net: dynamically allocate fqdir structures

Following patch will add rcu grace period before fqdir
rhashtable destruction, so we need to dynamically allocate
fqdir structures to not force expensive synchronize_rcu() calls
in netns dismantle path.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

11 files changed, 78 insertions, 63 deletions

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 37cde5c1498c..5f754c660cfa 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -105,14 +105,25 @@ struct inet_frags {
 int inet_frags_init(struct inet_frags *);
 void inet_frags_fini(struct inet_frags *);
 
-static inline int fqdir_init(struct fqdir *fqdir, struct inet_frags *f,
+static inline int fqdir_init(struct fqdir **fqdirp, struct inet_frags *f,
                              struct net *net)
 {
+        struct fqdir *fqdir = kzalloc(sizeof(*fqdir), GFP_KERNEL);
+        int res;
+
+        if (!fqdir)
+                return -ENOMEM;
         fqdir->f = f;
         fqdir->net = net;
-        atomic_long_set(&fqdir->mem, 0);
-        return rhashtable_init(&fqdir->rhashtable, &fqdir->f->rhash_params);
+        res = rhashtable_init(&fqdir->rhashtable, &fqdir->f->rhash_params);
+        if (res < 0) {
+                kfree(fqdir);
+                return res;
+        }
+        *fqdirp = fqdir;
+        return 0;
 }
+
 void fqdir_exit(struct fqdir *fqdir);
 
 void inet_frag_kill(struct inet_frag_queue *q);
diff --git a/include/net/netns/ieee802154_6lowpan.h b/include/net/netns/ieee802154_6lowpan.h
index d27ac64f8dfe..95406e1342cb 100644
--- a/include/net/netns/ieee802154_6lowpan.h
+++ b/include/net/netns/ieee802154_6lowpan.h
@@ -16,7 +16,7 @@ struct netns_sysctl_lowpan {
 
 struct netns_ieee802154_lowpan {
         struct netns_sysctl_lowpan sysctl;
-        struct fqdir            fqdir;
+        struct fqdir            *fqdir;
 };
 
 #endif
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 3c270baa32e0..c07cee1e0c9e 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -72,7 +72,7 @@ struct netns_ipv4 {
 
         struct inet_peer_base   *peers;
         struct sock  * __percpu *tcp_sk;
-        struct fqdir            fqdir;
+        struct fqdir            *fqdir;
 #ifdef CONFIG_NETFILTER
         struct xt_table         *iptable_filter;
         struct xt_table         *iptable_mangle;
diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h
index 3dd2ae2a38e2..022a0fd1a5a4 100644
--- a/include/net/netns/ipv6.h
+++ b/include/net/netns/ipv6.h
@@ -58,7 +58,7 @@ struct netns_ipv6 {
         struct ipv6_devconf     *devconf_all;
         struct ipv6_devconf     *devconf_dflt;
         struct inet_peer_base   *peers;
-        struct fqdir            fqdir;
+        struct fqdir            *fqdir;
 #ifdef CONFIG_NETFILTER
         struct xt_table         *ip6table_filter;
         struct xt_table         *ip6table_mangle;
@@ -116,7 +116,7 @@ struct netns_ipv6 {
 
 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 struct netns_nf_frag {
-        struct fqdir    fqdir;
+        struct fqdir    *fqdir;
 };
 #endif
 
diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index 03a444c9e191..e59c3b708969 100644
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -79,7 +79,7 @@ fq_find(struct net *net, const struct lowpan_802154_cb *cb,
         key.src = *src;
         key.dst = *dst;
 
-        q = inet_frag_find(&ieee802154_lowpan->fqdir, &key);
+        q = inet_frag_find(ieee802154_lowpan->fqdir, &key);
         if (!q)
                 return NULL;
 
@@ -377,11 +377,11 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net)
                         table[0].procname = NULL;
         }
 
