<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/net/bonding, branch v3.4.73</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>bonding: fix two race conditions in bond_store_updelay/downdelay</title>
<updated>2013-12-08T15:29:41+00:00</updated>
<author>
<name>Nikolay Aleksandrov</name>
<email>nikolay@redhat.com</email>
</author>
<published>2013-11-13T16:07:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e6f3fa48929dbcdcf3dd92507dbe32347645a969'/>
<id>e6f3fa48929dbcdcf3dd92507dbe32347645a969</id>
<content type='text'>
[ Upstream commit b869ccfab1e324507fa3596e3e1308444fb68227 ]

This patch fixes two race conditions between bond_store_updelay/downdelay
and bond_store_miimon which could lead to division by zero as miimon can
be set to 0 while either updelay/downdelay are being set and thus miss the
zero check in the beginning, the zero div happens because updelay/downdelay
are stored as new_value / bond-&gt;params.miimon. Use rtnl to synchronize with
miimon setting.

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
CC: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
CC: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Acked-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b869ccfab1e324507fa3596e3e1308444fb68227 ]

This patch fixes two race conditions between bond_store_updelay/downdelay
and bond_store_miimon which could lead to division by zero as miimon can
be set to 0 while either updelay/downdelay are being set and thus miss the
zero check in the beginning, the zero div happens because updelay/downdelay
are stored as new_value / bond-&gt;params.miimon. Use rtnl to synchronize with
miimon setting.

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
CC: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
CC: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Acked-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: don't permit to use ARP monitoring in 802.3ad mode</title>
<updated>2013-12-08T15:29:41+00:00</updated>
<author>
<name>Veaceslav Falico</name>
<email>vfalico@redhat.com</email>
</author>
<published>2013-11-12T14:37:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c22fc04e124631a59b4cca931b689841e38ff155'/>
<id>c22fc04e124631a59b4cca931b689841e38ff155</id>
<content type='text'>
[ Upstream commit ec9f1d15db8185f63a2c3143dc1e90ba18541b08 ]

Currently the ARP monitoring is not supported with 802.3ad, and it's
prohibited to use it via the module params.

However we still can set it afterwards via sysfs, cause we only check for
*LB modes there.

To fix this - add a check for 802.3ad mode in bonding_store_arp_interval.

Signed-off-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
CC: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ec9f1d15db8185f63a2c3143dc1e90ba18541b08 ]

Currently the ARP monitoring is not supported with 802.3ad, and it's
prohibited to use it via the module params.

However we still can set it afterwards via sysfs, cause we only check for
*LB modes there.

To fix this - add a check for 802.3ad mode in bonding_store_arp_interval.

Signed-off-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
CC: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: Fix broken promiscuity reference counting issue</title>
<updated>2013-10-13T22:42:48+00:00</updated>
<author>
<name>Neil Horman</name>
<email>nhorman@tuxdriver.com</email>
</author>
<published>2013-09-27T16:22:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4f7a6b6fa0ffe6432ba37a82c7f29e583ffd3dc7'/>
<id>4f7a6b6fa0ffe6432ba37a82c7f29e583ffd3dc7</id>
<content type='text'>
[ Upstream commit 5a0068deb611109c5ba77358be533f763f395ee4 ]

Recently grabbed this report:
https://bugzilla.redhat.com/show_bug.cgi?id=1005567

Of an issue in which the bonding driver, with an attached vlan encountered the
following errors when bond0 was taken down and back up:

dummy1: promiscuity touches roof, set promiscuity failed. promiscuity feature of
device might be broken.

The error occurs because, during __bond_release_one, if we release our last
slave, we take on a random mac address and issue a NETDEV_CHANGEADDR
notification.  With an attached vlan, the vlan may see that the vlan and bond
mac address were in sync, but no longer are.  This triggers a call to dev_uc_add
and dev_set_rx_mode, which enables IFF_PROMISC on the bond device.  Then, when
we complete __bond_release_one, we use the current state of the bond flags to
determine if we should decrement the promiscuity of the releasing slave.  But
since the bond changed promiscuity state during the release operation, we
incorrectly decrement the slave promisc count when it wasn't in promiscuous mode
to begin with, causing the above error

Fix is pretty simple, just cache the bonding flags at the start of the function
and use those when determining the need to set promiscuity.

This is also needed for the ALLMULTI flag

Reported-by: Mark Wu &lt;wudxw@linux.vnet.ibm.com&gt;
CC: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
CC: Mark Wu &lt;wudxw@linux.vnet.ibm.com&gt;
CC: "David S. Miller" &lt;davem@davemloft.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5a0068deb611109c5ba77358be533f763f395ee4 ]

Recently grabbed this report:
https://bugzilla.redhat.com/show_bug.cgi?id=1005567

Of an issue in which the bonding driver, with an attached vlan encountered the
following errors when bond0 was taken down and back up:

dummy1: promiscuity touches roof, set promiscuity failed. promiscuity feature of
device might be broken.

