After this patch none of the netlink callback support anything
except the initial network namespace but the rtnetlink infrastructure
now handles multiple network namespaces.
Changes from v2:
- IPv6 addrlabel processing
Changes from v1:
- no need for special rtnl_unlock handling
- fixed IPv6 ndisc
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Before I can enable rtnetlink to work in all network namespaces I need
to be certain that something won't break. So this patch deliberately
disables all of the rtnletlink methods in everything except the
initial network namespace. After the methods have been audited this
extra check can be disabled.
Changes from v1:
- added IPv6 addrlabel protection
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The IPv4 and IPv6 hook values are identical, yet some code tries to figure
out the "correct" value by looking at the address family. Introduce NF_INET_*
values for both IPv4 and IPv6. The old values are kept in a #ifndef __KERNEL__
section for userspace compatibility.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This converts the code to use the new kobject functions, cleaning up the
logic in doing so.
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The kobject in the bridge code is only used for registering with sysfs,
not for any lifespan rules. This patch changes it to be only a pointer
and use the simpler api for this kind of thing.
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When packets are flood-forwarded to multiple output devices, the
bridge-netfilter code reuses skb->nf_bridge for each clone to store
the bridge port. When queueing packets using NFQUEUE netfilter takes
a reference to skb->nf_bridge->physoutdev, which is overwritten
when the packet is forwarded to the second port. This causes
refcount unterflows for the first device and refcount leaks for all
others. Additionally this provides incorrect data to the iptables
physdev match.
Unshare skb->nf_bridge by copying it if it is shared before assigning
the physoutdev device.
Reported, tested and based on initial patch by
Jan Christoph Nordholz <hesso@pool.math.tu-berlin.de>.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bridge code incorrectly causes two POST_ROUTING hook invocations
for DNATed packets that end up on the same bridge device. This
happens because packets with a changed destination address are passed
to dst_output() to make them go through the neighbour output function
again to build a new destination MAC address, before they will continue
through the IP hooks simulated by bridge netfilter.
The resulting hook order is:
PREROUTING (bridge netfilter)
POSTROUTING (dst_output -> ip_output)
FORWARD (bridge netfilter)
POSTROUTING (bridge netfilter)
The deferred hooks used to abort the first POST_ROUTING invocation,
but since the only thing bridge netfilter actually really wants is
a new MAC address, we can avoid going through the IP stack completely
by simply calling the neighbour output function directly.
Tested, reported and lots of data provided by: Damien Thebault <damien.thebault@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Assigning a valid random address to bridge device solves problems
when bridge device is brought up before adding real device to bridge.
When the first real device is added to the bridge, it's address
will overide the bridges random address.
Note: any device added to a bridge must already have a valid
ethernet address.
br_add_if -> br_fdb_insert -> fdb_insert -> is_valid_ether_addr
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
WARNING: vmlinux.o(.init.text+0x204e2): Section mismatch: reference to .exit.text:br_fdb_fini (between 'br_init' and 'br_fdb_init')
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This hook is protected with the RCU, so simple
if (br_should_route_hook)
br_should_route_hook(...)
is not enough on some architectures.
Use the rcu_dereference/rcu_assign_pointer in this case.
Fixed Stephen's comment concerning using the typeof().
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In case the br_netfilter_init() (or any subsequent call)
fails, the br_fdb_fini() must be called to free the allocated
in br_fdb_init() br_fdb_cache kmem cache.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Packets routed between bridges have the POST_ROUTING hook invoked
twice since bridging mistakes them for bridged packets because
they have skb->nf_bridge set.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix --arp-gratuitous matching dependence on --arp-ip-{src,dst}
Signed-off-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: Lutz Preler <Lutz.Pressler@SerNet.DE>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
* Convert files to UTF-8.
* Also correct some people's names
(one example is Eißfeldt, which was found in a source file.
Given that the author used an ß at all in a source file
indicates that the real name has in fact a 'ß' and not an 'ss',
which is commonly used as a substitute for 'ß' when limited to
7bit.)