-        table[0].data   = &ieee802154_lowpan->fqdir.high_thresh;
-        table[0].extra1 = &ieee802154_lowpan->fqdir.low_thresh;
-        table[1].data   = &ieee802154_lowpan->fqdir.low_thresh;
-        table[1].extra2 = &ieee802154_lowpan->fqdir.high_thresh;
-        table[2].data   = &ieee802154_lowpan->fqdir.timeout;
+        table[0].data   = &ieee802154_lowpan->fqdir->high_thresh;
+        table[0].extra1 = &ieee802154_lowpan->fqdir->low_thresh;
+        table[1].data   = &ieee802154_lowpan->fqdir->low_thresh;
+        table[1].extra2 = &ieee802154_lowpan->fqdir->high_thresh;
+        table[2].data   = &ieee802154_lowpan->fqdir->timeout;
 
         hdr = register_net_sysctl(net, "net/ieee802154/6lowpan", table);
         if (hdr == NULL)
@@ -449,16 +449,18 @@ static int __net_init lowpan_frags_init_net(struct net *net)
                 net_ieee802154_lowpan(net);
         int res;
 
-        ieee802154_lowpan->fqdir.high_thresh = IPV6_FRAG_HIGH_THRESH;
-        ieee802154_lowpan->fqdir.low_thresh = IPV6_FRAG_LOW_THRESH;
-        ieee802154_lowpan->fqdir.timeout = IPV6_FRAG_TIMEOUT;
 
         res = fqdir_init(&ieee802154_lowpan->fqdir, &lowpan_frags, net);
         if (res < 0)
                 return res;
+
+        ieee802154_lowpan->fqdir->high_thresh = IPV6_FRAG_HIGH_THRESH;
+        ieee802154_lowpan->fqdir->low_thresh = IPV6_FRAG_LOW_THRESH;
+        ieee802154_lowpan->fqdir->timeout = IPV6_FRAG_TIMEOUT;
+
         res = lowpan_frags_ns_sysctl_register(net);
         if (res < 0)
-                fqdir_exit(&ieee802154_lowpan->fqdir);
+                fqdir_exit(ieee802154_lowpan->fqdir);
         return res;
 }
 
@@ -468,7 +470,7 @@ static void __net_exit lowpan_frags_exit_net(struct net *net)
                 net_ieee802154_lowpan(net);
 
         lowpan_frags_ns_sysctl_unregister(net);
-        fqdir_exit(&ieee802154_lowpan->fqdir);
+        fqdir_exit(ieee802154_lowpan->fqdir);
 }
 
 static struct pernet_operations lowpan_frags_ops = {
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index a5ec5d956793..b4432f209c71 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -150,6 +150,7 @@ void fqdir_exit(struct fqdir *fqdir)
         fqdir->high_thresh = 0; /* prevent creation of new frags */
 
         rhashtable_free_and_destroy(&fqdir->rhashtable, inet_frags_free_cb, NULL);
+        kfree(fqdir);
 }
 EXPORT_SYMBOL(fqdir_exit);
 
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index d59269bbe1b6..1ffaec056821 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -209,7 +209,7 @@ static struct ipq *ip_find(struct net *net, struct iphdr *iph,
         };
         struct inet_frag_queue *q;
 
-        q = inet_frag_find(&net->ipv4.fqdir, &key);
+        q = inet_frag_find(net->ipv4.fqdir, &key);
         if (!q)
                 return NULL;
 
@@ -589,12 +589,12 @@ static int __net_init ip4_frags_ns_ctl_register(struct net *net)
                         goto err_alloc;
 
         }
-        table[0].data   = &net->ipv4.fqdir.high_thresh;
-        table[0].extra1 = &net->ipv4.fqdir.low_thresh;
-        table[1].data   = &net->ipv4.fqdir.low_thresh;
-        table[1].extra2 = &net->ipv4.fqdir.high_thresh;
-        table[2].data   = &net->ipv4.fqdir.timeout;
-        table[3].data   = &net->ipv4.fqdir.max_dist;
+        table[0].data   = &net->ipv4.fqdir->high_thresh;
+        table[0].extra1 = &net->ipv4.fqdir->low_thresh;
+        table[1].data   = &net->ipv4.fqdir->low_thresh;
+        table[1].extra2 = &net->ipv4.fqdir->high_thresh;
+        table[2].data   = &net->ipv4.fqdir->timeout;
+        table[3].data   = &net->ipv4.fqdir->max_dist;
 
         hdr = register_net_sysctl(net, "net/ipv4", table);
         if (!hdr)
@@ -642,6 +642,9 @@ static int __net_init ipv4_frags_init_net(struct net *net)
 {
         int res;
 
