linux-toradex.git/net/core, branch v2.6.27.5

net: Fix recursive descent in __scm_destroy().

2008-11-07T17:55:19+00:00

commit f8d570a4745835f2238a33b537218a1bb03fc671 and
3b53fbf4314594fa04544b02b2fc6e607912da18 upstream (because once wasn't
good enough...)

__scm_destroy() walks the list of file descriptors in the scm_fp_list
pointed to by the scm_cookie argument.

Those, in turn, can close sockets and invoke __scm_destroy() again.

There is nothing which limits how deeply this can occur.

The idea for how to fix this is from Linus.  Basically, we do all of
the fput()s at the top level by collecting all of the scm_fp_list
objects hit by an fput().  Inside of the initial __scm_destroy() we
keep running the list until it is empty.

Signed-off-by: David S. Miller 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

net: Fix netdev_run_todo dead-lock

2008-10-07T22:50:03+00:00

Benjamin Thery tracked down a bug that explains many instances
of the error

unregister_netdevice: waiting for %s to become free. Usage count = %d

It turns out that netdev_run_todo can dead-lock with itself if
a second instance of it is run in a thread that will then free
a reference to the device waited on by the first instance.

The problem is really quite silly.  We were trying to create
parallelism where none was required.  As netdev_run_todo always
follows a RTNL section, and that todo tasks can only be added
with the RTNL held, by definition you should only need to wait
for the very ones that you've added and be done with it.

There is no need for a second mutex or spinlock.

This is exactly what the following patch does.

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

net: only invoke dev->change_rx_flags when device is UP

2008-10-07T22:26:48+00:00

Jesper Dangaard Brouer  reported a bug when setting a VLAN
device down that is in promiscous mode:

When the VLAN device is set down, the promiscous count on the real
device is decremented by one by vlan_dev_stop(). When removing the
promiscous flag from the VLAN device afterwards, the promiscous
count on the real device is decremented a second time by the
vlan_change_rx_flags() callback.

The root cause for this is that the ->change_rx_flags() callback is
invoked while the device is down. The synchronization is meant to mirror
the behaviour of the ->set_rx_mode callbacks, meaning the ->open function
is responsible for doing a full sync on open, the ->close() function is
responsible for doing full cleanup on ->stop() and ->change_rx_flags()
is meant to do incremental changes while the device is UP.

Only invoke ->change_rx_flags() while the device is UP to provide the
intended behaviour.

Tested-by: Jesper Dangaard Brouer 

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

netdev: simple_tx_hash shouldn't hash inside fragments

2008-09-21T05:05:50+00:00

Currently simple_tx_hash is hashing inside of udp fragments.  As a result
packets are getting getting sent to all queues when they shouldn't be.
This causes a serious performance regression which can be seen by sending
UDP frames larger than mtu on multiqueue devices.  This change will make
it so that fragments are hashed only as IP datagrams w/o any protocol
information.

Signed-off-by: Alexander Duyck 
Signed-off-by: David S. Miller

pkt_sched: Fix qdisc state in net_tx_action()

2008-09-08T01:41:21+00:00

net_tx_action() can skip __QDISC_STATE_SCHED bit clearing while qdisc
is neither ran nor rescheduled, which may cause endless loop in
dev_deactivate().

Reported-by: Denys Fedoryshchenko 
Tested-by: Denys Fedoryshchenko 
Signed-off-by: Jarek Poplawski 
Acked-by: Herbert Xu 
Signed-off-by: David S. Miller

pkt_sched: Prevent livelock in TX queue running.

2008-08-19T11:00:36+00:00

If dev_deactivate() is trying to quiesce the queue, it
is theoretically possible for another cpu to livelock
trying to process that queue.  This happens because
dev_deactivate() grabs the queue spinlock as it checks
the queue state, whereas net_tx_action() does a trylock
and reschedules the qdisc if it hits the lock.

This breaks the livelock by adding a check on
__QDISC_STATE_DEACTIVATED to net_tx_action() when
the trylock fails.

Based upon feedback from Herbert Xu and Jarek Poplawski.

Signed-off-by: David S. Miller

Revert "pkt_sched: Protect gen estimators under est_lock."

2008-08-19T05:32:10+00:00

This reverts commit d4766692e72422f3b0f0e9ac6773d92baad07d51.

qdisc_destroy() now runs in RTNL fully again, so this
change is no longer needed.

Signed-off-by: David S. Miller

pkt_sched: Fix missed RCU unlock in dev_queue_xmit()

2008-08-18T06:37:16+00:00

Noticed by Jarek Poplawski.

Signed-off-by: David S. Miller

net: Change handling of the __QDISC_STATE_SCHED flag in net_tx_action().

2008-08-18T04:54:43+00:00

Change handling of the __QDISC_STATE_SCHED flag in net_tx_action() to
enable proper control in dev_deactivate(). Now, if this flag is seen
as unset under root_lock means a qdisc can't be netif_scheduled.

Signed-off-by: Jarek Poplawski 
Signed-off-by: David S. Miller

pkt_sched: Add 'deactivated' state.

2008-08-18T04:51:03+00:00

This new state lets dev_deactivate() mark a qdisc as having been
deactivated.

dev_queue_xmit() and ing_filter() check for this bit and do not
try to process the qdisc if the bit is set.

dev_deactivate() polls the qdisc after setting the bit, waiting
for both __QDISC_STATE_RUNNING and __QDISC_STATE_SCHED to clear.

This isn't perfect yet, but subsequent changesets will make it so.
This part is just one piece of the puzzle.

Signed-off-by: David S. Miller