From 04190bf8944deb7e3ac165a1a494db23aa0160a9 Mon Sep 17 00:00:00 2001 From: Pavel Tikhomirov Date: Wed, 4 Aug 2021 10:55:56 +0300 Subject: 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 Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- arch/alpha/include/uapi/asm/socket.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/alpha/include') diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index 6b3daba60987..1dd9baf4a6c2 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -129,6 +129,8 @@ #define SO_NETNS_COOKIE 71 +#define SO_BUF_LOCK 72 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 -- cgit v1.2.3-59-g8ed1b