From 1691c63ea42d6f57ba769df401b9773664edb936 Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Thu, 11 Sep 2014 15:35:16 -0700 Subject: [PATCH] ipv6: refactor ipv6_dev_mc_inc() Refactor out allocation and initialization and make the refcount code more readable. Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- 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 d64e26366cb8..592eba61e78a 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);