netns: ipmr: store netns in struct mfc_cache

This patch stores into struct mfc_cache the network namespace each
mfc_cache belongs to. The new member is mfc_net.

mfc_net is assigned at cache allocation and doesn't change during
the rest of the cache entry life.
A new net parameter is added to ipmr_cache_alloc/ipmr_cache_alloc_unres.

This will help to retrieve the current netns around the IPv4 multicast
routing code.

At the moment, all mfc_cache are allocated in init_net.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 9 deletions

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 75a5f79cc226..8428a0fb5c10 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -327,6 +327,12 @@ static int vif_delete(int vifi, int notify)
         return 0;
 }
 
+static inline void ipmr_cache_free(struct mfc_cache *c)
+{
+        release_net(mfc_net(c));
+        kmem_cache_free(mrt_cachep, c);
+}
+
 /* Destroy an unresolved cache entry, killing queued skbs
    and reporting error to netlink readers.
  */
@@ -353,7 +359,7 @@ static void ipmr_destroy_unres(struct mfc_cache *c)
                         kfree_skb(skb);
         }
 
-        kmem_cache_free(mrt_cachep, c);
+        ipmr_cache_free(c);
 }
 
 
@@ -528,22 +534,24 @@ static struct mfc_cache *ipmr_cache_find(__be32 origin, __be32 mcastgrp)
 /*
  *      Allocate a multicast cache entry
  */
-static struct mfc_cache *ipmr_cache_alloc(void)
+static struct mfc_cache *ipmr_cache_alloc(struct net *net)
 {
         struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
         if (c == NULL)
                 return NULL;
         c->mfc_un.res.minvif = MAXVIFS;
+        mfc_net_set(c, net);
         return c;
 }
 
-static struct mfc_cache *ipmr_cache_alloc_unres(void)
+static struct mfc_cache *ipmr_cache_alloc_unres(struct net *net)
 {
         struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
         if (c == NULL)
                 return NULL;
         skb_queue_head_init(&c->mfc_un.unres.unresolved);
         c->mfc_un.unres.expires = jiffies + 10*HZ;
+        mfc_net_set(c, net);
         return c;
 }
 
@@ -695,7 +703,7 @@ ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
                  */
 
                 if (atomic_read(&cache_resolve_queue_len) >= 10 ||
-                    (c=ipmr_cache_alloc_unres())==NULL) {
+                    (c = ipmr_cache_alloc_unres(&init_net)) == NULL) {
                         spin_unlock_bh(&mfc_unres_lock);
 
                         kfree_skb(skb);
@@ -718,7 +726,7 @@ ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
                          */
                         spin_unlock_bh(&mfc_unres_lock);
 
-                        kmem_cache_free(mrt_cachep, c);
+                        ipmr_cache_free(c);
                         kfree_skb(skb);
                         return err;
                 }
@@ -763,7 +771,7 @@ static int ipmr_mfc_delete(struct mfcctl *mfc)
                         *cp = c->next;
                         write_unlock_bh(&mrt_lock);
 
-                        kmem_cache_free(mrt_cachep, c);
+                        ipmr_cache_free(c);
                         return 0;
                 }
         }
@@ -796,7 +804,7 @@ static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock)
         if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
                 return -EINVAL;
 
-        c = ipmr_cache_alloc();
+        c = ipmr_cache_alloc(&init_net);
         if (c == NULL)
                 return -ENOMEM;
 
@@ -831,7 +839,7 @@ static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock)
 
         if (uc) {
                 ipmr_cache_resolve(uc, c);
-                kmem_cache_free(mrt_cachep, uc);
+                ipmr_cache_free(uc);
         }
         return 0;
 }
@@ -868,7 +876,7 @@ static void mroute_clean_tables(struct sock *sk)
                         *cp = c->next;
                         write_unlock_bh(&mrt_lock);
 
-                        kmem_cache_free(mrt_cachep, c);
+                        ipmr_cache_free(c);
                 }
         }