bridge: Fix the way to find old local fdb entries in br_fdb_changeaddr

br_fdb_changeaddr() assumes that there is at most one local entry per port
per vlan. It used to be true, but since commit 36fd2b63e3b4 ("bridge: allow
creating/deleting fdb entries via netlink"), it has not been so.
Therefore, the function might fail to search a correct previous address
to be deleted and delete an arbitrary local entry if user has added local
entries manually.

Example of problematic case:
  ip link set eth0 address ee:ff:12:34:56:78
  brctl addif br0 eth0
  bridge fdb add 12:34:56:78:90:ab dev eth0 master
  ip link set eth0 address aa:bb:cc:dd:ee:ff
Then, the address 12:34:56:78:90:ab might be deleted instead of
ee:ff:12:34:56:78, the original mac address of eth0.

Address this issue by introducing a new flag, added_by_user, to struct
net_bridge_fdb_entry.

Note that br_fdb_delete_by_port() has to set added_by_user to 0 in cases
like:
  ip link set eth0 address 12:34:56:78:90:ab
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  bridge fdb add aa:bb:cc:dd:ee:ff dev eth0 master
  brctl addif br0 eth1
  brctl delif br0 eth0
In this case, kernel should delete the user-added entry aa:bb:cc:dd:ee:ff,
but it also should have been added by "brctl addif br0 eth1" originally,
so we don't delete it and treat it a new kernel-created entry.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge: Fix the way to insert new local fdb entries in br_fdb_changeaddr

Since commit bc9a25d21ef8 ("bridge: Add vlan support for local fdb entries"),
br_fdb_changeaddr() has inserted a new local fdb entry only if it can
find old one. But if we have two ports where they have the same address
or user has deleted a local entry, there will be no entry for one of the
ports.

Example of problematic case:
  ip link set eth0 address aa:bb:cc:dd:ee:ff
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  brctl addif br0 eth1 # eth1 will not have a local entry due to dup.
  ip link set eth1 address 12:34:56:78:90:ab
Then, the new entry for the address 12:34:56:78:90:ab will not be
created, and the bridge device will not be able to communicate.

Insert new entries regardless of whether we can find old entries or not.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge: Fix the way to find old local fdb entries in br_fdb_change_mac_address

We have been always failed to delete the old entry at
br_fdb_change_mac_address() because br_set_mac_address() updates
dev->dev_addr before calling br_fdb_change_mac_address() and
br_fdb_change_mac_address() uses dev->dev_addr to find the old entry.

That update of dev_addr is completely unnecessary because the same work
is done in br_stp_change_bridge_id() which is called right away after
calling br_fdb_change_mac_address().

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge: Change local fdb entries whenever mac address of bridge device changes

Vlan code may need fdb change when changing mac address of bridge device
even if it is caused by the mac address changing of a bridge port.

Example configuration:
  ip link set eth0 address 12:34:56:78:90:ab
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  brctl addif br0 eth1 # br0 will have mac address 12:34:56:78:90:ab
  bridge vlan add dev br0 vid 10 self
  bridge vlan add dev eth0 vid 10
We will have fdb entry such that f->dst == NULL, f->vlan_id == 10 and
f->addr == 12:34:56:78:90:ab at this time.
Next, change the mac address of eth0 to greater value.
  ip link set eth0 address ee:ff:12:34:56:78
Then, mac address of br0 will be recalculated and set to aa:bb:cc:dd:ee:ff.
However, an entry aa:bb:cc:dd:ee:ff will not be created and we will be not
able to communicate using br0 on vlan 10.

Address this issue by deleting and adding local entries whenever
changing the mac address of the bridge device.

If there already exists an entry that has the same address, for example,
in case that br_fdb_changeaddr() has already inserted it,
br_fdb_change_mac_address() will simply fail to insert it and no
duplicated entry will be made, as it was.

This approach also needs br_add_if() to call br_fdb_insert() before
br_stp_recalculate_bridge_id() so that we don't create an entry whose
dst == NULL in this function to preserve previous behavior.

Note that this is a slight change in behavior where the bridge device can
receive the traffic to the new address before calling
br_stp_recalculate_bridge_id() in br_add_if().
However, it is not a problem because we have already the address on the
new port and such a way to insert new one before recalculating bridge id
is taken in br_device_event() as well.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge: Fix the way to check if a local fdb entry can be deleted

We should take into account the followings when deleting a local fdb
entry.

- nbp_vlan_find() can be used only when vid != 0 to check if an entry is
  deletable, because a fdb entry with vid 0 can exist at any time while
  nbp_vlan_find() always return false with vid 0.

  Example of problematic case:
    ip link set eth0 address 12:34:56:78:90:ab
    ip link set eth1 address 12:34:56:78:90:ab
    brctl addif br0 eth0
    brctl addif br0 eth1
    ip link set eth0 address aa:bb:cc:dd:ee:ff
  Then, the fdb entry 12:34:56:78:90:ab will be deleted even though the
  bridge port eth1 still has that address.

