mld: do not remove mld souce list info when set link down

commit 1666d49e1d416fcc2cce708242a52fe3317ea8ba upstream.

This is an IPv6 version of commit 24803f38a5c0 ("igmp: do not remove igmp
souce list..."). In mld_del_delrec(), we will restore back all source filter
info instead of flush them.

Move mld_clear_delrec() from ipv6_mc_down() to ipv6_mc_destroy_dev() since
we should not remove source list info when set link down. Remove
igmp6_group_dropped() in ipv6_mc_destroy_dev() since we have called it in
ipv6_mc_down().

Also clear all source info after igmp6_group_dropped() instead of in it
because ipv6_mc_down() will call igmp6_group_dropped().

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
 - Timer code moved around in ipv6_mc_down() is different
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index be5466e..d21d424 100644 (file)
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -92,7 +92,7 @@ static void mld_gq_timer_expire(unsigned long data);
 static void mld_ifc_timer_expire(unsigned long data);
 static void mld_ifc_event(struct inet6_dev *idev);
 static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
-static void mld_del_delrec(struct inet6_dev *idev, const struct in6_addr *addr);
+static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
 static void mld_clear_delrec(struct inet6_dev *idev);
 static int sf_setstate(struct ifmcaddr6 *pmc);
 static void sf_markstate(struct ifmcaddr6 *pmc);
@@ -691,9 +691,9 @@ static void igmp6_group_dropped(struct ifmcaddr6 *mc)
                        dev_mc_del(dev, buf);
        }
 
-       if (mc->mca_flags & MAF_NOREPORT)
-               goto done;
        spin_unlock_bh(&mc->mca_lock);
+       if (mc->mca_flags & MAF_NOREPORT)
+               return;
 
        if (!mc->idev->dead)
                igmp6_leave_group(mc);
@@ -701,8 +701,6 @@ static void igmp6_group_dropped(struct ifmcaddr6 *mc)
        spin_lock_bh(&mc->mca_lock);
        if (del_timer(&mc->mca_timer))
                atomic_dec(&mc->mca_refcnt);
-done:
-       ip6_mc_clear_src(mc);
        spin_unlock_bh(&mc->mca_lock);
 }
 
@@ -747,10 +745,11 @@ static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
        spin_unlock_bh(&idev->mc_lock);
 }
 
-static void mld_del_delrec(struct inet6_dev *idev, const struct in6_addr *pmca)
+static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
 {
        struct ifmcaddr6 *pmc, *pmc_prev;
-       struct ip6_sf_list *psf, *psf_next;
+       struct ip6_sf_list *psf;
+       struct in6_addr *pmca = &im->mca_addr;
 
        spin_lock_bh(&idev->mc_lock);
        pmc_prev = NULL;
@@ -767,14 +766,20 @@ static void mld_del_delrec(struct inet6_dev *idev, const struct in6_addr *pmca)
        }
        spin_unlock_bh(&idev->mc_lock);
 
+       spin_lock_bh(&im->mca_lock);
        if (pmc) {
-               for (psf=pmc->mca_tomb; psf; psf=psf_next) {
-                       psf_next = psf->sf_next;
-                       kfree(psf);
+               im->idev = pmc->idev;
+               im->mca_crcount = idev->mc_qrv;
+               im->mca_sfmode = pmc->mca_sfmode;
+               if (pmc->mca_sfmode == MCAST_INCLUDE) {
+                       im->mca_tomb = pmc->mca_tomb;
+                       im->mca_sources = pmc->mca_sources;
+                       for (psf = im->mca_sources; psf; psf = psf->sf_next)
+                               psf->sf_crcount = im->mca_crcount;
                }
                in6_dev_put(pmc->idev);
-               kfree(pmc);
        }
+       spin_unlock_bh(&im->mca_lock);
 }
 
 static void mld_clear_delrec(struct inet6_dev *idev)
@@ -877,7 +882,7 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
        idev->mc_list = mc;
        write_unlock_bh(&idev->lock);
 
-       mld_del_delrec(idev, &mc->mca_addr);
+       mld_del_delrec(idev, mc);
        igmp6_group_added(mc);
        ma_put(mc);
        return 0;
@@ -898,6 +903,7 @@ int __ipv6_dev_mc_dec(struct inet6_dev *idev, const struct in6_addr *addr)
                                write_unlock_bh(&idev->lock);
 
                                igmp6_group_dropped(ma);
+                               ip6_mc_clear_src(ma);
 
                                ma_put(ma);
                                return 0;
@@ -2231,18 +2237,20 @@ void ipv6_mc_down(struct inet6_dev *idev)
        /* Withdraw multicast list */
 
        read_lock_bh(&idev->lock);
+
+       for (i = idev->mc_list; i; i=i->next)
+               igmp6_group_dropped(i);
+
+       /* Should stop timer after group drop. or we will
+        * start timer again in mld_ifc_event()
+        */
        idev->mc_ifc_count = 0;
        if (del_timer(&idev->mc_ifc_timer))
                __in6_dev_put(idev);
        idev->mc_gq_running = 0;
        if (del_timer(&idev->mc_gq_timer))
                __in6_dev_put(idev);
-
-       for (i = idev->mc_list; i; i=i->next)
-               igmp6_group_dropped(i);
        read_unlock_bh(&idev->lock);
-
-       mld_clear_delrec(idev);
 }
 
 
@@ -2255,8 +2263,10 @@ void ipv6_mc_up(struct inet6_dev *idev)
        /* Install multicast list, except for all-nodes (already installed) */
 
        read_lock_bh(&idev->lock);
-       for (i = idev->mc_list; i; i=i->next)
+       for (i = idev->mc_list; i; i = i->next) {
+               mld_del_delrec(idev, i);
                igmp6_group_added(i);
+       }
        read_unlock_bh(&idev->lock);
 }
 
@@ -2289,6 +2299,7 @@ void ipv6_mc_destroy_dev(struct inet6_dev *idev)
 
        /* Deactivate timers */
        ipv6_mc_down(idev);
+       mld_clear_delrec(idev);
 
        /* Delete all-nodes address. */
        /* We cannot call ipv6_dev_mc_dec() directly, our caller in
@@ -2303,11 +2314,9 @@ void ipv6_mc_destroy_dev(struct inet6_dev *idev)
        write_lock_bh(&idev->lock);
        while ((i = idev->mc_list) != NULL) {
                idev->mc_list = i->next;
-               write_unlock_bh(&idev->lock);
 
-               igmp6_group_dropped(i);
+               write_unlock_bh(&idev->lock);
                ma_put(i);
-
                write_lock_bh(&idev->lock);
        }
        write_unlock_bh(&idev->lock);