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Message-Id: <1410474916-21873-9-git-send-email-xiyou.wangcong@gmail.com>
Date: Thu, 11 Sep 2014 15:35:16 -0700
From: Cong Wang <xiyou.wangcong@...il.com>
To: netdev@...r.kernel.org
Cc: Hannes Frederic Sowa <hannes@...essinduktion.org>,
Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
"David S. Miller" <davem@...emloft.net>,
Cong Wang <xiyou.wangcong@...il.com>
Subject: [Patch net-next v2 8/8] ipv6: refactor ipv6_dev_mc_inc()
Refactor out allocation and initialization and make
the refcount code more readable.
Signed-off-by: Cong Wang <xiyou.wangcong@...il.com>
---
net/ipv6/mcast.c | 82 +++++++++++++++++++++++++++++++++-----------------------
1 file changed, 49 insertions(+), 33 deletions(-)
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index d64e263..592eba6 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -641,14 +641,6 @@ bool inet6_mc_check(struct sock *sk, const struct in6_addr *mc_addr,
return rv;
}
-static void ma_put(struct ifmcaddr6 *mc)
-{
- if (atomic_dec_and_test(&mc->mca_refcnt)) {
- in6_dev_put(mc->idev);
- kfree(mc);
- }
-}
-
static void igmp6_group_added(struct ifmcaddr6 *mc)
{
struct net_device *dev = mc->idev->dev;
@@ -814,6 +806,48 @@ static void mld_clear_delrec(struct inet6_dev *idev)
read_unlock_bh(&idev->lock);
}
+static void mca_get(struct ifmcaddr6 *mc)
+{
+ atomic_inc(&mc->mca_refcnt);
+}
+
+static void ma_put(struct ifmcaddr6 *mc)
+{
+ if (atomic_dec_and_test(&mc->mca_refcnt)) {
+ in6_dev_put(mc->idev);
+ kfree(mc);
+ }
+}
+
+static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
+ const struct in6_addr *addr)
+{
+ struct ifmcaddr6 *mc;
+
+ mc = kzalloc(sizeof(*mc), GFP_ATOMIC);
+ if (mc == NULL)
+ return NULL;
+
+ setup_timer(&mc->mca_timer, igmp6_timer_handler, (unsigned long)mc);
+
+ mc->mca_addr = *addr;
+ mc->idev = idev; /* reference taken by caller */
+ mc->mca_users = 1;
+ /* mca_stamp should be updated upon changes */
+ mc->mca_cstamp = mc->mca_tstamp = jiffies;
+ atomic_set(&mc->mca_refcnt, 1);
+ spin_lock_init(&mc->mca_lock);
+
+ /* initial mode is (EX, empty) */
+ mc->mca_sfmode = MCAST_EXCLUDE;
+ mc->mca_sfcount[MCAST_EXCLUDE] = 1;
+
+ if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||
+ IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
+ mc->mca_flags |= MAF_NOREPORT;
+
+ return mc;
+}
/*
* device multicast group inc (add if not found)
@@ -849,38 +883,20 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
}
}
- /*
- * not found: create a new one.
- */
-
- mc = kzalloc(sizeof(struct ifmcaddr6), GFP_ATOMIC);
-
- if (mc == NULL) {
+ mc = mca_alloc(idev, addr);
+ if (!mc) {
write_unlock_bh(&idev->lock);
in6_dev_put(idev);
return -ENOMEM;
}
- setup_timer(&mc->mca_timer, igmp6_timer_handler, (unsigned long)mc);
-
- mc->mca_addr = *addr;
- mc->idev = idev; /* (reference taken) */
- mc->mca_users = 1;
- /* mca_stamp should be updated upon changes */
- mc->mca_cstamp = mc->mca_tstamp = jiffies;
- atomic_set(&mc->mca_refcnt, 2);
- spin_lock_init(&mc->mca_lock);
-
- /* initial mode is (EX, empty) */
- mc->mca_sfmode = MCAST_EXCLUDE;
- mc->mca_sfcount[MCAST_EXCLUDE] = 1;
-
- if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||
- IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
- mc->mca_flags |= MAF_NOREPORT;
-
mc->next = idev->mc_list;
idev->mc_list = mc;
+
+ /* Hold this for the code below before we unlock,
+ * it is already exposed via idev->mc_list.
+ */
+ mca_get(mc);
write_unlock_bh(&idev->lock);
mld_del_delrec(idev, &mc->mca_addr);
--
1.8.3.1
--
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