linux.git/net/atm, branch v2.6.31

net: adding memory barrier to the poll and receive callbacks

2009-07-10T00:06:57+00:00

Adding memory barrier after the poll_wait function, paired with
receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper
to wrap the memory barrier.

Without the memory barrier, following race can happen.
The race fires, when following code paths meet, and the tp->rcv_nxt
and __add_wait_queue updates stay in CPU caches.

CPU1                         CPU2

sys_select                   receive packet
  ...                        ...
  __add_wait_queue           update tp->rcv_nxt
  ...                        ...
  tp->rcv_nxt check          sock_def_readable
  ...                        {
  schedule                      ...
                                if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                                        wake_up_interruptible(sk->sk_sleep)
                                ...
                             }

If there was no cache the code would work ok, since the wait_queue and
rcv_nxt are opposit to each other.

Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already
passed the tp->rcv_nxt check and sleeps, or will get the new value for
tp->rcv_nxt and will return with new data mask.
In both cases the process (CPU1) is being added to the wait queue, so the
waitqueue_active (CPU2) call cannot miss and will wake up CPU1.

The bad case is when the __add_wait_queue changes done by CPU1 stay in its
cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1 will then
endup calling schedule and sleep forever if there are no more data on the
socket.

Calls to poll_wait in following modules were ommited:
	net/bluetooth/af_bluetooth.c
	net/irda/af_irda.c
	net/irda/irnet/irnet_ppp.c
	net/mac80211/rc80211_pid_debugfs.c
	net/phonet/socket.c
	net/rds/af_rds.c
	net/rfkill/core.c
	net/sunrpc/cache.c
	net/sunrpc/rpc_pipe.c
	net/tipc/socket.c

Signed-off-by: Jiri Olsa 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

atm: sk_wmem_alloc initial value is one

2009-06-18T07:29:12+00:00

commit 2b85a34e911bf483c27cfdd124aeb1605145dc80
(net: No more expensive sock_hold()/sock_put() on each tx)
changed initial sk_wmem_alloc value.

This broke net/atm since this protocol assumed a null
initial value. This patch makes necessary changes.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: fix network drivers ndo_start_xmit() return values (part 7)

2009-06-13T08:18:43+00:00

Fix up ATM drivers that return an errno value to qdisc_restart(), causing
qdisc_restart() to print a warning an requeue/retransmit the skb.

- lec: condition can only be remedied by userspace, until that retransmissions

Compile tested only.

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

bridge: Simplify interface for ATM LANE

2009-06-12T04:03:21+00:00

This patch changes FDB entry check for ATM LANE bridge integration.
There's no point in holding a FDB entry around SKB building.

br_fdb_get()/br_fdb_put() pair are changed into single br_fdb_test_addr()
hook that checks if the addr has FDB entry pointing to other port
to the one the request arrived on.

FDB entry refcounting is removed as it's not used anywhere else.

Signed-off-by: Michał Mirosław 
Acked-by: Stephen Hemminger 
Signed-off-by: David S. Miller

net: skb->dst accessors

2009-06-03T09:51:04+00:00

Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb->dst)
skb->dst = NULL;

Delete skb->dst field

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

atm: unset IFF_XMIT_DST_RELEASE in clip_setup()

2009-05-29T08:46:28+00:00

clip_start_xmit() needs skb->dst so tell dev_hard_start_xmit()
to no release it.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

atm: Use SKB queue and list helpers instead of doing it by-hand.

2009-05-28T23:36:47+00:00

Signed-off-by: David S. Miller

Subject: [PATCH] br2684: restore net_dev initialization

2009-05-02T20:49:36+00:00

Commit 0ba25ff4c669e5395110ba6ab4958a97a9f96922 ("br2684: convert to
net_device_ops") inadvertently deleted the initialization of the net_dev
pointer in the br2684_dev structure, leading to crashes.  This patch
adds it back.

Reported-by: Mikko Vinni 
Tested-by: Mikko Vinni 
Signed-off-by: Rabin Vincent 
Signed-off-by: David S. Miller

proc 2/2: remove struct proc_dir_entry::owner

2009-03-30T21:14:44+00:00

Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454

Signed-off-by: Alexey Dobriyan

atm: convert clip driver to net_device_ops

2009-03-22T02:19:12+00:00

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller