After previous patches to simplify qstats the qstats can be
made per cpu with a packed union in Qdisc struct.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This removes the use of qstats->qlen variable from the classifiers
and makes it an explicit argument to gnet_stats_copy_queue().

The qlen represents the qdisc queue length and is packed into
the qstats at the last moment before passnig to user space. By
handling it explicitely we avoid, in the percpu stats case, having
to figure out which per_cpu variable to put it in.

It would probably be best to remove it from qstats completely
but qstats is a user space ABI and can't be broken. A future
patch could make an internal only qstats structure that would
avoid having to allocate an additional u32 variable on the
Qdisc struct. This would make the qstats struct 128bits instead
of 128+32.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds helpers to manipulate qstats logic and replaces locations
that touch the counters directly. This simplifies future patches
to push qstats onto per cpu counters.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to run qdisc's without locking statistics and estimators
need to be handled correctly.

To resolve bstats make the statistics per cpu. And because this is
only needed for qdiscs that are running without locks which is not
the case for most qdiscs in the near future only create percpu
stats when qdiscs set the TCQ_F_CPUSTATS flag.

Next because estimators use the bstats to calculate packets per
second and bytes per second the estimator code paths are updated
to use the per cpu statistics.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This completes the cls_rsvp conversion to RCU safe
copy, update semantics.

As a result all cases of tcf_exts_change occur on
empty lists now.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Clearly the following change is not expected:

	-       if (!cp.perfect && !cp.h)
	-               cp.alloc_hash = cp.hash;
	+       if (!cp->perfect && cp->h)
	+               cp->alloc_hash = cp->hash;

Fixes: commit 331b7292 ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When kmemdup() fails, we should return -ENOMEM.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

While using a MQ + NETEM setup, I had confirmation that the default
timer migration ( /proc/sys/kernel/timer_migration ) is killing us.

Installing this on a receiver side of a TCP_STREAM test, (NIC has 8 TX
queues) :

EST="est 1sec 4sec"
for ETH in eth1
do
 tc qd del dev $ETH root 2>/dev/null
 tc qd add dev $ETH root handle 1: mq
 tc qd add dev $ETH parent 1:1 $EST netem limit 70000 delay 6ms
 tc qd add dev $ETH parent 1:2 $EST netem limit 70000 delay 8ms
 tc qd add dev $ETH parent 1:3 $EST netem limit 70000 delay 10ms
 tc qd add dev $ETH parent 1:4 $EST netem limit 70000 delay 12ms
 tc qd add dev $ETH parent 1:5 $EST netem limit 70000 delay 14ms
 tc qd add dev $ETH parent 1:6 $EST netem limit 70000 delay 16ms
 tc qd add dev $ETH parent 1:7 $EST netem limit 80000 delay 18ms
 tc qd add dev $ETH parent 1:8 $EST netem limit 90000 delay 20ms
done

We can see that timers get migrated into a single cpu, presumably idle
at the time timers are set up.
Then all qdisc dequeues run from this cpu and huge lock contention
happens. This single cpu is stuck in softirq mode and cannot dequeue
fast enough.

    39.24%  [kernel]          [k] _raw_spin_lock
     2.65%  [kernel]          [k] netem_enqueue
     1.80%  [kernel]          [k] netem_dequeue
     1.63%  [kernel]          [k] copy_user_enhanced_fast_string
     1.45%  [kernel]          [k] _raw_spin_lock_bh

By pinning qdisc timers on the cpu running the qdisc, we respect proper
XPS setting and remove this lock contention.

     5.84%  [kernel]          [k] netem_enqueue
     4.83%  [kernel]          [k] _raw_spin_lock
     2.92%  [kernel]          [k] copy_user_enhanced_fast_string

Current Qdiscs that benefit from this change are :

	netem, cbq, fq, hfsc, tbf, htb.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

$ grep CONFIG_CLS_U32_MARK .config
# CONFIG_CLS_U32_MARK is not set

net/sched/cls_u32.c: In function 'u32_change':
net/sched/cls_u32.c:852:1: warning: label 'errout' defined but not used
[-Wunused-label]
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Changes to the cls_u32 classifier must appear atomic to the
readers. Before this patch if a change is requested for both
the exts and ifindex, first the ifindex is updated then the
exts with tcf_exts_change(). This opens a small window where
a reader can have a exts chain with an incorrect ifindex. This
violates the the RCU semantics.

Here we resolve this by always passing u32_set_parms() a copy
of the tc_u_knode to work on and then inserting it into the hash
table after the updates have been successfully applied.

