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net_sched: reintroduce dev->qdisc for use by sch_api

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Currently the multiqueue integration with the qdisc API suffers from
a few problems:

- with multiple queues, all root qdiscs use the same handle. This means
  they can't be exposed to userspace in a backwards compatible fashion.

- all API operations always refer to queue number 0. Newly created
  qdiscs are automatically shared between all queues, its not possible
  to address individual queues or restore multiqueue behaviour once a
  shared qdisc has been attached.

- Dumps only contain the root qdisc of queue 0, in case of non-shared
  qdiscs this means the statistics are incomplete.

This patch reintroduces dev->qdisc, which points to the (single) root qdisc
from userspace's point of view. Currently it either points to the first
(non-shared) default qdisc, or a qdisc shared between all queues. The
following patches will introduce a classful dummy qdisc, which will be used
as root qdisc and contain the per-queue qdiscs as children.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2009-09-04 06:41:18 +00:00 committed by David S. Miller
parent 5b9a9ccfad
commit af356afa01
5 changed files with 34 additions and 48 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

3
include/linux/netdevice.h
View file

@ -832,6 +832,9 @@ struct net_device
/* Number of TX queues currently active in device */
unsigned int real_num_tx_queues;
/* root qdisc from userspace point of view */
struct Qdisc *qdisc;
unsigned long tx_queue_len; /* Max frames per queue allowed */
spinlock_t tx_global_lock;
/*

6
net/core/rtnetlink.c
View file

@ -606,7 +606,6 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
int type, u32 pid, u32 seq, u32 change,
unsigned int flags)
{
struct netdev_queue *txq;
struct ifinfomsg *ifm;
struct nlmsghdr *nlh;
const struct net_device_stats *stats;
@ -637,9 +636,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
if (dev->master)
NLA_PUT_U32(skb, IFLA_MASTER, dev->master->ifindex);
txq = netdev_get_tx_queue(dev, 0);
if (txq->qdisc_sleeping)
NLA_PUT_STRING(skb, IFLA_QDISC, txq->qdisc_sleeping->ops->id);
if (dev->qdisc)
NLA_PUT_STRING(skb, IFLA_QDISC, dev->qdisc->ops->id);
if (dev->ifalias)
NLA_PUT_STRING(skb, IFLA_IFALIAS, dev->ifalias);

7
net/sched/cls_api.c
View file

@ -168,8 +168,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
/* Find qdisc */
if (!parent) {
struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
q = dev_queue->qdisc_sleeping;
q = dev->qdisc;
parent = q->handle;
} else {
q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
@ -408,7 +407,6 @@ static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct netdev_queue *dev_queue;
int t;
int s_t;
struct net_device *dev;
@ -427,9 +425,8 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
return skb->len;
dev_queue = netdev_get_tx_queue(dev, 0);
if (!tcm->tcm_parent)
q = dev_queue->qdisc_sleeping;
q = dev->qdisc;
else
q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
if (!q)

