On 08/06/2023 09:32, renmingshuai wrote:
>> On 07/06/2023 01:19, renmingshuai wrote:
>>>> On 06/06/2023 11:45, renmingshuai wrote:
>>>>> When a new chain is added by using tc, one soft lockup alarm will
>>>>> be
>>>>> generated after delete the prio 0 filter of the chain. To
>>>>> reproduce
>>>>> the problem, perform the following steps:
>>>>> (1) tc qdisc add dev eth0 root handle 1: htb default 1
>>>>> (2) tc chain add dev eth0
>>>>> (3) tc filter del dev eth0 chain 0 parent 1: prio 0
>>>>> (4) tc filter add dev eth0 chain 0 parent 1:
>>>>
>>>> This seems like it could be added to tdc or 3 and 4 must be run in
>>>> parallel?
>>> 3 and 4 do not need to be run inparallel. When a new chain is added
>>> by the
>>> way as step 1 and the step 3 is completed, this problem always
>>> occurs
>>> whenever step 4 is run.
>>
>> Got it,
>> The test still hangs with the provided patch.
>>
>> + tc qdisc add dev lo root handle 1: htb default 1
>> + tc chain add dev lo
>> + tc filter del dev lo chain 0 parent 1: prio 0
>> [ 68.790030][ T6704] [+]
>> [ 68.790060][ T6704] chain refcnt 2
>> [ 68.790951][ T6704] [-]
>> + tc filter add dev lo chain 0 parent 1:
>> <hangs>
>>
>> Also please add this test to tdc, it should be straightforward.
>>
> Sorry for not testing before. I forgot that the chain->refcnt was
> increased by 1 when tcf_chain_get() is called in tc_del_tfilter().
> The value of chain->refcnt is 2 after chain flush. The test
> result is as follows:
> [root@localhost ~]# tc qdisc add dev eth2 root handle 1: htb default 1
> [root@localhost ~]# tc chain add dev eth2
> [root@localhost ~]# tc filter del dev eth2 chain 0 parent 1: prio 0
> [root@localhost ~]# tc filter add dev eth2 chain 0 parent 1:
> Error: Filter kind and protocol must be specified.
> We have an error talking to the kernel
>
> And I have add this test to tdc:
> [root@localhost tc-testing]# ./tdc.py -f tc-tests/filters/tests.json
> ok 7 c2b4 - Adding a new fiter after deleting a filter in a chain does
> not cause an infinite loop
>
> Fixes: 726d061286ce ("net: sched: prevent insertion of new classifiers during chain flush")
> Signed-off-by: renmingshuai <[email protected]>
Please respin with the following applied:
diff --git
a/tools/testing/selftests/tc-testing/tc-tests/filters/tests.json
b/tools/testing/selftests/tc-testing/tc-tests/filters/tests.json
index c759c3db9a37..361235ad574b 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/filters/tests.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/filters/tests.json
@@ -125,25 +125,5 @@
"teardown": [
"$TC qdisc del dev $DEV2 ingress"
]
- },
- {
- "id": "c2b4",
- "name": "Adding a new fiter after deleting a filter in a chain
does not cause an infinite loop",
- "category": [
- "filter",
- "prio"
- ],
- "setup": [
- "$TC qdisc add dev $DEV1 root handle 1: htb default 1",
- "$TC chain add dev $DEV1"
- ],
- "cmdUnderTest": "$TC filter del dev $DEV1 chain 0 parent 1:
prio 0",
- "expExitCode": "0",
- "verifyCmd": "$TC filter add dev $DEV1 chain 0 parent 1:",
- "matchPattern": "Error: Filter kind and protocol must be
specified.",
- "matchCount": "1",
- "teardown": [
- "$TC qdisc del dev $DEV1 root handle 1: htb default 1"
- ]
}
]
diff --git
a/tools/testing/selftests/tc-testing/tc-tests/infra/filters.json
b/tools/testing/selftests/tc-testing/tc-tests/infra/filters.
json
new file mode 100644
index 000000000000..55d6f209c388
--- /dev/null
+++ b/tools/testing/selftests/tc-testing/tc-tests/infra/filters.json
@@ -0,0 +1,24 @@
+[
+ {
+ "id": "c2b4",
+ "name": "Adding a new filter after flushing empty chain doesnt
cause an infinite loop",
+ "category": [
+ "filter",
+ "chain"
+ ],
+ "setup": [
+ "$IP link add dev $DUMMY type dummy || /bin/true",
+ "$TC qdisc add dev $DUMMY root handle 1: htb default 1",
+ "$TC chain add dev $DUMMY",
+ "$TC filter del dev $DUMMY chain 0 parent 1: prio 0"
+ ],
+ "cmdUnderTest": "$TC filter add dev $DUMMY chain 0 parent 1:",
+ "expExitCode": "2",
+ "verifyCmd": "$TC chain ls dev $DUMMY",
+ "matchPattern": "chain parent 1: chain 0",
+ "matchCount": "1",
+ "teardown": [
+ "$TC qdisc del dev $DUMMY root handle 1: htb default 1"
+ ]
+ }
+]