Commit 0170d7f4 authored by Eric Dumazet's avatar Eric Dumazet Committed by Paolo Abeni
Browse files

net_sched: add tcf_kfree_skb_list() helper 



Using kfree_skb_list_reason() to free list of skbs from qdisc
operations seems wrong as each skb might have a different drop reason.

Cleanup __dev_xmit_skb() to call tcf_kfree_skb_list() once
in preparation of the following patch.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251121083256.674562-13-edumazet@google.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 4792c3a4

include/net/sch_generic.h

+11 −0
Original line number Diff line number Diff line
@@ -1105,6 +1105,17 @@ static inline void tcf_set_drop_reason(const struct sk_buff *skb, 
	tc_skb_cb(skb)->drop_reason = reason;

}



static inline void tcf_kfree_skb_list(struct sk_buff *skb)

{

	while (unlikely(skb)) {

		struct sk_buff *next = skb->next;



		prefetch(next);

		kfree_skb_reason(skb, tcf_get_drop_reason(skb));

		skb = next;

	}

}



/* Instead of calling kfree_skb() while root qdisc lock is held,

 * queue the skb for future freeing at end of __dev_xmit_skb()

 */

net/core/dev.c

+5 −10
Original line number Diff line number Diff line
@@ -4162,7 +4162,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, 
				__qdisc_run(q);

				qdisc_run_end(q);



				goto no_lock_out;

				goto free_skbs;

			}



			qdisc_bstats_cpu_update(q, skb);
@@ -4176,12 +4176,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, 


		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);

		qdisc_run(q);



no_lock_out:

		if (unlikely(to_free))

			kfree_skb_list_reason(to_free,

					      tcf_get_drop_reason(to_free));

		return rc;

		goto free_skbs;

	}



	/* Open code llist_add(&skb->ll_node, &q->defer_list) + queue limit.
@@ -4257,9 +4252,9 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, 
	}

unlock:

	spin_unlock(root_lock);

	if (unlikely(to_free))

		kfree_skb_list_reason(to_free,

				      tcf_get_drop_reason(to_free));



free_skbs:

	tcf_kfree_skb_list(to_free);

	return rc;

}