net: dqs: add NIC stall detector based on BQL

softnet_data->time_squeeze is sometimes used as a proxy for
host overload or indication of scheduling problems. In practice
this statistic is very noisy and has hard to grasp units -
e.g. is 10 squeezes a second to be expected, or high?

Delaying network (NAPI) processing leads to drops on NIC queues
but also RTT bloat, impacting pacing and CA decisions.
Stalls are a little hard to detect on the Rx side, because
there may simply have not been any packets received in given
period of time. Packet timestamps help a little bit, but
again we don't know if packets are stale because we're
not keeping up or because someone (*cough* cgroups)
disabled IRQs for a long time.

We can, however, use Tx as a proxy for Rx stalls. Most drivers
use combined Rx+Tx NAPIs so if Tx gets starved so will Rx.
On the Tx side we know exactly when packets get queued,
and completed, so there is no uncertainty.

This patch adds stall checks to BQL. Why BQL? Because
it's a convenient place to add such checks, already
called by most drivers, and it has copious free space
in its structures (this patch adds no extra cache
references or dirtying to the fast path).

The algorithm takes one parameter - max delay AKA stall
threshold and increments a counter whenever NAPI got delayed
for at least that amount of time. It also records the length
of the longest stall.

To be precise every time NAPI has not polled for at least
stall thrs we check if there were any Tx packets queued
between last NAPI run and now - stall_thrs/2.

Unlike the classic Tx watchdog this mechanism does not
ignore stalls caused by Tx being disabled, or loss of link.
I don't think the check is worth the complexity, and
stall is a stall, whether due to host overload, flow
control, link down... doesn't matter much to the application.

We have been running this detector in production at Meta
for 2 years, with the threshold of 8ms. It's the lowest
value where false positives become rare. There's still
a constant stream of reported stalls (especially without
the ksoftirqd deferral patches reverted), those who like
their stall metrics to be 0 may prefer higher value.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: introduce include/net/rps.h

Move RPS related structures and helpers from include/linux/netdevice.h
and include/net/sock.h to a new include file.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240306160031.874438-18-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: sysfs: Do not create sysfs for non BQL device

Creation of sysfs entries is expensive, mainly for workloads that
constantly creates netdev and netns often.

Do not create BQL sysfs entries for devices that don't need,
basically those that do not have a real queue, i.e, devices that has
NETIF_F_LLTX and IFF_NO_QUEUE, such as `lo` interface.

This will remove the /sys/class/net/eth0/queues/tx-X/byte_queue_limits/
directory for these devices.

In the example below, eth0 has the `byte_queue_limits` directory but not
`lo`.

# ls /sys/class/net/lo/queues/tx-0/
traffic_class tx_maxrate tx_timeout xps_cpus xps_rxqs

# ls /sys/class/net/eth0/queues/tx-0/byte_queue_limits/
hold_time inflight limit limit_max limit_min

This also removes the #ifdefs, since we can also use netdev_uses_bql() to
check if the config is enabled. (as suggested by Jakub).

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240216094154.3263843-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net-sysfs: convert netstat_show() to RCU

dev_get_stats() can be called from RCU, there is no need
to acquire dev_base_lock.

Change dev_isalive() comment to reflect we no longer use
dev_base_lock from net/core/net-sysfs.c

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: convert dev->operstate reads to lockless ones

operstate_show() can omit dev_base_lock acquisition only
to read dev->operstate.

Annotate accesses to dev->operstate.

Writers still acquire dev_base_lock for mutual exclusion.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: use dev_addr_sem to remove races in address_show()

Using dev_base_lock is not preventing from reading garbage.

Use dev_addr_sem instead.

v4: place dev_addr_sem extern in net/core/dev.h (Jakub Kicinski)
Link: https://lore.kernel.org/netdev/20240212175845.10f6680a@kernel.org/

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: convert netdev_show() to RCU

Make clear dev_isalive() can be called with RCU protection.

Then convert netdev_show() to RCU, to remove dev_base_lock
dependency.

Also add RCU to broadcast_show().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: annotate data-races around dev->name_assign_type

name_assign_type_show() runs locklessly, we should annotate
accesses to dev->name_assign_type.

Alternative would be to grab devnet_rename_sem semaphore
from name_assign_type_show(), but this would not bring
more accuracy.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sysfs: fix locking in carrier read

My previous patch added a call to linkwatch_sync_dev(),
but that of course needs to be called under RTNL, which
I missed earlier, but now saw RCU warnings from.

Fix that by acquiring the RTNL in a similar fashion to
how other files do it here.

Fixes: facd15dfd691 ("net: core: synchronize link-watch when carrier is queried")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20231206172122.859df6ba937f.I9c80608bcfbab171943ff4942b52dbd5e97fe06e@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: core: synchronize link-watch when carrier is queried

There are multiple ways to query for the carrier state: through
rtnetlink, sysfs, and (possibly) ethtool. Synchronize linkwatch
work before these operations so that we don't have a situation
where userspace queries the carrier state between the driver's
carrier off->on transition and linkwatch running and expects it
to work, when really (at least) TX cannot work until linkwatch
has run.

I previously posted a longer explanation of how this applies to
wireless [1] but with this wireless can simply query the state
before sending data, to ensure the kernel is ready for it.

[1] https://lore.kernel.org/all/346b21d87c69f817ea3c37caceb34f1f56255884.camel@sipsolutions.net/

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231204214706.303c62768415.I1caedccae72ee5a45c9085c5eb49c145ce1c0dd5@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: move struct netdev_rx_queue out of netdevice.h

struct netdev_rx_queue is touched in only a few places
and having it defined in netdevice.h brings in the dependency
on xdp.h, because struct xdp_rxq_info gets embedded in
struct netdev_rx_queue.

In prep for removal of xdp.h from netdevice.h move all
the netdev_rx_queue stuff to a new header.

We could technically break the new header up to avoid
the sysfs.h include but it's so rarely included it
doesn't seem to be worth it at this point.

Reviewed-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/20230803010230.1755386-3-kuba@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

net: make default_rps_mask a per netns attribute

That really was meant to be a per netns attribute from the beginning.

The idea is that once proper isolation is in place in the main
namespace, additional demux in the child namespaces will be redundant.
Let's make child netns default rps mask empty by default.

To avoid bloating the netns with a possibly large cpumask, allocate
it on-demand during the first write operation.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: make kobj_type structures constant

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definitions to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: introduce default_rps_mask netns attribute

If RPS is enabled, this allows configuring a default rps
mask, which is effective since receive queue creation time.

A default RPS mask allows the system admin to ensure proper
isolation, avoiding races at network namespace or device
creation time.

The default RPS mask is initially empty, and can be
modified via a newly added sysctl entry.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net-sysctl: factor-out rpm mask manipulation helpers

Will simplify the following patch. No functional change
intended.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

driver core: make struct class.dev_uevent() take a const *

The dev_uevent() in struct class should not be modifying the device that
is passed into it, so mark it as a const * and propagate the function
signature changes out into all relevant subsystems that use this
callback.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Russ Weight <russell.h.weight@intel.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Raed Salem <raeds@nvidia.com>
Cc: Chen Zhongjin <chenzhongjin@huawei.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Avihai Horon <avihaih@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Cc: Antoine Tenart <atenart@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Wang Yufen <wangyufen@huawei.com>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: linux-pm@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20221123122523.1332370-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kobject: make kobject_get_ownership() take a constant kobject *

The call, kobject_get_ownership(), does not modify the kobject passed
into it, so make it const. This propagates down into the kobj_type
function callbacks so make the kobject passed into them also const,
ensuring that nothing in the kobject is being changed here.

This helps make it more obvious what calls and callbacks do, and do not,
modify structures passed to them.

Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: linux-nfs@vger.kernel.org
Cc: bridge@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20221121094649.1556002-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: class: make namespace and get_ownership take const *

The callbacks in struct class namespace() and get_ownership() do not
modify the struct device passed to them, so mark the pointer as constant
and fix up all callbacks in the kernel to have the correct function
signature.

This helps make it more obvious what calls and callbacks do, and do not,
modify structures passed to them.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20221001165426.2690912-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: devlink: use devlink_port pointer instead of ndo_get_devlink_port

Use newly introduced devlink_port pointer instead of getting it calling
to ndo_get_devlink_port op.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net-sysfs: Convert to use sysfs_emit() APIs

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the value
to be returned to user space.

Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rename reference+tracking helpers

Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: fix data-race in dev_isalive()

dev_isalive() is called under RTNL or dev_base_lock protection.

This means that changes to dev->reg_state should be done with both locks held.

syzbot reported:

BUG: KCSAN: data-race in register_netdevice / type_show

write to 0xffff888144ecf518 of 1 bytes by task 20886 on cpu 0:
register_netdevice+0xb9f/0xdf0 net/core/dev.c:10050
lapbeth_new_device drivers/net/wan/lapbether.c:414 [inline]
lapbeth_device_event+0x4a0/0x6c0 drivers/net/wan/lapbether.c:456
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0x53/0xb0 kernel/notifier.c:455
__dev_notify_flags+0x1d6/0x3a0
dev_change_flags+0xa2/0xc0 net/core/dev.c:8607
do_setlink+0x778/0x2230 net/core/rtnetlink.c:2780
__rtnl_newlink net/core/rtnetlink.c:3546 [inline]
rtnl_newlink+0x114c/0x16a0 net/core/rtnetlink.c:3593
rtnetlink_rcv_msg+0x811/0x8c0 net/core/rtnetlink.c:6089
netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2501
rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:6107
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x58a/0x660 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x661/0x750 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg net/socket.c:734 [inline]
__sys_sendto+0x21e/0x2c0 net/socket.c:2119
__do_sys_sendto net/socket.c:2131 [inline]
__se_sys_sendto net/socket.c:2127 [inline]
__x64_sys_sendto+0x74/0x90 net/socket.c:2127
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff888144ecf518 of 1 bytes by task 20423 on cpu 1:
dev_isalive net/core/net-sysfs.c:38 [inline]
netdev_show net/core/net-sysfs.c:50 [inline]
type_show+0x24/0x90 net/core/net-sysfs.c:112
dev_attr_show+0x35/0x90 drivers/base/core.c:2095
sysfs_kf_seq_show+0x175/0x240 fs/sysfs/file.c:59
kernfs_seq_show+0x75/0x80 fs/kernfs/file.c:162
seq_read_iter+0x2c3/0x8e0 fs/seq_file.c:230
kernfs_fop_read_iter+0xd1/0x2f0 fs/kernfs/file.c:235
call_read_iter include/linux/fs.h:2052 [inline]
new_sync_read fs/read_write.c:401 [inline]
vfs_read+0x5a5/0x6a0 fs/read_write.c:482
ksys_read+0xe8/0x1a0 fs/read_write.c:620
__do_sys_read fs/read_write.c:630 [inline]
__se_sys_read fs/read_write.c:628 [inline]
__x64_sys_read+0x3e/0x50 fs/read_write.c:628
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20423 Comm: udevd Tainted: G W 5.19.0-rc2-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wrap the wireless pointers in struct net_device in an ifdef

Most protocol-specific pointers in struct net_device are under
a respective ifdef. Wireless is the notable exception. Since
there's a sizable number of custom-built kernels for datacenter
workloads which don't build wireless it seems reasonable to
ifdefy those pointers as well.

While at it move IPv4 and IPv6 pointers up, those are special
for obvious reasons.

Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> # ieee802154
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: extract a few internals from netdevice.h

There's a number of functions and static variables used
under net/core/ but not from the outside. We currently
dump most of them into netdevice.h. That bad for many
reasons:
- netdevice.h is very cluttered, hard to figure out
what the APIs are;
- netdevice.h is very long;
- we have to touch netdevice.h more which causes expensive
incremental builds.

Create a header under net/core/ and move some declarations.

The new header is also a bit of a catch-all but that's
fine, if we create more specific headers people will
likely over-think where their declaration fit best.
And end up putting them in netdevice.h, again.

More work should be done on splitting netdevice.h into more
targeted headers, but that'd be more time consuming so small
steps.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

sched/isolation: Use single feature type while referring to housekeeping cpumask

Refer to housekeeping APIs using single feature types instead of flags.
This prevents from passing multiple isolation features at once to
housekeeping interfaces, which soon won't be possible anymore as each
isolation features will have their own cpumask.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org

net: Decouple HK_FLAG_WQ and HK_FLAG_DOMAIN cpumask fetch

To prepare for supporting each feature of the housekeeping cpumask
toward cpuset, prepare each of the HK_FLAG_* entries to move to their
own cpumask with enforcing to fetch them individually. The new
constraint is that multiple HK_FLAG_* entries can't be mixed together
anymore in a single call to housekeeping cpumask().

This will later allow, for example, to runtime modify the cpulist passed
through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot
parameters.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-4-frederic@kernel.org

net-sysfs: add check for netdevice being present to speed_show

When bringing down the netdevice or system shutdown, a panic can be
triggered while accessing the sysfs path because the device is already
removed.

[ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called
[ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called
...
[ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280

crash> bt
...
PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd"
...
#9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778
[exception RIP: dma_pool_alloc+0x1ab]
RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046
RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000
RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090
RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00
R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0
R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core]
#11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core]
#12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core]
#13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core]
#14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core]
#15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core]
#16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core]
#17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46
#18 [ffff89240e1a3d48] speed_show at ffffffff8f277208
#19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3
#20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf
#21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596
#22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10
#23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5
#24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff
#25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f
#26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92

crash> net_device.state ffff89443b0c0000
state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER)

To prevent this scenario, we also make sure that the netdevice is present.

Signed-off-by: suresh kumar <suresh2514@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: warn if new queue objects are being created during device unregistration

Calling netdev_queue_update_kobjects is allowed during device
unregistration since commit 5c56580b74e5 ("net: Adjust TX queue kobjects
if number of queues changes during unregister"). But this is solely to
allow queue unregistrations. Any path attempting to add new queues after
a device started its unregistration should be fixed.

This patch adds a warning to detect such illegal use.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net-sysfs: update the queue counts in the unregistration path

When updating Rx and Tx queue kobjects, the queue count should always be
updated to match the queue kobjects count. This was not done in the net
device unregistration path, fix it. Tracking all queue count updates
will allow in a following up patch to detect illegal updates.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: add net device refcount tracker to struct netdev_queue

This will help debugging pesky netdev reference leaks.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: add net device refcount tracker to struct netdev_rx_queue

This helps debugging net device refcount leaks.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: remove .ndo_change_proto_down

.ndo_change_proto_down was added seemingly to enable out-of-tree
implementations. Over 2.5yrs later we still have no real users
upstream. Hardwire the generic implementation for now, we can
revert once real users materialize. (rocker is a test vehicle,
not a user.)

We need to drop the optimization on the sysfs side, because
unlike ndos priv_flags will be changed at runtime, so we'd
need READ_ONCE/WRITE_ONCE everywhere..

