[v4,net-next,00/18] Make .ndo_get_stats64 sleepable

From: Vladimir Oltean <vladimir.oltean@nxp.com>

There is a desire to standardize the counters that have previously been
reported through ethtool statistics into something that can be more
uniformly queried from user space. The ndo_get_stats64 are a good
candidate to keep standardized counters, as well as add new ones (like
RMON MIBs) but unfortunately, as things stand, migration will not be
smooth sailing if the ndo_get_stats64 does not offer the same calling
context as ethtool does. Namely, currently ndo_get_stats64 assumes
atomic context, and this series would like to change that.

The reason why sleeping while retrieving counters would be desirable in
the first place is that if we have hardware that needs to be accessed
through a slow bus like SPI, or through a firmware. Today we cannot do
that directly in .ndo_get_stats64, so we would have to poll counters
periodically and return a cached (not up to date) copy in the atomic NDO
callback. This is undesirable on both ends: more work than strictly
needed is being done, and the end result is also worse (not guaranteed
to be up to date). Also, retrieving counters from the hardware rather
than software counters incremented by the driver is more compatible with
the concept of interfaces with offload for L2 or L3 forwarding, where
the CPU otherwise never has a chance to keep accurate counters for most
of the traffic.

Changes in v4:
- Propagated errors from ndo_get_stats64.

Changes in v3:
- Resolved some memory leak issues in the bonding patch 10/12.

Changes in v2:
- Addressed the recursion issues in .ndo_get_stats64 from bonding and
  net_failover.
- Renamed netdev_lists_lock to netif_lists_lock
- Stopped taking netif_lists_lock from drivers as much as possible.

Vladimir Oltean (18):
  net: mark dev_base_lock for deprecation
  net: introduce a mutex for the netns interface lists
  net: procfs: hold netif_lists_lock when retrieving device statistics
  net: sysfs: don't hold dev_base_lock while retrieving device
    statistics
  s390/appldata_net_sum: hold the netdev lists lock when retrieving
    device statistics
  parisc/led: reindent the code that gathers device statistics
  parisc/led: hold the netdev lists lock when retrieving device
    statistics
  net: make dev_get_stats return void
  net: allow ndo_get_stats64 to return an int error code
  scsi: fcoe: propagate errors from dev_get_stats
  net: openvswitch: propagate errors from dev_get_stats
  net: propagate errors from dev_get_stats
  net: terminate errors from dev_get_stats
  net: openvswitch: ensure dev_get_stats can sleep
  net: net_failover: ensure .ndo_get_stats64 can sleep
  net: bonding: ensure .ndo_get_stats64 can sleep
  net: mark ndo_get_stats64 as being able to sleep
  net: remove obsolete comments about ndo_get_stats64 context from eth
    drivers

