Flushing must consistently return ENOMEM on failure of any allocation
Signed-off-by: NJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Flushing of actions has been broken since we changed
the semantics of netlink parsed tb[X] to mean X is an attribute type.
This makes the flushing work.
Signed-off-by: NJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since qdisc_stab_lock is used in qdisc_put_stab(), which is called in
BH context from __qdisc_destroy() RCU callback, softirq safe locking
is needed.
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon bug reports by Stephen Hemminger.

We still had some cases using ->qdisc instead of ->qdisc_sleeping.

Also, qdisc_lookup() should return ingress qdiscs.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an action is added several times with the same exact index
it gets deleted on every even-numbered attempt.
This fixes that issue.
Signed-off-by: NJamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bug reported by Stephen Hemminger.

We need to fetch the root from ->qdisc_sleeping not ->qdisc.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As noticed by Stephen Hemminger, the root qdisc is denoted by
TC_H_ROOT, not zero.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Patrick McHardy <kaber@trash.net> noticed that it would be nice to
handle NET_XMIT_BYPASS by NET_XMIT_SUCCESS with an internal qdisc flag
__NET_XMIT_BYPASS and to remove the mapping from dev_queue_xmit().

David Miller <davem@davemloft.net> spotted a serious bug in the first
version of this patch.
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Patrick McHardy <kaber@trash.net> noticed:
"The other problem that affects all qdiscs supporting actions is
TC_ACT_QUEUED/TC_ACT_STOLEN getting mapped to NET_XMIT_SUCCESS
even though the packet is not queued, corrupting upper qdiscs'
qlen counters."

and later explained:
"The reason why it translates it at all seems to be to not increase
the drops counter. Within a single qdisc this could be avoided by
other means easily, upper qdiscs would still increase the counter
when we return anything besides NET_XMIT_SUCCESS though.

This means we need a new NET_XMIT return value to indicate this to
the upper qdiscs. So I'd suggest to introduce NET_XMIT_STOLEN,
return that to upper qdiscs and translate it to NET_XMIT_SUCCESS
in dev_queue_xmit, similar to NET_XMIT_BYPASS."

David Miller <davem@davemloft.net> noticed:
"Maybe these NET_XMIT_* values being passed around should be a set of
bits. They could be composed of base meanings, combined with specific
attributes.

So you could say "NET_XMIT_DROP | __NET_XMIT_NO_DROP_COUNT"

The attributes get masked out by the top-level ->enqueue() caller,
such that the base meanings are the only thing that make their
way up into the stack. If it's only about communication within the
qdisc tree, let's simply code it that way."

This patch is trying to realize these ideas.
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based upon a bug report by Jeff Kirsher.

Don't use qdisc_root_lock() in these cases as the root
qdisc could have been changed, and we'd thus lock the
wrong object.

Tested by Emil S Tantilov who confirms that this seems
to fix the problem.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When support for multiple TX queues were added, the
netif_tx_lock() routines we converted to iterate over
all TX queues and grab each queue's spinlock.

This causes heartburn for lockdep and it's not a healthy
thing to do with lots of TX queues anyways.

So modify this to use a top-level lock and a "frozen"
state for the individual TX queues.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bug report from Steven Jan Springl:

	Issuing the following command causes a kernel oops:
		tc qdisc add dev eth0 handle ffff: ingress

The problem mostly stems from all of the special case handling of
ingress qdiscs.

So, to fix this, do the grafting operation the same way we do for TX
qdiscs.  Which means that dev_activate() and dev_deactivate() now do
the "qdisc_sleeping <--> qdisc" transitions on dev->rx_queue too.

Future simplifications are possible now, mainly because it is
impossible for dev_queue->{qdisc,qdisc_sleeping} to be NULL.  There
are NULL checks all over to handle the ingress qdisc special case
that used to exist before this commit.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

make it atomic_long_t; while we are at it, get rid of useless checks in affs,
hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This reverts commit f867e6af.

Based upon discussions between Jarek and Patrick McHardy
this is field being set is more a config parameter than a
statistic.  And we should add a true statistic to provide
this information if we really want it.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.

