Revert "net/sched: Fix mirred deadlock on device recursion"

This reverts commits 0f022d32c3eca477fbf79a205243a6123ed0fe11
and 44180feaccf266d9b0b28cc4ceaac019817deb5c.

Prior patch in this series implemented loop detection
in act_mirred, we can remove q->owner to save some cycles
in the fast path.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251014171907.3554413-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 738cd5b13c62fb8501619625880b87991f3dc17c..32e9961570b467b6066f1bb2c00ff1a270e342bc 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -117,7 +117,6 @@ struct Qdisc {
        struct qdisc_skb_head   q;
        struct gnet_stats_basic_sync bstats;
        struct gnet_stats_queue qstats;
-       int                     owner;
        unsigned long           state;
        unsigned long           state2; /* must be written under qdisc spinlock */
        struct Qdisc            *next_sched;

diff --git a/net/core/dev.c b/net/core/dev.c
index 35010faf0b787cec44c6a92cc46fa433441a666c..1d8e7a76d83b6780631ce64b1b6ce9db41cdbb13 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4167,10 +4167,6 @@ no_lock_out:
                return rc;
        }
 
-       if (unlikely(READ_ONCE(q->owner) == smp_processor_id())) {
-               kfree_skb_reason(skb, SKB_DROP_REASON_TC_RECLASSIFY_LOOP);
-               return NET_XMIT_DROP;
-       }
        /*
         * Heuristic to force contended enqueues to serialize on a
         * separate lock before trying to get qdisc main lock.
@@ -4210,9 +4206,7 @@ no_lock_out:
                qdisc_run_end(q);
                rc = NET_XMIT_SUCCESS;
        } else {
-               WRITE_ONCE(q->owner, smp_processor_id());
                rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
-               WRITE_ONCE(q->owner, -1);
                if (qdisc_run_begin(q)) {
                        if (unlikely(contended)) {
                                spin_unlock(&q->busylock);

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 1e008a228ebdf846d4ef7f83d655ac1142ec3596..dfa8e8e667d24a435b0c9cb3c1f05c8075f63e89 100644 (file)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -679,7 +679,6 @@ struct Qdisc noop_qdisc = {
                .qlen = 0,
                .lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.skb_bad_txq.lock),
        },
-       .owner = -1,
 };
 EXPORT_SYMBOL(noop_qdisc);
 
@@ -985,7 +984,6 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
        sch->enqueue = ops->enqueue;
        sch->dequeue = ops->dequeue;
        sch->dev_queue = dev_queue;
-       sch->owner = -1;
        netdev_hold(dev, &sch->dev_tracker, GFP_KERNEL);
        refcount_set(&sch->refcnt, 1);