net_sched: use idr to allocate basic filter handles

Instead of calling basic_get() in a loop to find
a unused handle, just switch to idr API to allocate
new handles.

Cc: Chris Mi <chrism@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index d89ebaf..cfeb6f1 100644 (file)
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -17,13 +17,14 @@
 #include <linux/errno.h>
 #include <linux/rtnetlink.h>
 #include <linux/skbuff.h>
+#include <linux/idr.h>
 #include <net/netlink.h>
 #include <net/act_api.h>
 #include <net/pkt_cls.h>
 
 struct basic_head {
-       u32                     hgenerator;
        struct list_head        flist;
+       struct idr              handle_idr;
        struct rcu_head         rcu;
 };
 
@@ -78,6 +79,7 @@ static int basic_init(struct tcf_proto *tp)
        if (head == NULL)
                return -ENOBUFS;
        INIT_LIST_HEAD(&head->flist);
+       idr_init(&head->handle_idr);
        rcu_assign_pointer(tp->root, head);
        return 0;
 }
@@ -99,8 +101,10 @@ static void basic_destroy(struct tcf_proto *tp)
        list_for_each_entry_safe(f, n, &head->flist, link) {
                list_del_rcu(&f->link);
                tcf_unbind_filter(tp, &f->res);
+               idr_remove_ext(&head->handle_idr, f->handle);
                call_rcu(&f->rcu, basic_delete_filter);
        }
+       idr_destroy(&head->handle_idr);
        kfree_rcu(head, rcu);
 }
 
@@ -111,6 +115,7 @@ static int basic_delete(struct tcf_proto *tp, void *arg, bool *last)
 
        list_del_rcu(&f->link);
        tcf_unbind_filter(tp, &f->res);
+       idr_remove_ext(&head->handle_idr, f->handle);
        call_rcu(&f->rcu, basic_delete_filter);
        *last = list_empty(&head->flist);
        return 0;
@@ -154,6 +159,7 @@ static int basic_change(struct net *net, struct sk_buff *in_skb,
        struct nlattr *tb[TCA_BASIC_MAX + 1];
        struct basic_filter *fold = (struct basic_filter *) *arg;
        struct basic_filter *fnew;
+       unsigned long idr_index;
 
        if (tca[TCA_OPTIONS] == NULL)
                return -EINVAL;
@@ -179,30 +185,31 @@ static int basic_change(struct net *net, struct sk_buff *in_skb,
        err = -EINVAL;
        if (handle) {
                fnew->handle = handle;
-       } else if (fold) {
-               fnew->handle = fold->handle;
+               if (!fold) {
+                       err = idr_alloc_ext(&head->handle_idr, fnew, &idr_index,
+                                           handle, handle + 1, GFP_KERNEL);
+                       if (err)
+                               goto errout;
+               }
        } else {
-               unsigned int i = 0x80000000;
-               do {
-                       if (++head->hgenerator == 0x7FFFFFFF)
-                               head->hgenerator = 1;
-               } while (--i > 0 && basic_get(tp, head->hgenerator));
-
-               if (i <= 0) {
-                       pr_err("Insufficient number of handles\n");
+               err = idr_alloc_ext(&head->handle_idr, fnew, &idr_index,
+                                   1, 0x7FFFFFFF, GFP_KERNEL);
+               if (err)
                        goto errout;
-               }
-
-               fnew->handle = head->hgenerator;
+               fnew->handle = idr_index;
        }
 
        err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr);
-       if (err < 0)
+       if (err < 0) {
+               if (!fold)
+                       idr_remove_ext(&head->handle_idr, fnew->handle);
                goto errout;
+       }
 
        *arg = fnew;
 
        if (fold) {
+               idr_replace_ext(&head->handle_idr, fnew, fnew->handle);
                list_replace_rcu(&fold->link, &fnew->link);
                tcf_unbind_filter(tp, &fold->res);
                call_rcu(&fold->rcu, basic_delete_filter);