41
net/sched/sch_api.c
View file

@ -207,7 +207,7 @@ static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
static void qdisc_list_add(struct Qdisc *q)
{
if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
list_add_tail(&q->list, &qdisc_root_sleeping(q)->list);
list_add_tail(&q->list, &qdisc_dev(q)->qdisc->list);
}
void qdisc_list_del(struct Qdisc *q)
@ -219,17 +219,11 @@ EXPORT_SYMBOL(qdisc_list_del);
struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
{
unsigned int i;
struct Qdisc *q;
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
struct Qdisc *txq_root = txq->qdisc_sleeping;
q = qdisc_match_from_root(txq_root, handle);
if (q)
goto out;
}
q = qdisc_match_from_root(dev->qdisc, handle);
if (q)
goto out;
q = qdisc_match_from_root(dev->rx_queue.qdisc_sleeping, handle);
out:
@ -720,9 +714,14 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
if (new && i > 0)
atomic_inc(&new->refcnt);
notify_and_destroy(skb, n, classid, old, new);
qdisc_destroy(old);
}
notify_and_destroy(skb, n, classid, dev->qdisc, new);
if (new)
atomic_inc(&new->refcnt);
dev->qdisc = new ? : &noop_qdisc;
if (dev->flags & IFF_UP)
dev_activate(dev);
} else {
@ -974,9 +973,7 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
q = dev->rx_queue.qdisc_sleeping;
}
} else {
struct netdev_queue *dev_queue;
dev_queue = netdev_get_tx_queue(dev, 0);
q = dev_queue->qdisc_sleeping;
q = dev->qdisc;
}
if (!q)
return -ENOENT;
@ -1044,9 +1041,7 @@ static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
q = dev->rx_queue.qdisc_sleeping;
}
} else {
struct netdev_queue *dev_queue;
dev_queue = netdev_get_tx_queue(dev, 0);
q = dev_queue->qdisc_sleeping;
q = dev->qdisc;
}
/* It may be default qdisc, ignore it */
@ -1291,8 +1286,7 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
s_q_idx = 0;
q_idx = 0;
dev_queue = netdev_get_tx_queue(dev, 0);
if (tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb, &q_idx, s_q_idx) < 0)
if (tc_dump_qdisc_root(dev->qdisc, skb, cb, &q_idx, s_q_idx) < 0)
goto done;
dev_queue = &dev->rx_queue;
@ -1323,7 +1317,6 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
{
struct net *net = sock_net(skb->sk);
struct netdev_queue *dev_queue;
struct tcmsg *tcm = NLMSG_DATA(n);
struct nlattr *tca[TCA_MAX + 1];
struct net_device *dev;
@ -1361,7 +1354,6 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
/* Step 1. Determine qdisc handle X:0 */
dev_queue = netdev_get_tx_queue(dev, 0);
if (pid != TC_H_ROOT) {
u32 qid1 = TC_H_MAJ(pid);
@ -1372,7 +1364,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
} else if (qid1) {
qid = qid1;
} else if (qid == 0)
qid = dev_queue->qdisc_sleeping->handle;
qid = dev->qdisc->handle;
/* Now qid is genuine qdisc handle consistent
both with parent and child.
@ -1383,7 +1375,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
pid = TC_H_MAKE(qid, pid);
} else {
if (qid == 0)
qid = dev_queue->qdisc_sleeping->handle;
qid = dev->qdisc->handle;
}
/* OK. Locate qdisc */
@ -1588,8 +1580,7 @@ static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
s_t = cb->args[0];
t = 0;
dev_queue = netdev_get_tx_queue(dev, 0);
if (tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb, &t, s_t) < 0)
if (tc_dump_tclass_root(dev->qdisc, skb, tcm, cb, &t, s_t) < 0)
goto done;
dev_queue = &dev->rx_queue;

25
net/sched/sch_generic.c
View file

@ -623,19 +623,6 @@ void qdisc_destroy(struct Qdisc *qdisc)
}
EXPORT_SYMBOL(qdisc_destroy);
static bool dev_all_qdisc_sleeping_noop(struct net_device *dev)
{
unsigned int i;
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
if (txq->qdisc_sleeping != &noop_qdisc)
return false;
}
return true;
}
static void attach_one_default_qdisc(struct net_device *dev,
struct netdev_queue *dev_queue,
void *_unused)
@ -677,6 +664,7 @@ static void transition_one_qdisc(struct net_device *dev,
void dev_activate(struct net_device *dev)
{
struct netdev_queue *txq;
int need_watchdog;
/* No queueing discipline is attached to device;
@ -685,9 +673,14 @@ void dev_activate(struct net_device *dev)
virtual interfaces
*/
if (dev_all_qdisc_sleeping_noop(dev))
if (dev->qdisc == &noop_qdisc) {
netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
txq = netdev_get_tx_queue(dev, 0);
dev->qdisc = txq->qdisc_sleeping;
atomic_inc(&dev->qdisc->refcnt);
}
if (!netif_carrier_ok(dev))
/* Delay activation until next carrier-on event */
return;
@ -777,6 +770,7 @@ static void dev_init_scheduler_queue(struct net_device *dev,
void dev_init_scheduler(struct net_device *dev)
{
dev->qdisc = &noop_qdisc;
netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
dev_init_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc);
@ -802,5 +796,8 @@ void dev_shutdown(struct net_device *dev)
{
netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
shutdown_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc);
qdisc_destroy(dev->qdisc);
dev->qdisc = &noop_qdisc;
WARN_ON(timer_pending(&dev->watchdog_timer));
}