* [net PATCH] net/sched: Get stab before calling ops->change()
@ 2024-05-09 2:40 Xiaolei Wang
2024-05-10 12:19 ` Simon Horman
0 siblings, 1 reply; 3+ messages in thread
From: Xiaolei Wang @ 2024-05-09 2:40 UTC (permalink / raw)
To: jhs, xiyou.wangcong, jiri, davem, edumazet, kuba, pabeni, netdev,
linux-kernel
ops->change() depends on stab, there is such a situation
When no parameters are passed in for the first time, stab
is omitted, as in configuration 1 below. At this time, a
warning "Warning: sch_taprio: Size table not specified, frame
length estimates may be inaccurate" will be received. When
stab is added for the second time, parameters, like configuration
2 below, because the stab is still empty when ops->change()
is running, you will also receive the above warning.
1. tc qdisc replace dev eth1 parent root handle 100 taprio \
num_tc 5 map 0 1 2 3 4 queues 1@0 1@1 1@2 1@3 1@4 base-time 0 \
sched-entry S 1 100000 \
sched-entry S 2 100000 \
sched-entry S 4 100000 \
max-sdu 0 0 0 0 0 0 0 200 \
flags 2
2. tc qdisc replace dev eth1 parent root overhead 24 handle 100 taprio \
num_tc 5 map 0 1 2 3 4 queues 1@0 1@1 1@2 1@3 1@4 base-time 0 \
sched-entry S 1 100000 \
sched-entry S 2 100000 \
sched-entry S 4 100000 \
max-sdu 0 0 0 0 0 0 0 200 \
flags 2
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
---
net/sched/sch_api.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 60239378d43f..fec358f497d5 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1404,6 +1404,16 @@ static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
struct qdisc_size_table *ostab, *stab = NULL;
int err = 0;
+ if (tca[TCA_STAB]) {
+ stab = qdisc_get_stab(tca[TCA_STAB], extack);
+ if (IS_ERR(stab))
+ return PTR_ERR(stab);
+ }
+
+ ostab = rtnl_dereference(sch->stab);
+ rcu_assign_pointer(sch->stab, stab);
+ qdisc_put_stab(ostab);
+
if (tca[TCA_OPTIONS]) {
if (!sch->ops->change) {
NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
@@ -1418,16 +1428,6 @@ static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
return err;
}
- if (tca[TCA_STAB]) {
- stab = qdisc_get_stab(tca[TCA_STAB], extack);
- if (IS_ERR(stab))
- return PTR_ERR(stab);
- }
-
- ostab = rtnl_dereference(sch->stab);
- rcu_assign_pointer(sch->stab, stab);
- qdisc_put_stab(ostab);
-
if (tca[TCA_RATE]) {
/* NB: ignores errors from replace_estimator
because change can't be undone. */
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [net PATCH] net/sched: Get stab before calling ops->change()
2024-05-09 2:40 [net PATCH] net/sched: Get stab before calling ops->change() Xiaolei Wang
@ 2024-05-10 12:19 ` Simon Horman
2024-05-15 13:39 ` wang xiaolei
0 siblings, 1 reply; 3+ messages in thread
From: Simon Horman @ 2024-05-10 12:19 UTC (permalink / raw)
To: Xiaolei Wang
Cc: jhs, xiyou.wangcong, jiri, davem, edumazet, kuba, pabeni, netdev,
linux-kernel
On Thu, May 09, 2024 at 10:40:43AM +0800, Xiaolei Wang wrote:
> ops->change() depends on stab, there is such a situation
> When no parameters are passed in for the first time, stab
> is omitted, as in configuration 1 below. At this time, a
> warning "Warning: sch_taprio: Size table not specified, frame
> length estimates may be inaccurate" will be received. When
> stab is added for the second time, parameters, like configuration
> 2 below, because the stab is still empty when ops->change()
> is running, you will also receive the above warning.
>
> 1. tc qdisc replace dev eth1 parent root handle 100 taprio \
> num_tc 5 map 0 1 2 3 4 queues 1@0 1@1 1@2 1@3 1@4 base-time 0 \
> sched-entry S 1 100000 \
> sched-entry S 2 100000 \
> sched-entry S 4 100000 \
> max-sdu 0 0 0 0 0 0 0 200 \
> flags 2
>
> 2. tc qdisc replace dev eth1 parent root overhead 24 handle 100 taprio \
> num_tc 5 map 0 1 2 3 4 queues 1@0 1@1 1@2 1@3 1@4 base-time 0 \
> sched-entry S 1 100000 \
> sched-entry S 2 100000 \
> sched-entry S 4 100000 \
> max-sdu 0 0 0 0 0 0 0 200 \
> flags 2
>
Hi Xiaolei Wang,
If this is a fix, targeted at the net tree, then it should probably have
a Fixes tag here (no blank line between it and other tags).
> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
> ---
> net/sched/sch_api.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
> index 60239378d43f..fec358f497d5 100644
> --- a/net/sched/sch_api.c
> +++ b/net/sched/sch_api.c
> @@ -1404,6 +1404,16 @@ static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
> struct qdisc_size_table *ostab, *stab = NULL;
> int err = 0;
>
> + if (tca[TCA_STAB]) {
> + stab = qdisc_get_stab(tca[TCA_STAB], extack);
> + if (IS_ERR(stab))
> + return PTR_ERR(stab);
> + }
> +
> + ostab = rtnl_dereference(sch->stab);
> + rcu_assign_pointer(sch->stab, stab);
> + qdisc_put_stab(ostab);
> +
> if (tca[TCA_OPTIONS]) {
> if (!sch->ops->change) {
> NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
I am concerned that in this case the stab will be updated even if the
change operation is rejected by the following code in the if
(tca[TCA_OPTIONS]) block, just below the above hunk.
if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
return -EOPNOTSUPP;
}
...
--
pw-bot: under-review
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [net PATCH] net/sched: Get stab before calling ops->change()
2024-05-10 12:19 ` Simon Horman
@ 2024-05-15 13:39 ` wang xiaolei
0 siblings, 0 replies; 3+ messages in thread
From: wang xiaolei @ 2024-05-15 13:39 UTC (permalink / raw)
To: Simon Horman
Cc: jhs, xiyou.wangcong, jiri, davem, edumazet, kuba, pabeni, netdev,
linux-kernel
On 5/10/24 11:19 PM, Simon Horman wrote:
> CAUTION: This email comes from a non Wind River email account!
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
> On Thu, May 09, 2024 at 10:40:43AM +0800, Xiaolei Wang wrote:
>> ops->change() depends on stab, there is such a situation
>> When no parameters are passed in for the first time, stab
>> is omitted, as in configuration 1 below. At this time, a
>> warning "Warning: sch_taprio: Size table not specified, frame
>> length estimates may be inaccurate" will be received. When
>> stab is added for the second time, parameters, like configuration
>> 2 below, because the stab is still empty when ops->change()
>> is running, you will also receive the above warning.
>>
>> 1. tc qdisc replace dev eth1 parent root handle 100 taprio \
>> num_tc 5 map 0 1 2 3 4 queues 1@0 1@1 1@2 1@3 1@4 base-time 0 \
>> sched-entry S 1 100000 \
>> sched-entry S 2 100000 \
>> sched-entry S 4 100000 \
>> max-sdu 0 0 0 0 0 0 0 200 \
>> flags 2
>>
>> 2. tc qdisc replace dev eth1 parent root overhead 24 handle 100 taprio \
>> num_tc 5 map 0 1 2 3 4 queues 1@0 1@1 1@2 1@3 1@4 base-time 0 \
>> sched-entry S 1 100000 \
>> sched-entry S 2 100000 \
>> sched-entry S 4 100000 \
>> max-sdu 0 0 0 0 0 0 0 200 \
>> flags 2
>>
> Hi Xiaolei Wang,
>
> If this is a fix, targeted at the net tree, then it should probably have
> a Fixes tag here (no blank line between it and other tags).
>
>> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
>> ---
>> net/sched/sch_api.c | 20 ++++++++++----------
>> 1 file changed, 10 insertions(+), 10 deletions(-)
>>
>> diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
>> index 60239378d43f..fec358f497d5 100644
>> --- a/net/sched/sch_api.c
>> +++ b/net/sched/sch_api.c
>> @@ -1404,6 +1404,16 @@ static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
>> struct qdisc_size_table *ostab, *stab = NULL;
>> int err = 0;
>>
>> + if (tca[TCA_STAB]) {
>> + stab = qdisc_get_stab(tca[TCA_STAB], extack);
>> + if (IS_ERR(stab))
>> + return PTR_ERR(stab);
>> + }
>> +
>> + ostab = rtnl_dereference(sch->stab);
>> + rcu_assign_pointer(sch->stab, stab);
>> + qdisc_put_stab(ostab);
>> +
>> if (tca[TCA_OPTIONS]) {
>> if (!sch->ops->change) {
>> NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc");
> I am concerned that in this case the stab will be updated even if the
> change operation is rejected by the following code in the if
> (tca[TCA_OPTIONS]) block, just below the above hunk.
>
> if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) {
> NL_SET_ERR_MSG(extack, "Change of blocks is not supported");
> return -EOPNOTSUPP;
> }
> ...
Well, that makes sense, I will research further
thanks
xiaolei
>
> --
> pw-bot: under-review
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-05-10 12:19 ` Simon Horman
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