net: sched: flower: protect flower classifier state with spinlock

struct tcf_proto was extended with spinlock to be used by classifiers
instead of global rtnl lock. Use it to protect shared flower classifier
data structures (handle_idr, mask hashtable and list) and fields of
individual filters that can be accessed concurrently. This patch set uses
tcf_proto->lock as per instance lock that protects all filters on
tcf_proto.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 25a4d64..04210d6 100644 (file)
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -384,7 +384,9 @@ static void fl_hw_destroy_filter(struct tcf_proto *tp, struct cls_fl_filter *f,
        cls_flower.cookie = (unsigned long) f;
 
        tc_setup_cb_call(block, TC_SETUP_CLSFLOWER, &cls_flower, false);
+       spin_lock(&tp->lock);
        tcf_block_offload_dec(block, &f->flags);
+       spin_unlock(&tp->lock);
 }
 
 static int fl_hw_replace_filter(struct tcf_proto *tp,
@@ -426,7 +428,9 @@ static int fl_hw_replace_filter(struct tcf_proto *tp,
                return err;
        } else if (err > 0) {
                f->in_hw_count = err;
+               spin_lock(&tp->lock);
                tcf_block_offload_inc(block, &f->flags);
+               spin_unlock(&tp->lock);
        }
 
        if (skip_sw && !(f->flags & TCA_CLS_FLAGS_IN_HW))
@@ -514,14 +518,19 @@ static int __fl_delete(struct tcf_proto *tp, struct cls_fl_filter *f,
 
        *last = false;
 
-       if (f->deleted)
+       spin_lock(&tp->lock);
+       if (f->deleted) {
+               spin_unlock(&tp->lock);
                return -ENOENT;
+       }
 
        f->deleted = true;
        rhashtable_remove_fast(&f->mask->ht, &f->ht_node,
                               f->mask->filter_ht_params);
        idr_remove(&head->handle_idr, f->handle);
        list_del_rcu(&f->list);
+       spin_unlock(&tp->lock);
+
        *last = fl_mask_put(head, f->mask, async);
        if (!tc_skip_hw(f->flags))
                fl_hw_destroy_filter(tp, f, extack);
@@ -1500,6 +1509,8 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
        if (!tc_in_hw(fnew->flags))
                fnew->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 
+       spin_lock(&tp->lock);
+
        /* tp was deleted concurrently. -EAGAIN will cause caller to lookup
         * proto again or create new one, if necessary.
         */
@@ -1530,6 +1541,8 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
                list_replace_rcu(&fold->list, &fnew->list);
                fold->deleted = true;
 
+               spin_unlock(&tp->lock);
+
                fl_mask_put(head, fold->mask, true);
                if (!tc_skip_hw(fold->flags))
                        fl_hw_destroy_filter(tp, fold, NULL);
@@ -1575,6 +1588,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
                        goto errout_idr;
 
                list_add_tail_rcu(&fnew->list, &fnew->mask->filters);
+               spin_unlock(&tp->lock);
        }
 
        *arg = fnew;
@@ -1586,6 +1600,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 errout_idr:
        idr_remove(&head->handle_idr, fnew->handle);
 errout_hw:
+       spin_unlock(&tp->lock);
        if (!tc_skip_hw(fnew->flags))
                fl_hw_destroy_filter(tp, fnew, NULL);
 errout_mask:
@@ -1688,8 +1703,10 @@ static int fl_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb,
                                continue;
                        }
 
+                       spin_lock(&tp->lock);
                        tc_cls_offload_cnt_update(block, &f->in_hw_count,
                                                  &f->flags, add);
+                       spin_unlock(&tp->lock);
                }
        }
 
@@ -2223,6 +2240,7 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh,
        struct cls_fl_filter *f = fh;
        struct nlattr *nest;
        struct fl_flow_key *key, *mask;
+       bool skip_hw;
 
        if (!f)
                return skb->len;
@@ -2233,21 +2251,26 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh,
        if (!nest)
                goto nla_put_failure;
 
+       spin_lock(&tp->lock);
+
        if (f->res.classid &&
            nla_put_u32(skb, TCA_FLOWER_CLASSID, f->res.classid))
-               goto nla_put_failure;
+               goto nla_put_failure_locked;
 
        key = &f->key;
        mask = &f->mask->key;
+       skip_hw = tc_skip_hw(f->flags);
 
        if (fl_dump_key(skb, net, key, mask))
-               goto nla_put_failure;
-
-       if (!tc_skip_hw(f->flags))
-               fl_hw_update_stats(tp, f);
+               goto nla_put_failure_locked;
 
        if (f->flags && nla_put_u32(skb, TCA_FLOWER_FLAGS, f->flags))
-               goto nla_put_failure;
+               goto nla_put_failure_locked;
+
+       spin_unlock(&tp->lock);
+
+       if (!skip_hw)
+               fl_hw_update_stats(tp, f);
 
        if (nla_put_u32(skb, TCA_FLOWER_IN_HW_COUNT, f->in_hw_count))
                goto nla_put_failure;
@@ -2262,6 +2285,8 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh,
 
        return skb->len;
 
+nla_put_failure_locked:
+       spin_unlock(&tp->lock);
 nla_put_failure:
        nla_nest_cancel(skb, nest);
        return -1;