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| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-08-25 02:51:29 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-08-26 03:19:10 +0300 |
| commit | 143976ce992fcf3bfc0f4d15d5726bb492dcf262 (patch) | |
| tree | a3f90e272ef152d3d262f1e56337d830315ba1b3 /net/sched/cls_api.c | |
| parent | 14546ba1e5653e5dd00d113e98bd21b5b235192b (diff) | |
| download | linux-143976ce992fcf3bfc0f4d15d5726bb492dcf262.tar.xz | |
net_sched: remove tc class reference counting
For TC classes, their ->get() and ->put() are always paired, and the
reference counting is completely useless, because:
1) For class modification and dumping paths, we already hold RTNL lock,
so all of these ->get(),->change(),->put() are atomic.
2) For filter bindiing/unbinding, we use other reference counter than
this one, and they should have RTNL lock too.
3) For ->qlen_notify(), it is special because it is called on ->enqueue()
path, but we already hold qdisc tree lock there, and we hold this
tree lock when graft or delete the class too, so it should not be gone
or changed until we release the tree lock.
Therefore, this patch removes ->get() and ->put(), but:
1) Adds a new ->find() to find the pointer to a class by classid, no
refcnt.
2) Move the original class destroy upon the last refcnt into ->delete(),
right after releasing tree lock. This is fine because the class is
already removed from hash when holding the lock.
For those who also use ->put() as ->unbind(), just rename them to reflect
this change.
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/cls_api.c')
| -rw-r--r-- | net/sched/cls_api.c | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index eef6b077f30e..d470a4e2de58 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -586,7 +586,7 @@ replay: /* Do we search for filter, attached to class? */ if (TC_H_MIN(parent)) { - cl = cops->get(q, parent); + cl = cops->find(q, parent); if (cl == 0) return -ENOENT; } @@ -716,8 +716,6 @@ replay: errout: if (chain) tcf_chain_put(chain); - if (cl) - cops->put(q, cl); if (err == -EAGAIN) /* Replay the request. */ goto replay; @@ -822,17 +820,17 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) goto out; cops = q->ops->cl_ops; if (!cops) - goto errout; + goto out; if (!cops->tcf_block) - goto errout; + goto out; if (TC_H_MIN(tcm->tcm_parent)) { - cl = cops->get(q, tcm->tcm_parent); + cl = cops->find(q, tcm->tcm_parent); if (cl == 0) - goto errout; + goto out; } block = cops->tcf_block(q, cl); if (!block) - goto errout; + goto out; index_start = cb->args[0]; index = 0; @@ -847,9 +845,6 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) cb->args[0] = index; -errout: - if (cl) - cops->put(q, cl); out: return skb->len; } |