I could make at least one BUILD_BUG_ON conversion.
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Qdisc locks need to be held with BH disabled.
Tested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dump the "flows" number according to the number of active flows
instead of repeating the "limit".
Reported-by: NDenys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: NJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes the needlessly global qdisc_class_hash_alloc() static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As suggested by Dave:

This patch adds a function to get the driver name from a struct net_device,
and consequently uses this in the watchdog timeout handler to print as 
part of the message. 
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit a0c80b80.

After discussions with Jamal and Herbert on netdev, we should
provide at least minimal prioritization at the qdisc level
even in multiqueue situations.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Removed unused variable 'skb' in the dev_deactivate_queue function
Signed-off-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The stab bits can't be referenced uniless the full
packet scheduler layer is enabled.

Reported by Stephen Rothwell.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add size table functions for qdiscs and calculate packet size in
qdisc_enqueue().

Based on patch by Patrick McHardy
 http://marc.info/?l=linux-netdev&m=115201979221729&w=2Signed-off-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like noop_qdisc, it needs a dummy backpointer and
explicit qdisc->q.lock initialization.

Based upon a report by Stephen Hemminger.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Idea is from Patrick McHardy.

Instead of managing the list of qdiscs on the device level, manage it
in the root qdisc of a netdev_queue.  This solves all kinds of
visibility issues during qdisc destruction.

The way to iterate over all qdiscs of a netdev_queue is to visit
the netdev_queue->qdisc, and then traverse it's list.

The only special case is to ignore builting qdiscs at the root when
dumping or doing a qdisc_lookup().  That was not needed previously
because builtin qdiscs were not added to the device's qdisc_list.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The u32_list is just an indirect way of maintaining a reference
to a U32 node on a per-qdisc basis.

Just add an explicit node pointer for u32 to struct Qdisc an do
away with this global list.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of 'pfifo_fast' we have just plain 'fifo_fast'.
No priority queues, just a straight FIFO.

This is necessary in order to legally have a seperate
qdisc per queue in multi-TX-queue setups, and thus get
full parallelization.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the destruction of the old queue into qdisc_graft().

When operating on a root qdisc (ie. "parent == NULL"), apply
the operation to all queues.  The caller has grabbed a single
implicit reference for this graft, therefore when we apply the
change to more than one queue we must grab additional qdisc
references.

Otherwise, we are operating on a class of a specific parent qdisc, and
therefore no multiqueue handling is necessary.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can simply use the qdisc->q.lock for all of the
qdisc tree synchronization.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No longer used.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Lock the root of the qdisc being operated upon.

All explicit references to qdisc_tree_lock() are now gone.
The only remaining uses are via the sch_tree_{lock,unlock}()
and tcf_tree_{lock,unlock}() macros.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And give it it's own lock.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It just wants the qdisc tree to be synchronized, so grabbing
qdisc_root_lock() is sufficient.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It just wants the qdisc tree for the filter to be synchronized.
So just BH lock qdisc_root_lock(q) instead.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This eliminates another qdisc_lock_tree user.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows less strict control of access to the qdisc attached to a
netdev_queue.  It is even allowed to enqueue into a qdisc which is
in the process of being destroyed.  The RCU handler will toss out
those packets.

We will need this to handle sharing of a qdisc amongst multiple
TX queues.  In such a setup the lock has to be shared, so will
be inside of the qdisc itself.  At which point the netdev_queue
lock cannot be used to hard synchronize access to the ->qdisc
pointer.

One operation we have to keep inside of qdisc_destroy() is the list
deletion.  It is the only piece of state visible after the RCU quiesce
period, so we have to undo it early and under the appropriate locking.

The operations in the RCU handler do not need any looking because the
qdisc tree is no longer visible to anything at that point.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are registering the device, there is no way anyone can get
at this object's qdiscs yet in any meaningful way.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we have shared qdiscs, packets come out of the qdiscs
for multiple transmit queues.

Therefore it doesn't make any sense to schedule the transmit
queue when logically we cannot know ahead of time the TX
queue of the SKB that the qdisc->dequeue() will give us.

Just for sanity I added a BUG check to make sure we never
get into a state where the noop_qdisc is scheduled.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>