When a list of filters at a given block is requested, tc first validates that the block exists before doing the filter query. Currently the validation routine checks ingress and egress blocks. But now that blocks can be bound to qevents as well, qevent blocks should be looked for as well:
# ip link add up type dummy # tc qdisc add dev dummy1 root handle 1: \ red min 30000 max 60000 avpkt 1000 qevent early_drop block 100 # tc filter add block 100 pref 1234 handle 102 matchall action drop # tc filter show block 100 Cannot find block "100" This patchset fixes this issue: # tc filter show block 100 filter protocol all pref 1234 matchall chain 0 filter protocol all pref 1234 matchall chain 0 handle 0x66 not_in_hw action order 1: gact action drop random type none pass val 0 index 2 ref 1 bind 1 In patch #1, the helpers and necessary infrastructure is introduced, including a new qdisc_util callback that implements sniffing out bound blocks in a given qdisc. In patch #2, RED implements the new callback. v2: - Patch #1: - In tc_qdisc_block_exists_cb(), do not initialize 'q'. - Propagate upwards errors from q->has_block. Petr Machata (2): tc: Look for blocks in qevents tc: q_red: Implement has_block for RED tc/q_red.c | 17 +++++++++++++++++ tc/tc_qdisc.c | 14 ++++++++++++++ tc/tc_qevent.c | 15 +++++++++++++++ tc/tc_qevent.h | 2 ++ tc/tc_util.h | 2 ++ 5 files changed, 50 insertions(+) -- 2.20.1