kernel.git/net/sched/act_api.c, branch linux-4.8.y

net_sched: reorder pernet ops and act ops registrations

2016-11-15T06:48:51Z

[ Upstream commit ab102b80cef28c20b3ef7794806c3a982c6444fc ] Krister reported a kernel NULL pointer dereference after tcf_action_init_1() invokes a_o->init(), it is a race condition where one thread calling tcf_register_action() to initialize the netns data after putting act ops in the global list and the other thread searching the list and then calling a_o->init(net, ...). Fix this by moving the pernet ops registration before making the action ops visible. This is fine because: a) we don't rely on act_base in pernet ops->init(), b) in the worst case we have a fully initialized netns but ops is still not ready so new actions still can't be created. Reported-by: Krister Johansen Tested-by: Krister Johansen Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net_sched: convert tcf_exts from list to pointer array

2016-08-17T23:27:51Z

As pointed out by Jamal, an action could be shared by multiple filters, so we can't use list to chain them any more after we get rid of the original tc_action. Instead, we could just save pointers to these actions in tcf_exts, since they are refcount'ed, so convert the list to an array of pointers. The "ugly" part is the action API still accepts list as a parameter, I just introduce a helper function to convert the array of pointers to a list, instead of relying on the C99 feature to iterate the array. Fixes: a85a970af265 ("net_sched: move tc_action into tcf_common") Reported-by: Jamal Hadi Salim Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller

net_sched: remove an unnecessary list_del()

2016-08-17T23:27:51Z

This list_del() for tc action is not needed actually, because we only use this list to chain bulk operations, therefore should not be carried for latter operations. Fixes: ec0595cc4495 ("net_sched: get rid of struct tcf_common") Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller

net_sched: remove the leftover cleanup_a()

2016-08-17T23:27:51Z

After refactoring tc_action into tcf_common, we no longer need to cleanup temporary "actions" in list, they are permanently stored in the hashtable. Fixes: a85a970af265 ("net_sched: move tc_action into tcf_common") Reported-by: Jamal Hadi Salim Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller

net_sched: get rid of struct tcf_common

2016-07-26T04:49:20Z

After the previous patch, struct tc_action should be enough to represent the generic tc action, tcf_common is not necessary any more. This patch gets rid of it to make tc action code more readable. Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller

net_sched: move tc_action into tcf_common

2016-07-26T04:49:19Z

struct tc_action is confusing, currently we use it for two purposes: 1) Pass in arguments and carry out results from helper functions 2) A generic representation for tc actions The first one is error-prone, since we need to make sure we don't miss anything. This patch aims to get rid of this use, by moving tc_action into tcf_common, so that they are allocated together in hashtable and can be cast'ed easily. And together with the following patch, we could really make tc_action a generic representation for all tc actions and each type of action can inherit from it. Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-06-30T09:03:36Z

Several cases of overlapping changes, except the packet scheduler conflicts which deal with the addition of the free list parameter to qdisc_enqueue(). Signed-off-by: David S. Miller

net sched actions: bug fix dumping actions directly didnt produce NLMSG_DONE

2016-06-15T21:02:53Z

This refers to commands to direct action access as follows: sudo tc actions add action drop index 12 sudo tc actions add action pipe index 10 And then dumping them like so: sudo tc actions ls action gact iproute2 worked because it depended on absence of TCA_ACT_TAB TLV as end of message. This fix has been tested with iproute2 and is backward compatible. Signed-off-by: Jamal Hadi Salim Acked-by: Cong Wang Signed-off-by: David S. Miller

net_sched: make tcf_hash_check() boolean

2016-06-15T19:43:35Z

Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller

net: sched: do not acquire qdisc spinlock in qdisc/class stats dump

2016-06-07T23:37:14Z

Large tc dumps (tc -s {qdisc|class} sh dev ethX) done by Google BwE host agent [1] are problematic at scale : For each qdisc/class found in the dump, we currently lock the root qdisc spinlock in order to get stats. Sampling stats every 5 seconds from thousands of HTB classes is a challenge when the root qdisc spinlock is under high pressure. Not only the dumps take time, they also slow down the fast path (queue/dequeue packets) by 10 % to 20 % in some cases. An audit of existing qdiscs showed that sch_fq_codel is the only qdisc that might need the qdisc lock in fq_codel_dump_stats() and fq_codel_dump_class_stats() In v2 of this patch, I now use the Qdisc running seqcount to provide consistent reads of packets/bytes counters, regardless of 32/64 bit arches. I also changed rate estimators to use the same infrastructure so that they no longer need to lock root qdisc lock. [1] http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdf Signed-off-by: Eric Dumazet Cc: Cong Wang Cc: Jamal Hadi Salim Cc: John Fastabend Cc: Kevin Athey Cc: Xiaotian Pei Signed-off-by: David S. Miller