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Slightly optimize 'xps_queue_show()'

The 'mask' bitmap is local to this function. So the non-atomic
'__set_bit()' can be used to save a few cycles.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use an atomic_long_t for queue->trans_timeout

tx_timeout_show() assumed dev_watchdog() would stop all
the queues, to fetch queue->trans_timeout under protection
of the queue->_xmit_lock.

As we want to no longer disrupt transmits, we use an
atomic_long_t instead.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: david decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: try not to restart the syscall if it will fail eventually

Due to deadlocks in the networking subsystem spotted 12 years ago[1],
a workaround was put in place[2] to avoid taking the rtnl lock when it
was not available and restarting the syscall (back to VFS, letting
userspace spin). The following construction is found a lot in the net
sysfs and sysctl code:

if (!rtnl_trylock())
return restart_syscall();

This can be problematic when multiple userspace threads use such
interfaces in a short period, making them to spin a lot. This happens
for example when adding and moving virtual interfaces: userspace
programs listening on events, such as systemd-udevd and NetworkManager,
do trigger actions reading files in sysfs. It gets worse when a lot of
virtual interfaces are created concurrently, say when creating
containers at boot time.

Returning early without hitting the above pattern when the syscall will
fail eventually does make things better. While it is not a fix for the
issue, it does ease things.

[1] https://lore.kernel.org/netdev/49A4D5D5.5090602@trash.net/
https://lore.kernel.org/netdev/m14oyhis31.fsf@fess.ebiederm.org/
and https://lore.kernel.org/netdev/20090226084924.16cb3e08@nehalam/
[2] Rightfully, those deadlocks are *hard* to solve.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

of: net: move of_net under net/

Rob suggests to move of_net.c from under drivers/of/ somewhere
to the networking code.

Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: initialize uid and gid before calling net_ns_get_ownership

Currently in net_ns_get_ownership() it may not be able to set uid or gid
if make_kuid or make_kgid returns an invalid value, and an uninit-value
issue can be triggered by this.

This patch is to fix it by initializing the uid and gid before calling
net_ns_get_ownership(), as it does in kobject_get_ownership()

Fixes: e6dee9f3893c ("net-sysfs: add netdev_change_owner()")
Reported-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: remove possible sleep from an RCU read-side critical section

xps_queue_show is mostly made of an RCU read-side critical section and
calls bitmap_zalloc with GFP_KERNEL in the middle of it. That is not
allowed as this call may sleep and such behaviours aren't allowed in RCU
read-side critical sections. Fix this by using GFP_NOWAIT instead.

Fixes: 5478fcd0f483 ("net: embed nr_ids in the xps maps")
Reported-by: kernel test robot <oliver.sang@intel.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: move the xps cpus/rxqs retrieval in a common function

Most of the xps_cpus_show and xps_rxqs_show functions share the same
logic. Having it in two different functions does not help maintenance.
This patch moves their common logic into a new function, xps_queue_show,
to improve this.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: move the rtnl unlock up in the xps show helpers

Now that nr_ids and num_tc are stored in the xps dev_maps, which are RCU
protected, we do not have the need to protect the maps in the rtnl lock.
Move the rtnl unlock up so we reduce the rtnl locking section.

We also increase the reference count on the subordinate device if any,
as we don't want this device to be freed while we use it (now that the
rtnl lock isn't protecting it in the whole function).

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: move the xps maps to an array

Move the xps maps (xps_cpus_map and xps_rxqs_map) to an array in
net_device. That will simplify a lot the code removing the need for lots
of if/else conditionals as the correct map will be available using its
offset in the array.

This should not modify the xps maps behaviour in any way.

Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove the xps possible_mask

Remove the xps possible_mask. It was an optimization but we can just
loop from 0 to nr_ids now that it is embedded in the xps dev_maps. That
simplifies the code a bit.

Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: embed nr_ids in the xps maps

Embed nr_ids (the number of cpu for the xps cpus map, and the number of
rxqs for the xps cpus map) in dev_maps. That will help not accessing out
of bound memory if those values change after dev_maps was allocated.

Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: embed num_tc in the xps maps

The xps cpus/rxqs map is accessed using dev->num_tc, which is used when
allocating the map. But later updates of dev->num_tc can lead to having
a mismatch between the maps and how they're accessed. In such cases the
map values do not make any sense and out of bound accesses can occur
(that can be easily seen using KASAN).

This patch aims at fixing this by embedding num_tc into the maps, using
the value at the time the map is created. This brings two improvements:
- The maps can be accessed using the embedded num_tc, so we know for
sure we won't have out of bound accesses.
- Checks can be made before accessing the maps so we know the values
retrieved will make sense.

We also update __netif_set_xps_queue to conditionally copy old maps from
dev_maps in the new one only if the number of traffic classes from both
maps match.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: make xps_cpus_show and xps_rxqs_show consistent

Make the implementations of xps_cpus_show and xps_rxqs_show to converge,
as the two share the same logic but diverted over time. This should not
modify their behaviour but will help future changes and improve
maintenance.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: store the return of get_netdev_queue_index in an unsigned int

In net-sysfs, get_netdev_queue_index returns an unsigned int. Some of
its callers use an unsigned long to store the returned value. Update the
code to be consistent, this should only be cosmetic.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: convert xps_cpus_show to bitmap_zalloc

Use bitmap_zalloc instead of zalloc_cpumask_var in xps_cpus_show to
align with xps_rxqs_show. This will improve maintenance and allow us to
factorize the two functions. The function should behave the same.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add sysfs attribute to control napi threaded mode

This patch adds a new sysfs attribute to the network device class.
Said attribute provides a per-device control to enable/disable the
threaded mode for all the napi instances of the given network device,
without the need for a device up/down.
User sets it to 1 or 0 to enable or disable threaded mode.
Note: when switching between threaded and the current softirq based mode
for a napi instance, it will not immediately take effect if the napi is
currently being polled. The mode switch will happen for the next time
napi_schedule() is called.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Co-developed-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Wei Wang <weiwan@google.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Add rtnl locking for getting Tx queue traffic class

In order to access the suboordinate dev for a device we should be holding
the rtnl_lock when outside of the transmit path. The existing code was not
doing that for the sysfs dump function and as a result we were open to a
possible race.

To resolve that take the rtnl lock prior to accessing the sb_dev field of
the Tx queue and release it after we have retrieved the tc for the queue.

Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: take the rtnl lock when accessing xps_rxqs_map and num_tc

Accesses to dev->xps_rxqs_map (when using dev->num_tc) should be
protected by the rtnl lock, like we do for netif_set_xps_queue. I didn't
see an actual bug being triggered, but let's be safe here and take the
rtnl lock while accessing the map in sysfs.

Fixes: 8af2c06ff4b1 ("net-sysfs: Add interface for Rx queue(s) map per Tx queue")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net-sysfs: take the rtnl lock when storing xps_rxqs

Two race conditions can be triggered when storing xps rxqs, resulting in
various oops and invalid memory accesses:

1. Calling netdev_set_num_tc while netif_set_xps_queue:

- netif_set_xps_queue uses dev->tc_num as one of the parameters to
compute the size of new_dev_maps when allocating it. dev->tc_num is
also used to access the map, and the compiler may generate code to
retrieve this field multiple times in the function.

- netdev_set_num_tc sets dev->tc_num.

If new_dev_maps is allocated using dev->tc_num and then dev->tc_num
is set to a higher value through netdev_set_num_tc, later accesses to
new_dev_maps in netif_set_xps_queue could lead to accessing memory
outside of new_dev_maps; triggering an oops.

2. Calling netif_set_xps_queue while netdev_set_num_tc is running:

2.1. netdev_set_num_tc starts by resetting the xps queues,
dev->tc_num isn't updated yet.

2.2. netif_set_xps_queue is called, setting up the map with the
*old* dev->num_tc.

2.3. netdev_set_num_tc updates dev->tc_num.

2.4. Later accesses to the map lead to out of bound accesses and
oops.

A similar issue can be found with netdev_reset_tc.

One way of triggering this is to set an iface up (for which the driver
uses netdev_set_num_tc in the open path, such as bnx2x) and writing to
xps_rxqs in a concurrent thread. With the right timing an oops is
triggered.

Both issues have the same fix: netif_set_xps_queue, netdev_set_num_tc
and netdev_reset_tc should be mutually exclusive. We do that by taking
the rtnl lock in xps_rxqs_store.

Fixes: 8af2c06ff4b1 ("net-sysfs: Add interface for Rx queue(s) map per Tx queue")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net-sysfs: take the rtnl lock when accessing xps_cpus_map and num_tc

Accesses to dev->xps_cpus_map (when using dev->num_tc) should be
protected by the rtnl lock, like we do for netif_set_xps_queue. I didn't
see an actual bug being triggered, but let's be safe here and take the
rtnl lock while accessing the map in sysfs.

Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net-sysfs: take the rtnl lock when storing xps_cpus

Two race conditions can be triggered when storing xps cpus, resulting in
various oops and invalid memory accesses:

1. Calling netdev_set_num_tc while netif_set_xps_queue:

- netif_set_xps_queue uses dev->tc_num as one of the parameters to
compute the size of new_dev_maps when allocating it. dev->tc_num is
also used to access the map, and the compiler may generate code to
retrieve this field multiple times in the function.

- netdev_set_num_tc sets dev->tc_num.

If new_dev_maps is allocated using dev->tc_num and then dev->tc_num
is set to a higher value through netdev_set_num_tc, later accesses to
new_dev_maps in netif_set_xps_queue could lead to accessing memory
outside of new_dev_maps; triggering an oops.

2. Calling netif_set_xps_queue while netdev_set_num_tc is running:

2.1. netdev_set_num_tc starts by resetting the xps queues,
dev->tc_num isn't updated yet.

2.2. netif_set_xps_queue is called, setting up the map with the
*old* dev->num_tc.

2.3. netdev_set_num_tc updates dev->tc_num.

2.4. Later accesses to the map lead to out of bound accesses and
oops.

A similar issue can be found with netdev_reset_tc.

One way of triggering this is to set an iface up (for which the driver
uses netdev_set_num_tc in the open path, such as bnx2x) and writing to
xps_cpus in a concurrent thread. With the right timing an oops is
triggered.

Both issues have the same fix: netif_set_xps_queue, netdev_set_num_tc
and netdev_reset_tc should be mutually exclusive. We do that by taking
the rtnl lock in xps_cpus_store.

Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net-sysfs: Fix inconsistent of format with argument type in net-sysfs.c

Fix follow warnings:
[net/core/net-sysfs.c:1161]: (warning) %u in format string (no. 1)
requires 'unsigned int' but the argument type is 'int'.
[net/core/net-sysfs.c:1162]: (warning) %u in format string (no. 1)
requires 'unsigned int' but the argument type is 'int'.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Use generic ns_common::count

Switch over network namespaces to use the newly introduced common lifetime
counter.
Network namespaces have an additional counter named "passive". This counter
does not guarantee that the network namespace is not already de-initialized
and so isn't concerned with the actual lifetime of the network namespace;
only the "count" counter is. So the latter is moved into struct ns_common.

Currently every namespace type has its own lifetime counter which is stored
in the specific namespace struct. The lifetime counters are used
identically for all namespaces types. Namespaces may of course have
additional unrelated counters and these are not altered.

This introduces a common lifetime counter into struct ns_common. The
ns_common struct encompasses information that all namespaces share. That
should include the lifetime counter since its common for all of them.

It also allows us to unify the type of the counters across all namespaces.
Most of them use refcount_t but one uses atomic_t and at least one uses
kref. Especially the last one doesn't make much sense since it's just a
wrapper around refcount_t since 2016 and actually complicates cleanup
operations by having to use container_of() to cast the correct namespace
struct out of struct ns_common.

Having the lifetime counter for the namespaces in one place reduces
maintenance cost. Not just because after switching all namespaces over we
will have removed more code than we added but also because the logic is
more easily understandable and we indicate to the user that the basic
lifetime requirements for all namespaces are currently identical.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
[christian.brauner@ubuntu.com: rewrite commit]
Link: https://lore.kernel.org/r/159644977635.604812.1319877322927063560.stgit@localhost.localdomain
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus

We must accept an empty mask in store_rps_map(), or we are not able
to disable RPS on a queue.

Fixes: 07bbecb34106 ("net: Restrict receive packets queuing to housekeeping CPUs")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Cc: Alex Belits <abelits@marvell.com>
Cc: Nitesh Narayan Lal <nitesh@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: add a newline when printing 'tx_timeout' by sysfs

When I cat 'tx_timeout' by sysfs, it displays as follows. It's better to
add a newline for easy reading.

root@syzkaller:~# cat /sys/devices/virtual/net/lo/queues/tx-0/tx_timeout
0root@syzkaller:~#

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Restrict receive packets queuing to housekeeping CPUs

With the existing implementation of store_rps_map(), packets are queued
in the receive path on the backlog queues of other CPUs irrespective of
whether they are isolated or not. This could add a latency overhead to
any RT workload that is running on the same CPU.

Ensure that store_rps_map() only uses available housekeeping CPUs for
storing the rps_map.

Signed-off-by: Alex Belits <abelits@marvell.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200625223443.2684-4-nitesh@redhat.com

net: core: recursively find netdev by device node

The assumption that a device node is associated either with the
netdev's device, or the parent of that device, does not hold for all
drivers. E.g. Freescale's DPAA has two layers of platform devices
above the netdev. Instead, recursively walk up the tree from the
netdev, allowing any parent to match against the sought after node.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: napi: use READ_ONCE()/WRITE_ONCE()

gro_flush_timeout and napi_defer_hard_irqs can be read
from napi_complete_done() while other cpus write the value,
whithout explicit synchronization.

Use READ_ONCE()/WRITE_ONCE() to annotate the races.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: napi: add hard irqs deferral feature

Back in commit 3b47d30396ba ("net: gro: add a per device gro flush timer")
we added the ability to arm one high resolution timer, that we used
to keep not-complete packets in GRO engine a bit longer, hoping that further
frames might be added to them.

Since then, we added the napi_complete_done() interface, and commit
364b6055738b ("net: busy-poll: return busypolling status to drivers")
allowed drivers to avoid re-arming NIC interrupts if we made a promise
that their NAPI poll() handler would be called in the near future.

This infrastructure can be leveraged, thanks to a new device parameter,
which allows to arm the napi hrtimer, instead of re-arming the device
hard IRQ.

We have noticed that on some servers with 32 RX queues or more, the chit-chat
between the NIC and the host caused by IRQ delivery and re-arming could hurt
throughput by ~20% on 100Gbit NIC.

In contrast, hrtimers are using local (percpu) resources and might have lower
cost.

The new tunable, named napi_defer_hard_irqs, is placed in the same hierarchy
than gro_flush_timeout (/sys/class/net/ethX/)

By default, both gro_flush_timeout and napi_defer_hard_irqs are zero.

This patch does not change the prior behavior of gro_flush_timeout
if used alone : NIC hard irqs should be rearmed as before.

