Commit a0417fa3a18a ("net: Make qdisc_skb_cb upper size bound
explicit.") made it possible for a netdev driver to use skb->cb
between its header_ops.create method and its .ndo_start_xmit
method.  Use this in ipoib_hard_header() to stash away the LL address
(GID + QPN), instead of the "ipoib_pseudoheader" hack.  This allows
IPoIB to stop lying about its hard_header_len, which will let us fix
the L2 check for GRO.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Reduce the number of dst_get_neighbour_noref() calls within a single
call chain.  Primarily by passing the neighbour pointer down to the
helper functions.

Handle dst_get_neighbour_noref() returning NULL in ipoib_start_xmit()
by incrementing the dropped counter and freeing the packet.  We don't
want it to fall through into the ARP/RARP/multicast handling, since
that should only happen when skb_dst() is NULL.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Roland Dreier <roland@purestorage.com>

To reflect the fact that a refrence is not obtained to the
resulting neighbour entry.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Roland Dreier <roland@purestorage.com>

netdev->neigh_priv_len records the private area length.

This will trigger for neigh_table objects which set tbl->entry_size
to zero, and the first instances of this will be forthcoming.

Signed-off-by: David S. Miller <davem@davemloft.net>

Commit f2c31e32b37 ("net: fix NULL dereferences in check_peer_redir()")
forgot to take care of infiniband uses of dst neighbours.

Many thanks to Marc Aurele who provided a nice bug report and feedback.

Reported-by: Marc Aurele La France <tsi@ualberta.ca>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

This following can occur with ipoib when processing a multicast reponse:

    BUG: soft lockup - CPU#0 stuck for 67s! [ib_mad1:982]
    Modules linked in: ...
    CPU 0:
    Modules linked in: ...
    Pid: 982, comm: ib_mad1 Not tainted 2.6.32-131.0.15.el6.x86_64 #1 ProLiant DL160 G5
    RIP: 0010:[<ffffffff814ddb27>]  [<ffffffff814ddb27>] _spin_unlock_irqrestore+0x17/0x20
    RSP: 0018:ffff8802119ed860  EFLAGS: 00000246
    0000000000000004 RBX: ffff8802119ed860 RCX: 000000000000a299
    RDX: ffff88021086c700 RSI: 0000000000000246 RDI: 0000000000000246
    RBP: ffffffff8100bc8e R08: ffff880210ac229c R09: 0000000000000000
    R10: ffff88021278aab8 R11: 0000000000000000 R12: ffff8802119ed860
    R13: ffffffff8100be6e R14: 0000000000000001 R15: 0000000000000003
    FS:  0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
    CR2: 00000000006d4840 CR3: 0000000209aa5000 CR4: 00000000000406f0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Call Trace:
    [<ffffffffa032c247>] ? ipoib_mcast_send+0x157/0x480 [ib_ipoib]
    [<ffffffff8100bc8e>] ? apic_timer_interrupt+0xe/0x20
    [<ffffffff8100bc8e>] ? apic_timer_interrupt+0xe/0x20
    [<ffffffffa03283d4>] ? ipoib_path_lookup+0x124/0x2d0 [ib_ipoib]
    [<ffffffffa03286fc>] ? ipoib_start_xmit+0x17c/0x430 [ib_ipoib]
    [<ffffffff8141e758>] ? dev_hard_start_xmit+0x2c8/0x3f0
    [<ffffffff81439d0a>] ? sch_direct_xmit+0x15a/0x1c0
    [<ffffffff81423098>] ? dev_queue_xmit+0x388/0x4d0
    [<ffffffffa032d6b7>] ? ipoib_mcast_join_finish+0x2c7/0x510 [ib_ipoib]
    [<ffffffffa032dab8>] ? ipoib_mcast_sendonly_join_complete+0x1b8/0x1f0 [ib_ipoib]
    [<ffffffffa02a0946>] ? mcast_work_handler+0x1a6/0x710 [ib_sa]
    [<ffffffffa015f01e>] ? ib_send_mad+0xfe/0x3c0 [ib_mad]
    [<ffffffffa00f6c93>] ? ib_get_cached_lmc+0xa3/0xb0 [ib_core]
    [<ffffffffa02a0f9b>] ? join_handler+0xeb/0x200 [ib_sa]
    [<ffffffffa029e4fc>] ? ib_sa_mcmember_rec_callback+0x5c/0xa0 [ib_sa]
    [<ffffffffa029e79c>] ? recv_handler+0x3c/0x70 [ib_sa]
    [<ffffffffa01603a4>] ? ib_mad_completion_handler+0x844/0x9d0 [ib_mad]
    [<ffffffffa015fb60>] ? ib_mad_completion_handler+0x0/0x9d0 [ib_mad]
    [<ffffffff81088830>] ? worker_thread+0x170/0x2a0
    [<ffffffff8108e160>] ? autoremove_wake_function+0x0/0x40
    [<ffffffff810886c0>] ? worker_thread+0x0/0x2a0
    [<ffffffff8108ddf6>] ? kthread+0x96/0xa0
    [<ffffffff8100c1ca>] ? child_rip+0xa/0x20

Coinciding with stack trace is the following message:

    ib0: ib_address_create failed

The code below in ipoib_mcast_join_finish() will note the above
failure in the address handle but otherwise continue:

                ah = ipoib_create_ah(dev, priv->pd, &av);
                if (!ah) {
                        ipoib_warn(priv, "ib_address_create failed\n");
                } else {

The while loop at the bottom of ipoib_mcast_join_finish() will attempt
to send queued multicast packets in mcast->pkt_queue and eventually
end up in ipoib_mcast_send():

        if (!mcast->ah) {
                if (skb_queue_len(&mcast->pkt_queue) < IPOIB_MAX_MCAST_QUEUE)
                        skb_queue_tail(&mcast->pkt_queue, skb);
                else {
                        ++dev->stats.tx_dropped;
                        dev_kfree_skb_any(skb);
                }

My read is that the code will requeue the packet and return to the
ipoib_mcast_join_finish() while loop and the stage is set for the
"hung" task diagnostic as the while loop never sees a non-NULL ah, and
will do nothing to resolve.

There are GFP_ATOMIC allocates in the provider routines, so this is
possible and should be dealt with.

The test that induced the failure is associated with a host SM on the
same server during a shutdown.

This patch causes ipoib_mcast_join_finish() to exit with an error
which will flush the queued mcast packets.  Nothing is done to unwind
the QP attached state so that subsequent sends from above will retry
the join.

Reviewed-by: Ram Vepa <ram.vepa@qlogic.com>
Reviewed-by: Gary Leshner <gary.leshner@qlogic.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

Signed-off-by: David S. Miller <davem@davemloft.net>

* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include <linux/module.h>
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include <linux/module.h>
  net: sch_generic remove redundant use of <linux/module.h>
  net: inet_timewait_sock doesnt need <linux/module.h>
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h