+        res = fqdir_init(&net->ipv4.fqdir, &ip4_frags, net);
+        if (res < 0)
+                return res;
         /* Fragment cache limits.
          *
          * The fragment memory accounting code, (tries to) account for
@@ -656,30 +659,27 @@ static int __net_init ipv4_frags_init_net(struct net *net)
          * we will prune down to 3MB, making room for approx 8 big 64K
          * fragments 8x128k.
          */
-        net->ipv4.fqdir.high_thresh = 4 * 1024 * 1024;
-        net->ipv4.fqdir.low_thresh  = 3 * 1024 * 1024;
+        net->ipv4.fqdir->high_thresh = 4 * 1024 * 1024;
+        net->ipv4.fqdir->low_thresh  = 3 * 1024 * 1024;
         /*
          * Important NOTE! Fragment queue must be destroyed before MSL expires.
          * RFC791 is wrong proposing to prolongate timer each fragment arrival
          * by TTL.
          */
-        net->ipv4.fqdir.timeout = IP_FRAG_TIME;
+        net->ipv4.fqdir->timeout = IP_FRAG_TIME;
 
-        net->ipv4.fqdir.max_dist = 64;
+        net->ipv4.fqdir->max_dist = 64;
 
-        res = fqdir_init(&net->ipv4.fqdir, &ip4_frags, net);
-        if (res < 0)
-                return res;
         res = ip4_frags_ns_ctl_register(net);
         if (res < 0)
-                fqdir_exit(&net->ipv4.fqdir);
+                fqdir_exit(net->ipv4.fqdir);
         return res;
 }
 
 static void __net_exit ipv4_frags_exit_net(struct net *net)
 {
         ip4_frags_ns_ctl_unregister(net);
-        fqdir_exit(&net->ipv4.fqdir);
+        fqdir_exit(net->ipv4.fqdir);
 }
 
 static struct pernet_operations ip4_frags_ops = {
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 3927e00084e8..b613572c6616 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -72,8 +72,8 @@ static int sockstat_seq_show(struct seq_file *seq, void *v)
         seq_printf(seq, "RAW: inuse %d\n",
                    sock_prot_inuse_get(net, &raw_prot));
         seq_printf(seq,  "FRAG: inuse %u memory %lu\n",
-                   atomic_read(&net->ipv4.fqdir.rhashtable.nelems),
-                   frag_mem_limit(&net->ipv4.fqdir));
+                   atomic_read(&net->ipv4.fqdir->rhashtable.nelems),
+                   frag_mem_limit(net->ipv4.fqdir));
         return 0;
 }
 
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index b6f7385ed93c..c5d59fa568d6 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -90,12 +90,12 @@ static int nf_ct_frag6_sysctl_register(struct net *net)
                         goto err_alloc;
         }
 
-        table[0].data   = &net->nf_frag.fqdir.timeout;
-        table[1].data   = &net->nf_frag.fqdir.low_thresh;
-        table[1].extra2 = &net->nf_frag.fqdir.high_thresh;
-        table[2].data   = &net->nf_frag.fqdir.high_thresh;
-        table[2].extra1 = &net->nf_frag.fqdir.low_thresh;
-        table[2].extra2 = &init_net.nf_frag.fqdir.high_thresh;
+        table[0].data   = &net->nf_frag.fqdir->timeout;
+        table[1].data   = &net->nf_frag.fqdir->low_thresh;
+        table[1].extra2 = &net->nf_frag.fqdir->high_thresh;
+        table[2].data   = &net->nf_frag.fqdir->high_thresh;
+        table[2].extra1 = &net->nf_frag.fqdir->low_thresh;
+        table[2].extra2 = &init_net.nf_frag.fqdir->high_thresh;
 
         hdr = register_net_sysctl(net, "net/netfilter", table);
         if (hdr == NULL)
@@ -162,7 +162,7 @@ static struct frag_queue *fq_find(struct net *net, __be32 id, u32 user,
         };
         struct inet_frag_queue *q;
 
-        q = inet_frag_find(&net->nf_frag.fqdir, &key);
+        q = inet_frag_find(net->nf_frag.fqdir, &key);
         if (!q)
                 return NULL;
 
@@ -489,23 +489,24 @@ static int nf_ct_net_init(struct net *net)
 {
         int res;
 