One concrete usage can be :

echo 20000 >/sys/class/net/eth1/gro_flush_timeout
echo 10 >/sys/class/net/eth1/napi_defer_hard_irqs

If at least one packet is retired, then we will reset napi counter
to 10 (napi_defer_hard_irqs), ensuring at least 10 periodic scans
of the queue.

On busy queues, this should avoid NIC hard IRQ, while before this patch IRQ
avoidance was only possible if napi->poll() was exhausting its budget
and not call napi_complete_done().

This feature also can be used to work around some non-optimal NIC irq
coalescing strategies.

Having the ability to insert XX usec delays between each napi->poll()
can increase cache efficiency, since we increase batch sizes.

It also keeps serving cpus not idle too long, reducing tail latencies.

Co-developed-by: Luigi Rizzo <lrizzo@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add testing sysfs attribute

Similar to speed, duplex and dorment, report the testing status
in sysfs.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: remove redundant assignment to variable ret

The variable ret is being initialized with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: add queue_change_owner()

Add a function to change the owner of the queue entries for a network device
when it is moved between network namespaces.

Currently, when moving network devices between network namespaces the
ownership of the corresponding queue sysfs entries are not changed. This leads
to problems when tools try to operate on the corresponding sysfs files. Fix
this.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: add netdev_change_owner()

Add a function to change the owner of a network device when it is moved
between network namespaces.

Currently, when moving network devices between network namespaces the
ownership of the corresponding sysfs entries is not changed. This leads
to problems when tools try to operate on the corresponding sysfs files.
This leads to a bug whereby a network device that is created in a
network namespaces owned by a user namespace will have its corresponding
sysfs entry owned by the root user of the corresponding user namespace.
If such a network device has to be moved back to the host network
namespace the permissions will still be set to the user namespaces. This
means unprivileged users can e.g. trigger uevents for such incorrectly
owned devices. They can also modify the settings of the device itself.
Both of these things are unwanted.

For example, workloads will create network devices in the host network
namespace. Other tools will then proceed to move such devices between
network namespaces owner by other user namespaces. While the ownership
of the device itself is updated in
net/core/net-sysfs.c:dev_change_net_namespace() the corresponding sysfs
entry for the device is not:

drwxr-xr-x 5 nobody nobody 0 Jan 25 18:08 .
drwxr-xr-x 9 nobody nobody 0 Jan 25 18:08 ..
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 addr_assign_type
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 addr_len
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 address
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 broadcast
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_changes
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_down_count
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_up_count
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dev_id
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dev_port
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dormant
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 duplex
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 flags
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 gro_flush_timeout
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 ifalias
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 ifindex
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 iflink
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 link_mode
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 mtu
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 name_assign_type
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 netdev_group
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 operstate
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_port_id
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_port_name
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_switch_id
drwxr-xr-x 2 nobody nobody 0 Jan 25 18:09 power
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 proto_down
drwxr-xr-x 4 nobody nobody 0 Jan 25 18:09 queues
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 speed
drwxr-xr-x 2 nobody nobody 0 Jan 25 18:09 statistics
lrwxrwxrwx 1 nobody nobody 0 Jan 25 18:08 subsystem -> ../../../../class/net
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 tx_queue_len
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 type
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:08 uevent

However, if a device is created directly in the network namespace then
the device's sysfs permissions will be correctly updated:

drwxr-xr-x 5 root root 0 Jan 25 18:12 .
drwxr-xr-x 9 nobody nobody 0 Jan 25 18:08 ..
-r--r--r-- 1 root root 4096 Jan 25 18:12 addr_assign_type
-r--r--r-- 1 root root 4096 Jan 25 18:12 addr_len
-r--r--r-- 1 root root 4096 Jan 25 18:12 address
-r--r--r-- 1 root root 4096 Jan 25 18:12 broadcast
-rw-r--r-- 1 root root 4096 Jan 25 18:12 carrier
-r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_changes
-r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_down_count
-r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_up_count
-r--r--r-- 1 root root 4096 Jan 25 18:12 dev_id
-r--r--r-- 1 root root 4096 Jan 25 18:12 dev_port
-r--r--r-- 1 root root 4096 Jan 25 18:12 dormant
-r--r--r-- 1 root root 4096 Jan 25 18:12 duplex
-rw-r--r-- 1 root root 4096 Jan 25 18:12 flags
-rw-r--r-- 1 root root 4096 Jan 25 18:12 gro_flush_timeout
-rw-r--r-- 1 root root 4096 Jan 25 18:12 ifalias
-r--r--r-- 1 root root 4096 Jan 25 18:12 ifindex
-r--r--r-- 1 root root 4096 Jan 25 18:12 iflink
-r--r--r-- 1 root root 4096 Jan 25 18:12 link_mode
-rw-r--r-- 1 root root 4096 Jan 25 18:12 mtu
-r--r--r-- 1 root root 4096 Jan 25 18:12 name_assign_type
-rw-r--r-- 1 root root 4096 Jan 25 18:12 netdev_group
-r--r--r-- 1 root root 4096 Jan 25 18:12 operstate
-r--r--r-- 1 root root 4096 Jan 25 18:12 phys_port_id
-r--r--r-- 1 root root 4096 Jan 25 18:12 phys_port_name
-r--r--r-- 1 root root 4096 Jan 25 18:12 phys_switch_id
drwxr-xr-x 2 root root 0 Jan 25 18:12 power
-rw-r--r-- 1 root root 4096 Jan 25 18:12 proto_down
drwxr-xr-x 4 root root 0 Jan 25 18:12 queues
-r--r--r-- 1 root root 4096 Jan 25 18:12 speed
drwxr-xr-x 2 root root 0 Jan 25 18:12 statistics
lrwxrwxrwx 1 nobody nobody 0 Jan 25 18:12 subsystem -> ../../../../class/net
-rw-r--r-- 1 root root 4096 Jan 25 18:12 tx_queue_len
-r--r--r-- 1 root root 4096 Jan 25 18:12 type
-rw-r--r-- 1 root root 4096 Jan 25 18:12 uevent

Now, when creating a network device in a network namespace owned by a
user namespace and moving it to the host the permissions will be set to
the id that the user namespace root user has been mapped to on the host
leading to all sorts of permission issues:

458752
drwxr-xr-x 5 458752 458752 0 Jan 25 18:12 .
drwxr-xr-x 9 root root 0 Jan 25 18:08 ..
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 addr_assign_type
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 addr_len
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 address
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 broadcast
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_changes
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_down_count
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_up_count
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dev_id
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dev_port
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dormant
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 duplex
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 flags
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 gro_flush_timeout
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 ifalias
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 ifindex
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 iflink
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 link_mode
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 mtu
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 name_assign_type
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 netdev_group
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 operstate
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_port_id
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_port_name
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_switch_id
drwxr-xr-x 2 458752 458752 0 Jan 25 18:12 power
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 proto_down
drwxr-xr-x 4 458752 458752 0 Jan 25 18:12 queues
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 speed
drwxr-xr-x 2 458752 458752 0 Jan 25 18:12 statistics
lrwxrwxrwx 1 root root 0 Jan 25 18:12 subsystem -> ../../../../class/net
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 tx_queue_len
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 type
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 uevent

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Call dev_hold always in rx_queue_add_kobject

Dev_hold has to be called always in rx_queue_add_kobject.
Otherwise usage count drops below 0 in case of failure in
kobject_init_and_add.

Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject")
Reported-by: syzbot <syzbot+30209ea299c09d8785c9@syzkaller.appspotmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Miller <davem@davemloft.net>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Call dev_hold always in netdev_queue_add_kobject

Dev_hold has to be called always in netdev_queue_add_kobject.
Otherwise usage count drops below 0 in case of failure in
kobject_init_and_add.

Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject")
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Miller <davem@davemloft.net>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: fix netdev_queue_add_kobject() breakage

kobject_put() should only be called in error path.

Fixes: b8eb718348b8 ("net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jouni Hogander <jouni.hogander@unikie.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Fix reference count leak in rx|netdev_queue_add_kobject

kobject_init_and_add takes reference even when it fails. This has
to be given up by the caller in error handling. Otherwise memory
allocated by kobject_init_and_add is never freed. Originally found
by Syzkaller:

BUG: memory leak
unreferenced object 0xffff8880679f8b08 (size 8):
comm "netdev_register", pid 269, jiffies 4294693094 (age 12.132s)
hex dump (first 8 bytes):
72 78 2d 30 00 36 20 d4 rx-0.6 .
backtrace:
[<000000008c93818e>] __kmalloc_track_caller+0x16e/0x290
[<000000001f2e4e49>] kvasprintf+0xb1/0x140
[<000000007f313394>] kvasprintf_const+0x56/0x160
[<00000000aeca11c8>] kobject_set_name_vargs+0x5b/0x140
[<0000000073a0367c>] kobject_init_and_add+0xd8/0x170
[<0000000088838e4b>] net_rx_queue_update_kobjects+0x152/0x560
[<000000006be5f104>] netdev_register_kobject+0x210/0x380
[<00000000e31dab9d>] register_netdevice+0xa1b/0xf00
[<00000000f68b2465>] __tun_chr_ioctl+0x20d5/0x3dd0
[<000000004c50599f>] tun_chr_ioctl+0x2f/0x40
[<00000000bbd4c317>] do_vfs_ioctl+0x1c7/0x1510
[<00000000d4c59e8f>] ksys_ioctl+0x99/0xb0
[<00000000946aea81>] __x64_sys_ioctl+0x78/0xb0
[<0000000038d946e5>] do_syscall_64+0x16f/0x580
[<00000000e0aa5d8f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[<00000000285b3d1a>] 0xffffffffffffffff

Cc: David Miller <davem@davemloft.net>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Jouni Hogander <jouni.hogander@unikie.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net-sysfs: Replace ktype default_attrs field with groups

The kobj_type default_attrs field is being replaced by the
default_groups field. Replace the default_attrs fields in rx_queue_ktype
and netdev_queue_ktype with default_groups. Use the ATTRIBUTE_GROUPS
macro to create rx_queue_default_groups and netdev_queue_default_groups.

This patch was tested by verifying that the sysfs files for the
attributes in the default groups were created.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "net-sysfs: Fix memory leak in netdev_register_kobject"

This reverts commit 6b70fc94afd165342876e53fc4b2f7d085009945.

The reverted bugfix will cause another issue.
Reported by syzbot+6024817a931b2830bc93@syzkaller.appspotmail.com.
See https://syzkaller.appspot.com/x/log.txt?x=1737671b200000 for
details.

Signed-off-by: Wang Hai <wanghai26@huawei.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert rps_needed and rfs_needed to new static branch api

We prefer static_branch_unlikely() over static_key_false() these days.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Fix memory leak in netdev_register_kobject

When registering struct net_device, it will call
register_netdevice ->
netdev_register_kobject ->
device_initialize(dev);
dev_set_name(dev, "%s", ndev->name)
device_add(dev)
register_queue_kobjects(ndev)

In netdev_register_kobject(), if device_add(dev) or
register_queue_kobjects(ndev) failed. Register_netdevice()
will return error, causing netdev_freemem(ndev) to be
called to free net_device, however put_device(&dev->dev)->..->
kobject_cleanup() won't be called, resulting in a memory leak.

syzkaller report this:
BUG: memory leak
unreferenced object 0xffff8881f4fad168 (size 8):
comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
hex dump (first 8 bytes):
77 70 61 6e 30 00 ff ff wpan0...
backtrace:
[<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
[<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
[<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
[<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
[<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
[<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
[<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
[<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
[<00000000e4b3df51>] 0xffffffffc1500e0e
[<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
[<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
[<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
[<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
[<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
[<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
[<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 1fa5ae857bb1 ("driver core: get rid of struct device's bus_id string array")
Signed-off-by: Wang Hai <wanghai26@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: call dev_hold if kobject_init_and_add success

In netdev_queue_add_kobject and rx_queue_add_kobject,
if sysfs_create_group failed, kobject_put will call
netdev_queue_release to decrease dev refcont, however
dev_hold has not be called. So we will see this while
unregistering dev:

unregister_netdevice: waiting for bcsh0 to become free. Usage count = -1

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: d0d668371679 ("net: don't decrement kobj reference count on init failure")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Switch to bitmap_zalloc()

Switch to bitmap_zalloc() to show clearly what we are allocating.
Besides that it returns pointer of bitmap type instead of opaque void *.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Fix mem leak in netdev_register_kobject

syzkaller report this:
BUG: memory leak
unreferenced object 0xffff88837a71a500 (size 256):
comm "syz-executor.2", pid 9770, jiffies 4297825125 (age 17.843s)
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff 20 c0 ef 86 ff ff ff ff ........ .......
backtrace:
[<00000000db12624b>] netdev_register_kobject+0x124/0x2e0 net/core/net-sysfs.c:1751
[<00000000dc49a994>] register_netdevice+0xcc1/0x1270 net/core/dev.c:8516
[<00000000e5f3fea0>] tun_set_iff drivers/net/tun.c:2649 [inline]
[<00000000e5f3fea0>] __tun_chr_ioctl+0x2218/0x3d20 drivers/net/tun.c:2883
[<000000001b8ac127>] vfs_ioctl fs/ioctl.c:46 [inline]
[<000000001b8ac127>] do_vfs_ioctl+0x1a5/0x10e0 fs/ioctl.c:690
[<0000000079b269f8>] ksys_ioctl+0x89/0xa0 fs/ioctl.c:705
[<00000000de649beb>] __do_sys_ioctl fs/ioctl.c:712 [inline]
[<00000000de649beb>] __se_sys_ioctl fs/ioctl.c:710 [inline]
[<00000000de649beb>] __x64_sys_ioctl+0x74/0xb0 fs/ioctl.c:710
[<000000007ebded1e>] do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
[<00000000db315d36>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[<00000000115be9bb>] 0xffffffffffffffff

It should call kset_unregister to free 'dev->queues_kset'
in error path of register_queue_kobjects, otherwise will cause a mem leak.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Get rid of SWITCHDEV_ATTR_ID_PORT_PARENT_ID

Now that we have a dedicated NDO for getting a port's parent ID, get rid
of SWITCHDEV_ATTR_ID_PORT_PARENT_ID and convert all callers to use the
NDO exclusively. This is a preliminary change to getting rid of
switchdev_ops eventually.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Introduce ndo_get_port_parent_id()

In preparation for getting rid of switchdev_ops, create a dedicated NDO
operation for getting the port's parent identifier. There are
essentially two classes of drivers that need to implement getting the
port's parent ID which are VF/PF drivers with a built-in switch, and
pure switchdev drivers such as mlxsw, ocelot, dsa etc.

We introduce a helper function: dev_get_port_parent_id() which supports
recursion into the lower devices to obtain the first port's parent ID.

Convert the bridge, core and ipv4 multicast routing code to check for
such ndo_get_port_parent_id() and call the helper function when valid
before falling back to switchdev_port_attr_get(). This will allow us to
convert all relevant drivers in one go instead of having to implement
both switchdev_port_attr_get() and ndo_get_port_parent_id() operations,
then get rid of switchdev_port_attr_get().

Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: dev: Add extack argument to dev_change_flags()

In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. One prominent API through which the notification is
invoked is dev_change_flags().

Therefore extend dev_change_flags() with and extra extack argument and
update all users. Most of the calls end up just encoding NULL, but
several sites (VLAN, ipvlan, VRF, rtnetlink) do have extack available.

Since the function declaration line is changed anyway, name the other
function arguments to placate checkpatch.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: allow to call netif_reset_xps_queues() under cpus_read_lock

The definition of static_key_slow_inc() has cpus_read_lock in place. In the
virtio_net driver, XPS queues are initialized after setting the queue:cpu
affinity in virtnet_set_affinity() which is already protected within
cpus_read_lock. Lockdep prints a warning when we are trying to acquire
cpus_read_lock when it is already held.

This patch adds an ability to call __netif_set_xps_queue under
cpus_read_lock().
Acked-by: Jason Wang <jasowang@redhat.com>

============================================
WARNING: possible recursive locking detected
4.18.0-rc3-next-20180703+ #1 Not tainted
--------------------------------------------
swapper/0/1 is trying to acquire lock:
00000000cf973d46 (cpu_hotplug_lock.rw_sem){++++}, at: static_key_slow_inc+0xe/0x20

but task is already holding lock:
00000000cf973d46 (cpu_hotplug_lock.rw_sem){++++}, at: init_vqs+0x513/0x5a0

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(cpu_hotplug_lock.rw_sem);
lock(cpu_hotplug_lock.rw_sem);

*** DEADLOCK ***

May be due to missing lock nesting notation

3 locks held by swapper/0/1:
#0: 00000000244bc7da (&dev->mutex){....}, at: __driver_attach+0x5a/0x110
#1: 00000000cf973d46 (cpu_hotplug_lock.rw_sem){++++}, at: init_vqs+0x513/0x5a0
#2: 000000005cd8463f (xps_map_mutex){+.+.}, at: __netif_set_xps_queue+0x8d/0xc60

v2: move cpus_read_lock() out of __netif_set_xps_queue()

Cc: "Nambiar, Amritha" <amritha.nambiar@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Fixes: 8af2c06ff4b1 ("net-sysfs: Add interface for Rx queue(s) map per Tx queue")

Signed-off-by: Andrei Vagin <avagin@gmail.com>

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

net: create reusable function for getting ownership info of sysfs inodes

Make net_ns_get_ownership() reusable by networking code outside of core.
This is useful, for example, to allow bridge related sysfs files to be
owned by container root.

Add a function comment since this is a potentially dangerous function to
use given the way that kobject_get_ownership() works by initializing uid
and gid before calling .get_ownership().

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: make sure objects belong to container's owner

When creating various objects in /sys/class/net/... make sure that they
belong to container's owner instead of global root (if they belong to a
container/namespace).

Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: require net admin in the init ns for setting tx_maxrate

An upcoming change will allow container root to open some /sys/class/net
files for writing. The tx_maxrate attribute can result in changes
to actual hardware devices so err on the side of caution by requiring
CAP_NET_ADMIN in the init namespace in the corresponding attribute store
operation.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add support for subordinate device traffic classes

This patch is meant to provide the basic tools needed to allow us to create
subordinate device traffic classes. The general idea here is to allow
subdividing the queues of a device into queue groups accessible through an
upper device such as a macvlan.

The idea here is to enforce the idea that an upper device has to be a
single queue device, ideally with IFF_NO_QUQUE set. With that being the
case we can pretty much guarantee that the tc_to_txq mappings and XPS maps
for the upper device are unused. As such we could reuse those in order to
support subdividing the lower device and distributing those queues between
the subordinate devices.

In order to distinguish between a regular set of traffic classes and if a
device is carrying subordinate traffic classes I changed num_tc from a u8
to a s16 value and use the negative values to represent the subordinate
pool values. So starting at -1 and running to -32768 we can encode those as
pool values, and the existing values of 0 to 15 can be maintained.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

net-sysfs: Drop support for XPS and traffic_class on single queue device

This patch makes it so that we do not report the traffic class or allow XPS
configuration on single queue devices. This is mostly to avoid unnecessary
complexity with changes I have planned that will allow us to reuse
the unused tc_to_txq and XPS configuration on a single queue device to
allow it to make use of a subset of queues on an underlying device.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

net-sysfs: Add interface for Rx queue(s) map per Tx queue

Extend transmit queue sysfs attribute to configure Rx queue(s) map
per Tx queue. By default no receive queues are configured for the
Tx queue.

- /sys/class/net/eth0/queues/tx-*/xps_rxqs

Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Refactor XPS for CPUs and Rx queues

Refactor XPS code to support Tx queue selection based on
CPU(s) map or Rx queue(s) map.

Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Fix memory leak in XPS configuration

This patch reorders the error cases in showing the XPS configuration so
that we hold off on memory allocation until after we have verified that we
can support XPS on a given ring.

Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes")
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Use octal not symbolic permissions

Prefer the direct use of octal for permissions.

Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace
and some typing.

Miscellanea:

o Whitespace neatening around these conversions.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: introduce helper dev_change_tx_queue_len()

This patch promotes the local change_tx_queue_len() to a core
helper function, dev_change_tx_queue_len(), so that rtnetlink
and net-sysfs could share the code. This also prepares for the
following patch.

Note, the -EFAULT in the original code doesn't make sense,
we should propagate the errno from notifiers.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: Expose number of link up/down transitions

Expose the number of times the link has been going UP or DOWN, and
update the "carrier_changes" counter to be the sum of these two events.
While at it, also update the sysfs-class-net documentation to cover:
carrier_changes (3.15), carrier_up_count (4.16) and carrier_down_count
(4.16)

Signed-off-by: David Decotigny <decot@googlers.com>
[Florian:
* rebase
* add documentation
* merge carrier_changes with up/down counters]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Convert atomic_t net::count to refcount_t

Since net could be obtained from RCU lists,
and there is a race with net destruction,
the patch converts net::count to refcount_t.

This provides sanity checks for the cases of
incrementing counter of already dead net,
when maybe_get_net() has to used instead
of get_net().

Drivers: allyesconfig and allmodconfig are OK.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: trigger netlink notification on ifalias change via sysfs

This patch adds netlink notifications on iflias changes via sysfs.
makes it consistent with the netlink path which also calls
netdev_state_change. Also makes it consistent with other sysfs
netdev_store operations.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: decouple ifalias get/set from rtnl lock

Device alias can be set by either rtnetlink (rtnl is held) or sysfs.

rtnetlink hold the rtnl mutex, sysfs acquires it for this purpose.
Add an extra mutex for it and use rcu to protect concurrent accesses.

This allows the sysfs path to not take rtnl and would later allow
to not hold it when dumping ifalias.

Based on suggestion from Eric Dumazet.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: style cleanups

Make code closer to current style. Mostly whitespace changes.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mark receive queue attributes ro_after_init

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make queue attributes ro_after_init

The XPS queue attributes can be ro_after_init.
Also use __ATTR_RX macros to simplify initialization.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make BQL sysfs attributes ro_after_init

Also fix macro to not have ; at end.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: drop unused attribute argument from sysfs queue funcs

The show and store functions don't need/use the attribute.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make net sysfs attributes ro_after_init

The attributes of net devices are immutable.

Ideally, attribute groups would contain const attributes
but there are too many places that do modifications of list
during startup (in other code) to allow that.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: constify net_ns_type_operations

This can be const.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make net_class ro_after_init

The net_class in sysfs is only modified on init.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: constify netdev_class_file

These functions are wrapper arount class_create_file which can take a
const attribute.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: don't decrement kobj reference count on init failure

If kobject_init_and_add failed, then the failure path would
decrement the reference count of the queue kobject whose reference
count was already zero.

Fixes: 114cf5802165 ("bql: Byte queue limits")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert net.passive from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: constify attribute_group structures.

attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/device.h> work with const
attribute_group. So mark the non-const structs as const.

File size before:
text data bss dec hex filename
9968 3168 16 13152 3360 net/core/net-sysfs.o

File size After adding 'const':
text data bss dec hex filename
10160 2976 16 13152 3360 net/core/net-sysfs.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make struct net_device::tx_queue_len unsigned int

4 billion packet queue is something unthinkable so use 32-bit value
for now.

Space savings on x86_64:

add/remove: 0/0 grow/shrink: 3/70 up/down: 16/-131 (-115)
function old new delta
change_tx_queue_len 94 108 +14
qdisc_create 1176 1177 +1
alloc_netdev_mqs 1124 1125 +1
xenvif_alloc 533 532 -1
x25_asy_setup 167 166 -1
...
tun_queue_resize 945 940 -5
pfifo_fast_enqueue 167 162 -5
qfq_init_qdisc 168 158 -10
tap_queue_resize 810 799 -11
transmit 719 698 -21

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use net->count to check whether a netns is alive or not

The previous idea was to check whether a net namespace is in
net_exit_list or not. It doesn't work, because net->exit_list is used in
__register_pernet_operations and __unregister_pernet_operations where
all namespaces are added to a temporary list to make cleanup in a error
case, so list_empty(&net->exit_list) always returns false.

Reported-by: Mantas Mikulėnas <grawity@gmail.com>
Fixes: 002d8a1a6c11 ("net: skip genenerating uevents for network namespaces that are exiting")
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

net: Add support for XPS with QoS via traffic classes

This patch adds support for setting and using XPS when QoS via traffic
classes is enabled. With this change we will factor in the priority and
traffic class mapping of the packet and use that information to correctly
select the queue.

This allows us to define a set of queues for a given traffic class via
mqprio and then configure the XPS mapping for those queues so that the
traffic flows can avoid head-of-line blocking between the individual CPUs
if so desired.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add sysfs value to determine queue traffic class

Add a sysfs attribute for a Tx queue that allows us to determine the
traffic class for a given queue. This will allow us to more easily
determine this in the future. It is needed as XPS will take the traffic
class for a group of queues into account in order to avoid pulling traffic
from one traffic class into another.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: skip genenerating uevents for network namespaces that are exiting

No one can see these events, because a network namespace can not be
destroyed, if it has sockets.

Unlike other devices, uevent-s for network devices are generated
only inside their network namespaces. They are filtered in
kobj_bcast_filter()

My experiments shows that net namespaces are destroyed more 30% faster
with this optimization.

Here is a perf output for destroying network namespaces without this
patch.

- 94.76% 0.02% kworker/u48:1 [kernel.kallsyms] [k] cleanup_net
- 94.74% cleanup_net
- 94.64% ops_exit_list.isra.4
- 41.61% default_device_exit_batch
- 41.47% unregister_netdevice_many
- rollback_registered_many
- 40.36% netdev_unregister_kobject
- 14.55% device_del
+ 13.71% kobject_uevent
- 13.04% netdev_queue_update_kobjects
+ 12.96% kobject_put
- 12.72% net_rx_queue_update_kobjects
kobject_put
- kobject_release
+ 12.69% kobject_uevent
+ 0.80% call_netdevice_notifiers_info
+ 19.57% nfsd_exit_net
+ 11.15% tcp_net_metrics_exit
+ 8.25% rpcsec_gss_exit_net

It's very critical to optimize the exit path for network namespaces,
because they are destroyed under net_mutex and many namespaces can be
destroyed for one iteration.

v2: use dev_set_uevent_suppress()

Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: introduce NETDEV_CHANGE_TX_QUEUE_LEN

This patch introduces a new event - NETDEV_CHANGE_TX_QUEUE_LEN, this
will be triggered when tx_queue_len. It could be used by net device
who want to do some processing at that time. An example is tun who may
want to resize tx array when tx_queue_len is changed.

Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: fix missing <linux/of_net.h>

The of_find_net_device_by_node() function is defined in
<linux/of_net.h> but not included in the .c file that
implements it. Fix the following warning by including the
header:

net/core/net-sysfs.c:1494:19: warning: symbol 'of_find_net_device_by_node' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: use __ethtool_get_ksettings

Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: remove unused fmt_long_hex

Ever since commit 04ed3e741d0f133e02bed7fa5c98edba128f90e7
("net: change netdev->features to u32") the format string
fmt_long_hex has not been used, so we may as well remove it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add rx_nohandler stat counter

This adds an rx_nohandler stat counter, along with a sysfs statistics
node, and copies the counter out via netlink as well.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@mellanox.com>
CC: Daniel Borkmann <daniel@iogearbox.net>
CC: Tom Herbert <tom@herbertland.com>
CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <gospo@cumulusnetworks.com>
CC: netdev@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: use to_net_dev in net_namespace()

Use to_net_dev() instead of open-coding it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

switchdev: Pass original device to port netdev driver

switchdev drivers need to know the netdev on which the switchdev op was
invoked. For example, the STP state of a VLAN interface configured on top
of a port can change while being member in a bridge. In this case, the
underlying driver should only change the STP state of that particular
VLAN and not of all the VLANs configured on the port.

However, current switchdev infrastructure only passes the port netdev down
to the driver. Solve that by passing the original device down to the
driver as part of the required switchdev object / attribute.

This doesn't entail any change in current switchdev drivers. It simply
enables those supporting stacked devices to know the originating device
and act accordingly.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

switchdev: rename SWITCHDEV_ATTR_* enum values to SWITCHDEV_ATTR_ID_*

To be aligned with obj.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net sysfs: Print link speed as signed integer

Otherwise 4294967295 (MBit/s) (-1) will be printed when there is no link.
Documentation/ABI/testing/sysfs-class-net does not state if this shall be
signed or unsigned.
Also remove the now unused variable fmt_udec.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: fix net_device refcounting

of_find_net_device_by_node() uses class_find_device() internally to
lookup the corresponding network device. class_find_device() returns
a reference to the embedded struct device, with its refcount
incremented.

Add a comment to the definition in net/core/net-sysfs.c indicating the
need to drop this refcount, and fix the DSA code to drop this refcount
when the OF-generated platform data is cleaned up and freed. Also
arrange for the ref to be dropped when handling errors.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: get_netdev_queue_index() cleanup

Redo commit ed1acc8cd8c22efa919da8d300bab646e01c2dce.

Commit 822b3b2ebfff8e9b3d006086c527738a7ca00cd0 ("net: Add max rate tx queue
attribute") moved get_netdev_queue_index around, but kept the old version.
Probably because of a reuse of the original patch from before Eric's change to
that function.

Remove one inline keyword, and no need for a loop to find
an index into a table.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Fixes: 822b3b2ebfff ("net: Add max rate tx queue attribute")
Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: allow sleeping when modifying store_rps_map

Commit 10e4ea751 ("net: Fix race condition in store_rps_map") has moved the
manipulation of the rps_needed jump label under a spinlock. Since changing
the state of a jump label may sleep this is incorrect and causes warnings
during runtime.

Make rps_map_lock a mutex to allow sleeping under it.

