There are two generics functions phy_ethtool_{get|set}_link_ksettings,
so we can use them instead of defining the same code in the driver.

There was a check on CAP_NET_ADMIN in cvm_oct_set_settings, but this
check is already done in dev_ethtool, so no need to repeat it before
calling the generic function.
Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The private structure contain a pointer to phydev, but the structure
net_device already contain such pointer. So we can remove the pointer
phydev in the private structure, and update the driver to use the
one contained in struct net_device.
Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ivan Vecera says:

====================
bna: remove useless global variables

The set removes useless global bnad_list as well as bnad->entry that track
a list of driver instances but it is not used anywhere. The associated
bnad_list_mutex is removed as well but as it is also used to protect
bna_id increment it is necessary to convert bna_id to atomic_t.
====================
Signed-off-by: Ivan Vecera <ivecera@redhat.com>

Remove global bnad_list_mutex as it is not used anymore. This makes
bnad_add_to_list() and bnad_remove_from_list() empty so remove them too.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change type of bna_id to atomic_t. The bnad_list_mutex is used to prevent
a race when bna_id is incremented. After the change the mutex can be
removed in the next step.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove global variable bnad_list and bnad->list_entry that are used
as list of bna driver instances. It is not necessary and useless.
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Uwe Kleine-König says:

====================
net: ipconfig: improve DHCP timeout handling

this series teaches the ipconfig code to handle a DHCP reply on eth0 even if a
request on eth1 was already sent out.
This is a follow fix to 2513dfb8 ("ipconfig: handle case of delayed DHCP
server") that dropped a late reply.

This makes it possible at all to work with slow DHCP servers at all in some
configurations and improves boot speed in general.

The first patch is not really necessary, it only helps decoding debug messages
when there is more than one device.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that ipconfig learned to handle "delayed replies" in the previous
commit, there is no reason any more to delay sending a first request per
device.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The dhcp code only waits 1s between sending DHCP requests on different
devices and only accepts an answer for the device that sent out the last
request. Only the timeout at the end of a loop is increased iteratively
which favours only the last device. This makes it impossible to work
with a dhcp server that takes little more than 1s connected to a device
that is not the last one.

Instead of also increasing the inter-device timeout, teach the code to
handle delayed replies.

To accomplish that, make *ic_dev track the current ic_device instead of
the current net_device and adapt all users accordingly. The relevant
change then is to reset d to ic_dev on a reply to assert that the
followup request goes through the right device.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

This simplifies understanding what happens when there is more than one
device.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sathya Perla says:

====================
be2net: patch set

Patch 1 fixes the driver to workaournd a bug in the Lancer FW in the
vlan-config cmd processing. The FW in some cases clears the vlan-promisc
setting even if it cannot apply the vlan filter. The driver has no means
of knowing if the vlan-promisc setting has been cleared or not. This
patch now explicitly clears the vlan-promisc setting via the RX-Filter cmd
and then tries to program the vlan-list.

Patch 2 fixes the failure path in the vlan vid add code.
The driver currently removes a new vid from the adapter->vids[] array if
be_vid_config() returns an error, which occurs when there is an error in
HW/FW. This is wrong. After the HW/FW error is recovered from, we need the
complete vids[] array to re-program the vlan list.

Patch 3 fixes the ndo_set_rx_mode() path to avoid unnecessary multicast
list updates to the FW. Each time the ndo_set_rx_mode() routine is called,
the driver programs the multicast list in the adapter without checking
if there are any changes to the list. This leads to a flood of RX_FILTER
cmds when a number of vlan interfaces are configured over the device,
as the ndo_ gets called for each vlan interface. To avoid this, we now
use __dev_mc_sync() and __dev_uc_sync() API, but only to detect if there
is a change in the mc/uc lists. Now that we use this API, the code has to
be-designed to issue these API calls for each invocation of the ndo_ call.

Patch 4 replaces polling with sleeping in the FW completion path.
The ndo_set_rx_mode() and ndo_add/del_vxlan_port() calls may be called with
BHs disabled. The driver currently issues the required cmds to the FW in
these contexts and polls on completions from the FW, while BHs remain
disabled.  This can cause either packet loss or packet reception to be
delayed on that CPU.  This patch defers processing of the above cmds to a
separate workqueue. With this change, FW cmds are now issued only in process
context. Now that the FW cmds are issued only in process context, they can
sleep waiting for a completion instead of polling.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The ndo_set_rx_mode() and ndo_add/del_vxlan_port() calls may be called with
BHs disabled. The driver currently issues the required cmds to the FW in
these contexts and polls on completions from the FW, while BHs remain
disabled.  This can cause either packet loss or packet reception to be
delayed on that CPU.

