From 401192113730947572d280ec465555ab9ff5a597 Mon Sep 17 00:00:00 2001 From: Vlad Buslov Date: Mon, 26 Aug 2019 16:44:59 +0300 Subject: net: sched: refactor block offloads counter usage Without rtnl lock protection filters can no longer safely manage block offloads counter themselves. Refactor cls API to protect block offloadcnt with tcf_block->cb_lock that is already used to protect driver callback list and nooffloaddevcnt counter. The counter can be modified by concurrent tasks by new functions that execute block callbacks (which is safe with previous patch that changed its type to atomic_t), however, block bind/unbind code that checks the counter value takes cb_lock in write mode to exclude any concurrent modifications. This approach prevents race conditions between bind/unbind and callback execution code but allows for concurrency for tc rule update path. Move block offload counter, filter in hardware counter and filter flags management from classifiers into cls hardware offloads API. Make functions tcf_block_offload_{inc|dec}() and tc_cls_offload_cnt_update() to be cls API private. Implement following new cls API to be used instead: tc_setup_cb_add() - non-destructive filter add. If filter that wasn't already in hardware is successfully offloaded, increment block offloads counter, set filter in hardware counter and flag. On failure, previously offloaded filter is considered to be intact and offloads counter is not decremented. tc_setup_cb_replace() - destructive filter replace. Release existing filter block offload counter and reset its in hardware counter and flag. Set new filter in hardware counter and flag. On failure, previously offloaded filter is considered to be destroyed and offload counter is decremented. tc_setup_cb_destroy() - filter destroy. Unconditionally decrement block offloads counter. tc_setup_cb_reoffload() - reoffload filter to single cb. Execute cb() and call tc_cls_offload_cnt_update() if cb() didn't return an error. Refactor all offload-capable classifiers to atomically offload filters to hardware, change block offload counter, and set filter in hardware counter and flag by means of the new cls API functions. Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- net/sched/cls_bpf.c | 38 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 20 deletions(-) (limited to 'net/sched/cls_bpf.c') diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c index 3f7a9c02b70c..bf10bdaf5012 100644 --- a/net/sched/cls_bpf.c +++ b/net/sched/cls_bpf.c @@ -163,17 +163,19 @@ static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog, cls_bpf.exts_integrated = obj->exts_integrated; if (oldprog) - tcf_block_offload_dec(block, &oldprog->gen_flags); + err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf, + skip_sw, &oldprog->gen_flags, + &oldprog->in_hw_count, + &prog->gen_flags, &prog->in_hw_count, + true); + else + err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf, + skip_sw, &prog->gen_flags, + &prog->in_hw_count, true); - err = tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, skip_sw); - if (prog) { - if (err < 0) { - cls_bpf_offload_cmd(tp, oldprog, prog, extack); - return err; - } else if (err > 0) { - prog->in_hw_count = err; - tcf_block_offload_inc(block, &prog->gen_flags); - } + if (prog && err) { + cls_bpf_offload_cmd(tp, oldprog, prog, extack); + return err; } if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW)) @@ -230,7 +232,7 @@ static void cls_bpf_offload_update_stats(struct tcf_proto *tp, cls_bpf.name = prog->bpf_name; cls_bpf.exts_integrated = prog->exts_integrated; - tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false); + tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true); } static int cls_bpf_init(struct tcf_proto *tp) @@ -673,15 +675,11 @@ static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb cls_bpf.name = prog->bpf_name; cls_bpf.exts_integrated = prog->exts_integrated; - err = cb(TC_SETUP_CLSBPF, &cls_bpf, cb_priv); - if (err) { - if (add && tc_skip_sw(prog->gen_flags)) - return err; - continue; - } - - tc_cls_offload_cnt_update(block, &prog->in_hw_count, - &prog->gen_flags, add); + err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF, + &cls_bpf, cb_priv, &prog->gen_flags, + &prog->in_hw_count); + if (err) + return err; } return 0; -- cgit v1.2.3