The error occurs because, during __bond_release_one, if we release our last
slave, we take on a random mac address and issue a NETDEV_CHANGEADDR
notification.  With an attached vlan, the vlan may see that the vlan and bond
mac address were in sync, but no longer are.  This triggers a call to dev_uc_add
and dev_set_rx_mode, which enables IFF_PROMISC on the bond device.  Then, when
we complete __bond_release_one, we use the current state of the bond flags to
determine if we should decrement the promiscuity of the releasing slave.  But
since the bond changed promiscuity state during the release operation, we
incorrectly decrement the slave promisc count when it wasn't in promiscuous mode
to begin with, causing the above error

Fix is pretty simple, just cache the bonding flags at the start of the function
and use those when determining the need to set promiscuity.

This is also needed for the ALLMULTI flag

Reported-by: Mark Wu &lt;wudxw@linux.vnet.ibm.com&gt;
CC: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
CC: Mark Wu &lt;wudxw@linux.vnet.ibm.com&gt;
CC: "David S. Miller" &lt;davem@davemloft.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: modify only neigh_parms owned by us</title>
<updated>2013-09-14T13:02:08+00:00</updated>
<author>
<name>Veaceslav Falico</name>
<email>vfalico@redhat.com</email>
</author>
<published>2013-08-02T17:07:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=71244e7b9f89ee8825f265a821475a553589a726'/>
<id>71244e7b9f89ee8825f265a821475a553589a726</id>
<content type='text'>
[ Upstream commit 9918d5bf329d0dc5bb2d9d293bcb772bdb626e65 ]

Otherwise, on neighbour creation, bond_neigh_init() will be called with a
foreign netdev.

Signed-off-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9918d5bf329d0dc5bb2d9d293bcb772bdb626e65 ]

Otherwise, on neighbour creation, bond_neigh_init() will be called with a
foreign netdev.

Signed-off-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: rlb mode of bond should not alter ARP originating via bridge</title>
<updated>2013-06-27T18:27:33+00:00</updated>
<author>
<name>Zheng Li</name>
<email>zheng.x.li@oracle.com</email>
</author>
<published>2013-06-19T07:53:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=322130dea90940d65b811bd67790aecf86e6340f'/>
<id>322130dea90940d65b811bd67790aecf86e6340f</id>
<content type='text'>
[ Upstream commit 567b871e503316b0927e54a3d7c86d50b722d955 ]

Do not modify or load balance ARP packets passing through balance-alb
mode (wherein the ARP did not originate locally, and arrived via a bridge).

Modifying pass-through ARP replies causes an incorrect MAC address
to be placed into the ARP packet, rendering peers unable to communicate
with the actual destination from which the ARP reply originated.

Load balancing pass-through ARP requests causes an entry to be
created for the peer in the rlb table, and bond_alb_monitor will
occasionally issue ARP updates to all peers in the table instrucing them
as to which MAC address they should communicate with; this occurs when
some event sets rx_ntt.  In the bridged case, however, the MAC address
used for the update would be the MAC of the slave, not the actual source
MAC of the originating destination.  This would render peers unable to
communicate with the destinations beyond the bridge.

Signed-off-by: Zheng Li &lt;zheng.x.li@oracle.com&gt;
Signed-off-by: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Matthew O'Connor &lt;liquidhorse@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 567b871e503316b0927e54a3d7c86d50b722d955 ]

Do not modify or load balance ARP packets passing through balance-alb
mode (wherein the ARP did not originate locally, and arrived via a bridge).

Modifying pass-through ARP replies causes an incorrect MAC address
to be placed into the ARP packet, rendering peers unable to communicate
with the actual destination from which the ARP reply originated.

Load balancing pass-through ARP requests causes an entry to be
created for the peer in the rlb table, and bond_alb_monitor will
occasionally issue ARP updates to all peers in the table instrucing them
as to which MAC address they should communicate with; this occurs when
some event sets rx_ntt.  In the bridged case, however, the MAC address
used for the update would be the MAC of the slave, not the actual source
MAC of the originating destination.  This would render peers unable to
communicate with the destinations beyond the bridge.

