The IFLA_XDP_ATTACHED nested attribute is meant for read-only, and while
do_setlink properly ignores it, it should be more paranoid and reject
commands that try to set it.
Signed-off-by: NBrenden Blanco <bblanco@plumgrid.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sets the bpf program represented by fd as an early filter in the rx path
of the netdev. The fd must have been created as BPF_PROG_TYPE_XDP.
Providing a negative value as fd clears the program. Getting the fd back
via rtnl is not possible, therefore reading of this value merely
provides a bool whether the program is valid on the link or not.
Signed-off-by: NBrenden Blanco <bblanco@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add one new netdev op for drivers implementing the BPF_PROG_TYPE_XDP
filter. The single op is used for both setup/query of the xdp program,
modelled after ndo_setup_tc.
Signed-off-by: NBrenden Blanco <bblanco@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a new bpf prog type that is intended to run in early stages of the
packet rx path. Only minimal packet metadata will be available, hence a
new context type, struct xdp_md, is exposed to userspace. So far only
expose the packet start and end pointers, and only in read mode.

An XDP program must return one of the well known enum values, all other
return codes are reserved for future use. Unfortunately, this
restriction is hard to enforce at verification time, so take the
approach of warning at runtime when such programs are encountered. Out
of bounds return codes should alias to XDP_ABORTED.
Signed-off-by: NBrenden Blanco <bblanco@plumgrid.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work addresses a couple of issues bpf_skb_event_output()
helper currently has: i) We need two copies instead of just a
single one for the skb data when it should be part of a sample.
The data can be non-linear and thus needs to be extracted via
bpf_skb_load_bytes() helper first, and then copied once again
into the ring buffer slot. ii) Since bpf_skb_load_bytes()
currently needs to be used first, the helper needs to see a
constant size on the passed stack buffer to make sure BPF
verifier can do sanity checks on it during verification time.
Thus, just passing skb->len (or any other non-constant value)
wouldn't work, but changing bpf_skb_load_bytes() is also not
the proper solution, since the two copies are generally still
needed. iii) bpf_skb_load_bytes() is just for rather small
buffers like headers, since they need to sit on the limited
BPF stack anyway. Instead of working around in bpf_skb_load_bytes(),
this work improves the bpf_skb_event_output() helper to address
all 3 at once.

We can make use of the passed in skb context that we have in
the helper anyway, and use some of the reserved flag bits as
a length argument. The helper will use the new __output_custom()
facility from perf side with bpf_skb_copy() as callback helper
to walk and extract the data. It will pass the data for setup
to bpf_event_output(), which generates and pushes the raw record
with an additional frag part. The linear data used in the first
frag of the record serves as programmatically defined meta data
passed along with the appended sample.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Define a tracepoint and allow user to trace messages going to and from
hardware associated with devlink instance.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

An important information for the napi_poll tracepoint is knowing
the work done (packets processed) by the napi_poll() call. Add
both the work done and budget, as they are related.

Handle trace_napi_poll() param change in dropwatch/drop_monitor
and in python perf script netdev-times.py in backward compat way,
as python fortunately supports optional parameter handling.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the data plane is offloaded the traffic doesn't go through the
networking stack. Therefore, after first resolving a neighbour the NUD
state machine will transition it from REACHABLE to STALE until it's
finally deleted by the garbage collector.

To prevent such situations the offloading driver should notify the NUD
state machine on any neighbours that were recently used. The driver's
polling interval should be set so that the NUD state machine can
function as if the traffic wasn't offloaded.

Currently, there are no in-tree drivers that can report confirmation for
a neighbour, but only 'used' indication. Therefore, the polling interval
should be set according to DELAY_FIRST_PROBE_TIME, as a neighbour will
transition from REACHABLE state to DELAY (instead of STALE) if "a packet
was sent within the last DELAY_FIRST_PROBE_TIME seconds" (RFC 4861).

