Subject: [PATCH net-next v12 3/8] net/sched: flower: Move filter handle initialization earlier

From: Paul Blakey <[email-masked]>
Date: Wed, 15 Feb 2023 23:10:09 +0200

To support miss to action during hardware offload the filter's
handle is needed when setting up the actions (tcf_exts_init()),
and before offloading.

Move filter handle initialization earlier.

Signed-off-by: Paul Blakey <[email-masked]>
Reviewed-by: Jiri Pirko <[email-masked]>
Reviewed-by: Simon Horman <[email-masked]>
---
 net/sched/cls_flower.c | 62 ++++++++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 27 deletions(-)

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 885c95191ccf..be01d39dd7b9 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -2187,10 +2187,6 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 	INIT_LIST_HEAD(&fnew->hw_list);
 	refcount_set(&fnew->refcnt, 1);
 
-	err = tcf_exts_init(&fnew->exts, net, TCA_FLOWER_ACT, 0);
-	if (err < 0)
-		goto errout;
-
 	if (tb[TCA_FLOWER_FLAGS]) {
 		fnew->flags = nla_get_u32(tb[TCA_FLOWER_FLAGS]);
 
@@ -2200,15 +2196,45 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 		}
 	}
 
+	if (!fold) {
+		spin_lock(&tp->lock);
+		if (!handle) {
+			handle = 1;
+			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
+					    INT_MAX, GFP_ATOMIC);
+		} else {
+			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
+					    handle, GFP_ATOMIC);
+
+			/* Filter with specified handle was concurrently
+			 * inserted after initial check in cls_api. This is not
+			 * necessarily an error if NLM_F_EXCL is not set in
+			 * message flags. Returning EAGAIN will cause cls_api to
+			 * try to update concurrently inserted rule.
+			 */
+			if (err == -ENOSPC)
+				err = -EAGAIN;
+		}
+		spin_unlock(&tp->lock);
+
+		if (err)
+			goto errout;
+	}
+	fnew->handle = handle;
+
+	err = tcf_exts_init(&fnew->exts, net, TCA_FLOWER_ACT, 0);
+	if (err < 0)
+		goto errout_idr;
+
 	err = fl_set_parms(net, tp, fnew, mask, base, tb, tca[TCA_RATE],
 			   tp->chain->tmplt_priv, flags, fnew->flags,
 			   extack);
 	if (err)
-		goto errout;
+		goto errout_idr;
 
 	err = fl_check_assign_mask(head, fnew, fold, mask);
 	if (err)
-		goto errout;
+		goto errout_idr;
 
 	err = fl_ht_insert_unique(fnew, fold, &in_ht);
 	if (err)
@@ -2274,29 +2300,9 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 		refcount_dec(&fold->refcnt);
 		__fl_put(fold);
 	} else {
-		if (handle) {
-			/* user specifies a handle and it doesn't exist */
-			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
-					    handle, GFP_ATOMIC);
-
-			/* Filter with specified handle was concurrently
-			 * inserted after initial check in cls_api. This is not
-			 * necessarily an error if NLM_F_EXCL is not set in
-			 * message flags. Returning EAGAIN will cause cls_api to
-			 * try to update concurrently inserted rule.
-			 */
-			if (err == -ENOSPC)
-				err = -EAGAIN;
-		} else {
-			handle = 1;
-			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
-					    INT_MAX, GFP_ATOMIC);
-		}
-		if (err)
-			goto errout_hw;
+		idr_replace(&head->handle_idr, fnew, fnew->handle);
 
 		refcount_inc(&fnew->refcnt);
-		fnew->handle = handle;
 		list_add_tail_rcu(&fnew->list, &fnew->mask->filters);
 		spin_unlock(&tp->lock);
 	}
@@ -2319,6 +2325,8 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 				       fnew->mask->filter_ht_params);
 errout_mask:
 	fl_mask_put(head, fnew->mask);
+errout_idr:
+	idr_remove(&head->handle_idr, fnew->handle);
 errout:
 	__fl_put(fnew);
 errout_tb:
-- 
2.30.1