Commit graph

112 commits

Author SHA1 Message Date
Jarek Poplawski
7c64b9f3f5 pkt_sched: Fix qdisc_create on stab error handling
If qdisc_get_stab returns error in qdisc_create there is skipped qdisc
ops->destroy, which is necessary because it's after ops->init at the
moment, so memory leaks are quite probable.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-15 23:42:05 -07:00
Jarek Poplawski
926e61b7c4 pkt_sched: Fix tx queue selection in tc_modify_qdisc
After the recent mq change there is the new select_queue qdisc class
method used in tc_modify_qdisc, but it works OK only for direct child
qdiscs of mq qdisc. Grandchildren always get the first tx queue, which
would give wrong qdisc_root etc. results (e.g. for sch_htb as child of
sch_prio). This patch fixes it by using parent's dev_queue for such
grandchildren qdiscs. The select_queue method's return type is changed
BTW.

With feedback from: Patrick McHardy <kaber@trash.net>

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-15 02:53:07 -07:00
Jarek Poplawski
036d6a673f pkt_sched: Fix qdisc_graft WRT ingress qdisc
After the recent mq change using ingress qdisc overwrites dev->qdisc;
there is also a wrong old qdisc pointer passed to notify_and_destroy.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-14 17:03:57 -07:00
Linus Torvalds
d7e9660ad9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1623 commits)
  netxen: update copyright
  netxen: fix tx timeout recovery
  netxen: fix file firmware leak
  netxen: improve pci memory access
  netxen: change firmware write size
  tg3: Fix return ring size breakage
  netxen: build fix for INET=n
  cdc-phonet: autoconfigure Phonet address
  Phonet: back-end for autoconfigured addresses
  Phonet: fix netlink address dump error handling
  ipv6: Add IFA_F_DADFAILED flag
  net: Add DEVTYPE support for Ethernet based devices
  mv643xx_eth.c: remove unused txq_set_wrr()
  ucc_geth: Fix hangs after switching from full to half duplex
  ucc_geth: Rearrange some code to avoid forward declarations
  phy/marvell: Make non-aneg speed/duplex forcing work for 88E1111 PHYs
  drivers/net/phy: introduce missing kfree
  drivers/net/wan: introduce missing kfree
  net: force bridge module(s) to be GPL
  Subject: [PATCH] appletalk: Fix skb leak when ipddp interface is not loaded
  ...

Fixed up trivial conflicts:

 - arch/x86/include/asm/socket.h

   converted to <asm-generic/socket.h> in the x86 tree.  The generic
   header has the same new #define's, so that works out fine.

 - drivers/net/tun.c

   fix conflict between 89f56d1e9 ("tun: reuse struct sock fields") that
   switched over to using 'tun->socket.sk' instead of the redundantly
   available (and thus removed) 'tun->sk', and 2b980dbd ("lsm: Add hooks
   to the TUN driver") which added a new 'tun->sk' use.

   Noted in 'next' by Stephen Rothwell.
2009-09-14 10:37:28 -07:00
Patrick McHardy
23bcf634c8 net_sched: fix estimator lock selection for mq child qdiscs
When new child qdiscs are attached to the mq qdisc, they are actually
attached as root qdiscs to the device queues. The lock selection for
new estimators incorrectly picks the root lock of the existing and
to be replaced qdisc, which results in a use-after-free once the old
qdisc has been destroyed.

Mark mq qdisc instances with a new flag and treat qdiscs attached to
mq as children similar to regular root qdiscs.

Additionally prevent estimators from being attached to the mq qdisc
itself since it only updates its byte and packet counters during dumps.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-09 18:11:23 -07:00
David S. Miller
6ec1c69a8f net_sched: add classful multiqueue dummy scheduler
This patch adds a classful dummy scheduler which can be used as root qdisc
for multiqueue devices and exposes each device queue as a child class.

This allows to address queues individually and graft them similar to regular
classes. Additionally it presents an accumulated view of the statistics of
all real root qdiscs in the dummy root.

Two new callbacks are added to the qdisc_ops and qdisc_class_ops:

- cl_ops->select_queue selects the tx queue number for new child classes.

- qdisc_ops->attach() overrides root qdisc device grafting to attach
  non-shared qdiscs to the queues.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06 02:07:05 -07:00
Patrick McHardy
589983cd21 net_sched: move dev_graft_qdisc() to sch_generic.c
It will be used in a following patch by the multiqueue qdisc.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06 02:07:05 -07:00
Patrick McHardy
af356afa01 net_sched: reintroduce dev->qdisc for use by sch_api
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>
2009-09-06 02:07:03 -07:00
Patrick McHardy
de6d5cdf88 net_sched: make cls_ops->change and cls_ops->delete optional
Some schedulers don't support creating, changing or deleting classes.
Make the respective callbacks optionally and consistently return
-EOPNOTSUPP for unsupported operations, instead of currently either
-EOPNOTSUPP, -ENOSYS or no error.

