Commit 26cfabf9 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David S. Miller
Browse files

net: add sock_set_rcvbuf 



Add a helper to directly set the SO_RCVBUFFORCE sockopt from kernel space
without going through a fake uaccess.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ce3d9544

fs/dlm/lowcomms.c

+1 −6
Original line number Diff line number Diff line
@@ -1180,7 +1180,6 @@ static int sctp_listen_for_all(void) 
	struct socket *sock = NULL;

	int result = -EINVAL;

	struct connection *con = nodeid2con(0, GFP_NOFS);

	int bufsize = NEEDED_RMEM;

	int one = 1;



	if (!con)
@@ -1195,11 +1194,7 @@ static int sctp_listen_for_all(void) 
		goto out;

	}



	result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE,

				 (char *)&bufsize, sizeof(bufsize));

	if (result)

		log_print("Error increasing buffer space on socket %d", result);



	sock_set_rcvbuf(sock->sk, NEEDED_RMEM);

	result = kernel_setsockopt(sock, SOL_SCTP, SCTP_NODELAY, (char *)&one,

				   sizeof(one));

	if (result < 0)

include/net/sock.h

+1 −0
Original line number Diff line number Diff line
@@ -2693,6 +2693,7 @@ void sock_enable_timestamps(struct sock *sk); 
void sock_no_linger(struct sock *sk);

void sock_set_keepalive(struct sock *sk);

void sock_set_priority(struct sock *sk, u32 priority);

void sock_set_rcvbuf(struct sock *sk, int val);

void sock_set_reuseaddr(struct sock *sk);

void sock_set_sndtimeo(struct sock *sk, s64 secs);

net/core/sock.c

+32 −27
Original line number Diff line number Diff line
@@ -789,6 +789,35 @@ void sock_set_keepalive(struct sock *sk) 
}

EXPORT_SYMBOL(sock_set_keepalive);



static void __sock_set_rcvbuf(struct sock *sk, int val)

{

	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it

	 * as a negative value.

	 */

	val = min_t(int, val, INT_MAX / 2);

	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;



	/* We double it on the way in to account for "struct sk_buff" etc.

	 * overhead.   Applications assume that the SO_RCVBUF setting they make

	 * will allow that much actual data to be received on that socket.

	 *

	 * Applications are unaware that "struct sk_buff" and other overheads

	 * allocate from the receive buffer during socket buffer allocation.

	 *

	 * And after considering the possible alternatives, returning the value

	 * we actually used in getsockopt is the most desirable behavior.

	 */

	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));

}



void sock_set_rcvbuf(struct sock *sk, int val)

{

	lock_sock(sk);

	__sock_set_rcvbuf(sk, val);

	release_sock(sk);

}

EXPORT_SYMBOL(sock_set_rcvbuf);



/*

 *	This is meant for all protocols to use and covers goings on

 *	at the socket level. Everything here is generic.
@@ -885,30 +914,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname, 
		 * play 'guess the biggest size' games. RCVBUF/SNDBUF

		 * are treated in BSD as hints

		 */

		val = min_t(u32, val, sysctl_rmem_max);

set_rcvbuf:

		/* Ensure val * 2 fits into an int, to prevent max_t()

		 * from treating it as a negative value.

		 */

		val = min_t(int, val, INT_MAX / 2);

		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;

		/*

		 * We double it on the way in to account for

		 * "struct sk_buff" etc. overhead.   Applications

		 * assume that the SO_RCVBUF setting they make will

		 * allow that much actual data to be received on that

		 * socket.

		 *

		 * Applications are unaware that "struct sk_buff" and

		 * other overheads allocate from the receive buffer

		 * during socket buffer allocation.

		 *

		 * And after considering the possible alternatives,

		 * returning the value we actually used in getsockopt

		 * is the most desirable behavior.

		 */

		WRITE_ONCE(sk->sk_rcvbuf,

			   max_t(int, val * 2, SOCK_MIN_RCVBUF));

		__sock_set_rcvbuf(sk, min_t(u32, val, sysctl_rmem_max));

		break;



	case SO_RCVBUFFORCE:
@@ -920,9 +926,8 @@ int sock_setsockopt(struct socket *sock, int level, int optname, 
		/* No negative values (to prevent underflow, as val will be

		 * multiplied by 2).

		 */

		if (val < 0)

			val = 0;

		goto set_rcvbuf;

		__sock_set_rcvbuf(sk, max(val, 0));

		break;



	case SO_KEEPALIVE:

		if (sk->sk_prot->keepalive)