This patch defers processing of the above cmds to a separate workqueue.
With this change, FW cmds are now issued only in process context.
Now that the FW cmds are issued only in process context, they can sleep
waiting for a completion instead of polling. All the spin_lock_bh(mcc_lock)
calls are now replaced with mutex calls.

Also a new rx_filter_lock is now needed to protect the RX filtering fields
like vids[] between be_vlan_add/rem_vid() and __be_set_rx_mode() contexts.
Signed-off-by: Sathya Perla <sathya.perla@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eachtime the ndo_set_rx_mode() routine is called, the driver programs the
multicast list in the adapter without checking if there are any changes to
the list. This leads to a flood of RX_FILTER cmds when a number of vlan
interfaces are configured over the device, as the ndo_ gets
called for each vlan interface. To avoid this, we now use __dev_mc_sync()
and __dev_uc_sync() API, but only to detect if there is a change in the
mc/uc lists. Now that we use this API, the code has to be-designed to
issue these API calls for each invocation of the be_set_rx_mode() call.
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Sathya Perla <sathya.perla@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver currently removes a new vid from the adapter->vids[] array if
be_vid_config() returns an error, which occurs when there is an error in
HW/FW. This is wrong. After the HW/FW error is recovered from, we need the
complete vids[] array to re-program the vlan list.
Signed-off-by: Sathya Perla <sathya.perla@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Lancer FW has a bug due to which in some cases vlan-promisc setting
is cleared eventhough the vlan-list programming did not succeed (via
VLAN_CONFIG) cmd. The driver has no way of knowing if the vlan-promisc
mode was cleared or not when this cmd fails. To work around this issue,
this patch first explicitly clears the vlan-promisc mode via RX_FILTER
cmd and then tries to program the vlan list.
Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Admin should be able to set any state. Currently, this fails
when lladdr is not changed and state is changed from
NUD_CONNECTED to NUD_STALE:

ip neigh add 192.168.8.1 lladdr 00:11:22:33:44:55 nud perm dev wlan0
ip neigh show to 192.168.8.1
192.168.8.1 dev wlan0 lladdr 00:11:22:33:44:55 PERMANENT
ip neigh change 192.168.8.1 lladdr 00:11:22:33:44:55 nud stale dev wlan0
ip neigh show to 192.168.8.1
192.168.8.1 dev wlan0 lladdr 00:11:22:33:44:55 PERMANENT

Problem may be from 2.1.X days.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Reviewed-by: Chunhui He <hchunhui@mail.ustc.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 52253db9 ("sctp: also point GSO head_skb to the sk when
it's available") used event->chunk->head_skb to get the head_skb in
sctp_ulpevent_set_owner().

But at that moment, the event->chunk was NULL, as it cloned the skb
in sctp_ulpevent_make_rcvmsg(). Therefore, that patch didn't really
work.

This patch is to move the event->chunk initialization before calling
sctp_ulpevent_receive_data() so that it uses event->chunk when it's
valid.

Fixes: 52253db9 ("sctp: also point GSO head_skb to the sk when it's available")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan driver has bypass for local vxlan traffic, but that
depends on information about all VNIs on local system in
vxlan driver. This is not available in case of LWT.
Therefore following patch disable encap bypass for LWT
vxlan traffic.

Fixes: ee122c79 ("vxlan: Flow based tunneling").
Reported-by: Jakub Libosvar <jlibosva@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

LWT user can specify destination as well as source ip address
for given tunnel endpoint. But vxlan is ignoring given source
ip address. Following patch uses both ip address to route the
tunnel packet. This consistent with other LWT implementations,
like GENEVE and GRE.

Fixes: ee122c79 ("vxlan: Flow based tunneling").
Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
Few BPF helper related checksum fixes

The set contains three fixes with regards to CHECKSUM_COMPLETE
and BPF helper functions. For details please see individual
patches.

Thanks!

v1 -> v2:
  - Fixed make htmldocs issue reported by kbuild bot.
  - Rest as is.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When having skbs on ingress with CHECKSUM_COMPLETE, tc BPF programs don't
push rcsum of mac header back in and after BPF run back pull out again as
opposed to some other subsystems (ovs, for example).

