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| author | Jiri Kosina <jkosina@suse.cz> | 2016-08-17 00:53:46 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-08-19 07:19:08 +0300 |
| commit | ea3274695353127d12155d45be1f2d62ab19c897 (patch) | |
| tree | 3c2021737a3e03e57190ccfc5c9c33a0fc4f2e07 /net/sched/sch_api.c | |
| parent | 69012ae425d76ecacc573ecdbd2c360bd8c2b842 (diff) | |
| download | linux-ea3274695353127d12155d45be1f2d62ab19c897.tar.xz | |
net: sched: avoid duplicates in qdisc dump
tc_dump_qdisc() performs dumping of the per-device qdiscs in two phases;
first, the "standard" dev->qdisc is being dumped. Second, if there is/are
ingress queue(s), they are being dumped as well.
After conversion of netdevice's qdisc linked-list into hashtable, these
two sets are not in two disjunctive sets/lists any more, but are both
"reachable" directly from netdevice's hashtable. As a consequence, the
"full-depth" dump of the ingress qdiscs results in immediately hitting the
netdevice hashtable again, and duplicating the dump that has already been
performed for dev->qdisc.
What in fact needs to be dumped in case of ingress queue is "just" the
top-level ingress qdisc, as everything else has been dumped already.
Fix this by extending tc_dump_qdisc_root() in a way that it can be instructed
whether it should (while performing the "full" per-netdev qdisc dump) perform
the whole recursion, or just dump "additional" top-level (ingress) qdiscs
without performing any kind of recursion.
This fixes duplicate dumps such as
qdisc mq 0: root
qdisc pfifo_fast 0: parent :4 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :3 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :1 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc clsact ffff: parent ffff:fff1
qdisc pfifo_fast 0: parent :4 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :3 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :2 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
qdisc pfifo_fast 0: parent :1 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
Fixes: 59cc1f61f ("net: sched: convert qdisc linked list to hashtable")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_api.c')
| -rw-r--r-- | net/sched/sch_api.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index ff515d01951e..d677b3484d81 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1435,7 +1435,7 @@ err_out: static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, struct netlink_callback *cb, - int *q_idx_p, int s_q_idx) + int *q_idx_p, int s_q_idx, bool recur) { int ret = 0, q_idx = *q_idx_p; struct Qdisc *q; @@ -1455,7 +1455,13 @@ static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, q_idx++; } - if (!qdisc_dev(root)) + /* If dumping singletons, there is no qdisc_dev(root) and the singleton + * itself has already been dumped. + * + * If we've already dumped the top-level (ingress) qdisc above and the global + * qdisc hashtable, we don't want to hit it again + */ + if (!qdisc_dev(root) || !recur) goto out; hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { @@ -1499,13 +1505,13 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) s_q_idx = 0; q_idx = 0; - if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0) + if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx, true) < 0) goto done; dev_queue = dev_ingress_queue(dev); if (dev_queue && tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb, - &q_idx, s_q_idx) < 0) + &q_idx, s_q_idx, false) < 0) goto done; cont: |