Send a netevent whenever the DELAY_FIRST_PROBE_TIME changes - either via
netlink or sysctl - so that offloading drivers can correctly set their
polling interval.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

L2 upper device needs to propagate neigh_construct/destroy calls down to
lower devices. Do this by defining default ndo functions and use them in
team, bond, bridge and vlan.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As the following patch will allow upper devices to follow the call down
lower devices, we need to add dev here and not rely on n->dev.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add functions that iterate over lower devices and find port device.
As a dependency add netdev_for_each_all_lower_dev and
netdev_for_each_all_lower_dev_rcu macro with
netdev_all_lower_get_next and netdev_all_lower_get_next_rcu shelpers.

Also, add functions to return mlxsw struct according to lower device
found and mlxsw_port struct with a reference to lower device.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If skb_clear_hash() was invoked due to mangling of relevant headers and
BPF program needs skb->hash later on, we can add a helper to trigger hash
recalculation via bpf_get_hash_recalc().

The helper will return the newly retrieved hash directly, but later access
can also be done via skb context again through skb->hash directly (inline)
without needing to call the helper once more.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add another xmit_mode to pktgen to allow testing xmit functionality
of qdiscs. The new mode "queue_xmit" injects packets at
__dev_queue_xmit() so that qdisc is called.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the commands to set and show the mode of SRIOV E-Switch, two modes
are supported:

* legacy: operating in the "old" L2 based mode (DMAC --> VF vport)

* switchdev: the E-Switch is referred to as whitebox switch configured
using standard tools such as tc, bridge, openvswitch etc. To allow
working with the tools, for each VF, a VF representor netdevice is
created by the E-Switch manager vendor device driver instance (e.g PF).
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adds a bpf helper, bpf_skb_in_cgroup, to decide if a skb->sk
belongs to a descendant of a cgroup2.  It is similar to the
feature added in netfilter:
commit c38c4597 ("netfilter: implement xt_cgroup cgroup2 path match")

The user is expected to populate a BPF_MAP_TYPE_CGROUP_ARRAY
which will be used by the bpf_skb_in_cgroup.

Modifications to the bpf verifier is to ensure BPF_MAP_TYPE_CGROUP_ARRAY
and bpf_skb_in_cgroup() are always used together.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to commit 9b368814 ("net: fix bridge multicast packet checksum validation")
we need to fixup the checksum for CHECKSUM_COMPLETE when
pushing skb on RX path. Otherwise we get similar splats.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

People who use PACKET_FANOUT_HASH want a symmetric hash, meaning that
they want packets going in both directions on a flow to hash to the
same bucket.

The core kernel SKB hash became non-symmetric when the ipv6 flow label
and other entities were incorporated into the standard flow hash order
to increase entropy.

But there are no users of PACKET_FANOUT_HASH who want an assymetric
hash, they all want a symmetric one.

Therefore, use the flow dissector to compute a flat symmetric hash
over only the protocol, addresses and ports.  This hash does not get
installed into and override the normal skb hash, so this change has
no effect whatsoever on the rest of the stack.
Reported-by: NEric Leblond <eric@regit.org>
Tested-by: NEric Leblond <eric@regit.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since bpf_prog_get() and program type check is used in a couple of places,
refactor this into a small helper function that we can make use of. Since
the non RO prog->aux part is not used in performance critical paths and a
program destruction via RCU is rather very unlikley when doing the put, we
shouldn't have an issue just doing the bpf_prog_get() + prog->type != type
check, but actually not taking the ref at all (due to being in fdget() /
fdput() section of the bpf fd) is even cleaner and makes the diff smaller
as well, so just go for that. Callsites are changed to make use of the new
helper where possible.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces a new event - NETDEV_CHANGE_TX_QUEUE_LEN, this
will be triggered when tx_queue_len. It could be used by net device
who want to do some processing at that time. An example is tun who may
want to resize tx array when tx_queue_len is changed.

Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When adding rule with NLM_F_EXCL flag then check if the same rule exist.
If yes then exit with -EEXIST.