For cases like q-in-q, meaning when a vlan tag for offloading is already
present and we're about to push another one, then skb_vlan_push() pushes the
inner one into the skb, increasing mac header and skb_postpush_rcsum()'ing
the 4 bytes vlan header diff. Likewise, for the reverse operation in
skb_vlan_pop() for the case where vlan header needs to be pulled out of the
skb, we're decreasing the mac header and skb_postpull_rcsum()'ing the 4 bytes
rcsum of the vlan header that was removed.

However mangling the rcsum here will lead to hw csum failure for BPF case,
since we're pulling or pushing data that was not part of the current rcsum.
Changing tc BPF programs in general to push/pull rcsum around BPF_PROG_RUN()
is also not really an option since current behaviour is ABI by now, but apart
from that would also mean to do quite a bit of useless work in the sense that
usually 12 bytes need to be rcsum pushed/pulled also when we don't need to
touch this vlan related corner case. One way to fix it would be to push the
necessary rcsum fixup down into vlan helpers that are (mostly) slow-path
anyway.

Fixes: 4e10df9a ("bpf: introduce bpf_skb_vlan_push/pop() helpers")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

bpf_skb_store_bytes() invocations above L2 header need BPF_F_RECOMPUTE_CSUM
flag for updates, so that CHECKSUM_COMPLETE will be fixed up along the way.
Where we ran into an issue with bpf_skb_store_bytes() is when we did a
single-byte update on the IPv6 hoplimit despite using BPF_F_RECOMPUTE_CSUM
flag; simple ping via ICMPv6 triggered a hw csum failure as a result. The
underlying issue has been tracked down to a buffer alignment issue.

Meaning, that csum_partial() computations via skb_postpull_rcsum() and
skb_postpush_rcsum() pair invoked had a wrong result since they operated on
an odd address for the hoplimit, while other computations were done on an
even address. This mix doesn't work as-is with skb_postpull_rcsum(),
skb_postpush_rcsum() pair as it always expects at least half-word alignment
of input buffers, which is normally the case. Thus, instead of these helpers
using csum_sub() and (implicitly) csum_add(), we need to use csum_block_sub(),
csum_block_add(), respectively. For unaligned offsets, they rotate the sum
to align it to a half-word boundary again, otherwise they work the same as
csum_sub() and csum_add().

Adding __skb_postpull_rcsum(), __skb_postpush_rcsum() variants that take the
offset as an input and adapting bpf_skb_store_bytes() to them fixes the hw
csum failures again. The skb_postpull_rcsum(), skb_postpush_rcsum() helpers
use a 0 constant for offset so that the compiler optimizes the offset & 1
test away and generates the same code as with csum_sub()/_add().

Fixes: 608cd71a ("tc: bpf: generalize pedit action")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Follow-up to commit f8ffad69 ("bpf: add skb_postpush_rcsum and fix
dev_forward_skb occasions") to fix an issue for dev_queue_xmit() redirect
locations which need CHECKSUM_COMPLETE fixups on ingress.

For the same reasons as described in f8ffad69 already, we of course
also need this here, since dev_queue_xmit() on a veth device will let us
end up in the dev_forward_skb() helper again to cross namespaces.

Latter then calls into skb_postpull_rcsum() to pull out L2 header, so
that netif_rx_internal() sees CHECKSUM_COMPLETE as it is expected. That
is, CHECKSUM_COMPLETE on ingress covering L2 _payload_, not L2 headers.

Also here we have to address bpf_redirect() and bpf_clone_redirect().

Fixes: 3896d655 ("bpf: introduce bpf_clone_redirect() helper")
Fixes: 27b29f63 ("bpf: add bpf_redirect() helper")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The call site for this function appears as:

  #ifdef DEBUG
        data->msg_enable = DEBUG;
        dump_eth_one(dev);
  #endif

...leading to the following warning for !DEBUG builds:

drivers/net/ethernet/tundra/tsi108_eth.c:169:13: warning: 'dump_eth_one' defined but not used [-Wunused-function]
 static void dump_eth_one(struct net_device *dev)
             ^

...when using the arch/powerpc/configs/mpc7448_hpc2_defconfig

Put the function definition under the same #ifdef as the call site
to avoid the warning.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: DCB fixes

Patches 1 and 2 fix a problem in which PAUSE frames settings are wrongly
overridden when ieee_setpfc() gets called.

