linux-mainline/net
Pavel Tikhomirov 04190bf894 sock: allow reading and changing sk_userlocks with setsockopt
SOCK_SNDBUF_LOCK and SOCK_RCVBUF_LOCK flags disable automatic socket
buffers adjustment done by kernel (see tcp_fixup_rcvbuf() and
tcp_sndbuf_expand()). If we've just created a new socket this adjustment
is enabled on it, but if one changes the socket buffer size by
setsockopt(SO_{SND,RCV}BUF*) it becomes disabled.

CRIU needs to call setsockopt(SO_{SND,RCV}BUF*) on each socket on
restore as it first needs to increase buffer sizes for packet queues
restore and second it needs to restore back original buffer sizes. So
after CRIU restore all sockets become non-auto-adjustable, which can
decrease network performance of restored applications significantly.

CRIU need to be able to restore sockets with enabled/disabled adjustment
to the same state it was before dump, so let's add special setsockopt
for it.

Let's also export SOCK_SNDBUF_LOCK and SOCK_RCVBUF_LOCK flags to uAPI so
that using these interface one can reenable automatic socket buffer
adjustment on their sockets.

Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-04 12:52:03 +01:00
..
6lowpan
9p
802
8021q
appletalk
atm
ax25
batman-adv
bluetooth
bpf
bpfilter
bridge
caif
can
ceph
core
dcb
dccp
decnet
dns_resolver
dsa
ethernet
ethtool
hsr
ieee802154
ife
ipv4
ipv6
iucv
kcm
key
l2tp
l3mdev
lapb
llc
mac80211
mac802154
mctp
mpls
mptcp
ncsi
netfilter
netlabel
netlink
netrom
nfc
nsh
openvswitch
packet
phonet
psample
qrtr
rds
rfkill
rose
rxrpc
sched
sctp
smc
strparser
sunrpc
switchdev
tipc
tls
unix
vmw_vsock
wireless
x25
xdp
xfrm
compat.c
devres.c
Kconfig
Makefile
socket.c
sysctl_net.c