From 42b18706469a02c1f84375ac0ee2f30f28d85d4c Mon Sep 17 00:00:00 2001
From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Mon, 6 Oct 2014 19:58:35 +0200
Subject: [PATCH] ipv6: make rt_sernum atomic and serial number fields ordinary
ints
Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/net/ip6_fib.h | 2 +-
net/ipv6/ip6_fib.c | 23 +++++++++++++----------
2 files changed, 14 insertions(+), 11 deletions(-)
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 9221bf4c64f75..8eea35d32a75b 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -64,7 +64,7 @@ struct fib6_node {
__u16 fn_bit; /* bit key */
__u16 fn_flags;
- __u32 fn_sernum;
+ int fn_sernum;
struct rt6_info *rr_ptr;
};
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index e8d7465b1597f..332f1e0ff8e2c 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -74,7 +74,7 @@ static int fib6_walk_continue(struct fib6_walker *w);
* result of redirects, path MTU changes, etc.
*/
-static __u32 rt_sernum;
+static atomic_t rt_sernum = ATOMIC_INIT(1);
static void fib6_gc_timer_cb(unsigned long arg);
@@ -95,12 +95,15 @@ static void fib6_walker_unlink(struct fib6_walker *w)
write_unlock_bh(&fib6_walker_lock);
}
-static u32 fib6_new_sernum(void)
+static int fib6_new_sernum(void)
{
- u32 n = ++rt_sernum;
- if ((__s32)n <= 0)
- rt_sernum = n = 1;
- return n;
+ int new, old;
+
+ do {
+ old = atomic_read(&rt_sernum);
+ new = old < INT_MAX ? old + 1 : 1;
+ } while (atomic_cmpxchg(&rt_sernum, old, new) != old);
+ return new;
}
/*
@@ -421,7 +424,7 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
struct rt6key *key;
int bit;
__be32 dir = 0;
- __u32 sernum = fib6_new_sernum();
+ int sernum = fib6_new_sernum();
RT6_TRACE("fib6_add_1\n");
@@ -1598,7 +1601,7 @@ static void fib6_prune_clones(struct net *net, struct fib6_node *fn)
static int fib6_update_sernum(struct rt6_info *rt, void *arg)
{
- __u32 sernum = *(__u32 *)arg;
+ int sernum = *(int *)arg;
if (rt->rt6i_node &&
rt->rt6i_node->fn_sernum != sernum)
@@ -1609,7 +1612,7 @@ static int fib6_update_sernum(struct rt6_info *rt, void *arg)
static void fib6_flush_trees(struct net *net)
{
- __u32 new_sernum = fib6_new_sernum();
+ int new_sernum = fib6_new_sernum();
fib6_clean_all(net, fib6_update_sernum, &new_sernum);
}
@@ -1822,7 +1825,7 @@ struct ipv6_route_iter {
struct fib6_walker w;
loff_t skip;
struct fib6_table *tbl;
- __u32 sernum;
+ int sernum;
};
static int ipv6_route_seq_show(struct seq_file *seq, void *v)
--
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