Commit 625b40dc authored by Paolo Abeni's avatar Paolo Abeni
Browse files

Merge branch 'net_sched-fix-hfsc-qlen-backlog-accounting-bug-and-add-selftest' 

Cong Wang says:

====================
net_sched: Fix HFSC qlen/backlog accounting bug and add selftest

This series addresses a long-standing bug in the HFSC qdisc where queue length
and backlog accounting could become inconsistent if a packet is dropped during
a peek-induced dequeue operation, and adds a corresponding selftest to tc-testing.
====================

Link: https://patch.msgid.link/20250518222038.58538-1-xiyou.wangcong@gmail.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parents 407e0efd c3572acf

net/sched/sch_hfsc.c

+3 −3
Original line number Diff line number Diff line
@@ -1569,6 +1569,9 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) 
		return err;

	}



	sch->qstats.backlog += len;

	sch->q.qlen++;



	if (first && !cl->cl_nactive) {

		if (cl->cl_flags & HFSC_RSC)

			init_ed(cl, len);
@@ -1584,9 +1587,6 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) 


	}



	sch->qstats.backlog += len;

	sch->q.qlen++;



	return NET_XMIT_SUCCESS;

}

tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json

+27 −0
Original line number Diff line number Diff line
@@ -573,5 +573,32 @@ 
        "teardown": [

            "$TC qdisc del dev $DEV1 handle 1: root"

        ]

    },

    {

        "id": "831d",

        "name": "Test HFSC qlen accounting with DRR/NETEM/BLACKHOLE chain",

        "category": ["qdisc", "hfsc", "drr", "netem", "blackhole"],

        "plugins": { "requires": ["nsPlugin", "scapyPlugin"] },

        "setup": [

            "$IP link set dev $DEV1 up || true",

            "$TC qdisc add dev $DEV1 root handle 1: drr",

            "$TC filter add dev $DEV1 parent 1: basic classid 1:1",

            "$TC class add dev $DEV1 parent 1: classid 1:1 drr",

            "$TC qdisc add dev $DEV1 parent 1:1 handle 2: hfsc def 1",

            "$TC class add dev $DEV1 parent 2: classid 2:1 hfsc rt m1 8 d 1 m2 0",

            "$TC qdisc add dev $DEV1 parent 2:1 handle 3: netem",

            "$TC qdisc add dev $DEV1 parent 3:1 handle 4: blackhole"

        ],

        "scapy": {

            "iface": "$DEV0",

            "count": 5,

            "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"

        },

        "cmdUnderTest": "$TC -s qdisc show dev $DEV1",

        "expExitCode": "0",

        "verifyCmd": "$TC -s qdisc show dev $DEV1",

        "matchPattern": "qdisc hfsc",

        "matchCount": "1",

        "teardown": ["$TC qdisc del dev $DEV1 root handle 1: drr"]

    }

]