Tested with the following short script:

#tc filter add dev p3p2 parent 8001:0 protocol ip prio 99 handle 1: \
	       u32 divisor 256

#tc filter add dev p3p2 parent 8001:0 protocol ip prio 99 \
	       u32 link 1: hashkey mask ffffff00 at 12    \
	       match ip src 192.168.8.0/2

#tc filter add dev p3p2 parent 8001:0 protocol ip prio 102    \
	       handle 1::10 u32 classid 1:2 ht 1: 	      \
	       match ip src 192.168.8.0/8 match ip tos 0x0a 1e

#tc filter change dev p3p2 parent 8001:0 protocol ip prio 102 \
		 handle 1::10 u32 classid 1:2 ht 1:        \
		 match ip src 1.1.0.0/8 match ip tos 0x0b 1e

CC: Eric Dumazet <edumazet@google.com>
CC: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes a missed free_percpu in the unwind code path and when
keys are destroyed.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We cannot make struct qdisc_skb_cb bigger without impacting IPoIB,
or increasing skb->cb[] size.

Commit e0f31d84 ("flow_keys: Record IP layer protocol in
skb_flow_dissect()") broke IPoIB.

Only current offender is sch_choke, and this one do not need an
absolutely precise flow key.

If we store 17 bytes of flow key, its more than enough. (Its the actual
size of flow_keys if it was a packed structure, but we might add new
fields at the end of it later)
Signed-off-by: NEric Dumazet <edumazet@google.com>
Fixes: e0f31d84 ("flow_keys: Record IP layer protocol in skb_flow_dissect()")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tc_u32_sel 'sel' in tc_u_knode expects to be the last element in the
structure and pads the structure with tc_u32_key fields for each key.

 kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL)

CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

pfifo_fast and htb use skb lists, without needing their spinlocks.
(They instead use the standard qdisc lock)

We can use __skb_queue_head_init() instead of skb_queue_head_init()
to be consistent.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This ensures the tcf_exts_init() is called for all cases.

Fixes: 952313bd ("net: sched: cls_cgroup use RCU")
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When allocating a new structure we also need to call tcf_exts_init
to initialize exts.

A follow up patch might be in order to remove some of this code
and do tcf_exts_assign(). With this we could remove the
tcf_exts_init/tcf_exts_change pattern for some of the classifiers.
As part of the future tcf_actions RCU series this will need to be
done. For now fix the call here.

Fixes e35a8ee5 ("net: sched: fw use RCU")
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git master
head:   54996b52
commit: c7953ef2 [625/646] net: sched: cls_cgroup use RCU

net/sched/cls_cgroup.c:130 cls_cgroup_change() warn: possible memory leak of 'new'
net/sched/cls_cgroup.c:135 cls_cgroup_change() warn: possible memory leak of 'new'
net/sched/cls_cgroup.c:139 cls_cgroup_change() warn: possible memory leak of 'new'

Fixes: c7953ef2 ("net: sched: cls_cgroup use RCU")
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add missing rcu_assign_pointer and missing  annotation for ht_up
in cls_u32.c

Caught by kbuild bot,

>> net/sched/cls_u32.c:378:36: sparse: incorrect type in initializer (different address spaces)
   net/sched/cls_u32.c:378:36:    expected struct tc_u_hnode *ht
   net/sched/cls_u32.c:378:36:    got struct tc_u_hnode [noderef] <asn:4>*ht_up
>> net/sched/cls_u32.c:610:54: sparse: incorrect type in argument 4 (different address spaces)
   net/sched/cls_u32.c:610:54:    expected struct tc_u_hnode *ht
   net/sched/cls_u32.c:610:54:    got struct tc_u_hnode [noderef] <asn:4>*ht_up
>> net/sched/cls_u32.c:684:18: sparse: incorrect type in assignment (different address spaces)
   net/sched/cls_u32.c:684:18:    expected struct tc_u_hnode [noderef] <asn:4>*ht_up
   net/sched/cls_u32.c:684:18:    got struct tc_u_hnode *[assigned] ht
>> net/sched/cls_u32.c:359:18: sparse: dereference of noderef expression
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

kbuild test robot reported an unused variable cpu in cls_u32.c
after the patch below. This happens when PERF and MARK config
variables are disabled

Fix this is to use separate variables for perf and mark
and define the cpu variable inside the ifdef logic.