Signed-off-by: Zheng Li &lt;zheng.x.li@oracle.com&gt;
Signed-off-by: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Matthew O'Connor &lt;liquidhorse@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: IFF_BONDING is not stripped on enslave failure</title>
<updated>2013-05-01T16:41:07+00:00</updated>
<author>
<name>nikolay@redhat.com</name>
<email>nikolay@redhat.com</email>
</author>
<published>2013-04-11T09:18:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2a11e5fe4e27757d6316f25119ec02d4b3ab199a'/>
<id>2a11e5fe4e27757d6316f25119ec02d4b3ab199a</id>
<content type='text'>
[ Upstream commit b6a5a7b9a528a8b4c8bec940b607c5dd9102b8cc ]

While enslaving a new device and after IFF_BONDING flag is set, in case
of failure it is not stripped from the device's priv_flags while
cleaning up, which could lead to other problems.
Cleaning at err_close because the flag is set after dev_open().

v2: no change

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b6a5a7b9a528a8b4c8bec940b607c5dd9102b8cc ]

While enslaving a new device and after IFF_BONDING flag is set, in case
of failure it is not stripped from the device's priv_flags while
cleaning up, which could lead to other problems.
Cleaning at err_close because the flag is set after dev_open().

v2: no change

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: fix bonding_masters race condition in bond unloading</title>
<updated>2013-05-01T16:41:06+00:00</updated>
<author>
<name>nikolay@redhat.com</name>
<email>nikolay@redhat.com</email>
</author>
<published>2013-04-06T00:54:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=643094adbef902c4a1f5a544f1f8eb8512e7ff8c'/>
<id>643094adbef902c4a1f5a544f1f8eb8512e7ff8c</id>
<content type='text'>
[ Upstream commit 69b0216ac255f523556fa3d4ff030d857eaaa37f ]

While the bonding module is unloading, it is considered that after
rtnl_link_unregister all bond devices are destroyed but since no
synchronization mechanism exists, a new bond device can be created
via bonding_masters before unregister_pernet_subsys which would
lead to multiple problems (e.g. NULL pointer dereference, wrong RIP,
list corruption).

This patch fixes the issue by removing any bond devices left in the
netns after bonding_masters is removed from sysfs.

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
Acked-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 69b0216ac255f523556fa3d4ff030d857eaaa37f ]

While the bonding module is unloading, it is considered that after
rtnl_link_unregister all bond devices are destroyed but since no
synchronization mechanism exists, a new bond device can be created
via bonding_masters before unregister_pernet_subsys which would
lead to multiple problems (e.g. NULL pointer dereference, wrong RIP,
list corruption).

This patch fixes the issue by removing any bond devices left in the
netns after bonding_masters is removed from sysfs.

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
Acked-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: get netdev_rx_handler_unregister out of locks</title>
<updated>2013-04-05T17:04:52+00:00</updated>
<author>
<name>Veaceslav Falico</name>
<email>vfalico@redhat.com</email>
</author>
<published>2013-04-02T05:15:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=aa5ec2292c944b46ac536056b89ddfeb4e35fde3'/>
<id>aa5ec2292c944b46ac536056b89ddfeb4e35fde3</id>
<content type='text'>
[ Upstream commit fcd99434fb5c137274d2e15dd2a6a7455f0f29ff ]

Now that netdev_rx_handler_unregister contains synchronize_net(), we need
to call it outside of bond-&gt;lock, cause it might sleep. Also, remove the
already unneded synchronize_net().

Signed-off-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fcd99434fb5c137274d2e15dd2a6a7455f0f29ff ]

Now that netdev_rx_handler_unregister contains synchronize_net(), we need
to call it outside of bond-&gt;lock, cause it might sleep. Also, remove the
already unneded synchronize_net().

Signed-off-by: Veaceslav Falico &lt;vfalico@redhat.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: fix disabling of arp_interval and miimon</title>
<updated>2013-04-05T17:04:39+00:00</updated>
<author>
<name>nikolay@redhat.com</name>
<email>nikolay@redhat.com</email>
</author>
<published>2013-03-27T03:32:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ae8c63b03d7b70c0b65f1b6e304ed1976fb3019b'/>
<id>ae8c63b03d7b70c0b65f1b6e304ed1976fb3019b</id>
<content type='text'>
[ Upstream commit 1bc7db16782c2a581fb4d53ca853631050f31611 ]

Currently if either arp_interval or miimon is disabled, they both get
disabled, and upon disabling they get executed once more which is not
the proper behaviour. Also when doing a no-op and disabling an already
disabled one, the other again gets disabled.
Also fix the error messages with the proper valid ranges, and a small
typo fix in the up delay error message (outputting "down delay", instead
of "up delay").

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 1bc7db16782c2a581fb4d53ca853631050f31611 ]

Currently if either arp_interval or miimon is disabled, they both get
disabled, and upon disabling they get executed once more which is not
the proper behaviour. Also when doing a no-op and disabling an already
disabled one, the other again gets disabled.
Also fix the error messages with the proper valid ranges, and a small
typo fix in the up delay error message (outputting "down delay", instead
of "up delay").