Patch 3 adds a missing rollback in port's creation error path.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

We correctly execute mlxsw_sp_port_dcb_fini() when port is removed, but
I missed its rollback in the error path of port creation, so add it.

Fixes: f00817df ("mlxsw: spectrum: Introduce support for Data Center Bridging (DCB)")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The PFCC register is used to configure both PAUSE and PFC frames.
Therefore, when PFC frames are disabled we must make sure we don't
mistakenly also disable PAUSE frames (which might be enabled).

Fix this by packing the PFCC register with the current PAUSE settings.

Note that this register is also accessed via ethtool ops, but there we
are guaranteed to have PFC disabled.

Fixes: d81a6bdb ("mlxsw: spectrum: Add IEEE 802.1Qbb PFC support")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When ieee_setpfc() gets called, PAUSE frames are not necessarily
disabled on the port.

Check if PAUSE frames are disabled or enabled and configure the port's
headroom buffer accordingly.

Fixes: d81a6bdb ("mlxsw: spectrum: Add IEEE 802.1Qbb PFC support")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Looks like a simple copy'n'paste error.

Fixes: 1aa661f5 ("rhashtable-test: Measure time to insert, remove & traverse entries")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

Phil Sutter says:

====================
sctp_diag: A bunch of fixes for upcoming 'ss' support

The following series contains a number of fixes necessary to make my yet
unpublished 'ss' support patch functional.

Changes since v1:
- Fixed patch 2/3
- Rebased whole series onto current net-next/master

Changes since v2:
- Improved description of patch 2/3
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Since 'ss' always adds TCPF_CLOSE to idiag_states flags, sctp_diag can't
rely upon TCPF_LISTEN flag solely being present when listening sockets
are requested.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

The asoc's timer value is not kept in asoc->timeouts array but in it's
primary transport instead.

Furthermore, we must export the timer only if it is pending, otherwise
the value will underrun when stored in an unsigned variable and
user space will only see a very large timeout value.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is required to correctly interpret INET_DIAG_INFO messages exported
by sctp_diag module.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

USRIO and JUMBO CAPS have the same mask.
Fix the same.

Fixes: ce721a70 ("net: ethernet: cadence-macb: Add disabled usrio caps")
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Harini Katakam <harinik@xilinx.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'mac80211-for-davem-2016-08-05' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
First set of fixes for the current cycle:
 * fix 80+80 bandwidth warning
 * fix powersave with mac80211 TXQ implementation
 * use correct way to free SKBs from multicast buffering
 * mesh: fix operation ordering to work with all drivers
 * mesh: end service period even when peer goes away
 * mesh: correct HT opmode validity checks
 * pass hw pointer from mac80211 to driver in TPT method,
   fixing a bug (in a bit the wrong way, but that's what
   we have right now)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

increase test coverage to check previously missing 'update when full'
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The introduction of pre-allocated hash elements inadvertently broke
the behavior of bpf hash maps where users expected to call
bpf_map_update_elem() without considering that the map can be full.
Some programs do:
old_value = bpf_map_lookup_elem(map, key);
if (old_value) {
  ... prepare new_value on stack ...
  bpf_map_update_elem(map, key, new_value);
}
Before pre-alloc the update() for existing element would work even
in 'map full' condition. Restore this behavior.

The above program could have updated old_value in place instead of
update() which would be faster and most programs use that approach,
but sometimes the values are large and the programs use update()
helper to do atomic replacement of the element.
Note we cannot simply update element's value in-place like percpu
hash map does and have to allocate extra num_possible_cpu elements
and use this extra reserve when the map is full.

Fixes: 6c905981 ("bpf: pre-allocate hash map elements")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

On 32-bit (e.g. with m68k-linux-gnu-gcc-4.1):

    drivers/net/dsa/b53/b53_common.c: In function ‘b53_arl_read’:
    drivers/net/dsa/b53/b53_common.c:1072: warning: integer constant is too large for ‘long’ type

Fixes: 1da6df85 ("net: dsa: b53: Implement ARL add/del/dump operations")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Panic occurs when issuing "cat /proc/net/route" whilst
populating FIB with > 1M routes.

Use of cached node pointer in fib_route_get_idx is unsafe.

