net/sched: sch_qfq: Avoid triggering might_sleep in atomic context in qfq_delete_class

might_sleep could be trigger in the atomic context in qfq_delete_class.

qfq_destroy_class was moved into atomic context locked
by sch_tree_lock to avoid a race condition bug on
qfq_aggregate. However, might_sleep could be triggered by
qfq_destroy_class, which introduced sleeping in atomic context (path:
qfq_destroy_class->qdisc_put->__qdisc_destroy->lockdep_unregister_key
->might_sleep).

Considering the race is on the qfq_aggregate objects, keeping
qfq_rm_from_agg in the lock but moving the left part out can solve
this issue.

Fixes: 5e28d5a3f774 ("net/sched: sch_qfq: Fix race condition on qfq_aggregate")
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Xiang Mei <[email protected]>
Link: https://patch.msgid.link/[email protected]
Reviewed-by: Cong Wang <[email protected]>
Reviewed-by: Dan Carpenter <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

0 files changed, 0 insertions, 0 deletions