-        net->nf_frag.fqdir.high_thresh = IPV6_FRAG_HIGH_THRESH;
-        net->nf_frag.fqdir.low_thresh = IPV6_FRAG_LOW_THRESH;
-        net->nf_frag.fqdir.timeout = IPV6_FRAG_TIMEOUT;
-
         res = fqdir_init(&net->nf_frag.fqdir, &nf_frags, net);
         if (res < 0)
                 return res;
+
+        net->nf_frag.fqdir->high_thresh = IPV6_FRAG_HIGH_THRESH;
+        net->nf_frag.fqdir->low_thresh = IPV6_FRAG_LOW_THRESH;
+        net->nf_frag.fqdir->timeout = IPV6_FRAG_TIMEOUT;
+
         res = nf_ct_frag6_sysctl_register(net);
         if (res < 0)
-                fqdir_exit(&net->nf_frag.fqdir);
+                fqdir_exit(net->nf_frag.fqdir);
         return res;
 }
 
 static void nf_ct_net_exit(struct net *net)
 {
         nf_ct_frags6_sysctl_unregister(net);
-        fqdir_exit(&net->nf_frag.fqdir);
+        fqdir_exit(net->nf_frag.fqdir);
 }
 
 static struct pernet_operations nf_ct_net_ops = {
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index f3e3118393c4..0bbefc440bcd 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -48,8 +48,8 @@ static int sockstat6_seq_show(struct seq_file *seq, void *v)
         seq_printf(seq, "RAW6: inuse %d\n",
                        sock_prot_inuse_get(net, &rawv6_prot));
         seq_printf(seq, "FRAG6: inuse %u memory %lu\n",
-                   atomic_read(&net->ipv6.fqdir.rhashtable.nelems),
-                   frag_mem_limit(&net->ipv6.fqdir));
+                   atomic_read(&net->ipv6.fqdir->rhashtable.nelems),
+                   frag_mem_limit(net->ipv6.fqdir));
         return 0;
 }
 
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index a6f26aa648fb..836ea964cf14 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -98,7 +98,7 @@ fq_find(struct net *net, __be32 id, const struct ipv6hdr *hdr, int iif)
                                             IPV6_ADDR_LINKLOCAL)))
                 key.iif = 0;
 
-        q = inet_frag_find(&net->ipv6.fqdir, &key);
+        q = inet_frag_find(net->ipv6.fqdir, &key);
         if (!q)
                 return NULL;
 
@@ -443,11 +443,11 @@ static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
                         goto err_alloc;
 
         }
-        table[0].data   = &net->ipv6.fqdir.high_thresh;
-        table[0].extra1 = &net->ipv6.fqdir.low_thresh;
-        table[1].data   = &net->ipv6.fqdir.low_thresh;
-        table[1].extra2 = &net->ipv6.fqdir.high_thresh;
-        table[2].data   = &net->ipv6.fqdir.timeout;
+        table[0].data   = &net->ipv6.fqdir->high_thresh;
+        table[0].extra1 = &net->ipv6.fqdir->low_thresh;
+        table[1].data   = &net->ipv6.fqdir->low_thresh;
+        table[1].extra2 = &net->ipv6.fqdir->high_thresh;
+        table[2].data   = &net->ipv6.fqdir->timeout;
 
         hdr = register_net_sysctl(net, "net/ipv6", table);
         if (!hdr)
@@ -510,24 +510,24 @@ static int __net_init ipv6_frags_init_net(struct net *net)
 {
         int res;
 
-        net->ipv6.fqdir.high_thresh = IPV6_FRAG_HIGH_THRESH;
-        net->ipv6.fqdir.low_thresh = IPV6_FRAG_LOW_THRESH;
-        net->ipv6.fqdir.timeout = IPV6_FRAG_TIMEOUT;
-
         res = fqdir_init(&net->ipv6.fqdir, &ip6_frags, net);
         if (res < 0)
                 return res;
 
+        net->ipv6.fqdir->high_thresh = IPV6_FRAG_HIGH_THRESH;
+        net->ipv6.fqdir->low_thresh = IPV6_FRAG_LOW_THRESH;
+        net->ipv6.fqdir->timeout = IPV6_FRAG_TIMEOUT;
+
         res = ip6_frags_ns_sysctl_register(net);
         if (res < 0)
-                fqdir_exit(&net->ipv6.fqdir);
+                fqdir_exit(net->ipv6.fqdir);
         return res;
 }
 
 static void __net_exit ipv6_frags_exit_net(struct net *net)
 {
         ip6_frags_ns_sysctl_unregister(net);
-        fqdir_exit(&net->ipv6.fqdir);
+        fqdir_exit(net->ipv6.fqdir);
 }
 
 static struct pernet_operations ip6_frags_ops = {