 BUG: unable to handle kernel paging request at ffffc90001630024
 IP: [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
 PGD 11b08d067 PUD 11b08e067 PMD dac4b067 PTE 0
 Oops: 0000 [#1] SMP
 Modules linked in: nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscac
 snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep virti
 acpi_cpufreq button parport_pc ppdev lp parport autofs4 ext4 crc16 mbcache jbd
tio_ring virtio floppy uhci_hcd ehci_hcd usbcore usb_common libata scsi_mod
 CPU: 1 PID: 785 Comm: cat Not tainted 4.2.0-rc8+ #4
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
 task: ffff8800da1c0bc0 ti: ffff88011a05c000 task.ti: ffff88011a05c000
 RIP: 0010:[<ffffffff814cf6a0>]  [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
 RSP: 0018:ffff88011a05fda0  EFLAGS: 00010202
 RAX: ffff8800d8a40c00 RBX: ffff8800da4af940 RCX: ffff88011a05ff20
 RDX: ffffc90001630020 RSI: 0000000001013531 RDI: ffff8800da4af950
 RBP: 0000000000000000 R08: ffff8800da1f9a00 R09: 0000000000000000
 R10: ffff8800db45b7e4 R11: 0000000000000246 R12: ffff8800da4af950
 R13: ffff8800d97a74c0 R14: 0000000000000000 R15: ffff8800d97a7480
 FS:  00007fd3970e0700(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffffc90001630024 CR3: 000000011a7e4000 CR4: 00000000000006e0
 Stack:
  ffffffff814d00d3 0000000000000000 ffff88011a05ff20 ffff8800da1f9a00
  ffffffff811dd8b9 0000000000000800 0000000000020000 00007fd396f35000
  ffffffff811f8714 0000000000003431 ffffffff8138dce0 0000000000000f80
 Call Trace:
  [<ffffffff814d00d3>] ? fib_route_seq_start+0x93/0xc0
  [<ffffffff811dd8b9>] ? seq_read+0x149/0x380
  [<ffffffff811f8714>] ? fsnotify+0x3b4/0x500
  [<ffffffff8138dce0>] ? process_echoes+0x70/0x70
  [<ffffffff8121cfa7>] ? proc_reg_read+0x47/0x70
  [<ffffffff811bb823>] ? __vfs_read+0x23/0xd0
  [<ffffffff811bbd42>] ? rw_verify_area+0x52/0xf0
  [<ffffffff811bbe61>] ? vfs_read+0x81/0x120
  [<ffffffff811bcbc2>] ? SyS_read+0x42/0xa0
  [<ffffffff81549ab2>] ? entry_SYSCALL_64_fastpath+0x16/0x75
 Code: 48 85 c0 75 d8 f3 c3 31 c0 c3 f3 c3 66 66 66 66 66 66 2e 0f 1f 84 00 00
a 04 89 f0 33 02 44 89 c9 48 d3 e8 0f b6 4a 05 49 89
 RIP  [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0
  RSP <ffff88011a05fda0>
 CR2: ffffc90001630024
Signed-off-by: Dave Forster <dforster@brocade.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Inside the kafs filesystem it is possible to occasionally have a call
processed and terminated before we've had a chance to check whether we need
to clean up the rx queue for that call because afs_send_simple_reply() ends
the call when it is done, but this is done in a workqueue item that might
happen to run to completion before afs_deliver_to_call() completes.

Further, it is possible for rxrpc_kernel_send_data() to be called to send a
reply before the last request-phase data skb is released.  The rxrpc skb
destructor is where the ACK processing is done and the call state is
advanced upon release of the last skb.  ACK generation is also deferred to
a work item because it's possible that the skb destructor is not called in
a context where kernel_sendmsg() can be invoked.

To this end, the following changes are made:

 (1) kernel_rxrpc_data_consumed() is added.  This should be called whenever
     an skb is emptied so as to crank the ACK and call states.  This does
     not release the skb, however.  kernel_rxrpc_free_skb() must now be
     called to achieve that.  These together replace
     rxrpc_kernel_data_delivered().

 (2) kernel_rxrpc_data_consumed() is wrapped by afs_data_consumed().

     This makes afs_deliver_to_call() easier to work as the skb can simply
     be discarded unconditionally here without trying to work out what the
     return value of the ->deliver() function means.

     The ->deliver() functions can, via afs_data_complete(),
     afs_transfer_reply() and afs_extract_data() mark that an skb has been
     consumed (thereby cranking the state) without the need to
     conditionally free the skb to make sure the state is correct on an
     incoming call for when the call processor tries to send the reply.

