From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Mon, 25 Sep 2017 10:13:49 -0700
Subject: net_sched: use idr to allocate bpf filter handles
Patch-mainline: v4.15-rc1
Git-commit: 76cf546c2802f6e25113ba481d7e85d0298768c6
References: bsc#1109837
Instead of calling cls_bpf_get() in a loop to find
a unused handle, just switch to idr API to allocate
new handles.
Cc: Daniel Borkmann <daniel@iogearbox.net>
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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sched/cls_bpf.c | 57 +++++++++++++++++++++++++---------------------------
1 file changed, 28 insertions(+), 29 deletions(-)
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -17,6 +17,7 @@
#include <linux/skbuff.h>
#include <linux/filter.h>
#include <linux/bpf.h>
+#include <linux/idr.h>
#include <net/rtnetlink.h>
#include <net/pkt_cls.h>
@@ -32,7 +33,7 @@ MODULE_DESCRIPTION("TC BPF based classif
struct cls_bpf_head {
struct list_head plist;
- u32 hgen;
+ struct idr handle_idr;
struct rcu_head rcu;
};
@@ -241,6 +242,7 @@ static int cls_bpf_init(struct tcf_proto
return -ENOBUFS;
INIT_LIST_HEAD_RCU(&head->plist);
+ idr_init(&head->handle_idr);
rcu_assign_pointer(tp->root, head);
return 0;
@@ -280,6 +282,9 @@ static void cls_bpf_delete_prog_rcu(stru
static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog)
{
+ struct cls_bpf_head *head = rtnl_dereference(tp->root);
+
+ idr_remove_ext(&head->handle_idr, prog->handle);
cls_bpf_stop_offload(tp, prog);
list_del_rcu(&prog->link);
tcf_unbind_filter(tp, &prog->res);
@@ -306,6 +311,7 @@ static void cls_bpf_destroy(struct tcf_p
list_for_each_entry_safe(prog, tmp, &head->plist, link)
__cls_bpf_delete(tp, prog);
+ idr_destroy(&head->handle_idr);
kfree_rcu(head, rcu);
}
@@ -440,27 +446,6 @@ static int cls_bpf_set_parms(struct net
return 0;
}
-static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
- struct cls_bpf_head *head)
-{
- unsigned int i = 0x80000000;
- u32 handle;
-
- do {
- if (++head->hgen == 0x7FFFFFFF)
- head->hgen = 1;
- } while (--i > 0 && cls_bpf_get(tp, head->hgen));
-
- if (unlikely(i == 0)) {
- pr_err("Insufficient number of handles\n");
- handle = 0;
- } else {
- handle = head->hgen;
- }
-
- return handle;
-}
-
static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
struct tcf_proto *tp, unsigned long base,
u32 handle, struct nlattr **tca,
@@ -470,6 +455,7 @@ static int cls_bpf_change(struct net *ne
struct cls_bpf_prog *oldprog = *arg;
struct nlattr *tb[TCA_BPF_MAX + 1];
struct cls_bpf_prog *prog;
+ unsigned long idr_index;
int ret;
if (tca[TCA_OPTIONS] == NULL)
@@ -495,21 +481,30 @@ static int cls_bpf_change(struct net *ne
}
}
- if (handle == 0)
- prog->handle = cls_bpf_grab_new_handle(tp, head);
- else
+ if (handle == 0) {
+ ret = idr_alloc_ext(&head->handle_idr, prog, &idr_index,
+ 1, 0x7FFFFFFF, GFP_KERNEL);
+ if (ret)
+ goto errout;
+ prog->handle = idr_index;
+ } else {
+ if (!oldprog) {
+ ret = idr_alloc_ext(&head->handle_idr, prog, &idr_index,
+ handle, handle + 1, GFP_KERNEL);
+ if (ret)
+ goto errout;
+ }
prog->handle = handle;
- if (prog->handle == 0) {
- ret = -EINVAL;
- goto errout;
}
ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr);
if (ret < 0)
- goto errout;
+ goto errout_idr;
ret = cls_bpf_offload(tp, prog, oldprog);
if (ret) {
+ if (!oldprog)
+ idr_remove_ext(&head->handle_idr, prog->handle);
__cls_bpf_delete_prog(prog);
return ret;
}
@@ -518,6 +513,7 @@ static int cls_bpf_change(struct net *ne
prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
if (oldprog) {
+ idr_replace_ext(&head->handle_idr, prog, handle);
list_replace_rcu(&oldprog->link, &prog->link);
tcf_unbind_filter(tp, &oldprog->res);
tcf_exts_get_net(&oldprog->exts);
@@ -529,6 +525,9 @@ static int cls_bpf_change(struct net *ne
*arg = prog;
return 0;
+errout_idr:
+ if (!oldprog)
+ idr_remove_ext(&head->handle_idr, prog->handle);
errout:
tcf_exts_destroy(&prog->exts);
kfree(prog);