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>

1 files changed, 22 insertions, 15 deletions

diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index d89ebafd2239..cfeb6f158566 100644
--- 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);