Fixes: 10e4ea751 ("net: Fix race condition in store_rps_map")
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Fix race condition in store_rps_map

There is a race condition in store_rps_map that allows jump label
count in rps_needed to go below zero. This can happen when
concurrently attempting to set and a clear map.

Scenario:

1. rps_needed count is zero
2. New map is assigned by setting thread, but rps_needed count _not_ yet
incremented (rps_needed count still zero)
2. Map is cleared by second thread, old_map set to that just assigned
3. Second thread performs static_key_slow_dec, rps_needed count now goes
negative

Fix is to increment or decrement rps_needed under the spinlock.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net core: Add protodown support.

This patch introduces the proto_down flag that can be used by user space
applications to notify switch drivers that errors have been detected on the
device.

The switch driver can react to protodown notification by doing a phys down
on the associated switch port.

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Wilson Kok <wkok@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

switchdev: don't use anonymous union on switchdev attr/obj structs

Older gcc versions (e.g. gcc version 4.4.6) don't like anonymous unions
which was causing build issues on the newly added switchdev attr/obj
structs. Fix this by using named union on structs.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

switchdev: convert parent_id_get to switchdev attr get

Switch ID is just a gettable port attribute. Convert switchdev op
switchdev_parent_id_get to a switchdev attr.

Note: for sysfs and netlink interfaces, SWITCHDEV_ATTR_PORT_PARENT_ID is
called with SWITCHDEV_F_NO_RECUSE to limit switch ID user-visiblity to only
port netdevs. So when a port is stacked under bond/bridge, the user can
only query switch id via the switch ports, but not via the upper devices

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

switchdev: s/netdev_switch_/switchdev_/ and s/NETDEV_SWITCH_/SWITCHDEV_/

Turned out that "switchdev" sticks. So just unify all related terms to use
this prefix.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

dev: introduce dev_get_iflink()

The goal of this patch is to prepare the removal of the iflink field. It
introduces a new ndo function, which will be implemented by virtual interfaces.

There is no functional change into this patch. All readers of iflink field
now call dev_get_iflink().

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add support for phys_port_name

Similar to port id allow netdevices to specify port names and export
the name via sysfs. Drivers can implement the netdevice operation to
assist udev in having sane default names for the devices using the
rule:

$ cat /etc/udev/rules.d/80-net-setup-link.rules
SUBSYSTEM=="net", ACTION=="add", ATTR{phys_port_name}!="",
NAME="$attr{phys_port_name}"

Use of phys_name versus phys_id was suggested-by Jiri Pirko.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add max rate tx queue attribute

This adds a tx_maxrate attribute to the tx queue sysfs entry allowing
for max-rate limiting. Along with DCB-ETS and BQL this provides another
knob to tune queue performance. The limit units are Mbps.

By default it is disabled. To disable the rate limitation after it
has been set for a queue, it should be set to zero.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: add of_find_net_device_by_node()

Add a helper function which allows getting the struct net_device pointer
associated with a given struct device_node pointer. This is useful for
instance for DSA Ethernet devices not backed by a platform_device, but a PCI
device.

Since we need to access net_class which is not accessible outside of
net/core/net-sysfs.c, this helper function is also added here and gated
with CONFIG_OF_NET.

Network devices initialized with SET_NETDEV_DEV() are also taken into
account by checking for dev->parent first and then falling back to
checking the device pointer within struct net_device.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use %*pb[l] to print bitmaps including cpumasks and nodemasks

printk and friends can now format bitmaps using '%*pb[l]'. cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net-sysfs: expose physical switch id for particular device

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: Thomas Graf <tgraf@suug.ch>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rename netdev_phys_port_id to more generic name

So this can be reused for identification of other "items" as well.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: Thomas Graf <tgraf@suug.ch>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: gro: add a per device gro flush timer

Tuning coalescing parameters on NIC can be really hard.

Servers can handle both bulk and RPC like traffic, with conflicting
goals : bulk flows want as big GRO packets as possible, RPC want minimal
latencies.

To reach big GRO packets on 10Gbe NIC, one can use :

ethtool -C eth0 rx-usecs 4 rx-frames 44

But this penalizes rpc sessions, with an increase of latencies, up to
50% in some cases, as NICs generally do not force an interrupt when
a packet with TCP Push flag is received.

Some NICs do not have an absolute timer, only a timer rearmed for every
incoming packet.

This patch uses a different strategy : Let GRO stack decides what do do,
based on traffic pattern.

Packets with Push flag wont be delayed.
Packets without Push flag might be held in GRO engine, if we keep
receiving data.

This new mechanism is off by default, and shall be enabled by setting
/sys/class/net/ethX/gro_flush_timeout to a value in nanosecond.

To fully enable this mechanism, drivers should use napi_complete_done()
instead of napi_complete().

Tested:
Ran 200 netperf TCP_STREAM from A to B (10Gbe mlx4 link, 8 RX queues)

Without this feature, we send back about 305,000 ACK per second.

GRO aggregation ratio is low (811/305 = 2.65 segments per GRO packet)

Setting a timer of 2000 nsec is enough to increase GRO packet sizes
and reduce number of ACK packets. (811/19.2 = 42)

Receiver performs less calls to upper stacks, less wakes up.
This also reduces cpu usage on the sender, as it receives less ACK
packets.

Note that reducing number of wakes up increases cpu efficiency, but can
decrease QPS, as applications wont have the chance to warmup cpu caches
doing a partial read of RPC requests/answers if they fit in one skb.

B:~# sar -n DEV 1 10 | grep eth0 | tail -1
Average: eth0 811269.80 305732.30 1199462.57 19705.72 0.00
0.00 0.50

B:~# echo 2000 >/sys/class/net/eth0/gro_flush_timeout

B:~# sar -n DEV 1 10 | grep eth0 | tail -1
Average: eth0 811577.30 19230.80 1199916.51 1239.80 0.00
0.00 0.50

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: do not name the pointer to struct net_device net

"net" is normally for struct net*, pointer to struct net_device
should be named to either "dev" or "ndev" etc.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add name_assign_type netdev attribute

Based on a patch by David Herrmann.

The name_assign_type attribute gives hints where the interface name of a
given net-device comes from. These values are currently defined:
NET_NAME_ENUM:
The ifname is provided by the kernel with an enumerated
suffix, typically based on order of discovery. Names may
be reused and unpredictable.
NET_NAME_PREDICTABLE:
The ifname has been assigned by the kernel in a predictable way
that is guaranteed to avoid reuse and always be the same for a
given device. Examples include statically created devices like
the loopback device and names deduced from hardware properties
(including being given explicitly by the firmware). Names
depending on the order of discovery, or in any other way on the
existence of other devices, must not be marked as PREDICTABLE.
NET_NAME_USER:
The ifname was provided by user-space during net-device setup.
NET_NAME_RENAMED:
The net-device has been renamed from userspace. Once this type is set,
it cannot change again.
NET_NAME_UNKNOWN:
This is an internal placeholder to indicate that we yet haven't yet
categorized the name. It will not be exposed to userspace, rather
-EINVAL is returned.

The aim of these patches is to improve user-space renaming of interfaces. As
a general rule, userspace must rename interfaces to guarantee that names stay
the same every time a given piece of hardware appears (at boot, or when
attaching it). However, there are several situations where userspace should
not perform the renaming, and that depends on both the policy of the local
admin, but crucially also on the nature of the current interface name.

If an interface was created in repsonse to a userspace request, and userspace
already provided a name, we most probably want to leave that name alone. The
main instance of this is wifi-P2P devices created over nl80211, which currently
have a long-standing bug where they are getting renamed by udev. We label such
names NET_NAME_USER.

If an interface, unbeknown to us, has already been renamed from userspace, we
most probably want to leave also that alone. This will typically happen when
third-party plugins (for instance to udev, but the interface is generic so could
be from anywhere) renames the interface without informing udev about it. A
typical situation is when you switch root from an installer or an initrd to the
real system and the new instance of udev does not know what happened before
the switch. These types of problems have caused repeated issues in the past. To
solve this, once an interface has been renamed, its name is labelled
NET_NAME_RENAMED.

In many cases, the kernel is actually able to name interfaces in such a
way that there is no need for userspace to rename them. This is the case when
the enumeration order of devices, or in fact any other (non-parent) device on
the system, can not influence the name of the interface. Examples include
statically created devices, or any naming schemes based on hardware properties
of the interface. In this case the admin may prefer to use the kernel-provided
names, and to make that possible we label such names NET_NAME_PREDICTABLE.
We want the kernel to have tho possibilty of performing predictable interface
naming itself (and exposing to userspace that it has), as the information
necessary for a proper naming scheme for a certain class of devices may not
be exposed to userspace.

The case where renaming is almost certainly desired, is when the kernel has
given the interface a name using global device enumeration based on order of
discovery (ethX, wlanY, etc). These naming schemes are labelled NET_NAME_ENUM.

Lastly, a fallback is left as NET_NAME_UNKNOWN, to indicate that a driver has
not yet been ported. This is mostly useful as a transitionary measure, allowing
us to label the various naming schemes bit by bit.

v8: minor documentation fixes
v9: move comment to the right commit

Signed-off-by: Tom Gundersen <teg@jklm.no>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert "net: return actual error on register_queue_kobjects"

This reverts commit d36a4f4b472334562b8e7252e35d3d770db83815.

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

net: return actual error on register_queue_kobjects

Return the actual error code if call kset_create_and_add() failed

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: expose number of carrier on/off changes

This allows to monitor carrier on/off transitions and detect link
flapping issues:
- new /sys/class/net/X/carrier_changes
- new rtnetlink IFLA_CARRIER_CHANGES (getlink)

Tested:
- grep . /sys/class/net/*/carrier_changes
+ ip link set dev X down/up
+ plug/unplug cable
- updated iproute2: prints IFLA_CARRIER_CHANGES
- iproute2 20121211-2 (debian): unchanged behavior

Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add sysfs file for port number

Add a sysfs file to enable user space to query the device
port number used by a netdevice instance. This is needed for
devices that have multiple ports on the same PCI function.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: fix comment typo 'CONFIG_SYFS'

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

net-sysfs: get_netdev_queue_index() cleanup

Remove one inline keyword, and no need for a loop to find
an index into a table.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: fix "queues" uevent between network namespaces

When I create a new namespace with 'ip netns add net0', or add/remove
new links in a namespace with 'ip link add/delete type veth', rx/tx
queues events can be got in all namespaces. That is because rx/tx queue
ktypes do not have namespace support, and their kobj parents are setted to
NULL. This patch is to fix it.

Reported-by: Libo Chen <chenlibo@huawei.com>
Signed-off-by: Libo Chen <chenlibo@huawei.com>
Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: add support for device-specific rx queue sysfs attributes

Extend existing support for netdevice receive queue sysfs attributes to
permit a device-specific attribute group. Initial use case for this
support will be to allow the virtio-net device to export per-receive
queue mergeable receive buffer size.

Signed-off-by: Michael Dalton <mwdalton@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: netdev_kobject_init: annotate with __init

netdev_kobject_init() is only being called from __init context,
that is, net_dev_init(), so annotate it with __init as well, thus
the kernel can take this as a hint that the function is used only
during the initialization phase and free up used memory resources
after its invocation.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: more spelling fixes

Various spelling fixes in networking stack

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: extend net_device allocation to vmalloc()

Joby Poriyath provided a xen-netback patch to reduce the size of
xenvif structure as some netdev allocation could fail under
memory pressure/fragmentation.

This patch is handling the problem at the core level, allowing
any netdev structures to use vmalloc() if kmalloc() failed.

As vmalloc() adds overhead on a critical network path, add __GFP_REPEAT
to kzalloc() flags to do this fallback only when really needed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Joby Poriyath <joby.poriyath@citrix.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sysfs: make attr namespace interface less convoluted

sysfs ns (namespace) implementation became more convoluted than
necessary while trying to hide ns information from visible interface.
The relatively recent attr ns support is a good example.

* attr ns tag is determined by sysfs_ops->namespace() callback while
dir tag is determined by kobj_type->namespace(). The placement is
arbitrary.

* Instead of performing operations with explicit ns tag, the namespace
callback is routed through sysfs_attr_ns(), sysfs_ops->namespace(),
class_attr_namespace(), class_attr->namespace(). It's not simpler
in any sense. The only thing this convolution does is traversing
the whole stack backwards.

The namespace callbacks are unncessary because the operations involved
are inherently synchronous. The information can be provided in in
straight-forward top-down direction and reversing that direction is
unnecessary and against basic design principles.

This backward interface is unnecessarily convoluted and hinders
properly separating out sysfs from driver model / kobject for proper
layering. This patch updates attr ns support such that

* sysfs_ops->namespace() and class_attr->namespace() are dropped.

* sysfs_{create|remove}_file_ns(), which take explicit @ns param, are
added and sysfs_{create|remove}_file() are now simple wrappers
around the ns aware functions.

* ns handling is dropped from sysfs_chmod_file(). Nobody uses it at
this point. sysfs_chmod_file_ns() can be added later if necessary.

* Explicit @ns is propagated through class_{create|remove}_file_ns()
and netdev_class_{create|remove}_file_ns().

* driver/net/bonding which is currently the only user of attr
namespace is updated to use netdev_class_{create|remove}_file_ns()
with @bh->net as the ns tag instead of using the namespace callback.

This patch should be an equivalent conversion without any functional
difference. It makes the code easier to follow, reduces lines of code
a bit and helps proper separation and layering.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sysfs: Restrict mounting sysfs

Don't allow mounting sysfs unless the caller has CAP_SYS_ADMIN rights
over the net namespace. The principle here is if you create or have
capabilities over it you can mount it, otherwise you get to live with
what other people have mounted.

Instead of testing this with a straight forward ns_capable call,
perform this check the long and torturous way with kobject helpers,
this keeps direct knowledge of namespaces out of sysfs, and preserves
the existing sysfs abstractions.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

net: export physical port id via sysfs

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Narendra K <narendra_k@dell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: convert class code to use dev_groups

The dev_attrs field of struct class is going away soon, dev_groups
should be used instead. This converts the networking core class code to
use the correct field.

In order to do this in the "cleanest" way, some of the macros had to be
changed to reflect the driver core format of naming show/store
functions, which accounts for the majority of the churn in this file.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rps_dev_flow_table_release(): no need to delay vfree()

The same story as with fib_trie patch - vfree() from RCU callbacks
is legitimate now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: apply pm_runtime_set_memalloc_noio on network devices

Deadlock might be caused by allocating memory with GFP_KERNEL in
runtime_resume and runtime_suspend callback of network devices in iSCSI
situation, so mark network devices and its ancestor as 'memalloc_noio'
with the introduced pm_runtime_set_memalloc_noio().

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Decotigny <david.decotigny@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Jiri Kosina <jiri.kosina@suse.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net: Add support for XPS without sysfs being defined

This patch makes it so that we can support transmit packet steering without
sysfs needing to be enabled. The reason for making this change is to make
it so that a driver can make use of the XPS even while the sysfs portion of
the interface is not present.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add functions netif_reset_xps_queue and netif_set_xps_queue

This patch adds two functions, netif_reset_xps_queue and
netif_set_xps_queue. The main idea behind these two functions is to
provide a mechanism through which drivers can update their defaults in
regards to XPS.

