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authorVladimir Oltean <vladimir.oltean@nxp.com>2023-02-07 14:54:35 +0100
committerDavid S. Miller <davem@davemloft.net>2023-02-08 10:48:53 +0100
commit1f62879e36324d710dfd5ab92833fb1c51d8334a (patch)
treebfcbd394a0ca299c6976a251cbdbbe192c912def
parentnet/sched: taprio: calculate guard band against actual TC gate close time (diff)
downloadlinux-1f62879e36324d710dfd5ab92833fb1c51d8334a.tar.xz
linux-1f62879e36324d710dfd5ab92833fb1c51d8334a.zip
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 <vladimir.oltean@nxp.com> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sched/sch_api.c29
1 files changed, 11 insertions, 18 deletions
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,