Fixes: 459d5f62 ("net: sched: make cls_u32 per cpu")'
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NCong Wang <cwang@twopensource.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes the following crash:

[   42.199159] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[   42.200027] IP: [<ffffffff817e3fc4>] tcindex_set_parms+0x45c/0x526
[   42.200027] PGD d2319067 PUD d4ffe067 PMD 0
[   42.200027] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[   42.200027] CPU: 0 PID: 541 Comm: tc Not tainted 3.17.0-rc4+ #603
[   42.200027] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   42.200027] task: ffff8800d22d2670 ti: ffff8800ce790000 task.ti: ffff8800ce790000
[   42.200027] RIP: 0010:[<ffffffff817e3fc4>]  [<ffffffff817e3fc4>] tcindex_set_parms+0x45c/0x526
[   42.200027] RSP: 0018:ffff8800ce793898  EFLAGS: 00010202
[   42.200027] RAX: 0000000000000001 RBX: ffff8800d1786498 RCX: 0000000000000000
[   42.200027] RDX: ffffffff82114ec8 RSI: ffffffff82114ec8 RDI: ffffffff82114ec8
[   42.200027] RBP: ffff8800ce793958 R08: 00000000000080d0 R09: 0000000000000001
[   42.200027] R10: ffff8800ce7939a0 R11: 0000000000000246 R12: ffff8800d017d238
[   42.200027] R13: 0000000000000018 R14: ffff8800d017c6a0 R15: ffff8800d1786620
[   42.200027] FS:  00007f4e24539740(0000) GS:ffff88011a600000(0000) knlGS:0000000000000000
[   42.200027] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   42.200027] CR2: 0000000000000018 CR3: 00000000cff38000 CR4: 00000000000006f0
[   42.200027] Stack:
[   42.200027]  ffff8800ce0949f0 0000000000000000 0000000200000003 ffff880000000000
[   42.200027]  ffff8800ce7938b8 ffff8800ce7938b8 0000000600000007 0000000000000000
[   42.200027]  ffff8800ce7938d8 ffff8800ce7938d8 0000000600000007 ffff8800ce0949f0
[   42.200027] Call Trace:
[   42.200027]  [<ffffffff817e4169>] tcindex_change+0xdb/0xee
[   42.200027]  [<ffffffff817c16ca>] tc_ctl_tfilter+0x44d/0x63f
[   42.200027]  [<ffffffff8179d161>] rtnetlink_rcv_msg+0x181/0x194
[   42.200027]  [<ffffffff8179cf9d>] ? rtnl_lock+0x17/0x19
[   42.200027]  [<ffffffff8179cfe0>] ? __rtnl_unlock+0x17/0x17
[   42.200027]  [<ffffffff817ee296>] netlink_rcv_skb+0x49/0x8b
[   43.462494]  [<ffffffff8179cfc2>] rtnetlink_rcv+0x23/0x2a
[   43.462494]  [<ffffffff817ec8df>] netlink_unicast+0xc7/0x148
[   43.462494]  [<ffffffff817ed413>] netlink_sendmsg+0x5cb/0x63d
[   43.462494]  [<ffffffff810ad781>] ? mark_lock+0x2e/0x224
[   43.462494]  [<ffffffff817757b8>] __sock_sendmsg_nosec+0x25/0x27
[   43.462494]  [<ffffffff81778165>] sock_sendmsg+0x57/0x71
[   43.462494]  [<ffffffff81152bbd>] ? might_fault+0x57/0xa4
[   43.462494]  [<ffffffff81152c06>] ? might_fault+0xa0/0xa4
[   43.462494]  [<ffffffff81152bbd>] ? might_fault+0x57/0xa4
[   43.462494]  [<ffffffff817838fd>] ? verify_iovec+0x69/0xb7
[   43.462494]  [<ffffffff817784f8>] ___sys_sendmsg+0x21d/0x2bb
[   43.462494]  [<ffffffff81009db3>] ? native_sched_clock+0x35/0x37
[   43.462494]  [<ffffffff8109ab53>] ? sched_clock_local+0x12/0x72
[   43.462494]  [<ffffffff810ad781>] ? mark_lock+0x2e/0x224
[   43.462494]  [<ffffffff8109ada4>] ? sched_clock_cpu+0xa0/0xb9
[   43.462494]  [<ffffffff810aee37>] ? __lock_acquire+0x5fe/0xde4
[   43.462494]  [<ffffffff8119f570>] ? rcu_read_lock_held+0x36/0x38
[   43.462494]  [<ffffffff8119f75a>] ? __fcheck_files.isra.7+0x4b/0x57
[   43.462494]  [<ffffffff8119fbf2>] ? __fget_light+0x30/0x54
[   43.462494]  [<ffffffff81779012>] __sys_sendmsg+0x42/0x60
[   43.462494]  [<ffffffff81779042>] SyS_sendmsg+0x12/0x1c
[   43.462494]  [<ffffffff819d24d2>] system_call_fastpath+0x16/0x1b

'p->h' could be NULL while 'cp->h' is always update to date.