 Documentation/networking/netdevices.rst       |   8 +-
 Documentation/networking/statistics.rst       |   9 +-
 arch/s390/appldata/appldata_net_sum.c         |  41 +++---
 drivers/infiniband/hw/hfi1/vnic_main.c        |   6 +-
 drivers/infiniband/ulp/ipoib/ipoib_main.c     |   9 +-
 .../infiniband/ulp/opa_vnic/opa_vnic_netdev.c |   9 +-
 drivers/leds/trigger/ledtrig-netdev.c         |  16 +-
 drivers/net/bonding/bond_main.c               | 138 +++++++++---------
 drivers/net/dummy.c                           |   6 +-
 drivers/net/ethernet/alacritech/slicoss.c     |   6 +-
 drivers/net/ethernet/amazon/ena/ena_netdev.c  |   8 +-
 drivers/net/ethernet/amd/xgbe/xgbe-drv.c      |   6 +-
 drivers/net/ethernet/apm/xgene-v2/main.c      |   6 +-
 .../ethernet/apm/xgene/xgene_enet_ethtool.c   |   9 +-
 .../net/ethernet/apm/xgene/xgene_enet_main.c  |   7 +-
 drivers/net/ethernet/atheros/alx/main.c       |   6 +-
 drivers/net/ethernet/broadcom/b44.c           |   6 +-
 drivers/net/ethernet/broadcom/bcmsysport.c    |   6 +-
 drivers/net/ethernet/broadcom/bnx2.c          |   5 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     |   6 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt_vfr.c |   4 +-
 drivers/net/ethernet/broadcom/tg3.c           |   8 +-
 drivers/net/ethernet/brocade/bna/bnad.c       |   4 +-
 drivers/net/ethernet/calxeda/xgmac.c          |   4 +-
 .../net/ethernet/cavium/liquidio/lio_main.c   |   6 +-
 .../ethernet/cavium/liquidio/lio_vf_main.c    |   6 +-
 .../net/ethernet/cavium/liquidio/lio_vf_rep.c |   8 +-
 .../net/ethernet/cavium/thunder/nicvf_main.c  |   5 +-
 .../net/ethernet/chelsio/cxgb4/cxgb4_main.c   |   8 +-
 drivers/net/ethernet/cisco/enic/enic_main.c   |   9 +-
 drivers/net/ethernet/cortina/gemini.c         |   6 +-
 drivers/net/ethernet/ec_bhf.c                 |   4 +-
 drivers/net/ethernet/emulex/benet/be_main.c   |   6 +-
 .../net/ethernet/freescale/dpaa/dpaa_eth.c    |   6 +-
 .../net/ethernet/freescale/dpaa2/dpaa2-eth.c  |   6 +-
 drivers/net/ethernet/google/gve/gve_main.c    |   4 +-
 drivers/net/ethernet/hisilicon/hns/hns_enet.c |   6 +-
 .../net/ethernet/hisilicon/hns/hns_ethtool.c  |  56 +++----
 .../net/ethernet/hisilicon/hns3/hns3_enet.c   |   8 +-
 .../net/ethernet/huawei/hinic/hinic_main.c    |   6 +-
 drivers/net/ethernet/ibm/ehea/ehea_main.c     |   6 +-
 drivers/net/ethernet/intel/e1000e/e1000.h     |   4 +-
 drivers/net/ethernet/intel/e1000e/ethtool.c   |   9 +-
 drivers/net/ethernet/intel/e1000e/netdev.c    |   6 +-
 .../net/ethernet/intel/fm10k/fm10k_netdev.c   |   6 +-
 drivers/net/ethernet/intel/i40e/i40e_main.c   |  10 +-
 drivers/net/ethernet/intel/ice/ice_main.c     |   6 +-
 drivers/net/ethernet/intel/igb/igb_main.c     |  10 +-
 drivers/net/ethernet/intel/igc/igc_main.c     |   6 +-
 .../net/ethernet/intel/ixgbe/ixgbe_ethtool.c  |  14 +-
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   6 +-
 drivers/net/ethernet/intel/ixgbevf/ethtool.c  |  14 +-
 .../net/ethernet/intel/ixgbevf/ixgbevf_main.c |   6 +-
 drivers/net/ethernet/marvell/mvneta.c         |   4 +-
 .../net/ethernet/marvell/mvpp2/mvpp2_main.c   |   4 +-
 .../marvell/octeontx2/nic/otx2_common.c       |   6 +-
 .../marvell/octeontx2/nic/otx2_common.h       |   4 +-
 .../ethernet/marvell/prestera/prestera_main.c |   6 +-
 drivers/net/ethernet/marvell/sky2.c           |   6 +-
 drivers/net/ethernet/mediatek/mtk_eth_soc.c   |   6 +-
 drivers/net/ethernet/mediatek/mtk_star_emac.c |   6 +-
 .../net/ethernet/mellanox/mlx4/en_netdev.c    |   4 +-
 drivers/net/ethernet/mellanox/mlx5/core/en.h  |   2 +-
 .../net/ethernet/mellanox/mlx5/core/en_main.c |   4 +-
 .../net/ethernet/mellanox/mlx5/core/en_rep.c  |   4 +-
 .../ethernet/mellanox/mlx5/core/ipoib/ipoib.c |   4 +-
 .../ethernet/mellanox/mlx5/core/ipoib/ipoib.h |   2 +-
 .../net/ethernet/mellanox/mlxsw/spectrum.c    |   4 +-
 .../net/ethernet/mellanox/mlxsw/switchx2.c    |   4 +-
 drivers/net/ethernet/microchip/lan743x_main.c |   6 +-
 drivers/net/ethernet/mscc/ocelot_net.c        |   6 +-
 .../net/ethernet/myricom/myri10ge/myri10ge.c  |  12 +-
 .../net/ethernet/neterion/vxge/vxge-main.c    |   4 +-
