Patchwork [net-next,01/11] ndisc: Update neigh->updated with write lock.

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Submitter YOSHIFUJI Hideaki / 吉藤英明
Date Jan. 17, 2013, 5:41 p.m.
Message ID <50F837DD.9020005@linux-ipv6.org>
Download mbox | patch
Permalink /patch/213330/
State Changes Requested
Delegated to: David Miller
Headers show

Comments

YOSHIFUJI Hideaki / 吉藤英明 - Jan. 17, 2013, 5:41 p.m.
neigh->nud_state and neigh->updated are under protection of
neigh->lock.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
---
 net/ipv6/route.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Patch

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 7c34c01..1341f68 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -499,22 +499,26 @@  static void rt6_probe(struct rt6_info *rt)
 	 * to no more than one per minute.
 	 */
 	neigh = rt ? rt->n : NULL;
-	if (!neigh || (neigh->nud_state & NUD_VALID))
+	if (!neigh)
+		return;
+	write_lock_bh(&neigh->lock);
+	if (neigh->nud_state & NUD_VALID) {
+		write_unlock_bh(&neigh->lock);
 		return;
-	read_lock_bh(&neigh->lock);
+	}
 	if (!(neigh->nud_state & NUD_VALID) &&
 	    time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
 		struct in6_addr mcaddr;
 		struct in6_addr *target;
 
 		neigh->updated = jiffies;
-		read_unlock_bh(&neigh->lock);
+		write_unlock_bh(&neigh->lock);
 
 		target = (struct in6_addr *)&neigh->primary_key;
 		addrconf_addr_solict_mult(target, &mcaddr);
 		ndisc_send_ns(rt->dst.dev, NULL, target, &mcaddr, NULL);
 	} else {
-		read_unlock_bh(&neigh->lock);
+		write_unlock_bh(&neigh->lock);
 	}
 }
 #else