 (3) rxrpc_recvmsg() now has to call kernel_rxrpc_data_consumed() when it
     has finished with a packet and MSG_PEEK isn't set.

 (4) rxrpc_packet_destructor() no longer calls rxrpc_hard_ACK_data().

     Because of this, we no longer need to clear the destructor and put the
     call before we free the skb in cases where we don't want the ACK/call
     state to be cranked.

 (5) The ->deliver() call-type callbacks are made to return -EAGAIN rather
     than 0 if they expect more data (afs_extract_data() returns -EAGAIN to
     the delivery function already), and the caller is now responsible for
     producing an abort if that was the last packet.

 (6) There are many bits of unmarshalling code where:

 		ret = afs_extract_data(call, skb, last, ...);
		switch (ret) {
		case 0:		break;
		case -EAGAIN:	return 0;
		default:	return ret;
		}

     is to be found.  As -EAGAIN can now be passed back to the caller, we
     now just return if ret < 0:

 		ret = afs_extract_data(call, skb, last, ...);
		if (ret < 0)
			return ret;

 (7) Checks for trailing data and empty final data packets has been
     consolidated as afs_data_complete().  So:

		if (skb->len > 0)
			return -EBADMSG;
		if (!last)
			return 0;

     becomes:

		ret = afs_data_complete(call, skb, last);
		if (ret < 0)
			return ret;

 (8) afs_transfer_reply() now checks the amount of data it has against the
     amount of data desired and the amount of data in the skb and returns
     an error to induce an abort if we don't get exactly what we want.

Without these changes, the following oops can occasionally be observed,
particularly if some printks are inserted into the delivery path:

general protection fault: 0000 [#1] SMP
Modules linked in: kafs(E) af_rxrpc(E) [last unloaded: af_rxrpc]
CPU: 0 PID: 1305 Comm: kworker/u8:3 Tainted: G            E   4.7.0-fsdevel+ #1303
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Workqueue: kafsd afs_async_workfn [kafs]
task: ffff88040be041c0 ti: ffff88040c070000 task.ti: ffff88040c070000
RIP: 0010:[<ffffffff8108fd3c>]  [<ffffffff8108fd3c>] __lock_acquire+0xcf/0x15a1
RSP: 0018:ffff88040c073bc0  EFLAGS: 00010002
RAX: 6b6b6b6b6b6b6b6b RBX: 0000000000000000 RCX: ffff88040d29a710
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88040d29a710
RBP: ffff88040c073c70 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88040be041c0 R15: ffffffff814c928f
FS:  0000000000000000(0000) GS:ffff88041fa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa4595f4750 CR3: 0000000001c14000 CR4: 00000000001406f0
Stack:
 0000000000000006 000000000be04930 0000000000000000 ffff880400000000
 ffff880400000000 ffffffff8108f847 ffff88040be041c0 ffffffff81050446
 ffff8803fc08a920 ffff8803fc08a958 ffff88040be041c0 ffff88040c073c38
Call Trace:
 [<ffffffff8108f847>] ? mark_held_locks+0x5e/0x74
 [<ffffffff81050446>] ? __local_bh_enable_ip+0x9b/0xa1
 [<ffffffff8108f9ca>] ? trace_hardirqs_on_caller+0x16d/0x189
 [<ffffffff810915f4>] lock_acquire+0x122/0x1b6
 [<ffffffff810915f4>] ? lock_acquire+0x122/0x1b6
 [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61
 [<ffffffff81609dbf>] _raw_spin_lock_irqsave+0x35/0x49
 [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61
 [<ffffffff814c928f>] skb_dequeue+0x18/0x61
 [<ffffffffa009aa92>] afs_deliver_to_call+0x344/0x39d [kafs]
 [<ffffffffa009ab37>] afs_process_async_call+0x4c/0xd5 [kafs]
 [<ffffffffa0099e9c>] afs_async_workfn+0xe/0x10 [kafs]
 [<ffffffff81063a3a>] process_one_work+0x29d/0x57c
 [<ffffffff81064ac2>] worker_thread+0x24a/0x385
 [<ffffffff81064878>] ? rescuer_thread+0x2d0/0x2d0
 [<ffffffff810696f5>] kthread+0xf3/0xfb
 [<ffffffff8160a6ff>] ret_from_fork+0x1f/0x40
 [<ffffffff81069602>] ? kthread_create_on_node+0x1cf/0x1cf
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>