Currently no such mechanism exists and as a result we cannot use XPS for
things such as ATR which would require a basic configuration to start in
which the Tx queues are mapped to CPUs via a 1:1 mapping. With this change
I am making it possible for drivers such as ixgbe to be able to use the XPS
feature by controlling the default configuration.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: allow to change carrier via sysfs

Make carrier writable

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

CONFIG_HOTPLUG removal from networking core

CONFIG_HOTPLUG is always enabled now, so remove the unused code that was
trying to be compiled out when this option was disabled, in the
networking core.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove unnecessary wireless includes

The wireless and wext includes in net-sysfs.c aren't
needed, so remove them.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Allow userns root control of the core of the network stack.

Allow an unpriviled user who has created a user namespace, and then
created a network namespace to effectively use the new network
namespace, by reducing capable(CAP_NET_ADMIN) and
capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.

Settings that merely control a single network device are allowed.
Either the network device is a logical network device where
restrictions make no difference or the network device is hardware NIC
that has been explicity moved from the initial network namespace.

In general policy and network stack state changes are allowed
while resource control is left unchanged.

Allow ethtool ioctls.

Allow binding to network devices.
Allow setting the socket mark.
Allow setting the socket priority.

Allow setting the network device alias via sysfs.
Allow setting the mtu via sysfs.
Allow changing the network device flags via sysfs.
Allow setting the network device group via sysfs.

Allow the following network device ioctls.
SIOCGMIIPHY
SIOCGMIIREG
SIOCSIFNAME
SIOCSIFFLAGS
SIOCSIFMETRIC
SIOCSIFMTU
SIOCSIFHWADDR
SIOCSIFSLAVE
SIOCADDMULTI
SIOCDELMULTI
SIOCSIFHWBROADCAST
SIOCSMIIREG
SIOCBONDENSLAVE
SIOCBONDRELEASE
SIOCBONDSETHWADDR
SIOCBONDCHANGEACTIVE
SIOCBRADDIF
SIOCBRDELIF
SIOCSHWTSTAMP

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

wireless: add back sysfs directory

commit 35b2a113cb0298d4f9a1263338b456094a414057 broke (at least)
Fedora's networking scripts, they check for the existence of the
wireless directory. As the files aren't used, add the directory
back and not the files. Also do it for both drivers based on the
old wireless extensions and cfg80211, regardless of whether the
compat code for wext is built into cfg80211 or not.

Cc: stable@vger.kernel.org [3.6]
Reported-by: Dave Airlie <airlied@gmail.com>
Reported-by: Bill Nottingham <notting@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net: add unknown state to sysfs NIC duplex export

Currently when the NIC duplex state is DUPLEX_UNKNOWN it is exported as
full through sysfs, this patch adds support for DUPLEX_UNKNOWN. It is
handled the same way as in ethtool.

Signed-off-by: Nikolay Aleksandrov <naleksan@redhat.com>

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

wireless: remove wext sysfs

The only user of this was hal prior to its 0.5.12
release which happened over two years ago, so I'm
sure this can be removed without issues.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net: cleanup unsigned to unsigned int

Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: simple_strtoul cleanup

Changed net/core/net-sysfs.c: netdev_store() to use kstrtoul()
instead of obsolete simple_strtoul().

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()

So here's a boot tested patch on top of Jason's series that does
all the cleanups I talked about and turns jump labels into a
more intuitive to use facility. It should also address the
various misconceptions and confusions that surround jump labels.

Typical usage scenarios:

#include <linux/static_key.h>

struct static_key key = STATIC_KEY_INIT_TRUE;

if (static_key_false(&key))
do unlikely code
else
do likely code

Or:

if (static_key_true(&key))
do likely code
else
do unlikely code

The static key is modified via:

static_key_slow_inc(&key);
...
static_key_slow_dec(&key);

The 'slow' prefix makes it abundantly clear that this is an
expensive operation.

I've updated all in-kernel code to use this everywhere. Note
that I (intentionally) have not pushed through the rename
blindly through to the lowest levels: the actual jump-label
patching arch facility should be named like that, so we want to
decouple jump labels from the static-key facility a bit.

On non-jump-label enabled architectures static keys default to
likely()/unlikely() branches.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jason Baron <jbaron@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: a.p.zijlstra@chello.nl
Cc: mathieu.desnoyers@efficios.com
Cc: davem@davemloft.net
Cc: ddaney.cavm@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.hu
Signed-off-by: Ingo Molnar <mingo@elte.hu>

bql: Fix inconsistency between file mode and attr method.

There is no store() method for inflight attribute in the
tx-<n>/byte_queue_limits sysfs directory.
So remove S_IWUSR bit.

Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: reintroduce missing rcu_assign_pointer() calls

commit a9b3cd7f32 (rcu: convert uses of rcu_assign_pointer(x, NULL) to
RCU_INIT_POINTER) did a lot of incorrect changes, since it did a
complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x,
y).

We miss needed barriers, even on x86, when y is not NULL.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rfs: better sizing of dev_flow_table

Aim of this patch is to provide full range of rps_flow_cnt on 64bit arches.

Theorical limit on number of flows is 2^32

Fix some buggy RPS/RFS macros as well.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
CC: Xi Wang <xi.wang@gmail.com>
CC: Laurent Chavey <chavey@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rps: fix insufficient bounds checking in store_rps_dev_flow_table_cnt()

Setting a large rps_flow_cnt like (1 << 30) on 32-bit platform will
cause a kernel oops due to insufficient bounds checking.

if (count > 1<<30) {
/* Enforce a limit to prevent overflow */
return -EINVAL;
}
count = roundup_pow_of_two(count);
table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(count));

Note that the macro RPS_DEV_FLOW_TABLE_SIZE(count) is defined as:

... + (count * sizeof(struct rps_dev_flow))

where sizeof(struct rps_dev_flow) is 8. (1 << 30) * 8 will overflow
32 bits.

This patch replaces the magic number (1 << 30) with a symbolic bound.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bql: fix CONFIG_XPS=n build

netdev_queue_release() should be called even if CONFIG_XPS=n
to properly release device reference.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bql: Byte queue limits

Networking stack support for byte queue limits, uses dynamic queue
limits library. Byte queue limits are maintained per transmit queue,
and a dql structure has been added to netdev_queue structure for this
purpose.

Configuration of bql is in the tx-<n> sysfs directory for the queue
under the byte_queue_limits directory. Configuration includes:
limit_min, bql minimum limit
limit_max, bql maximum limit
hold_time, bql slack hold time

Also under the directory are:
limit, current byte limit
inflight, current number of bytes on the queue

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xps: Add xps_queue_release function

This patch moves the xps specific parts in netdev_queue_release into
its own function which netdev_queue_release can call. This allows
netdev_queue_release to be more generic (for adding new attributes
to tx queues).

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use jump_label to shortcut RPS if not setup

Most machines dont use RPS/RFS, and pay a fair amount of instructions in
netif_receive_skb() / netif_rx() / get_rps_cpu() just to discover
RPS/RFS is not setup.

Add a jump_label named rps_needed.

If no device rps_map or global rps_sock_flow_table is setup,
netif_receive_skb() / netif_rx() do a single instruction instead of many
ones, including conditional jumps.

jmp +0 (if CONFIG_JUMP_LABEL=y)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: new counter for tx_timeout errors in sysfs

This adds the /sys/class/net/DEV/queues/Q/tx_timeout attribute
containing the total number of timeout events on the given queue. It
is always available with CONFIG_SYSFS, independently of
CONFIG_RPS/XPS.

Credits to Stephen Hemminger for a preliminary version of this patch.

Tested:
without CONFIG_SYSFS (compilation only)
with sysfs and without CONFIG_RPS & CONFIG_XPS
with sysfs and without CONFIG_RPS
with sysfs and without CONFIG_XPS
with defaults

Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: fixed minor sparse warning

This commit fixes following warning:
net/core/net-sysfs.c:921:6: warning: symbol 'numa_node' shadows an earlier one
include/linux/topology.h:222:1: originally declared here

Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules

These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

net: consolidate and fix ethtool_ops->get_settings calling

This patch does several things:
- introduces __ethtool_get_settings which is called from ethtool code and
from drivers as well. Put ASSERT_RTNL there.
- dev_ethtool_get_settings() is replaced by __ethtool_get_settings()
- changes calling in drivers so rtnl locking is respected. In
iboe_get_rate was previously ->get_settings() called unlocked. This
fixes it. Also prb_calc_retire_blk_tmo() in af_packet.c had the same
problem. Also fixed by calling __dev_get_by_index() instead of
dev_get_by_index() and holding rtnl_lock for both calls.
- introduces rtnl_lock in bnx2fc_vport_create() and fcoe_vport_create()
so bnx2fc_if_create() and fcoe_if_create() are called locked as they
are from other places.
- use __ethtool_get_settings() in bonding code

Signed-off-by: Jiri Pirko <jpirko@redhat.com>

v2->v3:
-removed dev_ethtool_get_settings()
-added ASSERT_RTNL into __ethtool_get_settings()
-prb_calc_retire_blk_tmo - use __dev_get_by_index() and lock
around it and __ethtool_get_settings() call
v1->v2:
add missing export_symbol
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> [except FCoE bits]
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: cleanup some rcu_dereference_raw

RCU api had been completed and rcu_access_pointer() or
rcu_dereference_protected() are better than generic
rcu_dereference_raw()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove /sys/class/net/*/features

The same information and more can be obtained by using ethtool
with ETHTOOL_GFEATURES.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

Delay struct net freeing while there's a sysfs instance refering to it

* new refcount in struct net, controlling actual freeing of the memory
* new method in kobj_ns_type_operations (->drop_ns())
* ->current_ns() semantics change - it's supposed to be followed by
corresponding ->drop_ns(). For struct net in case of CONFIG_NET_NS it bumps
the new refcount; net_drop_ns() decrements it and calls net_free() if the
last reference has been dropped. Method renamed to ->grab_current_ns().
* old net_free() callers call net_drop_ns() instead.
* sysfs_exit_ns() is gone, along with a large part of callchain
leading to it; now that the references stored in ->ns[...] stay valid we
do not need to hunt them down and replace them with NULL. That fixes
problems in sysfs_lookup() and sysfs_readdir(), along with getting rid
of sb->s_instances abuse.

Note that struct net *shutdown* logics has not changed - net_cleanup()
is called exactly when it used to be called. The only thing postponed by
having a sysfs instance refering to that struct net is actual freeing of
memory occupied by struct net.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

net: convert to new cpumask API

We plan to remove cpu_xx() old api later. Thus this patch
convert it.

This patch has no functional change.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net,rcu: convert call_rcu(xps_dev_maps_release) to kfree_rcu()

The rcu callback xps_dev_maps_release() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(xps_dev_maps_release).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

net,rcu: convert call_rcu(xps_map_release) to kfree_rcu()

The rcu callback xps_map_release() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(xps_map_release).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

net,rcu: convert call_rcu(rps_map_release) to kfree_rcu()

The rcu callback rps_map_release() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(rps_map_release).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

ethtool: Call ethtool's get/set_settings callbacks with cleaned data

This makes sure that when a driver calls the ethtool's
get/set_settings() callback of another driver, the data passed to it
is clean. This guarantees that speed_hi will be zeroed correctly if
the called callback doesn't explicitely set it: we are sure we don't
get a corrupted speed from the underlying driver. We also take care of
setting the cmd field appropriately (ETHTOOL_GSET/SSET).

This applies to dev_ethtool_get_settings(), which now makes sure it
sets up that ethtool command parameter correctly before passing it to
drivers. This also means that whoever calls dev_ethtool_get_settings()
does not have to clean the ethtool command parameter. This function
also becomes an exported symbol instead of an inline.

All drivers visible to make allyesconfig under x86_64 have been
updated.

Signed-off-by: David Decotigny <decot@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rename group sysfs entry to netdev_group

commit a512b92 adds sysfs entry for net device group, but
before this commit, tun also uses group sysfs, so after this
commit checkin, kernel warns like this:
sysfs: cannot create duplicate filename '/devices/virtual/net/vnet0/group'

Since tun has used this for years, rename sysfs under tun might
break existing userspace, so rename group sysfs entry for net device
group is a better choice.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add sysfs entry for device group

The group of a network device can be queried or changed from userspace
using sysfs.

For example, considering sysfs mounted in /sys, one can change the group
that interface lo belongs to:
echo 1 > /sys/class/net/lo/group

Signed-off-by: Vlad Dogaru <ddvlad@rosedu.org>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: change netdev->features to u32

Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.

Occurences found by `grep -r` on net/, drivers/net, include/

[ Move features and vlan_features next to each other in
struct netdev, as per Eric Dumazet's suggestion -DaveM ]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use NUMA_NO_NODE instead of the magic number -1

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net sched: use xps information for qdisc NUMA affinity

Allocate qdisc memory according to NUMA properties of cpus included in
xps map.

To be effective, qdisc should be (re)setup after changes
of /sys/class/net/eth<n>/queues/tx-<n>/xps_cpus

I added a numa_node field in struct netdev_queue, containing NUMA node
if all cpus included in xps_cpus share same node, else -1.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xps: add __rcu annotations

Avoid sparse warnings : add __rcu annotations and use
rcu_dereference_protected() where necessary.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xps: NUMA allocations for per cpu data

store_xps_map() allocates maps that are used by single cpu, it makes
sense to use NUMA allocations.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xps: Add CONFIG_XPS

This patch adds XPS_CONFIG option to enable and disable XPS. This is
done in the same manner as RPS_CONFIG. This is also fixes build
failure in XPS code when SMP is not enabled.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xps: Transmit Packet Steering

This patch implements transmit packet steering (XPS) for multiqueue
devices. XPS selects a transmit queue during packet transmission based
on configuration. This is done by mapping the CPU transmitting the
packet to a queue. This is the transmit side analogue to RPS-- where
RPS is selecting a CPU based on receive queue, XPS selects a queue
based on the CPU (previously there was an XPS patch from Eric
Dumazet, but that might more appropriately be called transmit completion
steering).

Each transmit queue can be associated with a number of CPUs which will
use the queue to send packets. This is configured as a CPU mask on a
per queue basis in:

/sys/class/net/eth<n>/queues/tx-<n>/xps_cpus

The mappings are stored per device in an inverted data structure that
maps CPUs to queues. In the netdevice structure this is an array of
num_possible_cpu structures where each structure holds and array of
queue_indexes for queues which that CPU can use.

The benefits of XPS are improved locality in the per queue data
structures. Also, transmit completions are more likely to be done
nearer to the sending thread, so this should promote locality back
to the socket on free (e.g. UDP). The benefits of XPS are dependent on
cache hierarchy, application load, and other factors. XPS would
nominally be configured so that a queue would only be shared by CPUs
which are sharing a cache, the degenerative configuration woud be that
each CPU has it's own queue.

