Subject: [PATCH 0/9 v1 RFC] Generic zcopy_* functions

From: Jonathan Lemon <[email-masked]>
Date: Fri, 18 Dec 2020 12:16:24 -0800

From: Jonathan Lemon <[email-masked]>

This is set of cleanup patches for zerocopy which are intended
to allow a introduction of a different zerocopy implementation.

The top level api will use the skb_zcopy_*() functions, while
the current TCP specific zerocopy would use the sock_zerocopy_*()
calls.

There should be no functional changes from these patches.

Patch 1:
  Move zerocopy bits from tx_flags into zc_flags for clarity.
  These bits will be used in the RX path in the future.
Patch 2: remove dead function
Patch 3:
  Replace sock_zerocopy_put() with skb_zcopy_put(), moving
  the zerocopy logic into sock_zerocopy_callback().  Push the
  refcounting into the callback, since not all implemenetations
  will have a refcount.
Patch 4: rename sock_zerocopy_get for consistency.
Patch 5:
  Add an optional skb parameter to callback, allowing access to
  the attached skb from the callback.
Patch 6:
  Add skb_zcopy_put_abort, and move zerocopy logic into the 
  callback function.  There unfortunately is still a check 
  against the callback type here.
Patch 7:
  Set the skb zc_flags from the ubuf being attached, instead
  of a fixed value, allowing different initialization types.
Patch 8: Replace open-coded assignments
Patch 9: Relocate skb_zcopy_clear() in skb_release_data()

Jonathan Lemon (9):
  net: group skb_shinfo zerocopy related bits together.
  skbuff: remove unused skb_zcopy_abort function
  skbuff: replace sock_zerocopy_put() with skb_zcopy_put()
  skbuff: replace sock_zerocopy_get with skb_zcopy_get
  skbuff: Add skb parameter to the ubuf zerocopy callback
  skbuff: Call sock_zerocopy_put_abort from skb_zcopy_put_abort
  skbuff: add zc_flags to ubuf_info for ubuf setup
  tap/tun: use skb_zcopy_set() instead of open coded assignment
  skbuff: Call skb_zcopy_clear() before unref'ing fragments

 drivers/net/tap.c                   |  6 +--
 drivers/net/tun.c                   |  6 +--
 drivers/net/xen-netback/common.h    |  3 +-
 drivers/net/xen-netback/interface.c |  4 +-
 drivers/net/xen-netback/netback.c   |  7 +--
 drivers/vhost/net.c                 |  4 +-
 include/linux/skbuff.h              | 77 +++++++++++++++--------------
 net/core/skbuff.c                   | 48 +++++++++---------
 net/ipv4/ip_output.c                |  3 +-
 net/ipv4/tcp.c                      |  6 +--
 net/ipv6/ip6_output.c               |  3 +-
 net/kcm/kcmsock.c                   |  4 +-
 12 files changed, 85 insertions(+), 86 deletions(-)

-- 
2.24.1