Fixes: commit 331b7292 ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-By: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: commit 331b7292 ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-By: NJohn Fastabend <john.r.fastabend@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: commit 331b7292 ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes the following kernel warning:

[   44.805900] [ INFO: suspicious RCU usage. ]
[   44.808946] 3.17.0-rc4+ #610 Not tainted
[   44.811831] -------------------------------
[   44.814873] net/sched/cls_tcindex.c:84 suspicious rcu_dereference_check() usage!

Fixes: commit 331b7292 ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: commit 331b7292 ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: commit 1f947bf1 ("net: sched: rcu'ify cls_bpf")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes the cls_bpf classifier RCU safe. The tcf_lock
was being used to protect a list of cls_bpf_prog now this list
is RCU safe and updates occur with rcu_replace.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make cls_u32 classifier safe to run without holding lock. This patch
converts statistics that are kept in read section u32_classify into
per cpu counters.

This patch was tested with a tight u32 filter add/delete loop while
generating traffic with pktgen. By running pktgen on vlan devices
created on top of a physical device we can hit the qdisc layer
correctly. For ingress qdisc's a loopback cable was used.

for i in {1..100}; do
        q=`echo $i%8|bc`;
        echo -n "u32 tos: iteration $i on queue $q";
        tc filter add dev p3p2 parent $p prio $i u32 match ip tos 0x10 0xff \
                  action skbedit queue_mapping $q;
        sleep 1;
        tc filter del dev p3p2 prio $i;

        echo -n "u32 tos hash table: iteration $i on queue $q";
        tc filter add dev p3p2 parent $p protocol ip prio $i handle 628: u32 divisor 1
        tc filter add dev p3p2 parent $p protocol ip prio $i u32 \
                match ip protocol 17 0xff link 628: offset at 0 mask 0xf00 shift 6 plus 0
        tc filter add dev p3p2 parent $p protocol ip prio $i u32 \
                ht 628:0 match ip tos 0x10 0xff action skbedit queue_mapping $q
        sleep 2;
        tc filter del dev p3p2 prio $i
        sleep 1;
done
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This uses per cpu counters in cls_u32 in preparation
to convert over to rcu.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make cls_tcindex RCU safe.

This patch addds a new RCU routine rcu_dereference_bh_rtnl() to check
caller either holds the rcu read lock or RTNL. This is needed to
handle the case where tcindex_lookup() is being called in both cases.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RCUify the route classifier. For now however spinlock's are used to
protect fastmap cache.

The issue here is the fastmap may be read by one CPU while the
cache is being updated by another. An array of pointers could be
one possible solution.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RCU'ify fw classifier.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make cgroup classifier safe for RCU.

Also drops the calls in the classify routine that were doing a
rcu_read_lock()/rcu_read_unlock(). If the rcu_read_lock() isn't held
entering this routine we have issues with deleting the classifier
chain so remove the unnecessary rcu_read_lock()/rcu_read_unlock()
pair noting all paths AFAIK hold rcu_read_lock.

If there is a case where classify is called without the rcu read lock
then an rcu splat will occur and we can correct it.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Enable basic classifier for RCU.

Dereferencing tp->root may look a bit strange here but it is needed
by my accounting because it is allocated at init time and needs to
be kfree'd at destroy time. However because it may be referenced in
the classify() path we must wait an RCU grace period before free'ing
it. We use kfree_rcu() and rcu_ APIs to enforce this. This pattern
is used in all the classifiers.

Also the hgenerator can be incremented without concern because it
is always incremented under RTNL.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rcu'ify tcf_proto this allows calling tc_classify() without holding
any locks. Updaters are protected by RTNL.

This patch prepares the core net_sched infrastracture for running
the classifier/action chains without holding the qdisc lock however
it does nothing to ensure cls_xxx and act_xxx types also work without
locking. Additional patches are required to address the fall out.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add __rcu notation to qdisc handling by doing this we can make
smatch output more legible. And anyways some of the cases should
be using rcu_dereference() see qdisc_all_tx_empty(),
qdisc_tx_chainging(), and so on.

Also *wake_queue() API is commonly called from driver timer routines
without rcu lock or rtnl lock. So I added rcu_read_lock() blocks
around netif_wake_subqueue and netif_tx_wake_queue.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes the cls_bpf classifier RCU safe. The tcf_lock
was being used to protect a list of cls_bpf_prog now this list
is RCU safe and updates occur with rcu_replace.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>