Commits · 3f6b2c4420610cf0882b395338c0daee15dc102d · Kirill Smelkov / linux

25 Oct, 2019 2 commits

net: mvneta: make stub functions static inline · 3f6b2c44

Ben Dooks (Codethink) authored Oct 23, 2019

If the CONFIG_MVNET_BA is not set, then make the stub functions
static inline to avoid trying to export them, and remove hte
following sparse warnings:

drivers/net/ethernet/marvell/mvneta_bm.h:163:6: warning: symbol 'mvneta_bm_pool_destroy' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:165:6: warning: symbol 'mvneta_bm_bufs_free' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:167:5: warning: symbol 'mvneta_bm_construct' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:168:5: warning: symbol 'mvneta_bm_pool_refill' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:170:23: warning: symbol 'mvneta_bm_pool_use' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:181:18: warning: symbol 'mvneta_bm_get' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:182:6: warning: symbol 'mvneta_bm_put' was not declared. Should it be static?
Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

3f6b2c44

net: sch_generic: Use pfifo_fast as fallback scheduler for CAN hardware · fa784f2a

Vincent Prince authored Oct 22, 2019

There is networking hardware that isn't based on Ethernet for layers 1 and 2.

For example CAN.

CAN is a multi-master serial bus standard for connecting Electronic Control
Units [ECUs] also known as nodes. A frame on the CAN bus carries up to 8 bytes
of payload. Frame corruption is detected by a CRC. However frame loss due to
corruption is possible, but a quite unusual phenomenon.

While fq_codel works great for TCP/IP, it doesn't for CAN. There are a lot of
legacy protocols on top of CAN, which are not build with flow control or high
CAN frame drop rates in mind.

When using fq_codel, as soon as the queue reaches a certain delay based length,
skbs from the head of the queue are silently dropped. Silently meaning that the
user space using a send() or similar syscall doesn't get an error. However
TCP's flow control algorithm will detect dropped packages and adjust the
bandwidth accordingly.

When using fq_codel and sending raw frames over CAN, which is the common use
case, the user space thinks the package has been sent without problems, because
send() returned without an error. pfifo_fast will drop skbs, if the queue
length exceeds the maximum. But with this scheduler the skbs at the tail are
dropped, an error (-ENOBUFS) is propagated to user space. So that the user
space can slow down the package generation.

On distributions, where fq_codel is made default via CONFIG_DEFAULT_NET_SCH
during compile time, or set default during runtime with sysctl
net.core.default_qdisc (see [1]), we get a bad user experience. In my test case
with pfifo_fast, I can transfer thousands of million CAN frames without a frame
drop. On the other hand with fq_codel there is more then one lost CAN frame per
thousand frames.

As pointed out fq_codel is not suited for CAN hardware, so this patch changes
attach_one_default_qdisc() to use pfifo_fast for "ARPHRD_CAN" network devices.

During transition of a netdev from down to up state the default queuing
discipline is attached by attach_default_qdiscs() with the help of
attach_one_default_qdisc(). This patch modifies attach_one_default_qdisc() to
attach the pfifo_fast (pfifo_fast_ops) if the network device type is
"ARPHRD_CAN".

[1] https://github.com/systemd/systemd/issues/9194Signed-off-by: Vincent Prince <vincent.prince.fr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

fa784f2a

24 Oct, 2019 14 commits

Merge branch 'net-fix-nested-device-bugs' · 65921376

David S. Miller authored Oct 24, 2019

Taehee Yoo says:

====================
net: fix nested device bugs

This patchset fixes several bugs that are related to nesting
device infrastructure.
Current nesting infrastructure code doesn't limit the depth level of
devices. nested devices could be handled recursively. at that moment,
it needs huge memory and stack overflow could occur.
Below devices type have same bug.
VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, and VXLAN.
But I couldn't test all interface types so there could be more device
types, which have similar problems.
Maybe qmi_wwan.c code could have same problem.
So, I would appreciate if someone test qmi_wwan.c and other modules.

Test commands:
    ip link add dummy0 type dummy
    ip link add vlan1 link dummy0 type vlan id 1

    for i in {2..100}
    do
	    let A=$i-1
	    ip link add name vlan$i link vlan$A type vlan id $i
    done
    ip link del dummy0

1st patch actually fixes the root cause.
It adds new common variables {upper/lower}_level that represent
depth level. upper_level variable is depth of upper devices.
lower_level variable is depth of lower devices.

      [U][L]       [U][L]
vlan1  1  5  vlan4  1  4
vlan2  2  4  vlan5  2  3
vlan3  3  3    |
  |            |
  +------------+
  |
vlan6  4  2
dummy0 5  1

After this patch, the nesting infrastructure code uses this variable to
check the depth level.

2nd patch fixes Qdisc lockdep related problem.
Before this patch, devices use static lockdep map.
So, if devices that are same types are nested, lockdep will warn about
recursive situation.
These patches make these devices use dynamic lockdep key instead of
static lock or subclass.

3rd patch fixes unexpected IFF_BONDING bit unset.
When nested bonding interface scenario, bonding interface could lost it's
IFF_BONDING flag. This should not happen.
This patch adds a condition before unsetting IFF_BONDING.

4th patch fixes nested locking problem in bonding interface
Bonding interface has own lock and this uses static lock.
Bonding interface could be nested and it uses same lockdep key.
So that unexisting lockdep warning occurs.

5th patch fixes nested locking problem in team interface
Team interface has own lock and this uses static lock.
Team interface could be nested and it uses same lockdep key.
So that unexisting lockdep warning occurs.

6th patch fixes a refcnt leak in the macsec module.
When the macsec module is unloaded, refcnt leaks occur.
But actually, that holding refcnt is unnecessary.
So this patch just removes these code.

7th patch adds ignore flag to an adjacent structure.
In order to exchange an adjacent node safely, ignore flag is needed.

8th patch makes vxlan add an adjacent link to limit depth level.
Vxlan interface could set it's lower interface and these lower interfaces
are handled recursively.
So, if the depth of lower interfaces is too deep, stack overflow could
happen.

9th patch removes unnecessary variables and callback.
After 1st patch, subclass callback and variables are unnecessary.
This patch just removes these variables and callback.

10th patch fix refcnt leaks in the virt_wifi module
Like every nested interface, the upper interface should be deleted
before the lower interface is deleted.
In order to fix this, the notifier routine is added in this patch.

v4 -> v5 :
 - Update log messages
 - Move variables position, 1st patch
 - Fix iterator routine, 1st patch
 - Add generic lockdep key code, which replaces 2, 4, 5, 6, 7 patches.
 - Log message update, 10th patch
 - Fix wrong error value in error path of __init routine, 10th patch
 - hold module refcnt when interface is created, 10th patch
v3 -> v4 :
 - Add new 12th patch to fix refcnt leaks in the virt_wifi module
 - Fix wrong usage netdev_upper_dev_link() in the vxlan.c
 - Preserve reverse christmas tree variable ordering in the vxlan.c
 - Add missing static keyword in the dev.c
 - Expose netdev_adjacent_change_{prepare/commit/abort} instead of
   netdev_adjacent_dev_{enable/disable}
v2 -> v3 :
 - Modify nesting infrastructure code to use iterator instead of recursive.
v1 -> v2 :
 - Make the 3rd patch do not add a new priv_flag.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

65921376