This is already implemented in iproute2:
        if (cmd == RTM_NEWRULE) {
                req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;
                req.r.rtm_type = RTN_UNICAST;
        }

Tested ipv4 and ipv6 with net-next linux on qemu x86

expected behavior after patch:
localhost ~ # ip rule
0:    from all lookup local
32766:    from all lookup main
32767:    from all lookup default
localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005
localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005
RTNETLINK answers: File exists
localhost ~ # ip rule
0:    from all lookup local
1005:    from 10.46.177.97 lookup 104
32766:    from all lookup main
32767:    from all lookup default

There was already topic regarding this but I don't see any changes
merged and problem still occurs.
https://lkml.kernel.org/r/1135778809.5944.7.camel+%28%29+localhost+%21+localdomainSigned-off-by: NMateusz Bajorski <mateusz.bajorski@nokia.com>
Acked-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for the IFLA_STATS_LINK_XSTATS_SLAVE attribute
which allows to export per-slave statistics if the master device supports
the linkxstats callback. The attribute is passed down to the linkxstats
callback and it is up to the callback user to use it (an example has been
added to the only current user - the bridge). This allows us to query only
specific slaves of master devices like bridge ports and export only what
we're interested in instead of having to dump all ports and searching only
for a single one. This will be used to export per-port IGMP/MLD stats and
also per-port vlan stats in the future, possibly other statistics as well.
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work adds a helper for changing skb->pkt_type in a controlled way.
We only allow a subset of possible values and can extend that in future
should other use cases come up. Doing this as a helper has the advantage
that errors can be handeled gracefully and thus helper kept extensible.

It's a write counterpart to pkt_type member we can already read from
struct __sk_buff context. Major use case is to change incoming skbs to
PACKET_HOST in a programmatic way instead of having to recirculate via
redirect(..., BPF_F_INGRESS), for example.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a minimal helper for doing the groundwork of changing
the skb->protocol in a controlled way. Currently supported is v4 to
v6 and vice versa transitions, which allows f.e. for a minimal, static
nat64 implementation where applications in containers that still
require IPv4 can be transparently operated in an IPv6-only environment.
For example, host facing veth of the container can transparently do
the transitions in a programmatic way with the help of clsact qdisc
and cls_bpf.

Idea is to separate concerns for keeping complexity of the helper
lower, which means that the programs utilize bpf_skb_change_proto(),
bpf_skb_store_bytes() and bpf_lX_csum_replace() to get the job done,
instead of doing everything in a single helper (and thus partially
duplicating helper functionality). Also, bpf_skb_change_proto()
shouldn't need to deal with raw packet data as this is done by other
helpers.

bpf_skb_proto_6_to_4() and bpf_skb_proto_4_to_6() unclone the skb to
operate on a private one, push or pop additionally required header
space and migrate the gso/gro meta data from the shared info. We do
mark the gso type as dodgy so that headers are checked and segs
recalculated by the gso/gro engine. The gso_size target is adapted
as well. The flags argument added is currently reserved and can be
used for future extensions.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use smp_processor_id() for the generic helper bpf_get_smp_processor_id()
instead of the raw variant. This allows for preemption checks when we
have DEBUG_PREEMPT, and otherwise uses the raw variant anyway. We only
need to keep the raw variant for socket filters, but we can reuse the
helper that is already there from cBPF side.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

neigh_xmit() expects to be called inside an RCU-bh read side critical
section, and while one of its two current callers gets this right, the
other one doesn't.

More specifically, neigh_xmit() has two callers, mpls_forward() and
mpls_output(), and while both callers call neigh_xmit() under
rcu_read_lock(), this provides sufficient protection for neigh_xmit()
only in the case of mpls_forward(), as that is always called from
softirq context and therefore doesn't need explicit BH protection,
while mpls_output() can be called from process context with softirqs
enabled.

When mpls_output() is called from process context, with softirqs
enabled, we can be preempted by a softirq at any time, and RCU-bh
considers the completion of a softirq as signaling the end of any
pending read-side critical sections, so if we do get a softirq
while we are in the part of neigh_xmit() that expects to be run inside
an RCU-bh read side critical section, we can end up with an unexpected
RCU grace period running right in the middle of that critical section,
making things go boom.

This patch fixes this impedance mismatch in the callee, by making
neigh_xmit() always take rcu_read_{,un}lock_bh() around the code that
expects to be treated as an RCU-bh read side critical section, as this
seems a safer option than fixing it in the callers.