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: fix miimon and arp_interval delayed work race conditions</title>
<updated>2013-04-05T17:04:39+00:00</updated>
<author>
<name>nikolay@redhat.com</name>
<email>nikolay@redhat.com</email>
</author>
<published>2012-11-29T01:31:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d98ea1888738fea067a1411eaefc46637f1dad8d'/>
<id>d98ea1888738fea067a1411eaefc46637f1dad8d</id>
<content type='text'>
[ Upstream commit fbb0c41b814d497c656fc7be9e35456f139cb2fb ]

First I would give three observations which will be used later.
Observation 1: if (delayed_work_pending(wq)) cancel_delayed_work(wq)
 This usage is wrong because the pending bit is cleared just before the
 work's fn is executed and if the function re-arms itself we might end up
 with the work still running. It's safe to call cancel_delayed_work_sync()
 even if the work is not queued at all.
Observation 2: Use of INIT_DELAYED_WORK()
 Work needs to be initialized only once prior to (de/en)queueing.
Observation 3: IFF_UP is set only after ndo_open is called

Related race conditions:
1. Race between bonding_store_miimon() and bonding_store_arp_interval()
 Because of Obs.1 we can end up having both works enqueued.
2. Multiple races with INIT_DELAYED_WORK()
 Since the works are not protected by anything between INIT_DELAYED_WORK()
 and calls to (en/de)queue it is possible for races between the following
 functions:
 (races are also possible between the calls to INIT_DELAYED_WORK()
  and workqueue code)
 bonding_store_miimon() - bonding_store_arp_interval(), bond_close(),
			  bond_open(), enqueued functions
 bonding_store_arp_interval() - bonding_store_miimon(), bond_close(),
				bond_open(), enqueued functions
3. By Obs.1 we need to change bond_cancel_all()

Bugs 1 and 2 are fixed by moving all work initializations in bond_open
which by Obs. 2 and Obs. 3 and the fact that we make sure that all works
are cancelled in bond_close(), is guaranteed not to have any work
enqueued.
Also RTNL lock is now acquired in bonding_store_miimon/arp_interval so
they can't race with bond_close and bond_open. The opposing work is
cancelled only if the IFF_UP flag is set and it is cancelled
unconditionally. The opposing work is already cancelled if the interface
is down so no need to cancel it again. This way we don't need new
synchronizations for the bonding workqueue. These bugs (and fixes) are
tied together and belong in the same patch.
Note: I have left 1 line intentionally over 80 characters (84) because I
      didn't like how it looks broken down. If you'd prefer it otherwise,
      then simply break it.

 v2: Make description text &lt; 75 columns

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
Signed-off-by: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fbb0c41b814d497c656fc7be9e35456f139cb2fb ]

First I would give three observations which will be used later.
Observation 1: if (delayed_work_pending(wq)) cancel_delayed_work(wq)
 This usage is wrong because the pending bit is cleared just before the
 work's fn is executed and if the function re-arms itself we might end up
 with the work still running. It's safe to call cancel_delayed_work_sync()
 even if the work is not queued at all.
Observation 2: Use of INIT_DELAYED_WORK()
 Work needs to be initialized only once prior to (de/en)queueing.
Observation 3: IFF_UP is set only after ndo_open is called

Related race conditions:
1. Race between bonding_store_miimon() and bonding_store_arp_interval()
 Because of Obs.1 we can end up having both works enqueued.
2. Multiple races with INIT_DELAYED_WORK()
 Since the works are not protected by anything between INIT_DELAYED_WORK()
 and calls to (en/de)queue it is possible for races between the following
 functions:
 (races are also possible between the calls to INIT_DELAYED_WORK()
  and workqueue code)
 bonding_store_miimon() - bonding_store_arp_interval(), bond_close(),
			  bond_open(), enqueued functions
 bonding_store_arp_interval() - bonding_store_miimon(), bond_close(),
				bond_open(), enqueued functions
3. By Obs.1 we need to change bond_cancel_all()

Bugs 1 and 2 are fixed by moving all work initializations in bond_open
which by Obs. 2 and Obs. 3 and the fact that we make sure that all works
are cancelled in bond_close(), is guaranteed not to have any work
enqueued.
Also RTNL lock is now acquired in bonding_store_miimon/arp_interval so
they can't race with bond_close and bond_open. The opposing work is
cancelled only if the IFF_UP flag is set and it is cancelled
unconditionally. The opposing work is already cancelled if the interface
is down so no need to cancel it again. This way we don't need new
synchronizations for the bonding workqueue. These bugs (and fixes) are
tied together and belong in the same patch.
Note: I have left 1 line intentionally over 80 characters (84) because I
      didn't like how it looks broken down. If you'd prefer it otherwise,
      then simply break it.

 v2: Make description text &lt; 75 columns

Signed-off-by: Nikolay Aleksandrov &lt;nikolay@redhat.com&gt;
Signed-off-by: Jay Vosburgh &lt;fubar@us.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
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