 .../ethernet/netronome/nfp/nfp_net_common.c   |   6 +-
 .../net/ethernet/netronome/nfp/nfp_net_repr.c |   6 +-
 drivers/net/ethernet/nvidia/forcedeth.c       |   6 +-
 .../net/ethernet/pensando/ionic/ionic_lif.c   |   6 +-
 .../net/ethernet/pensando/ionic/ionic_lif.h   |   4 +-
 .../ethernet/qlogic/netxen/netxen_nic_main.c  |  10 +-
 drivers/net/ethernet/qlogic/qede/qede_main.c  |   6 +-
 drivers/net/ethernet/qualcomm/emac/emac.c     |   6 +-
 .../net/ethernet/qualcomm/rmnet/rmnet_vnd.c   |   8 +-
 drivers/net/ethernet/realtek/8139too.c        |   8 +-
 drivers/net/ethernet/realtek/r8169_main.c     |   4 +-
 .../net/ethernet/samsung/sxgbe/sxgbe_main.c   |   6 +-
 drivers/net/ethernet/sfc/efx_common.c         |   5 +-
 drivers/net/ethernet/sfc/efx_common.h         |   2 +-
 drivers/net/ethernet/sfc/falcon/efx.c         |   7 +-
 drivers/net/ethernet/socionext/sni_ave.c      |   6 +-
 drivers/net/ethernet/sun/niu.c                |   6 +-
 .../net/ethernet/synopsys/dwc-xlgmac-net.c    |   6 +-
 drivers/net/ethernet/ti/am65-cpsw-nuss.c      |   6 +-
 drivers/net/ethernet/ti/netcp_core.c          |   4 +-
 drivers/net/ethernet/via/via-rhine.c          |   8 +-
 drivers/net/fjes/fjes_main.c                  |   6 +-
 drivers/net/hyperv/netvsc_drv.c               |   6 +-
 drivers/net/ifb.c                             |   5 +-
 drivers/net/ipvlan/ipvlan_main.c              |   6 +-
 drivers/net/loopback.c                        |   6 +-
 drivers/net/macsec.c                          |   8 +-
 drivers/net/macvlan.c                         |   6 +-
 drivers/net/mhi_net.c                         |   6 +-
 drivers/net/net_failover.c                    |  78 +++++++---
 drivers/net/netdevsim/netdev.c                |   4 +-
 drivers/net/nlmon.c                           |   4 +-
 drivers/net/ppp/ppp_generic.c                 |   4 +-
 drivers/net/slip/slip.c                       |   4 +-
 drivers/net/team/team.c                       |   4 +-
 drivers/net/thunderbolt.c                     |   6 +-
 drivers/net/tun.c                             |   4 +-
 drivers/net/veth.c                            |   6 +-
 drivers/net/virtio_net.c                      |   6 +-
 drivers/net/vmxnet3/vmxnet3_ethtool.c         |   4 +-
 drivers/net/vmxnet3/vmxnet3_int.h             |   4 +-
 drivers/net/vrf.c                             |   6 +-
 drivers/net/vsockmon.c                        |   4 +-
 drivers/net/xen-netfront.c                    |   6 +-
 drivers/parisc/led.c                          |  42 ++++--
 drivers/s390/net/qeth_core.h                  |   2 +-
 drivers/s390/net/qeth_core_main.c             |   4 +-
 drivers/scsi/fcoe/fcoe_sysfs.c                |   9 +-
 drivers/scsi/fcoe/fcoe_transport.c            |  28 ++--
 drivers/scsi/libfc/fc_rport.c                 |   5 +-
 drivers/staging/fsl-dpaa2/ethsw/ethsw.c       |   8 +-
 drivers/staging/netlogic/xlr_net.c            |   4 +-
 drivers/usb/gadget/function/rndis.c           |  47 +++---
 include/linux/netdevice.h                     |  21 ++-
 include/net/bonding.h                         |  49 ++++++-
 include/net/net_failover.h                    |   9 +-
 include/net/net_namespace.h                   |   6 +
 include/scsi/fcoe_sysfs.h                     |  12 +-
 include/scsi/libfc.h                          |   2 +-
 include/scsi/libfcoe.h                        |   8 +-
 net/8021q/vlan_dev.c                          |   6 +-
 net/8021q/vlanproc.c                          |  20 +--
 net/core/dev.c                                |  78 ++++++----
 net/core/net-procfs.c                         |  62 ++++----
 net/core/net-sysfs.c                          |  12 +-
 net/core/rtnetlink.c                          |   9 +-
 net/l2tp/l2tp_eth.c                           |   6 +-
 net/mac80211/iface.c                          |   4 +-
 net/openvswitch/datapath.c                    |  58 ++++----
 net/openvswitch/vport.c                       |  35 +++--
 net/openvswitch/vport.h                       |   2 +-
 net/sched/sch_teql.c                          |   6 +-
 145 files changed, 984 insertions(+), 573 deletions(-)