- The port to which the bridge device is attached might needs a local entry
  if its mac address is set manually.

  Example of problematic case:
    ip link set eth0 address 12:34:56:78:90:ab
    brctl addif br0 eth0
    ip link set br0 address 12:34:56:78:90:ab
    ip link set eth0 address aa:bb:cc:dd:ee:ff
  Then, the fdb still must have the entry 12:34:56:78:90:ab, but it will be
  deleted.

We can use br->dev->addr_assign_type to check if the address is manually
set or not, but I propose another approach.

Since we delete and insert local entries whenever changing mac address
of the bridge device, we can change dst of the entry to NULL regardless of
addr_assign_type when deleting an entry associated with a certain port,
and if it is found to be unnecessary later, then delete it.
That is, if changing mac address of a port, the entry might be changed
to its dst being NULL first, but is eventually deleted when recalculating
and changing bridge id.

This approach is especially useful when we want to share the code with
deleting vlan in which the bridge device might want such an entry regardless
of addr_assign_type, and makes things easy because we don't have to consider
if mac address of the bridge device will be changed or not at the time we
delete a local entry of a port, which means fdb code will not be bothered
even if the bridge id calculating logic is changed in the future.

Also, this change reduces inconsistent state, where frames whose dst is the
mac address of the bridge, can't reach the bridge because of premature fdb
entry deletion. This change reduces the possibility that the bridge device
replies unreachable mac address to arp requests, which could occur during
the short window between calling del_nbp() and br_stp_recalculate_bridge_id()
in br_del_if(). This will effective after br_fdb_delete_by_port() starts to
use the same code by following patch.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge: Properly check if local fdb entry can be deleted in br_fdb_change_mac_address

br_fdb_change_mac_address() doesn't check if the local entry has the
same address as any of bridge ports.
Although I'm not sure when it is beneficial, current implementation allow
the bridge device to receive any mac address of its ports.
To preserve this behavior, we have to check if the mac address of the
entry being deleted is identical to that of any port.

As this check is almost the same as that in br_fdb_changeaddr(), create
a common function fdb_delete_local() and call it from
br_fdb_changeadddr() and br_fdb_change_mac_address().

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge: Properly check if local fdb entry can be deleted in br_fdb_delete_by_port

br_fdb_delete_by_port() doesn't care about vlan and mac address of the
bridge device.

As the check is almost the same as mac address changing, slightly modify
fdb_delete_local() and use it.

Note that we can always set added_by_user to 0 in fdb_delete_local() because
- br_fdb_delete_by_port() calls fdb_delete_local() for local entries
  regardless of its added_by_user. In this case, we have to check if another
  port has the same address and vlan, and if found, we have to create the
  entry (by changing dst). This is kernel-added entry, not user-added.
- br_fdb_changeaddr() doesn't call fdb_delete_local() for user-added entry.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge: Properly check if local fdb entry can be deleted when deleting vlan

Vlan codes unconditionally delete local fdb entries.
We should consider the possibility that other ports have the same
address and vlan.

Example of problematic case:
  ip link set eth0 address 12:34:56:78:90:ab
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  brctl addif br0 eth1 # br0 will have mac address 12:34:56:78:90:ab
  bridge vlan add dev eth0 vid 10
  bridge vlan add dev eth1 vid 10
  bridge vlan add dev br0 vid 10 self
We will have fdb entry such that f->dst == eth0, f->vlan_id == 10 and
f->addr == 12:34:56:78:90:ab at this time.
Next, delete eth0 vlan 10.
  bridge vlan del dev eth0 vid 10
In this case, we still need the entry for br0, but it will be deleted.

Note that br0 needs the entry even though its mac address is not set
manually. To delete the entry with proper condition checking,
fdb_delete_local() is suitable to use.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bridge: Prevent possible race condition in br_fdb_change_mac_address

br_fdb_change_mac_address() calls fdb_insert()/fdb_delete() without
br->hash_lock.

These hash list updates are racy with br_fdb_update()/br_fdb_cleanup().

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'bridge'

Toshiaki Makita says:

====================
bridge: Fix corner case problems around local fdb entries

There are so many corner cases that are not handled properly around local
fdb entries.
- We might fail to delete the old entry and might delete an arbitrary local
  entry when changing mac address of a bridge port.
- We always fail to delete the old entry when changing mac address of the
  bridge device.
- We might incorrectly delete a necessary entry when detaching a bridge port.
- We might incorrectly delete a necessary entry when deleting a vlan.
and so on.

This is a patch series to fix these issues.

v3:
- Handle NTF_USE case in patch 1/9, commented by Vlad Yasevich.

- Tested port detach/attach and didn't find any problem with patch 5/9,
  suggested by Stephen Hemminger.