In case of sch_prio and sch_multiq, the removed operations additionally
checked for an invalid class. This is not necessary since the class
argument can only orginate from ->get() or in case of ->change is 0
for creation of new classes, in which case ->change() incorrectly
returned -ENOENT.

As a side-effect, this patch fixes a possible (root-only) NULL pointer
function call in sch_ingress, which didn't implement a so far mandatory
->delete() operation.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06 02:07:02 -07:00
Patrick McHardy
c9f1d0389b net_sched: fix class grafting errno codes
If the parent qdisc doesn't support classes, use EOPNOTSUPP.
If the parent class doesn't exist, use ENOENT. Currently EINVAL
is returned in both cases.

Additionally check whether grafting is supported and remove a now
unnecessary graft function from sch_ingress.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-04 23:10:15 -07:00
Eric Dumazet
16ebb5e0b3 tc: Fix unitialized kernel memory leak
Three bytes of uninitialized kernel memory are currently leaked to user

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-02 22:55:17 -07:00
David S. Miller
2fbd3da387 pkt_sched: Revert tasklet_hrtimer changes.
These are full of unresolved problems, mainly that conversions don't
work 1-1 from hrtimers to tasklet_hrtimers because unlike hrtimers
tasklets can't be killed from softirq context.

And when a qdisc gets reset, that's exactly what we need to do here.

We'll work this out in the net-next-2.6 tree and if warranted we'll
backport that work to -stable.

This reverts the following 3 changesets:

a2cb6a4dd4
("pkt_sched: Fix bogon in tasklet_hrtimer changes.")

38acce2d79
("pkt_sched: Convert CBQ to tasklet_hrtimer.")

ee5f9757ea
("pkt_sched: Convert qdisc_watchdog to tasklet_hrtimer")

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-01 17:59:25 -07:00
David S. Miller
a2cb6a4dd4 pkt_sched: Fix bogon in tasklet_hrtimer changes.
Reported by Stephen Rothwell, luckily it's harmless:

net/sched/sch_api.c: In function 'qdisc_watchdog':
net/sched/sch_api.c:460: warning: initialization from incompatible pointer type
net/sched/sch_cbq.c: In function 'cbq_undelay':
net/sched/sch_cbq.c:595: warning: initialization from incompatible pointer type

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-24 19:37:05 -07:00
David S. Miller
ee5f9757ea pkt_sched: Convert qdisc_watchdog to tasklet_hrtimer
None of this stuff should execute in hw IRQ context, therefore
use a tasklet_hrtimer so that it runs in softirq context.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-22 18:09:17 -07:00
Jarek Poplawski
ca44d6e60f pkt_sched: Rename PSCHED_US2NS and PSCHED_NS2US
Let's use TICKS instead of US, so PSCHED_TICKS2NS and PSCHED_NS2TICKS
(like in PSCHED_TICKS_PER_SEC already) to avoid misleading.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-15 02:31:47 -07:00
Jarek Poplawski
b00355db3f pkt_sched: sch_hfsc: sch_htb: Add non-work-conserving warning handler.
Patrick McHardy <kaber@trash.net> suggested:
> How about making this flag and the warning message (in a out-of-line
> function) globally available? Other qdiscs (f.i. HFSC) can't deal with
> inner non-work-conserving qdiscs as well.

This patch uses qdisc->flags field of "suspected" child qdisc.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-01 01:12:42 -08:00
Jarek Poplawski
05a8c1cbfe pkt_sched: Remove smp_wmb() in qdisc_watchdog()
While implementing a TCQ_F_THROTTLED flag there was used an smp_wmb()
in qdisc_watchdog(), but since this flag is practically used only in
sch_netem(), and since it's not even clear what reordering is avoided
here (TCQ_F_THROTTLED vs. __QDISC_STATE_SCHED?) it seems the barrier
could be safely removed.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-22 19:44:13 -08:00
Hannes Eder
6113b748fb pkt_sched: fix sparse warning
Impact: make global function static

Fix the following sparse warning:

  net/sched/sch_api.c:192:14: warning: symbol 'qdisc_match_from_root' was not declared. Should it be static?

