[PATCH v2] openvswitch: Disable bottom half when grabbing stats lock in userspace context

From: Zoltan Kiss
Date: Thu Feb 27 2014 - 17:11:16 EST


The megaflow feature introduced per-CPU stats, and the new code did some
refactoring as well [1]. However the new functions doesn't disable bottom halves
when locking the stat, and as they can be called from userspace context, they
can be interrupted by netif_receive_skb.

[1] e298e50570: openvswitch: Per cpu flow stats.

Signed-off-by: Zoltan Kiss <zoltan.kiss@xxxxxxxxxx>
---
v2: use _bh instead of _irqsave/restore
net/openvswitch/flow.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 16f4b46..9110cf4 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -90,13 +90,13 @@ static void stats_read(struct flow_stats *stats,
struct ovs_flow_stats *ovs_stats,
unsigned long *used, __be16 *tcp_flags)
{
- spin_lock(&stats->lock);
+ spin_lock_bh(&stats->lock);
if (time_after(stats->used, *used))
*used = stats->used;
*tcp_flags |= stats->tcp_flags;
ovs_stats->n_packets += stats->packet_count;
ovs_stats->n_bytes += stats->byte_count;
- spin_unlock(&stats->lock);
+ spin_unlock_bh(&stats->lock);
}

void ovs_flow_stats_get(struct sw_flow *flow, struct ovs_flow_stats *ovs_stats,
@@ -130,12 +130,12 @@ void ovs_flow_stats_get(struct sw_flow *flow, struct ovs_flow_stats *ovs_stats,

static void stats_reset(struct flow_stats *stats)
{
- spin_lock(&stats->lock);
+ spin_lock_bh(&stats->lock);
stats->used = 0;
stats->packet_count = 0;
stats->byte_count = 0;
stats->tcp_flags = 0;
- spin_unlock(&stats->lock);
+ spin_unlock_bh(&stats->lock);
}

void ovs_flow_stats_clear(struct sw_flow *flow)
--
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