* Correct town names (Goettingen -> Göttingen)
* Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313)
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
With all the users of the double pointers removed, this patch mops up by
finally replacing all occurances of sk_buff ** in the netfilter API by
sk_buff *.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch replaces unnecessary uses of skb_copy, pskb_copy and
skb_realloc_headroom by functions such as skb_make_writable and
pskb_expand_head.
This allows us to remove the double pointers later.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Due to the special location of the bridging hook, it should never see a
shared packet anyway (certainly not with any in-kernel code). So it
makes sense to unshare the skb there if necessary as that will greatly
simplify the code below it (in particular, netfilter).
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
A number of different drivers incorrect access the kobject name field
directly. This is not correct as the name might not be in the array.
Use the proper accessor function instead.
The netfilter sysctls in the bridging code don't set strategy routines:
sysctl table check failed: /net/bridge/bridge-nf-call-arptables .3.10.1 Missing strategy
sysctl table check failed: /net/bridge/bridge-nf-call-iptables .3.10.2 Missing strategy
sysctl table check failed: /net/bridge/bridge-nf-call-ip6tables .3.10.3 Missing strategy
sysctl table check failed: /net/bridge/bridge-nf-filter-vlan-tagged .3.10.4 Missing strategy
sysctl table check failed: /net/bridge/bridge-nf-filter-pppoe-tagged .3.10.5 Missing strategy
These binary sysctls can't work. The binary sysctl numbers of
other netfilter sysctls with this problem are being removed. These
need to go as well.
Signed-off-by: Joseph Fannin <jfannin@gmail.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the operations
get-tx-csum
get-sg
get-tso
get-ufo
the default ethtool_op_xxx behavior is fine for all drivers, so we
permit op==NULL to imply the default behavior.
This provides a more uniform behavior across all drivers, eliminating
ethtool(8) "ioctl not supported" errors on older drivers that had
not been updated for the latest sub-ioctls.
The ethtool_op_xxx() functions are left exported, in case anyone
wishes to call them directly from a driver-private implementation --
a not-uncommon case. Should an ethtool_op_xxx() helper remain unused
for a while, except by net/core/ethtool.c, we can un-export it at a
later date.
[ Resolved conflicts with set/get value ethtool patch... -DaveM ]
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's been a useless no-op for long enough in 2.6 so I figured it's time to
remove it. The number of people that could object because they're
maintaining unified 2.4 and 2.6 drivers is probably rather small.
[ Handled drivers added by netdev tree and some missed IRDA cases... -DaveM ]
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes most of the generic device layer network
namespace safe. This patch makes dev_base_head a
network namespace variable, and then it picks up
a few associated variables. The functions:
dev_getbyhwaddr
dev_getfirsthwbytype
dev_get_by_flags
dev_get_by_name
__dev_get_by_name
dev_get_by_index
__dev_get_by_index
dev_ioctl
dev_ethtool
dev_load
wireless_process_ioctl
were modified to take a network namespace argument, and
deal with it.
vlan_ioctl_set and brioctl_set were modified so their
hooks will receive a network namespace argument.
So basically anthing in the core of the network stack that was
affected to by the change of dev_base was modified to handle
multiple network namespaces. The rest of the network stack was
simply modified to explicitly use &init_net the initial network
namespace. This can be fixed when those components of the network
stack are modified to handle multiple network namespaces.
For now the ifindex generator is left global.
Fundametally ifindex numbers are per namespace, or else
we will have corner case problems with migration when
we get that far.
At the same time there are assumptions in the network stack
that the ifindex of a network device won't change. Making
the ifindex number global seems a good compromise until
the network stack can cope with ifindex changes when
you change namespaces, and the like.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each netlink socket will live in exactly one network namespace,
this includes the controlling kernel sockets.
This patch updates all of the existing netlink protocols
to only support the initial network namespace. Request
by clients in other namespaces will get -ECONREFUSED.
As they would if the kernel did not have the support for
that netlink protocol compiled in.
As each netlink protocol is updated to be multiple network
namespace safe it can register multiple kernel sockets
to acquire a presence in the rest of the network namespaces.
The implementation in af_netlink is a simple filter implementation
at hash table insertion and hash table look up time.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Every user of the network device notifiers is either a protocol
stack or a pseudo device. If a protocol stack that does not have
support for multiple network namespaces receives an event for a
device that is not in the initial network namespace it quite possibly
can get confused and do the wrong thing.
