[PATCH net-next v2 0/6] splice, net: Handle MSG_SPLICE_PAGES in AF_TLS

From: David Howells
Date: Wed May 31 2023 - 08:46:26 EST

Here are patches to make AF_TLS handle the MSG_SPLICE_PAGES internal
sendmsg flag. MSG_SPLICE_PAGES is an internal hint that tells the protocol
that it should splice the pages supplied if it can. Its sendpage
implementations are then turned into wrappers around that.

The following changes are made:

(1) The first patch fixes MSG_MORE signalling in splice_direct_to_actor().

The problem is that MSG_MORE is asserted if a short splice from a file
occurs because we hit the EOF[1]. This is fixed by checking the EOF
if the file is seekable.

(2) Implement MSG_SPLICE_PAGES support in the AF_TLS-sw sendmsg and make
tls_sw_sendpage() just a wrapper around sendmsg().

(3) Implement MSG_SPLICE_PAGES support in AF_TLS-device and make
tls_device_sendpage() just a wrapper around sendmsg().

I've pushed the patches here also:



ver #2)
- Dropped the slab data copying.
- "rls_" should be "tls_".
- Attempted to fix splice_direct_to_actor().
- Blocked MSG_SENDPAGE_* from being set by userspace.

Link: https://lore.kernel.org/r/499791.1685485603@xxxxxxxxxxxxxxxxxxxxxx/ [1]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=51c78a4d532efe9543a4df019ff405f05c6157f6 # part 1
Link: https://lore.kernel.org/r/20230524153311.3625329-1-dhowells@xxxxxxxxxx/ # v1

David Howells (6):
splice, net: Fix MSG_MORE signalling in splice_direct_to_actor()
net: Block MSG_SENDPAGE_* from being passed to sendmsg() by userspace
tls/sw: Support MSG_SPLICE_PAGES
tls/sw: Convert tls_sw_sendpage() to use MSG_SPLICE_PAGES
tls/device: Support MSG_SPLICE_PAGES
tls/device: Convert tls_device_sendpage() to use MSG_SPLICE_PAGES

fs/splice.c | 17 +++-
include/linux/socket.h | 4 +-
net/tls/tls_device.c | 94 ++++++++----------
net/tls/tls_sw.c | 211 +++++++++++++++--------------------------
4 files changed, 131 insertions(+), 195 deletions(-)