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-28 03:06:46 -08:00
Stephen Hemminger
71bcb09a57 tc: check for errors in gen_rate_estimator creation
The functions gen_new_estimator and gen_replace_estimator can return
errors, but they were being ignored.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 21:13:31 -08:00
Jarek Poplawski
f6486d40b3 pkt_sched: sch_api: Remove qdisc_list_lock
After implementing qdisc->ops->peek() there is no more calling
qdisc_tree_decrease_qlen() without rtnl_lock(), so qdisc_list_lock
added by commit: f6e0b239a2 "pkt_sched:
Fix qdisc list locking" can be removed.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 13:56:06 -08:00
David S. Miller
6ab33d5171 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/ixgbe/ixgbe_main.c
	include/net/mac80211.h
	net/phonet/af_phonet.c
2008-11-20 16:44:00 -08:00
Patrick McHardy
3aa4614da7 pkt_sched: fix missing check for packet overrun in qdisc_dump_stab()
nla_nest_start() might return NULL, causing a NULL pointer dereference.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20 04:07:14 -08:00
Jarek Poplawski
f30ab418a1 pkt_sched: Remove qdisc->ops->requeue() etc.
After implementing qdisc->ops->peek() and changing sch_netem into
classless qdisc there are no more qdisc->ops->requeue() users. This
patch removes this method with its wrappers (qdisc_requeue()), and
also unused qdisc->requeue structure. There are a few minor fixes of
warnings (htb_enqueue()) and comments btw.

The idea to kill ->requeue() and a similar patch were first developed
by David S. Miller.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-13 22:56:30 -08:00
Jarek Poplawski
99c0db2679 pkt_sched: sch_generic: Add generic qdisc->ops->peek() implementation.
With feedback from Patrick McHardy.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31 00:45:27 -07:00
Johannes Berg
95a5afca4a net: Remove CONFIG_KMOD from net/ (towards removing CONFIG_KMOD entirely)
Some code here depends on CONFIG_KMOD to not try to load
protocol modules or similar, replace by CONFIG_MODULES
where more than just request_module depends on CONFIG_KMOD
and and also use try_then_request_module in ebtables.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-16 15:24:51 -07:00
Jarek Poplawski
102396ae65 pkt_sched: Fix locking of qdisc_root with qdisc_root_sleeping_lock()
Use qdisc_root_sleeping_lock() instead of qdisc_root_lock() where
appropriate. The only difference is while dev is deactivated, when
currently we can use a sleeping qdisc with the lock of noop_qdisc.
This shouldn't be dangerous since after deactivation root lock could
be used only by gen_estimator code, but looks wrong anyway.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-29 14:27:52 -07:00
Jarek Poplawski
f6f9b93f16 pkt_sched: Fix gen_estimator locks
While passing a qdisc root lock to gen_new_estimator() and
gen_replace_estimator() dev could be deactivated or even before
grafting proper root qdisc as qdisc_sleeping (e.g. qdisc_create), so
using qdisc_root_lock() is not enough. This patch adds
qdisc_root_sleeping_lock() for this, plus additional checks, where
necessary.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-27 02:25:17 -07:00
Jarek Poplawski
f7a54c13c7 pkt_sched: Use rcu_assign_pointer() to change dev_queue->qdisc
These pointers are RCU protected, so proper primitives should be used.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-27 02:22:07 -07:00
Jarek Poplawski
666d9bbedf pkt_sched: Fix dev_graft_qdisc() locking
During dev_graft_qdisc() dev is deactivated, so qdisc_root_lock()
returns wrong lock of noop_qdisc instead of qdisc_sleeping.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-27 02:15:20 -07:00
Jarek Poplawski
f6e0b239a2 pkt_sched: Fix qdisc list locking
Since some qdiscs call qdisc_tree_decrease_qlen() (so qdisc_lookup())
without rtnl_lock(), adding and deleting from a qdisc list needs
additional locking. This patch adds global spinlock qdisc_list_lock
and wrapper functions for modifying the list. It is considered as a
temporary solution until hfsc_dequeue(), netem_dequeue() and
tbf_dequeue() (or qdisc_tree_decrease_qlen()) are redone.

With feedback from Herbert Xu and David S. Miller.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-22 03:31:39 -07:00
Jarek Poplawski
2540e0511e pkt_sched: Fix qdisc_watchdog() vs. dev_deactivate() race
dev_deactivate() can skip rescheduling of a qdisc by qdisc_watchdog()
or other timer calling netif_schedule() after dev_queue_deactivate().
We prevent this checking aliveness before scheduling the timer. Since
during deactivation the root qdisc is available only as qdisc_sleeping
additional accessor qdisc_root_sleeping() is created.