- Add comments about possible inconsistent state in current implementation
  into commit log of patch 5/9, found by the above test.

- Reword unintensive changelog of patch 7/9, commented by Vlad Yasevich.

v2:
- Change the way to find the old entry in br_fdb_changeaddr() from memorizing
  previous port address to introducing a new flag indicating whether a fdb
  entry is added by user or not, commented by Stephen Hemminger.

- Add a fix for the way to insert a new address in br_fdb_changeaddr().

- Prevent creating an entry such that its dst is NULL in br_add_if() to
  preserve old behavior, commented by Vlad Yasevich.

- Add more comments about slight behavior change, where the bridge device
  come to be able to receive traffic to an address it has during short
  window, to changelogs, commented by Vlad Yasevich.

- Add a fix for possible race in br_fdb_change_mac_address().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
tcp: tsq: fix nonagle handling

Commit 46d3ceabd8d9 ("tcp: TCP Small Queues") introduced a possible
regression for applications using TCP_NODELAY.

If TCP session is throttled because of tsq, we should consult
tp->nonagle when TX completion is done and allow us to send additional
segment, especially if this segment is not a full MSS.
Otherwise this segment is sent after an RTO.

[edumazet] : Cooked the changelog, added another fix about testing
sk_wmem_alloc twice because TX completion can happen right before
setting TSQ_THROTTLED bit.

This problem is particularly visible with recent auto corking,
but might also be triggered with low tcp_limit_output_bytes
values or NIC drivers delaying TX completion by hundred of usec,
and very low rtt.

Thomas Glanzmann for example reported an iscsi regression, caused
by tcp auto corking making this bug quite visible.

Fixes: 46d3ceabd8d9 ("tcp: TCP Small Queues")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
USB2NET : SR9800 : One chip USB2.0 USB2NET SR9800 Device Driver Support

Signed-off-by: Liu Junliang <liujunliang_ljl@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bonding: remove unwanted bond lock for enslave processing

The bond enslave processing don't hold bond->lock anymore,
so release an unlocked rw lock will cause warning message,
remove the unwanted read_unlock(&bond->lock).

Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers

The 9p-virtio transport does zero copy on things larger than 1024 bytes
in size. It accomplishes this by returning the physical addresses of
pages to the virtio-pci device. At present, the translation is usually a
bit shift.

That approach produces an invalid page address when we read/write to
vmalloc buffers, such as those used for Linux kernel modules. Any
attempt to load a Linux kernel module from 9p-virtio produces the
following stack.

[<ffffffff814878ce>] p9_virtio_zc_request+0x45e/0x510
[<ffffffff814814ed>] p9_client_zc_rpc.constprop.16+0xfd/0x4f0
[<ffffffff814839dd>] p9_client_read+0x15d/0x240
[<ffffffff811c8440>] v9fs_fid_readn+0x50/0xa0
[<ffffffff811c84a0>] v9fs_file_readn+0x10/0x20
[<ffffffff811c84e7>] v9fs_file_read+0x37/0x70
[<ffffffff8114e3fb>] vfs_read+0x9b/0x160
[<ffffffff81153571>] kernel_read+0x41/0x60
[<ffffffff810c83ab>] copy_module_from_fd.isra.34+0xfb/0x180

Subsequently, QEMU will die printing:

qemu-system-x86_64: virtio: trying to map MMIO memory

This patch enables 9p-virtio to correctly handle this case. This not
only enables us to load Linux kernel modules off virtfs, but also
enables ZFS file-based vdevs on virtfs to be used without killing QEMU.

Special thanks to both Avi Kivity and Alexander Graf for their
interpretation of QEMU backtraces. Without their guidence, tracking down
this bug would have taken much longer. Also, special thanks to Linus
Torvalds for his insightful explanation of why this should use
is_vmalloc_addr() instead of is_vmalloc_or_module_addr():

https://lkml.org/lkml/2014/2/8/272

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
alx: add missing stats_lock spinlock init

Trivial fix for init time stack trace occuring in
alx_get_stats64 upon start up. Should have been part of
commit adding the spinlock:
f1b6b106 alx: add alx_get_stats64 operation

Signed-off-by: John Greene <jogreene@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
6lowpan: fix lockdep splats

When a device ndo_start_xmit() calls again dev_queue_xmit(),
lockdep can complain because dev_queue_xmit() is re-entered and the
spinlocks protecting tx queues share a common lockdep class.

Same issue was fixed for bonding/l2tp/ppp in commits

0daa2303028a6 ("[PATCH] bonding: lockdep annotation")
49ee49202b4ac ("bonding: set qdisc_tx_busylock to avoid LOCKDEP splat")
23d3b8bfb8eb2 ("net: qdisc busylock needs lockdep annotations ")
303c07db487be ("ppp: set qdisc_tx_busylock to avoid LOCKDEP splat ")

Reported-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>