net: Declare MSG_SPLICE_PAGES internal sendmsg() flag

[ Upstream commit b841b901c4 ]

Declare MSG_SPLICE_PAGES, an internal sendmsg() flag, that hints to a
network protocol that it should splice pages from the source iterator
rather than copying the data if it can.  This flag is added to a list that
is cleared by sendmsg syscalls on entry.

This is intended as a replacement for the ->sendpage() op, allowing a way
to splice in several multipage folios in one go.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: a0002127cd ("udp: move udp->no_check6_tx to udp->udp_flags")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
David Howells 2023-05-22 13:11:10 +01:00 • committed by Greg Kroah-Hartman
commit 6bcc79a4e7
3 changed files with 7 additions and 0 deletions