Fixes: 4fd3d7d9 ("neigh: Add helper function neigh_xmit")
Signed-off-by: NDavid Barroso <dbarroso@fastly.com>
Signed-off-by: NLennert Buytenhek <lbuytenhek@fastly.com>
Acked-by: NDavid Ahern <dsa@cumulusnetworks.com>
Acked-by: NRobert Shearman <rshearma@brocade.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The space is missing before the open parenthesis '(', and this
will introduce much more noise when checking patch around.
Signed-off-by: NWei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Qdisc performance suffers when packets are dropped at enqueue()
time because drops (kfree_skb()) are done while qdisc lock is held,
delaying a dequeue() draining the queue.

Nominal throughput can be reduced by 50 % when this happens,
at a time we would like the dequeue() to proceed as fast as possible.

Even FQ is vulnerable to this problem, while one of FQ goals was
to provide some flow isolation.

This patch adds a 'struct sk_buff **to_free' parameter to all
qdisc->enqueue(), and in qdisc_drop() helper.

I measured a performance increase of up to 12 %, but this patch
is a prereq so that future batches in enqueue() can fly.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The space is missing after ',', and this will introduce much more
noise when checking patch around.
Signed-off-by: NWei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes the checkpatch.pl error to dev.c:

ERROR: do not initialise statics to 0
Signed-off-by: NWei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ctx structure passed into bpf programs is different depending on bpf
program type. The verifier incorrectly marked ctx->data and ctx->data_end
access based on ctx offset only. That caused loads in tracing programs
int bpf_prog(struct pt_regs *ctx) { .. ctx->ax .. }
to be incorrectly marked as PTR_TO_PACKET which later caused verifier
to reject the program that was actually valid in tracing context.
Fix this by doing program type specific matching of ctx offsets.

Fixes: 969bf05e ("bpf: direct packet access")
Reported-by: NSasha Goldshtein <goldshtn@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qdisc are changed under RTNL protection and often
while blocking BH and root qdisc spinlock.

When lots of skbs need to be dropped, we free
them under these locks causing TX/RX freezes,
and more generally latency spikes.

This commit adds rtnl_kfree_skbs(), used to queue
skbs for deferred freeing.

Actual freeing happens right after RTNL is released,
with appropriate scheduling points.

rtnl_qdisc_drop() can also be used in place
of disc_drop() when RTNL is held.

qdisc_reset_queue() and __qdisc_reset_queue() get
the new behavior, so standard qdiscs like pfifo, pfifo_fast...
have their ->reset() method automatically handled.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sch_atm returns this when TC_ACT_SHOT classification occurs.

But all other schedulers that use tc_classify
(htb, hfsc, drr, fq_codel ...) return NET_XMIT_SUCCESS | __BYPASS
in this case so just do that in atm.

BATMAN uses it as an intermediate return value to signal
forwarding vs. buffering, but it did not return POLICED to
callers outside of BATMAN.
Reviewed-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a bpf_check_basics_ok() and reject filters that are of invalid
size much earlier, so we don't do any useless work such as invoking
bpf_prog_alloc(). Currently, rejection happens in bpf_check_classic()
only, but it's really unnecessarily late and they should be rejected
at earliest point. While at it, also clean up one bpf_prog_size() to
make it consistent with the remaining invocations.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Respect the stack's xmit_recursion limit for calls into dev_queue_xmit().
Currently, they are not handeled by the limiter when attached to clsact's
egress parent, for example, and a buggy program redirecting it to the
same device again could run into stack overflow eventually. It would be
good if we could notify an admin to give him a chance to react. We reuse
xmit_recursion instead of having one private to eBPF, so that the stack's
current recursion depth will be taken into account as well. Follow-up to
commit 3896d655 ("bpf: introduce bpf_clone_redirect() helper") and
27b29f63 ("bpf: add bpf_redirect() helper").
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, VRFs require 1 oif and 1 iif rule per address family per
VRF. As the number of VRF devices increases it brings scalability
issues with the increasing rule list. All of the VRF rules have the
same format with the exception of the specific table id to direct the
lookup. Since the table id is available from the oif or iif in the
loopup, the VRF rules can be consolidated to a single rule that pulls
the table from the VRF device.

