Andrii suggested moving the attach_type into bpf_link, the previous discussion
is as follows:
https://lore.kernel.org/bpf/CAEf4BzY7TZRjxpCJM-+LYgEqe23YFj5Uv3isb7gat2-HU4OSng@mail.gmail.com

patch1 add attach_type in bpf_link, and pass it to bpf_link_init, which
will init the attach_type field.

patch2-6 remove the attach_type in struct bpf_xx_link, update the info
with bpf_link attach_type.

There are some functions finally call bpf_link_init but do not have bpf_attr
from user or do not need to init attach_type from user like bpf_raw_tracepoint_open,
now use prog->expected_attach_type to init attach_type.

bpf_struct_ops_map_update_elem
bpf_raw_tracepoint_open
bpf_struct_ops_test_run

Feedback of any kind is welcome, thanks.

Tao Chen (6):
  bpf: Add attach_type in bpf_link
  bpf: Remove attach_type in bpf_cgroup_link
  bpf: Remove attach_type in bpf_sockmap_link
  bpf: Remove location field in tcx_link
  bpf: Remove attach_type in bpf_netns_link
  bpf: Remove attach_type in bpf_tracing_link

 include/linux/bpf-cgroup.h     |  1 -
 include/linux/bpf.h            | 18 +++++++++------
 include/net/tcx.h              |  1 -
 kernel/bpf/bpf_iter.c          |  3 ++-
 kernel/bpf/bpf_struct_ops.c    |  5 +++--
 kernel/bpf/cgroup.c            | 17 +++++++--------
 kernel/bpf/net_namespace.c     |  8 +++----
 kernel/bpf/syscall.c           | 40 ++++++++++++++++++++--------------
 kernel/bpf/tcx.c               | 16 +++++++-------
 kernel/bpf/trampoline.c        | 10 +++++----
 kernel/trace/bpf_trace.c       |  4 ++--
 net/bpf/bpf_dummy_struct_ops.c |  3 ++-
 net/core/dev.c                 |  3 ++-
 net/core/sock_map.c            | 13 +++++------
 net/netfilter/nf_bpf_link.c    |  3 ++-
 15 files changed, 79 insertions(+), 66 deletions(-)

-- 
2.48.1