Below are some benchmark results which show the potential benfit of
this patch. The netperf test has 500 instances of netperf TCP_RR test
with 1 byte req. and resp.

bnx2x on 16 core AMD
XPS (16 queues, 1 TX queue per CPU) 1234K at 100% CPU
No XPS (16 queues) 996K at 100% CPU

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: zero kobject in rx_queue_release

netif_set_real_num_rx_queues() can decrement and increment
the number of rx queues. For example ixgbe does this as
features and offloads are toggled. Presumably this could
also happen across down/up on most devices if the available
resources changed (cpu offlined).

The kobject needs to be zero'd in this case so that the
state is not preserved across kobject_put()/kobject_init_and_add().

This resolves the following error report.

ixgbe 0000:03:00.0: eth2: NIC Link is Up 10 Gbps, Flow Control: RX/TX
kobject (ffff880324b83210): tried to init an initialized object, something is seriously wrong.
Pid: 1972, comm: lldpad Not tainted 2.6.37-rc18021qaz+ #169
Call Trace:
[<ffffffff8121c940>] kobject_init+0x3a/0x83
[<ffffffff8121cf77>] kobject_init_and_add+0x23/0x57
[<ffffffff8107b800>] ? mark_lock+0x21/0x267
[<ffffffff813c6d11>] net_rx_queue_update_kobjects+0x63/0xc6
[<ffffffff813b5e0e>] netif_set_real_num_rx_queues+0x5f/0x78
[<ffffffffa0261d49>] ixgbe_set_num_queues+0x1c6/0x1ca [ixgbe]
[<ffffffffa0262509>] ixgbe_init_interrupt_scheme+0x1e/0x79c [ixgbe]
[<ffffffffa0274596>] ixgbe_dcbnl_set_state+0x167/0x189 [ixgbe]

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: zero kobject in rx_queue_release

netif_set_real_num_rx_queues() can decrement and increment
the number of rx queues. For example ixgbe does this as
features and offloads are toggled. Presumably this could
also happen across down/up on most devices if the available
resources changed (cpu offlined).

The kobject needs to be zero'd in this case so that the
state is not preserved across kobject_put()/kobject_init_and_add().

This resolves the following error report.

ixgbe 0000:03:00.0: eth2: NIC Link is Up 10 Gbps, Flow Control: RX/TX
kobject (ffff880324b83210): tried to init an initialized object, something is seriously wrong.
Pid: 1972, comm: lldpad Not tainted 2.6.37-rc18021qaz+ #169
Call Trace:
[<ffffffff8121c940>] kobject_init+0x3a/0x83
[<ffffffff8121cf77>] kobject_init_and_add+0x23/0x57
[<ffffffff8107b800>] ? mark_lock+0x21/0x267
[<ffffffff813c6d11>] net_rx_queue_update_kobjects+0x63/0xc6
[<ffffffff813b5e0e>] netif_set_real_num_rx_queues+0x5f/0x78
[<ffffffffa0261d49>] ixgbe_set_num_queues+0x1c6/0x1ca [ixgbe]
[<ffffffffa0262509>] ixgbe_init_interrupt_scheme+0x1e/0x79c [ixgbe]
[<ffffffffa0274596>] ixgbe_dcbnl_set_state+0x167/0x189 [ixgbe]

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Simplify RX queue allocation

This patch move RX queue allocation to alloc_netdev_mq and freeing of
the queues to free_netdev (symmetric to TX queue allocation). Each
kobject RX queue takes a reference to the queue's device so that the
device can't be freed before all the kobjects have been released-- this
obviates the need for reference counts specific to RX queues.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rps: add __rcu annotations

Add __rcu annotations to :
(struct netdev_rx_queue)->rps_map
(struct netdev_rx_queue)->rps_flow_table
struct rps_sock_flow_table *rps_sock_flow_table;

And use appropriate rcu primitives.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Fix rxq ref counting

The rx->count reference is used to track reference counts to the
number of rx-queue kobjects created for the device. This patch
eliminates initialization of the counter in netif_alloc_rx_queues
and instead increments the counter each time a kobject is created.
This is now symmetric with the decrement that is done when an object is
released.

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Allow changing number of RX queues after device allocation

For RPS, we create a kobject for each RX queue based on the number of
queues passed to alloc_netdev_mq(). However, drivers generally do not
determine the numbers of hardware queues to use until much later, so
this usually represents the maximum number the driver may use and not
the actual number in use.

For TX queues, drivers can update the actual number using
netif_set_real_num_tx_queues(). Add a corresponding function for RX
queues, netif_set_real_num_rx_queues().

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make rx_queue sysfs_ops const

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

cfg80211: support sysfs namespaces

Enable using network namespaces with
wireless devices even when sysfs is
enabled using the same infrastructure
that was built for netdevs.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

sysfs: add attribute to indicate hw address assignment type

Add addr_assign_type to struct net_device and expose it via sysfs.
This new attribute has the purpose of giving user-space the ability to
distinguish between different assignment types of MAC addresses.

For example user-space can treat NICs with randomly generated MAC
addresses differently than NICs that have permanent (locally assigned)
MAC addresses.
For the former udev could write a persistent net rule by matching the
device path instead of the MAC address.
There's also the case of devices that 'steal' MAC addresses from slave
devices. In which it is also be beneficial for user-space to be aware
of the fact.

This patch also introduces a helper function to assist adoption of
drivers that generate MAC addresses randomly.

Signed-off-by: Stefan Assmann <sassmann@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: EXPORT_SYMBOL cleanups

CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: fix 64 bit counters on 32 bit arches

There is a small possibility that a reader gets incorrect values on 32
bit arches. SNMP applications could catch incorrect counters when a
32bit high part is changed by another stats consumer/provider.

One way to solve this is to add a rtnl_link_stats64 param to all
ndo_get_stats64() methods, and also add such a parameter to
dev_get_stats().

Rule is that we are not allowed to use dev->stats64 as a temporary
storage for 64bit stats, but a caller provided area (usually on stack)

Old drivers (only providing get_stats() method) need no changes.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Enable 64-bit net device statistics on 32-bit architectures

Use struct rtnl_link_stats64 as the statistics structure.

On 32-bit architectures, insert 32 bits of padding after/before each
field of struct net_device_stats to make its layout compatible with
struct rtnl_link_stats64. Add an anonymous union in net_device; move
stats into the union and add struct rtnl_link_stats64 stats64.

Add net_device_ops::ndo_get_stats64, implementations of which will
return a pointer to struct rtnl_link_stats64. Drivers that implement
this operation must not update the structure asynchronously.

Change dev_get_stats() to call ndo_get_stats64 if available, and to
return a pointer to struct rtnl_link_stats64. Change callers of
dev_get_stats() accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Expose all network devices in a namespaces in sysfs

This reverts commit aaf8cdc34ddba08122f02217d9d684e2f9f5d575.

Drivers like the ipw2100 call device_create_group when they
are initialized and device_remove_group when they are shutdown.
Moving them between namespaces deletes their sysfs groups early.

In particular the following call chain results.
netdev_unregister_kobject -> device_del -> kobject_del -> sysfs_remove_dir
With sysfs_remove_dir recursively deleting all of it's subdirectories,
and nothing adding them back.

Ouch!

Therefore we need to call something that ultimate calls sysfs_mv_dir
as that sysfs function can move sysfs directories between namespaces
without deleting their subdirectories or their contents. Allowing
us to avoid placing extra boiler plate into every driver that does
something interesting with sysfs.

Currently the function that provides that capability is device_rename.
That is the code works without nasty side effects as originally written.

So remove the misguided fix for moving devices between namespaces. The
bug in the kobject layer that inspired it has now been recognized and
fixed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

net/sysfs: Fix the bitrot in network device kobject namespace support

I had a couple of stupid bugs in:
netns: Teach network device kobjects which namespace they are in.

- I duplicated the Kconfig for the NET_NS
- The build was broken when sysfs was not compiled in

The sysfs breakage is because after I moved the operations
for the sysfs to the kobject layer, to make things cleaner
I forgot to move the ifdefs. Opps.

I'm not quite certain how I got introduced a second NET_NS Kconfig,
but it was probably a 3 way merge somewhere along the way that
did not notice that the NET_NS Kconfig option had mvoed and thout
that was a bug. It probably slipped in because it used to be the
sysfs patches were the first patches in my network namespace patches.
Some things just don't go like you would expect.

Neither of these bugs actually affect anything in the common case
but they should be fixed.

Thanks to Serge for noticing they were present.

Reported-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Acked-by: David S. Miller <davem@davemloft.net>

netns: Teach network device kobjects which namespace they are in.

The problem. Network devices show up in sysfs and with the network
namespace active multiple devices with the same name can show up in
the same directory, ouch!

To avoid that problem and allow existing applications in network namespaces
to see the same interface that is currently presented in sysfs, this
patch enables the tagging directory support in sysfs.

By using the network namespace pointers as tags to separate out the
the sysfs directory entries we ensure that we don't have conflicts
in the directories and applications only see a limited set of
the network devices.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

rps: static functions

store_rps_map() & store_rps_dev_flow_table_cnt() are static.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rfs: Receive Flow Steering

This patch implements receive flow steering (RFS). RFS steers
received packets for layer 3 and 4 processing to the CPU where
the application for the corresponding flow is running. RFS is an
extension of Receive Packet Steering (RPS).

The basic idea of RFS is that when an application calls recvmsg
(or sendmsg) the application's running CPU is stored in a hash
table that is indexed by the connection's rxhash which is stored in
the socket structure. The rxhash is passed in skb's received on
the connection from netif_receive_skb. For each received packet,
the associated rxhash is used to look up the CPU in the hash table,
if a valid CPU is set then the packet is steered to that CPU using
the RPS mechanisms.

The convolution of the simple approach is that it would potentially
allow OOO packets. If threads are thrashing around CPUs or multiple
threads are trying to read from the same sockets, a quickly changing
CPU value in the hash table could cause rampant OOO packets--
we consider this a non-starter.

To avoid OOO packets, this solution implements two types of hash
tables: rps_sock_flow_table and rps_dev_flow_table.

rps_sock_table is a global hash table. Each entry is just a CPU
number and it is populated in recvmsg and sendmsg as described above.
This table contains the "desired" CPUs for flows.

rps_dev_flow_table is specific to each device queue. Each entry
contains a CPU and a tail queue counter. The CPU is the "current"
CPU for a matching flow. The tail queue counter holds the value
of a tail queue counter for the associated CPU's backlog queue at
the time of last enqueue for a flow matching the entry.

Each backlog queue has a queue head counter which is incremented
on dequeue, and so a queue tail counter is computed as queue head
count + queue length. When a packet is enqueued on a backlog queue,
the current value of the queue tail counter is saved in the hash
entry of the rps_dev_flow_table.

And now the trick: when selecting the CPU for RPS (get_rps_cpu)
the rps_sock_flow table and the rps_dev_flow table for the RX queue
are consulted. When the desired CPU for the flow (found in the
rps_sock_flow table) does not match the current CPU (found in the
rps_dev_flow table), the current CPU is changed to the desired CPU
if one of the following is true:

- The current CPU is unset (equal to RPS_NO_CPU)
- Current CPU is offline
- The current CPU's queue head counter >= queue tail counter in the
rps_dev_flow table. This checks if the queue tail has advanced
beyond the last packet that was enqueued using this table entry.
This guarantees that all packets queued using this entry have been
dequeued, thus preserving in order delivery.

Making each queue have its own rps_dev_flow table has two advantages:
1) the tail queue counters will be written on each receive, so
keeping the table local to interrupting CPU s good for locality. 2)
this allows lockless access to the table-- the CPU number and queue
tail counter need to be accessed together under mutual exclusion
from netif_receive_skb, we assume that this is only called from
device napi_poll which is non-reentrant.

This patch implements RFS for TCP and connected UDP sockets.
It should be usable for other flow oriented protocols.

There are two configuration parameters for RFS. The
"rps_flow_entries" kernel init parameter sets the number of
entries in the rps_sock_flow_table, the per rxqueue sysfs entry
"rps_flow_cnt" contains the number of entries in the rps_dev_flow
table for the rxqueue. Both are rounded to power of two.

The obvious benefit of RFS (over just RPS) is that it achieves
CPU locality between the receive processing for a flow and the
applications processing; this can result in increased performance
(higher pps, lower latency).

The benefits of RFS are dependent on cache hierarchy, application
load, and other factors. On simple benchmarks, we don't necessarily
see improvement and sometimes see degradation. However, for more
complex benchmarks and for applications where cache pressure is
much higher this technique seems to perform very well.

Below are some benchmark results which show the potential benfit of
this patch. The netperf test has 500 instances of netperf TCP_RR
test with 1 byte req. and resp. The RPC test is an request/response
test similar in structure to netperf RR test ith 100 threads on
each host, but does more work in userspace that netperf.

e1000e on 8 core Intel
No RFS or RPS 104K tps at 30% CPU
No RFS (best RPS config): 290K tps at 63% CPU
RFS 303K tps at 61% CPU

RPC test tps CPU% 50/90/99% usec latency Latency StdDev
No RFS/RPS 103K 48% 757/900/3185 4472.35
RPS only: 174K 73% 415/993/2468 491.66
RFS 223K 73% 379/651/1382 315.61

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

rps: fix net-sysfs build for !CONFIG_RPS

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rps: Fix build with CONFIG_SYSFS enabled

Fix build with CONFIG_SYSFS not enabled.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rps: Receive Packet Steering

This patch implements software receive side packet steering (RPS). RPS
distributes the load of received packet processing across multiple CPUs.

Problem statement: Protocol processing done in the NAPI context for received
packets is serialized per device queue and becomes a bottleneck under high
packet load. This substantially limits pps that can be achieved on a single
queue NIC and provides no scaling with multiple cores.

This solution queues packets early on in the receive path on the backlog queues
of other CPUs. This allows protocol processing (e.g. IP and TCP) to be
performed on packets in parallel. For each device (or each receive queue in
a multi-queue device) a mask of CPUs is set to indicate the CPUs that can
process packets. A CPU is selected on a per packet basis by hashing contents
of the packet header (e.g. the TCP or UDP 4-tuple) and using the result to index
into the CPU mask. The IPI mechanism is used to raise networking receive
softirqs between CPUs. This effectively emulates in software what a multi-queue
NIC can provide, but is generic requiring no device support.

Many devices now provide a hash over the 4-tuple on a per packet basis
(e.g. the Toeplitz hash). This patch allow drivers to set the HW reported hash
in an skb field, and that value in turn is used to index into the RPS maps.
Using the HW generated hash can avoid cache misses on the packet when
steering it to a remote CPU.

The CPU mask is set on a per device and per queue basis in the sysfs variable
/sys/class/net/<device>/queues/rx-<n>/rps_cpus. This is a set of canonical
bit maps for receive queues in the device (numbered by <n>). If a device
does not support multi-queue, a single variable is used for the device (rx-0).