This patch introduces a new rule attribute l3mdev. The l3mdev rule
means the table id used for the lookup is pulled from the L3 master
device (e.g., VRF) rather than being statically defined. With the
l3mdev rule all of the basic VRF FIB rules are reduced to 1 l3mdev
rule per address family (IPv4 and IPv6).

If an admin wishes to insert higher priority rules for specific VRFs
those rules will co-exist with the l3mdev rule. This capability means
current VRF scripts will co-exist with this new simpler implementation.

Currently, the rules list for both ipv4 and ipv6 look like this:
    $ ip  ru ls
    1000:       from all oif vrf1 lookup 1001
    1000:       from all iif vrf1 lookup 1001
    1000:       from all oif vrf2 lookup 1002
    1000:       from all iif vrf2 lookup 1002
    1000:       from all oif vrf3 lookup 1003
    1000:       from all iif vrf3 lookup 1003
    1000:       from all oif vrf4 lookup 1004
    1000:       from all iif vrf4 lookup 1004
    1000:       from all oif vrf5 lookup 1005
    1000:       from all iif vrf5 lookup 1005
    1000:       from all oif vrf6 lookup 1006
    1000:       from all iif vrf6 lookup 1006
    1000:       from all oif vrf7 lookup 1007
    1000:       from all iif vrf7 lookup 1007
    1000:       from all oif vrf8 lookup 1008
    1000:       from all iif vrf8 lookup 1008
    ...
    32765:      from all lookup local
    32766:      from all lookup main
    32767:      from all lookup default

With the l3mdev rule the list is just the following regardless of the
number of VRFs:
    $ ip ru ls
    1000:       from all lookup [l3mdev table]
    32765:      from all lookup local
    32766:      from all lookup main
    32767:      from all lookup default

(Note: the above pretty print of the rule is based on an iproute2
       prototype. Actual verbage may change)
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

"make htmldocs" complains otherwise:

.//net/core/gen_stats.c:168: warning: No description found for parameter 'running'
.//include/linux/netdevice.h:1867: warning: No description found for parameter 'qdisc_running_key'

Fixes: f9eb8aea ("net_sched: transform qdisc running bit into a seqcount")
Fixes: edb09eb1 ("net: sched: do not acquire qdisc spinlock in qdisc/class stats dump")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

"make htmldocs" complains otherwise:

.//net/core/gen_stats.c:65: warning: No description found for parameter 'padattr'
.//net/core/gen_stats.c:101: warning: No description found for parameter 'padattr'

Fixes: 9854518e ("sched: align nlattr properly when needed")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When in kdump kernel, reduce memory usage by only using a single Queue
Set for multiqueue devices. So make netif_get_num_default_rss_queues()
return one, when in kdump kernel.
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The of_find_net_device_by_node() function is defined in
<linux/of_net.h> but not included in the .c file that
implements it. Fix the following warning by including the
header:

net/core/net-sysfs.c:1494:19: warning: symbol 'of_find_net_device_by_node' was not declared. Should it be static?
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Large tc dumps (tc -s {qdisc|class} sh dev ethX) done by Google BwE host
agent [1] are problematic at scale :

For each qdisc/class found in the dump, we currently lock the root qdisc
spinlock in order to get stats. Sampling stats every 5 seconds from
thousands of HTB classes is a challenge when the root qdisc spinlock is
under high pressure. Not only the dumps take time, they also slow
down the fast path (queue/dequeue packets) by 10 % to 20 % in some cases.

An audit of existing qdiscs showed that sch_fq_codel is the only qdisc
that might need the qdisc lock in fq_codel_dump_stats() and
fq_codel_dump_class_stats()

In v2 of this patch, I now use the Qdisc running seqcount to provide
consistent reads of packets/bytes counters, regardless of 32/64 bit arches.

I also changed rate estimators to use the same infrastructure
so that they no longer need to lock root qdisc lock.

[1]
http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdfSigned-off-by: NEric Dumazet <edumazet@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Kevin Athey <kda@google.com>
Cc: Xiaotian Pei <xiaotian@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>