[PATCH v2 0/2] net: io_uring/zcrx: call netdev_queue_get_dma_dev() under instance lock

netdev ops must be called under instance lock or rtnl_lock, but
io_register_zcrx_ifq() isn't doing this for netdev_queue_get_dma_dev().
Fix this by taking the instance lock using netdev_get_by_index_lock().

netdev_get_by_index_lock() isn't exported by default, so the first patch
is a prep patch to export this under linux/netdevice.h.

Extended the instance lock section to include attaching a memory
provider. Could not move io_zcrx_create_area() outside, since the dmabuf
codepath IORING_ZCRX_AREA_DMABUF requires ifq->dev. Happy to do whatever
here, either keep this extended section or relock for net_mp_open_rxq().

v2:
 - add Fixes tag
 - export netdev_get_by_index_lock()
 - use netdev_get_by_index_lock() + netdev_hold()
 - extend lock section to include net_mp_open_rxq()

David Wei (2):
  net: export netdev_get_by_index_lock()
  net: io_uring/zcrx: call netdev_queue_get_dma_dev() under instance
    lock

 include/linux/netdevice.h |  1 +
 io_uring/zcrx.c           | 15 +++++++++------
 net/core/dev.c            |  1 +
 net/core/dev.h            |  1 -
 4 files changed, 11 insertions(+), 7 deletions(-)

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2.47.3