packet: rollover prepare: per-socket state

Replace rollover state per fanout group with state per socket. Future
patches will add fields to the new structure.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 5c88ecf..ad3d9ff 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1321,16 +1321,18 @@ static unsigned int fanout_demux_rollover(struct packet_fanout *f,
                                          unsigned int idx, bool try_self,
                                          unsigned int num)
 {
+       struct packet_sock *po;
        unsigned int i, j;
 
-       if (try_self && packet_rcv_has_room(pkt_sk(f->arr[idx]), skb))
+       po = pkt_sk(f->arr[idx]);
+       if (try_self && packet_rcv_has_room(po, skb))
                return idx;
 
-       i = j = min_t(int, f->next[idx], num - 1);
+       i = j = min_t(int, po->rollover->sock, num - 1);
        do {
                if (i != idx && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
                        if (i != j)
-                               f->next[idx] = i;
+                               po->rollover->sock = i;
                        return i;
                }
 
@@ -1468,6 +1470,12 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
        if (po->fanout)
                return -EALREADY;
 
+       if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) {
+               po->rollover = kzalloc(sizeof(*po->rollover), GFP_KERNEL);
+               if (!po->rollover)
+                       return -ENOMEM;
+       }
+
        mutex_lock(&fanout_mutex);
        match = NULL;
        list_for_each_entry(f, &fanout_list, list) {
@@ -1516,6 +1524,10 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
        }
 out:
        mutex_unlock(&fanout_mutex);
+       if (err) {
+               kfree(po->rollover);
+               po->rollover = NULL;
+       }
        return err;
 }
 
@@ -1537,6 +1549,8 @@ static void fanout_release(struct sock *sk)
                kfree(f);
        }
        mutex_unlock(&fanout_mutex);
+
+       kfree(po->rollover);
 }
 
 static const struct proto_ops packet_ops;
@@ -2866,6 +2880,7 @@ static int packet_create(struct net *net, struct socket *sock, int protocol,
 
        spin_lock_init(&po->bind_lock);
        mutex_init(&po->pg_vec_lock);
+       po->rollover = NULL;
        po->prot_hook.func = packet_rcv;
 
        if (sock->type == SOCK_PACKET)

diff --git a/net/packet/internal.h b/net/packet/internal.h
index fe6e20c..a9d33a2 100644 (file)
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -82,12 +82,15 @@ struct packet_fanout {
        atomic_t                rr_cur;
        struct list_head        list;
        struct sock             *arr[PACKET_FANOUT_MAX];
-       int                     next[PACKET_FANOUT_MAX];
        spinlock_t              lock;
        atomic_t                sk_ref;
        struct packet_type      prot_hook ____cacheline_aligned_in_smp;
 };
 
+struct packet_rollover {
+       int                     sock;
+} ____cacheline_aligned_in_smp;
+
 struct packet_sock {
        /* struct sock has to be the first member of packet_sock */
        struct sock             sk;
@@ -104,6 +107,7 @@ struct packet_sock {
                                has_vnet_hdr:1;
        int                     ifindex;        /* bound device         */
        __be16                  num;
+       struct packet_rollover  *rollover;
        struct packet_mclist    *mclist;
        atomic_t                mapped;
        enum tpacket_versions   tp_version;