[PATCH 1/2] ipv6: do not hold route table lock when send ndisc probe
From: Cong Wang <hidden>
Date: 2012-08-17 07:12:01
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
In rt6_probe(), we call ndisc_send_ns() with root->rwlock, but this is not necessary, so we can drop it before calling ndisc_send_ns(). This could probably fix the deadlock reported by Debabrata: https://lkml.org/lkml/2012/8/16/432 Reported-by: "Banerjee, Debabrata" <redacted> Cc: "Banerjee, Debabrata" <redacted> Cc: "David S. Miller" <davem@davemloft.net> Cc: Hideaki YOSHIFUJI <redacted> Cc: Patrick McHardy <redacted> Signed-off-by: Cong Wang <redacted> --- net/ipv6/route.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 0ddf2d1..7a36df2 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c@@ -460,13 +460,18 @@ static void rt6_probe(struct rt6_info *rt) time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) { struct in6_addr mcaddr; struct in6_addr *target; + struct net_device *dev = rt->dst.dev; + struct fib6_table *table = rt->rt6i_table; neigh->updated = jiffies; read_unlock_bh(&neigh->lock); + read_unlock_bh(&table->tb6_lock); target = (struct in6_addr *)&neigh->primary_key; addrconf_addr_solict_mult(target, &mcaddr); - ndisc_send_ns(rt->dst.dev, NULL, target, &mcaddr, NULL); + ndisc_send_ns(dev, NULL, target, &mcaddr, NULL); + + read_lock_bh(&table->tb6_lock); } else { read_unlock_bh(&neigh->lock); }
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1.7.7.6