Generally, we have found this technique increases pps capabilities of a single
queue device with good CPU utilization. Optimal settings for the CPU mask
seem to depend on architectures and cache hierarcy. Below are some results
running 500 instances of netperf TCP_RR test with 1 byte req. and resp.
Results show cumulative transaction rate and system CPU utilization.

e1000e on 8 core Intel
Without RPS: 108K tps at 33% CPU
With RPS: 311K tps at 64% CPU

forcedeth on 16 core AMD
Without RPS: 156K tps at 15% CPU
With RPS: 404K tps at 49% CPU

bnx2x on 16 core AMD
Without RPS 567K tps at 61% CPU (4 HW RX queues)
Without RPS 738K tps at 96% CPU (8 HW RX queues)
With RPS: 854K tps at 76% CPU (4 HW RX queues)

Caveats:
- The benefits of this patch are dependent on architecture and cache hierarchy.
Tuning the masks to get best performance is probably necessary.
- This patch adds overhead in the path for processing a single packet. In
a lightly loaded server this overhead may eliminate the advantages of
increased parallelism, and possibly cause some relative performance degradation.
We have found that masks that are cache aware (share same caches with
the interrupting CPU) mitigate much of this.
- The RPS masks can be changed dynamically, however whenever the mask is changed
this introduces the possibility of generating out of order packets. It's
probably best not change the masks too frequently.

Signed-off-by: Tom Herbert <therbert@google.com>

include/linux/netdevice.h | 32 ++++-
include/linux/skbuff.h | 3 +
net/core/dev.c | 335 +++++++++++++++++++++++++++++++++++++--------
net/core/net-sysfs.c | 225 ++++++++++++++++++++++++++++++-
net/core/skbuff.c | 2 +
5 files changed, 538 insertions(+), 59 deletions(-)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: Use rtnl_trylock in wireless sysfs methods.

The wireless sysfs methods like the rest of the networking sysfs
methods are removed with the rtnl_lock held and block until
the existing methods stop executing. So use rtnl_trylock
and restart_syscall so that the code continues to work.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use net_eq to compare nets

Generated with the following semantic patch

@@
struct net *n1;
struct net *n2;
@@
- n1 == n2
+ net_eq(n1, n2)

@@
struct net *n1;
struct net *n2;
@@
- n1 != n2
+ !net_eq(n1, n2)

applied over {include,net,drivers/net}.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Allow devices to specify a device specific sysfs group.

This isn't beautifully abstracted, but it is simple,
simplifies uses and so far is only needed for the bonding driver.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sysfs: ethtool_ops can be NULL

commit d519e17e2d01a0ee9abe083019532061b4438065
(net: export device speed and duplex via sysfs)
made the wrong assumption that netdev->ethtool_ops was always set.

This makes possible to crash kernel and let rtnl in locked state.

modprobe dummy
ip link set dummy0 up
(udev runs and crash)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

wext: refactor

Refactor wext to
* split out iwpriv handling
* split out iwspy handling
* split out procfs support
* allow cfg80211 to have wireless extensions compat code
w/o CONFIG_WIRELESS_EXT

After this, drivers need to
- select WIRELESS_EXT - for wext support
- select WEXT_PRIV - for iwpriv support
- select WEXT_SPY - for iwspy support

except cfg80211 -- which gets new hooks in wext-core.c
and can then get wext handlers without CONFIG_WIRELESS_EXT.

Wireless extensions procfs support is auto-selected
based on PROC_FS and anything that requires the wext core
(i.e. WIRELESS_EXT or CFG80211_WEXT).

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

wext: let get_wireless_stats() sleep

A number of drivers (recently including cfg80211-based ones)
assume that all wireless handlers, including statistics, can
sleep and they often also implicitly assume that the rtnl is
held around their invocation. This is almost always true now
except when reading from sysfs:

BUG: sleeping function called from invalid context at kernel/mutex.c:280
in_atomic(): 1, irqs_disabled(): 0, pid: 10450, name: head
2 locks held by head/10450:
#0: (&buffer->mutex){+.+.+.}, at: [<c10ceb99>] sysfs_read_file+0x24/0xf4
#1: (dev_base_lock){++.?..}, at: [<c12844ee>] wireless_show+0x1a/0x4c
Pid: 10450, comm: head Not tainted 2.6.32-rc3 #1
Call Trace:
[<c102301c>] __might_sleep+0xf0/0xf7
[<c1324355>] mutex_lock_nested+0x1a/0x33
[<f8cea53b>] wdev_lock+0xd/0xf [cfg80211]
[<f8cea58f>] cfg80211_wireless_stats+0x45/0x12d [cfg80211]
[<c13118d6>] get_wireless_stats+0x16/0x1c
[<c12844fe>] wireless_show+0x2a/0x4c

Fix this by using the rtnl instead of dev_base_lock.

Reported-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: export device speed and duplex via sysfs

This patch exports the link-speed (in Mbps) and duplex of an interface
via sysfs. This eliminates the need to use ethtool just to check the
link-speed. Not requiring 'ethtool' and not relying on the SIOCETHTOOL
ioctl should be helpful in an embedded environment where space is at a
premium as well.

NOTE: This patch also intentionally allows non-root users to check the link
speed and duplex -- something not possible with ethtool.

Here's some sample output:

# cat /sys/class/net/eth0/speed
100
# cat /sys/class/net/eth0/duplex
half
# ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: Not reported
Advertised auto-negotiation: No
Speed: 100Mb/s
Duplex: Half
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: off
Supports Wake-on: g
Wake-on: g
Current message level: 0x000000ff (255)
Link detected: yes

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

wext: add back wireless/ dir in sysfs for cfg80211 interfaces

The move away from having drivers assign wireless handlers,
in favour of making cfg80211 assign them, broke the sysfs
registration (the wireless/ dir went missing) because the
handlers are now assigned only after registration, which is
too late.

Fix this by special-casing cfg80211-based devices, all
of which are required to have an ieee80211_ptr, in the
sysfs code, and also using get_wireless_stats() to have
the same values reported as in procfs.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Tested-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

driver model: constify attribute groups

Let attribute group vectors be declared "const". We'd
like to let most attribute metadata live in read-only
sections... this is a start.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

net: mark read-only arrays as const

String literals are constant, and usually, we can also tag the array
of pointers const too, moving it to the .rodata section.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Remove bogus reference to BUS_ID_SIZE in sysfs code.

BUS_ID_SIZE is really no more, and device names are dynamically
allocated and thus can be any necessary size.

So remove the BUG check here making sure BUS_ID_SIZE is at least
as large as IFNAMSIZ.

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

net-sysfs: Use rtnl_trylock in sysfs methods.

The earlier patch to fix the deadlock between a network device going
away and writing to sysfs attributes was incomplete.
- It did not set signal_pending so we would leak ERSTARTSYS to user space.
- It used ERESTARTSYS which only restarts if sigaction configures it to.
- It did not cover store and show for ifalias.

So fix all of these up and use the new helper restart_syscall so we get
the details correct on what it takes.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: fix warning about non-const string

Since dev_set_name takes a printf style string, new gcc complains
if arg is not const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Avoid race between network down and sysfs

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: filter out uevent not belonging to init_net

This patch will filter out the uevent not related to the init_net.
Without this patch if a network device is created in a network
namespace with the same name as one network device belonging to the
initial network namespace (eg. eth0), when the network namespace
will die and the network device will be destroyed, an event will
be sent and catched by the udevd daemon. That will result to have
the real network device to be shutdown because the udevd/uevent are
not namespace aware.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netdev: introduce dev_get_stats()

In order for the network device ops get_stats call to be immutable, the handling
of the default internal network device stats block has to be changed. Add a new
helper function which replaces the old use of internal_get_stats.

Note: change return code to make it clear that the caller should not
go changing the returned statistics.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: struct device - replace bus_id with dev_name(), dev_set_name()

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: Coexist with the sysfs limitations v2

To make testing of the network namespace simpler allow
the network namespace code and the sysfs code to be
compiled and run at the same time. To do this only
virtual devices are allowed in the additional network
namespaces and those virtual devices are not placed
in the kobject tree.

Since virtual devices don't actually do anything interesting
hardware wise that needs device management there should
be no loss in keeping them out of the kobject tree and
by implication sysfs. The gain in ease of testing
and code coverage should be significant.

Changelog:

v2: As pointed out by Benjamin Thery it only makes sense to call
device_rename in the initial network namespace for now.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Tested-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: network device name ifalias support

This patch add support for keeping an additional character alias
associated with an network interface. This is useful for maintaining
the SNMP ifAlias value which is a user defined value. Routers use this
to hold information like which circuit or line it is connected to. It
is just an arbitrary text label on the network device.

There are two exposed interfaces with this patch, the value can be
read/written either via netlink or sysfs.

This could be maintained just by the snmp daemon, but it is more
generally useful for other management tools, and the kernel is good
place to act as an agreed upon interface to store it.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

wext: make sysfs bits optional and deprecate them

The /sys/class/net/*/wireless/ direcory is, as far as I know, not
used by anyone. Additionally, the same data is available via wext
ioctls. Hence the sysfs files are pretty much useless. This patch
makes them optional and schedules them for removal.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Jean Tourrilhes <jt@hpl.hp.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

bonding: Allow setting max_bonds to zero

Permit bonding to function rationally if max_bonds is set to
zero. This will load the module, but create no master devices (which can
be created via sysfs).

Requires some change to bond_create_sysfs; currently, the
netdev sysfs directory is determined from the first bonding device created,
but this is no longer possible. Instead, an interface from net/core is
created to create and destroy files in net_class.

Based on a patch submitted by Phil Oester <kernel@linuxaces.com>.
Modified by Jay Vosburgh to fix the sysfs issue mentioned above and to
update the documentation.

Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

net: The dev->get_stats pointer is not NULL nowadays.

And so does the pointer is returns, but sysfs and netlinks still
check for both cases.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: Fix device renaming for sysfs

When a netdev is moved across namespaces with the
'dev_change_net_namespace' function, the 'device_rename' function is
used to fixup kobject and refresh the sysfs tree. The device_rename
function will call kobject_rename and this one will check if there is
an object with the same name and this is the case because we are
renaming the object with the same name.

The use of 'device_rename' seems for me wrong because we usually don't
rename it but just move it across namespaces. As we just want to do a
mini "netdev_[un]register", IMO the functions
'netdev_[un]register_kobject' should be used instead, like an usual
network device [un]registering.

This patch replace device_rename by netdev_unregister_kobject,
followed by netdev_register_kobject.

The netdev_register_kobject will call device_initialize and will raise
a warning indicating the device was already initialized. In order to
fix that, I split the device initialization into a separate function
and use it together with 'netdev_register_kobject' into
register_netdevice. So we can safely call 'netdev_register_kobject' in
'dev_change_net_namespace'.

This fix will allow to properly use the sysfs per namespace which is
coming from -mm tree.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Expose netdevice dev_id through sysfs

Expose dev_id to userspace, because it helps to disambiguate between
interfaces where the MAC address is unique.

This should allow us to simplify the handling of persistent naming for
S390 network devices in udev -- because it can depend on a simple
attribute of the device like the other match criteria, rather than
having a special case for SUBSYSTEMS=="ccwgroup".

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[ETH]: Combine format_addr() with print_mac().

print_mac() used many most net drivers and format_addr() used by
net-sysfs.c are very similar and they can be intergrated.

format_addr() is also identically redefined in the qla4xxx iscsi
driver.

Export a new function sysfs_format_mac() to be used by net-sysfs,
qla4xxx and others in the future. Both print_mac() and
sysfs_format_mac() call _format_mac_addr() to do the formatting.

Changed print_mac() to use unsigned char * to be consistent with
net_device struct's dev_addr. Added buffer length overrun checking
as suggested by Joe Perches.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Nicer WARN_ON in netstat_show

The

if (statement)
WARN_ON(1);

looks much better as

WARN_ON(statement);

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Remove in-code externs for some functions from net/core/dev.c

Inconsistent prototype and real type for functions may have worse
consequences, than those for variables, so move them into a header.

Since they are used privately in net/core, make this file reside in
the same place.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Driver core: change add_uevent_var to use a struct

This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[NET]: Fix running without sysfs

When sysfs support is compiled out the kernel still keeps and maintains
the kobject tree. So it is not safe to skip our kobject reference counting or
to avoid becoming members of the kobject tree. It is safe to not add
the networking specific sysfs attributes.

This patch removes the sysfs special cases from net/core/dev.c
renames functions from netdev_sysfs_xxxx to netdev_kobject_xxxx
and always compiles in net-sysfs.c

net-sysfs.c is modified with a CONFIG_SYSFS guard around the parts
that are actually sysfs specific.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Make NAPI polling independent of struct net_device objects.

Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.

In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.

The signature of the ->poll() call back goes from:

int foo_poll(struct net_device *dev, int *budget)

to

int foo_poll(struct napi_struct *napi, int budget)

The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract). The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.

The napi_struct is to be embedded in the device driver private data
structures.

Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler. Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.

With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.

Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.

[ Ported to current tree and all drivers converted. Integrated
Stephen's follow-on kerneldoc additions, and restored poll_list
handling to the old style to fix mutual exclusion issues. -DaveM ]

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Fix race condition about network device name allocation.

Kenji Kaneshige found this race between device removal and
registration. On unregister it is possible for the old device to
exist, because sysfs file is still open. A new device with 'eth%d'
will select the same name, but sysfs kobject register will fial.

The following changes the shutdown order slightly. It hold a removes
the sysfs entries earlier (on unregister_netdevice), but holds a
kobject reference. Then when todo runs the actual last put free
happens.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

uevent: use add_uevent_var() instead of open coding it

Make use of add_uevent_var() instead of (often incorrectly) open coding it.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Eric Rannaud <eric.rannaud@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: notify userspace of network device renames

Provide rename event for when we rename network devices.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[NET] core: whitespace cleanup

Fix whitespace around keywords. Fix indentation especially of switch
statements.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] CORE: Fix whitespace errors.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[PATCH] Replace incorrect macro name "WIRELESS_EXT" with "CONFIG_WIRELESS_EXT"

Rename the (apparently) incorrect macro name WIRELESS_EXT to
CONFIG_WIRELESS_EXT.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Network: convert network devices to use struct device instead of class_device

This lets the network core have the ability to handle suspend/resume
issues, if it wants to.

Thanks to Frederik Deweerdt <frederik.deweerdt@gmail.com> for the arm
driver fixes.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] WE-21 support (core API)

This is version 21 of the Wireless Extensions. Changelog :
o finishes migrating the ESSID API (remove the +1)
o netdev->get_wireless_stats is no more
o long/short retry

This is a redacted version of a patch originally submitted by Jean
Tourrilhes. I removed most of the additions, in order to minimize
future support requirements for nl80211 (or other WE successor).

CC: Jean Tourrilhes <jt@hpl.hp.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>