To avoid problems until all of the protocol stacks are converted
this patch modifies all netdev event handlers to ignore events on
devices that are not in the initial network namespace.
As the rest of the code is made network namespace aware these
checks can be removed.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch modifies every packet receive function
registered with dev_add_pack() to drop packets if they
are not from the initial network namespace.
This should ensure that the various network stacks do
not receive packets in a anything but the initial network
namespace until the code has been converted and is ready
for them.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hopefully captured all single statement cases under net/. I'm
not too sure if there is some policy about #includes that are
"guaranteed" (ie., in the current tree) to be available through
some other #included header, so I just added linux/kernel.h to
each changed file that didn't #include it previously.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds an optimised version of skb_cow that avoids the copy if
the header can be modified even if the rest of the payload is cloned.
This can be used in encapsulating paths where we only need to modify the
header. As it is, this can be used in PPPOE and bridging.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The clone argument is only used by one caller and that caller can clone
the packet itself. This patch moves the clone call into the caller and
kills the clone argument.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
So I've had a deadlock reported to me. I've found that the sequence of
events goes like this:
1) process A (modprobe) runs to remove ip_tables.ko
2) process B (iptables-restore) runs and calls setsockopt on a netfilter socket,
increasing the ip_tables socket_ops use count
3) process A acquires a file lock on the file ip_tables.ko, calls remove_module
in the kernel, which in turn executes the ip_tables module cleanup routine,
which calls nf_unregister_sockopt
4) nf_unregister_sockopt, seeing that the use count is non-zero, puts the
calling process into uninterruptible sleep, expecting the process using the
socket option code to wake it up when it exits the kernel
4) the user of the socket option code (process B) in do_ipt_get_ctl, calls
ipt_find_table_lock, which in this case calls request_module to load
ip_tables_nat.ko
5) request_module forks a copy of modprobe (process C) to load the module and
blocks until modprobe exits.
6) Process C. forked by request_module process the dependencies of
ip_tables_nat.ko, of which ip_tables.ko is one.
7) Process C attempts to lock the request module and all its dependencies, it
blocks when it attempts to lock ip_tables.ko (which was previously locked in
step 3)
Theres not really any great permanent solution to this that I can see, but I've
developed a two part solution that corrects the problem
Part 1) Modifies the nf_sockopt registration code so that, instead of using a
use counter internal to the nf_sockopt_ops structure, we instead use a pointer
to the registering modules owner to do module reference counting when nf_sockopt
calls a modules set/get routine. This prevents the deadlock by preventing set 4
from happening.
Part 2) Enhances the modprobe utilty so that by default it preforms non-blocking
remove operations (the same way rmmod does), and add an option to explicity
request blocking operation. So if you select blocking operation in modprobe you
can still cause the above deadlock, but only if you explicity try (and since
root can do any old stupid thing it would like.... :) ).
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Bridge code calls ethtool to get speed. The conversion to using
only ethtool_ops broke the case of devices without ethtool_ops.
This is a new regression in 2.6.23.
Rearranged the switch to a logical order, and use gcc initializer.
Ps: speed should have been part of the network device structure from
the start rather than burying it in ethtool.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes some packet leakage in bridge. The bridging code was
allowing forward table entries to be generated even if a device was
being blocked. The fix is to not add forwarding database entries
unless the port is active.
The bug arose as part of the conversion to processing STP frames
through normal receive path (in 2.6.17).
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Acked-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I tried to preserve bridging code as it was before, but logic is quite
strange - I think we should free skb on error, since it is already
unshared and thus will just leak.
Herbert Xu states:
> + if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
> + goto out;
If this happens it'll be a double-free on skb since we'll
return NF_DROP which makes the caller free it too.
We could return NF_STOLEN to prevent that but I'm not sure
whether that's correct netfilter semantics. Patrick, could
you please make a call on this?
Patrick McHardy states:
NF_STOLEN should work fine here.
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The stp change code generates "sleeping function called from invalid
context" because rtnl_lock() called with BH disabled. This fixes it by
not acquiring then dropping the bridge lock.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
http://bugzilla.kernel.org/show_bug.cgi?id=8797 shows that the
bonding driver may produce bogus combinations of the checksum
flags and SG/TSO.
