From 1f62879e36324d710dfd5ab92833fb1c51d8334a Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Tue, 7 Feb 2023 15:54:35 +0200 Subject: net/sched: make stab available before ops->init() call Some qdiscs like taprio turn out to be actually pretty reliant on a well configured stab, to not underestimate the skb transmission time (by properly accounting for L1 overhead). In a future change, taprio will need the stab, if configured by the user, to be available at ops->init() time. It will become even more important in upcoming work, when the overhead will be used for the queueMaxSDU calculation that is passed to an offloading driver. However, rcu_assign_pointer(sch->stab, stab) is called right after ops->init(), making it unavailable, and I don't really see a good reason for that. Move it earlier, which nicely seems to simplify the error handling path as well. Signed-off-by: Vladimir Oltean Reviewed-by: Kurt Kanzenbach Signed-off-by: David S. Miller --- net/sched/sch_api.c | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) (limited to 'net/sched') diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index c14018a8052c..e9780631b5b5 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1282,12 +1282,6 @@ static struct Qdisc *qdisc_create(struct net_device *dev, if (err) goto err_out3; - if (ops->init) { - err = ops->init(sch, tca[TCA_OPTIONS], extack); - if (err != 0) - goto err_out5; - } - if (tca[TCA_STAB]) { stab = qdisc_get_stab(tca[TCA_STAB], extack); if (IS_ERR(stab)) { @@ -1296,11 +1290,18 @@ static struct Qdisc *qdisc_create(struct net_device *dev, } rcu_assign_pointer(sch->stab, stab); } + + if (ops->init) { + err = ops->init(sch, tca[TCA_OPTIONS], extack); + if (err != 0) + goto err_out5; + } + if (tca[TCA_RATE]) { err = -EOPNOTSUPP; if (sch->flags & TCQ_F_MQROOT) { NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc"); - goto err_out4; + goto err_out5; } err = gen_new_estimator(&sch->bstats, @@ -1311,7 +1312,7 @@ static struct Qdisc *qdisc_create(struct net_device *dev, tca[TCA_RATE]); if (err) { NL_SET_ERR_MSG(extack, "Failed to generate new estimator"); - goto err_out4; + goto err_out5; } } @@ -1321,6 +1322,8 @@ static struct Qdisc *qdisc_create(struct net_device *dev, return sch; err_out5: + qdisc_put_stab(rtnl_dereference(sch->stab)); +err_out4: /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */ if (ops->destroy) ops->destroy(sch); @@ -1332,16 +1335,6 @@ err_out2: err_out: *errp = err; return NULL; - -err_out4: - /* - * Any broken qdiscs that would require a ops->reset() here? - * The qdisc was never in action so it shouldn't be necessary. - */ - qdisc_put_stab(rtnl_dereference(sch->stab)); - if (ops->destroy) - ops->destroy(sch); - goto err_out3; } static int qdisc_change(struct Qdisc *sch, struct nlattr **tca, -- cgit v1.2.3