When MLX5_CORE=m there is no dependency
on the value of VXLAN.

Fixes: b3f63c3d ('net/mlx5e: Add netdev support for VXLAN tunneling')
Signed-off-by: NMatthew Finlay <matt@mellanox.com>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When freeing UAR the driver tries to unmap uar->map and uar->bf_map
which are mutually exclusive thus always unmapping a NULL pointer.
Make sure we only call iounmap() once, for the actual mapping.

Fixes: 0ba42241 ('net/mlx5: Fix global UAR mapping')
Signed-off-by: NGal Pressman <galp@mellanox.com>
Reported-by: NDoron Tsur <doront@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently register functions for events will be called
through the 'reg' field of event class directly without
any check when seting up triggers.

Triggers for events that don't support register through
debug fs (events under events/ftrace are for trace-cmd to
read event format, and most of them don't have a register
function except events/ftrace/functionx) can't be enabled
at all, and an oops will be hit when setting up trigger
for those events, so just not creating them is an easy way
to avoid the oops.

Link: http://lkml.kernel.org/r/1462275274-3911-1-git-send-email-chuhu@redhat.com

Cc: stable@vger.kernel.org # 3.14+
Fixes: 85f2b082 ("tracing: Add basic event trigger framework")
Signed-off-by: NChunyu Hu <chuhu@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Commit 7e129783 ("HID: wacom: break out wacom_intuos_get_tool_type") by accident
removed stylus_in_proximity flag for Intuos series while shuffling the code
around.

Fix that by reintroducing that flag setting in wacom_intuos_inout(), where
it originally was.

Fixes: 7e129783 ("HID: wacom: break out wacom_intuos_get_tool_type")
Signed-off-by: NPing Cheng <pingc@wacom.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The fuse mailing list seems not to be open anymore.  The discussion on
fuse-devel@... is mostly userspace related anyway.

Reported-by: Andreas Gruenbacher <agruenba@redhat.com> 
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

This was recently reported to me, and reproduced on the latest net kernel,
when attempting to run netperf from a host that had a netem qdisc attached
to the egress interface:

[  788.073771] ---------------------[ cut here ]---------------------------
[  788.096716] WARNING: at net/core/dev.c:2253 skb_warn_bad_offload+0xcd/0xda()
[  788.129521] bnx2: caps=(0x00000001801949b3, 0x0000000000000000) len=2962
data_len=0 gso_size=1448 gso_type=1 ip_summed=3
[  788.182150] Modules linked in: sch_netem kvm_amd kvm crc32_pclmul ipmi_ssif
ghash_clmulni_intel sp5100_tco amd64_edac_mod aesni_intel lrw gf128mul
glue_helper ablk_helper edac_mce_amd cryptd pcspkr sg edac_core hpilo ipmi_si
i2c_piix4 k10temp fam15h_power hpwdt ipmi_msghandler shpchp acpi_power_meter
pcc_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c
sd_mod crc_t10dif crct10dif_generic mgag200 syscopyarea sysfillrect sysimgblt
i2c_algo_bit drm_kms_helper ahci ata_generic pata_acpi ttm libahci
crct10dif_pclmul pata_atiixp tg3 libata crct10dif_common drm crc32c_intel ptp
serio_raw bnx2 r8169 hpsa pps_core i2c_core mii dm_mirror dm_region_hash dm_log
dm_mod
[  788.465294] CPU: 16 PID: 0 Comm: swapper/16 Tainted: G        W
------------   3.10.0-327.el7.x86_64 #1
[  788.511521] Hardware name: HP ProLiant DL385p Gen8, BIOS A28 12/17/2012
[  788.542260]  ffff880437c036b8 f7afc56532a53db9 ffff880437c03670
ffffffff816351f1
[  788.576332]  ffff880437c036a8 ffffffff8107b200 ffff880633e74200
ffff880231674000
[  788.611943]  0000000000000001 0000000000000003 0000000000000000
ffff880437c03710
[  788.647241] Call Trace:
[  788.658817]  <IRQ>  [<ffffffff816351f1>] dump_stack+0x19/0x1b
[  788.686193]  [<ffffffff8107b200>] warn_slowpath_common+0x70/0xb0
[  788.713803]  [<ffffffff8107b29c>] warn_slowpath_fmt+0x5c/0x80
[  788.741314]  [<ffffffff812f92f3>] ? ___ratelimit+0x93/0x100
[  788.767018]  [<ffffffff81637f49>] skb_warn_bad_offload+0xcd/0xda
[  788.796117]  [<ffffffff8152950c>] skb_checksum_help+0x17c/0x190
[  788.823392]  [<ffffffffa01463a1>] netem_enqueue+0x741/0x7c0 [sch_netem]
[  788.854487]  [<ffffffff8152cb58>] dev_queue_xmit+0x2a8/0x570
[  788.880870]  [<ffffffff8156ae1d>] ip_finish_output+0x53d/0x7d0
...

The problem occurs because netem is not prepared to handle GSO packets (as it
uses skb_checksum_help in its enqueue path, which cannot manipulate these
frames).

The solution I think is to simply segment the skb in a simmilar fashion to the
way we do in __dev_queue_xmit (via validate_xmit_skb), with some minor changes.
When we decide to corrupt an skb, if the frame is GSO, we segment it, corrupt
the first segment, and enqueue the remaining ones.

tested successfully by myself on the latest net kernel, to which this applies
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
CC: Jamal Hadi Salim <jhs@mojatatu.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: netem@lists.linux-foundation.org
CC: eric.dumazet@gmail.com
CC: stephen@networkplumber.org
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Antonio Quartulli says:

====================
In this small batch of patches you have:
- a fix for our Distributed ARP Table that makes sure that the input
  provided to the hash function during a query is the same as the one
  provided during an insert (so to prevent false negatives), by Antonio
  Quartulli
- a fix for our new protocol implementation B.A.T.M.A.N. V that ensures
  that a hard interface is properly re-activated when it is brought down
  and then up again, by Antonio Quartulli
- two fixes respectively to the reference counting of the tt_local_entry
  and neigh_node objects, by Sven Eckelmann. Such bug is rather severe
  as it would prevent the netdev objects references by batman-adv from
  being released after shutdown.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>