For example, if you bond devices with NETIF_F_HW_CSUM and
NETIF_F_IP_CSUM you'll end up with a bonding device that
has neither flag set. If both have TSO then this produces
an illegal combination.
The bridge device on the other hand has the correct code to
deal with this.
In fact, the same code can be used for both. So this patch
moves that logic into net/core/dev.c and uses it for both
bonding and bridging.
In the process I've made small adjustments such as only
setting GSO_ROBUST if at least one constituent device
supports it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
During the transition to the ethtool_ops way of doing things, we supported
calling the device's ->do_ioctl method to allow unconverted drivers to
continue working. Those days are long behind us, all in-tree drivers
use the ethtool_ops way, and so we no longer need to support this.
The bonding driver is the biggest beneficiary of this; it no longer
needs to call ioctl() as a fallback if ethtool_ops aren't supported.
Also put a proper copyright statement on ethtool.c.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch cleans up duplicate includes in
net/bridge/
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Loading one of the LOG target fails if a different target has already
registered itself as backend for the same family. This can affect the
ipt_LOG and ipt_ULOG modules when both are loaded.
Reported and tested by: <t.artem@mailcity.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Rather than using a tri-state integer for the wait flag in
call_usermodehelper_exec, define a proper enum, and use that. I've
preserved the integer values so that any callers I've missed should
still work OK.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Lower ip6tables, arptables and ebtables printk severity similar to
Dan Aloni's patch for iptables.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (61 commits)
sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes
sysfs: make directory dentries and inodes reclaimable
sysfs: implement sysfs_get_dentry()
sysfs: move sysfs_drop_dentry() to dir.c and make it static
sysfs: restructure add/remove paths and fix inode update
sysfs: use sysfs_mutex to protect the sysfs_dirent tree
sysfs: consolidate sysfs spinlocks
sysfs: make kobj point to sysfs_dirent instead of dentry
sysfs: implement sysfs_find_dirent() and sysfs_get_dirent()
sysfs: implement SYSFS_FLAG_REMOVED flag
sysfs: rename sysfs_dirent->s_type to s_flags and make room for flags
sysfs: make sysfs_drop_dentry() access inodes using ilookup()
sysfs: Fix oops in sysfs_drop_dentry on x86_64
sysfs: use singly-linked list for sysfs_dirent tree
sysfs: slim down sysfs_dirent->s_active
sysfs: move s_active functions to fs/sysfs/dir.c
sysfs: fix root sysfs_dirent -> root dentry association
sysfs: use iget_locked() instead of new_inode()
sysfs: reorganize sysfs_new_indoe() and sysfs_create()
sysfs: fix parent refcounting during rename and move
...
Well, first of all, I don't want to change so many files either.
What I do:
Adding a new parameter "struct bin_attribute *" in the
.read/.write methods for the sysfs binary attributes.
In fact, only the four lines change in fs/sysfs/bin.c and
include/linux/sysfs.h do the real work.
But I have to update all the files that use binary attributes
to make them compatible with the new .read and .write methods.
I'm not sure if I missed any. :(
Why I do this:
For a sysfs attribute, we can get a pointer pointing to the
struct attribute in the .show/.store method,
while we can't do this for the binary attributes.
I don't know why this is different, but this does make it not
so handy to use the binary attributes as the regular ones.
So I think this patch is reasonable. :)
Who benefits from it:
The patch that exposes ACPI tables in sysfs
requires such an improvement.
All the table binary attributes share the same .read method.
Parameter "struct bin_attribute *" is used to get
the table signature and instance number which are used to
distinguish different ACPI table binary attributes.
Without this parameter, we need to offer different .read methods
for different ACPI table binary attributes.
This is impossible as there are various ACPI tables on different
platforms, and we don't know what they are until they are loaded.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs is now completely out of driver/module lifetime game. After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners. Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.
This patch kills now unnecessary attribute->owner. Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.
For more info regarding lifetime rule cleanup, please read the
following message.
http://article.gmane.org/gmane.linux.kernel/510293
(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>