Future patches will change the recirc action implementation to not
using recursion. The stack depth detection is no longer necessary.
Signed-off-by: Andy Zhou <az...@nicira.com>
---
datapath/actions.c | 34 ++++++++++------------------------
datapath/datapath.c | 6 +++---
datapath/datapath.h | 4 ++--
datapath/vport.c | 2 +-
4 files changed, 16 insertions(+), 30 deletions(-)
diff --git a/datapath/actions.c b/datapath/actions.c
index b16e0b2..bccf397 100644
--- a/datapath/actions.c
+++ b/datapath/actions.c
@@ -816,7 +816,7 @@ static int execute_recirc(struct datapath *dp, struct
sk_buff *skb,
flow_key_clone(skb, &recirc_key);
flow_key_set_recirc_id(skb, nla_get_u32(a));
- ovs_dp_process_packet(skb, true);
+ ovs_dp_process_packet(skb);
return 0;
}
@@ -904,18 +904,11 @@ static int do_execute_actions(struct datapath *dp, struct
sk_buff *skb,
}
/* We limit the number of times that we pass into execute_actions()
- * to avoid blowing out the stack in the event that we have a loop.
- *
- * Each loop adds some (estimated) cost to the kernel stack.
- * The loop terminates when the max cost is exceeded.
- * */
-#define RECIRC_STACK_COST 1
-#define DEFAULT_STACK_COST 4
-/* Allow up to 4 regular services, and up to 3 recirculations */
-#define MAX_STACK_COST (DEFAULT_STACK_COST * 4 + RECIRC_STACK_COST * 3)
+ * * to avoid blowing out the stack in the event that we have a loop. */
+#define MAX_LOOPS 4
struct loop_counter {
- u8 stack_cost; /* loop stack cost. */
+ u8 count; /* Count. */
bool looping; /* Loop detected? */
};
@@ -924,24 +917,22 @@ static DEFINE_PER_CPU(struct loop_counter, loop_counters);
static int loop_suppress(struct datapath *dp, struct sw_flow_actions *actions)
{
if (net_ratelimit())
- pr_warn("%s: flow loop detected, dropping\n",
- ovs_dp_name(dp));
+ pr_warn("%s: flow looped %d times, dropping\n",
+ ovs_dp_name(dp), MAX_LOOPS);
actions->actions_len = 0;
return -ELOOP;
}
/* Execute a list of actions against 'skb'. */
-int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb, bool recirc)
+int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb)
{
struct sw_flow_actions *acts =
rcu_dereference(OVS_CB(skb)->flow->sf_acts);
- const u8 stack_cost = recirc ? RECIRC_STACK_COST : DEFAULT_STACK_COST;
struct loop_counter *loop;
int error;
/* Check whether we've looped too much. */
loop = &__get_cpu_var(loop_counters);
- loop->stack_cost += stack_cost;
- if (unlikely(loop->stack_cost > MAX_STACK_COST))
+ if (unlikely(++loop->count > MAX_LOOPS))
loop->looping = true;
if (unlikely(loop->looping)) {
error = loop_suppress(dp, acts);
@@ -951,14 +942,9 @@ int ovs_execute_actions(struct datapath *dp, struct
sk_buff *skb, bool recirc)
error = do_execute_actions(dp, skb, acts->actions, acts->actions_len);
- /* Check whether sub-actions looped too much. */
- if (unlikely(loop->looping))
- error = loop_suppress(dp, acts);
-
out_loop:
- /* Decrement loop stack cost. */
- loop->stack_cost -= stack_cost;
- if (!loop->stack_cost)
+ /* Decrement loop counter. */
+ if (!--loop->count)
loop->looping = false;
return error;
diff --git a/datapath/datapath.c b/datapath/datapath.c
index 6131b2a..e477c72 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -251,7 +251,7 @@ void ovs_dp_detach_port(struct vport *p)
}
/* Must be called with rcu_read_lock. */
-void ovs_dp_process_packet(struct sk_buff *skb, bool recirc)
+void ovs_dp_process_packet(struct sk_buff *skb)
{
const struct vport *p = OVS_CB(skb)->input_vport;
struct sw_flow_key *pkt_key = OVS_CB(skb)->pkt_key;
@@ -281,7 +281,7 @@ void ovs_dp_process_packet(struct sk_buff *skb, bool recirc)
OVS_CB(skb)->flow = flow;
ovs_flow_stats_update(OVS_CB(skb)->flow, pkt_key->tp.flags, skb);
- ovs_execute_actions(dp, skb, recirc);
+ ovs_execute_actions(dp, skb);
stats_counter = &stats->n_hit;
out:
@@ -566,7 +566,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb,
struct genl_info *info)
OVS_CB(packet)->input_vport = input_vport;
local_bh_disable();
- err = ovs_execute_actions(dp, packet, false);
+ err = ovs_execute_actions(dp, packet);
local_bh_enable();
rcu_read_unlock();
diff --git a/datapath/datapath.h b/datapath/datapath.h
index cd2acbc..4874ab5 100644
--- a/datapath/datapath.h
+++ b/datapath/datapath.h
@@ -188,7 +188,7 @@ extern struct notifier_block ovs_dp_device_notifier;
extern struct genl_family dp_vport_genl_family;
extern struct genl_multicast_group ovs_dp_vport_multicast_group;
-void ovs_dp_process_packet(struct sk_buff *, bool recirc);
+void ovs_dp_process_packet(struct sk_buff *c);
void ovs_dp_detach_port(struct vport *);
int ovs_dp_upcall(struct datapath *, struct sk_buff *,
const struct dp_upcall_info *);
@@ -197,7 +197,7 @@ const char *ovs_dp_name(const struct datapath *dp);
struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 portid, u32 seq,
u8 cmd);
-int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb, bool recirc);
+int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb);
void ovs_dp_notify_wq(struct work_struct *work);
#define OVS_NLERR(fmt, ...) \
diff --git a/datapath/vport.c b/datapath/vport.c
index c44182c..4c68bae 100644
--- a/datapath/vport.c
+++ b/datapath/vport.c
@@ -495,7 +495,7 @@ void ovs_vport_receive(struct vport *vport, struct sk_buff
*skb,
return;
}
- ovs_dp_process_packet(skb, false);
+ ovs_dp_process_packet(skb);
}
/**
--
1.9.1
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