linux.git/net/core/net-sysfs.c, branch v4.19

net: allow to call netif_reset_xps_queues() under cpus_read_lock

2018-08-09T21:25:06+00:00

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 

============================================
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" 
Cc: "Michael S. Tsirkin" 
Cc: Jason Wang 
Fixes: 8af2c06ff4b1 ("net-sysfs: Add interface for Rx queue(s) map per Tx queue")

Signed-off-by: Andrei Vagin 

Signed-off-by: David S. Miller

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

2018-07-21T06:44:36+00:00

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 
Signed-off-by: David S. Miller

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

2018-07-21T06:44:35+00:00

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 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Tyler Hicks 
Signed-off-by: David S. Miller

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

2018-07-21T06:44:35+00:00

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 
Signed-off-by: David S. Miller

net: Add support for subordinate device traffic classes

2018-07-09T19:11:23+00:00

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 
Tested-by: Andrew Bowers 
Signed-off-by: Jeff Kirsher

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

2018-07-09T18:33:41+00:00

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 
Tested-by: Andrew Bowers 
Signed-off-by: Jeff Kirsher

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

2018-07-02T00:06:24+00:00

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 
Signed-off-by: David S. Miller

net: Refactor XPS for CPUs and Rx queues

2018-07-02T00:06:23+00:00

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

Signed-off-by: Amritha Nambiar 
Signed-off-by: David S. Miller

net-sysfs: Fix memory leak in XPS configuration

2018-06-01T03:02:42+00:00

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 
Signed-off-by: David S. Miller

net: Use octal not symbolic permissions

2018-03-26T16:07:48+00:00

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 
Signed-off-by: David S. Miller