With feedback from Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-21 05:11:14 -07:00
David S. Miller
f3b9605d74 Revert "pkt_sched: Add BH protection for qdisc_stab_lock."
This reverts commit 1cfa26661a.

qdisc_destroy() runs fully under RTNL again and not from softint any
longer, so this change is no longer needed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-18 22:33:05 -07:00
Ilpo Järvinen
e5befbd952 pkt_sched: remove bogus block (cleanup)
...Last block local var got just deleted.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-18 22:30:01 -07:00
David S. Miller
4d8863a29c pkt_sched: Don't hold qdisc lock over qdisc_destroy().
Based upon reports by Denys Fedoryshchenko, and feedback
and help from Jarek Poplawski and Herbert Xu.

We always either:

1) Never made an external reference to this qdisc.

or

2) Did a dev_deactivate() which purged all asynchronous
   references.

So do not lock the qdisc when we call qdisc_destroy(),
it's illegal anyways as when we drop the lock this is
free'd memory.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-18 21:06:19 -07:00
Jarek Poplawski
25bfcd5a78 pkt_sched: Add lockdep annotation for qdisc locks
Qdisc locks are initialized in the same function, qdisc_alloc(), so
lockdep can't distinguish tx qdisc lock from rx and reports "possible
recursive locking detected" when both these locks are taken eg. while
using act_mirred with ifb. This looks like a false positive. Anyway,
after this patch these locks will be reported more exactly.

Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-18 21:06:09 -07:00
David S. Miller
8608db031b pkt_sched: Never schedule non-root qdiscs.
Based upon initial discovery and patch by Jarek Poplawski.

The qdisc watchdogs can be attached to any qdisc, not just the root,
so make sure we schedule the correct one.

CBQ has a similar bug.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-18 21:05:56 -07:00
Jarek Poplawski
3a76e3716b pkt_sched: Grab correct lock in notify_and_destroy().
From: Jarek Poplawski <jarkao2@gmail.com>

When we are destroying non-root qdiscs, we need to lock
the root of the qdisc tree not the the qdisc itself.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-17 22:02:11 -07:00
Jarek Poplawski
1cfa26661a pkt_sched: Add BH protection for qdisc_stab_lock.
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: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-11 18:11:06 -07:00
David S. Miller
8123b421e8 pkt_sched: Fix ingress deletion and filter attachment.
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: David S. Miller <davem@davemloft.net>
2008-08-08 23:23:39 -07:00
David S. Miller
827ebd6410 pkt_sched: Fix qdisc config when link is down.
Bug reported by Stephen Hemminger.

We need to fetch the root from ->qdisc_sleeping not ->qdisc.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-07 20:26:40 -07:00
David S. Miller
ee7af8264d pkt_sched: Fix "parent is root" test in qdisc_create().
As noticed by Stephen Hemminger, the root qdisc is denoted by
TC_H_ROOT, not zero.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-06 23:35:59 -07:00
David S. Miller
8d50b53d66 pkt_sched: Fix OOPS on ingress qdisc add.
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: David S. Miller <davem@davemloft.net>
2008-07-30 02:44:25 -07:00
Adrian Bunk
a94f779f9d pkt_sched: make qdisc_class_hash_alloc() static
This patch makes the needlessly global qdisc_class_hash_alloc() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-22 14:20:11 -07:00
Jussi Kivilinna
175f9c1bba net_sched: Add size table for qdiscs
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=2

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-20 00:08:47 -07:00
David S. Miller
3072367300 pkt_sched: Manage qdisc list inside of root qdisc.
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: David S. Miller <davem@davemloft.net>
2008-07-18 22:50:15 -07:00
David S. Miller
99194cff39 pkt_sched: Add multiqueue handling to qdisc_graft().
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: David S. Miller <davem@davemloft.net>
2008-07-17 19:21:30 -07:00
David S. Miller
53049978df pkt_sched: Make qdisc grafting locking more specific.
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: David S. Miller <davem@davemloft.net>
2008-07-17 19:21:27 -07:00
David S. Miller
ead81cc5fc netdevice: Move qdisc_list back into net_device proper.
And give it it's own lock.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17 19:21:26 -07:00
David S. Miller
37437bb2e1 pkt_sched: Schedule qdiscs instead of netdev_queue.
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: David S. Miller <davem@davemloft.net>
2008-07-17 19:21:20 -07:00
David S. Miller
7698b4fcab pkt_sched: Add and use qdisc_root() and qdisc_root_lock().
When code wants to lock the qdisc tree state, the logic
operation it's doing is locking the top-level qdisc that
sits of the root of the netdev_queue.

Add qdisc_root_lock() to represent this and convert the
easiest cases.

In order for this to work out in all cases, we have to
hook up the noop_qdisc to a dummy netdev_queue.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-17 19:21:19 -07:00