[PATCH 19/21] netlink: add SOCK_VMIO support to AF_NETLINK

Peter Zijlstra
2006-09-06T13:16:49Z

[-- Attachment #1: netlink_vmio.patch --]
[-- Type: text/plain, Size: 3699 bytes --]

Propagate SOCK_VMIO from kernel socket to userspace sockets.
Allow sys_{send,recv}msg to succeed under memory pressure for
SOCK_VMIO netlink sockets.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Mike Christie <michaelc@cs.wisc.edu>
---
include/linux/netlink.h | 1 +
net/netlink/af_netlink.c | 8 +++++---
net/socket.c | 6 +++---
3 files changed, 9 insertions(+), 6 deletions(-)

Index: linux-2.6/net/netlink/af_netlink.c
===================================================================
--- linux-2.6.orig/net/netlink/af_netlink.c
+++ linux-2.6/net/netlink/af_netlink.c
@@ -199,7 +199,7 @@ netlink_unlock_table(void)
wake_up(&nl_table_wait);
}

-static __inline__ struct sock *netlink_lookup(int protocol, u32 pid)
+__inline__ struct sock *netlink_lookup(int protocol, u32 pid)
{
struct nl_pid_hash *hash = &nl_table[protocol].hash;
struct hlist_head *head;
@@ -1147,7 +1147,7 @@ static int netlink_sendmsg(struct kiocb
if (len > sk->sk_sndbuf - 32)
goto out;
err = -ENOBUFS;
- skb = alloc_skb(len, GFP_KERNEL);
+ skb = __alloc_skb(len, GFP_KERNEL, SKB_ALLOC_RX);
if (skb==NULL)
goto out;

@@ -1178,7 +1178,8 @@ static int netlink_sendmsg(struct kiocb

if (dst_group) {
atomic_inc(&skb->users);
- netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
+ netlink_broadcast(sk, skb, dst_pid, dst_group,
+ sk->sk_allocation);
}
err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);

@@ -1788,6 +1789,7 @@ panic:

core_initcall(netlink_proto_init);

+EXPORT_SYMBOL(netlink_lookup);
EXPORT_SYMBOL(netlink_ack);
EXPORT_SYMBOL(netlink_run_queue);
EXPORT_SYMBOL(netlink_queue_skip);
Index: linux-2.6/net/socket.c
===================================================================
--- linux-2.6.orig/net/socket.c
+++ linux-2.6/net/socket.c
@@ -1790,7 +1790,7 @@ asmlinkage long sys_sendmsg(int fd, stru
err = -ENOMEM;
iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
if (msg_sys.msg_iovlen > UIO_FASTIOV) {
- iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
+ iov = sock_kmalloc(sock->sk, iov_size, sock->sk->sk_allocation);
if (!iov)
goto out_put;
}
@@ -1818,7 +1818,7 @@ asmlinkage long sys_sendmsg(int fd, stru
} else if (ctl_len) {
if (ctl_len > sizeof(ctl))
{
- ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
+ ctl_buf = sock_kmalloc(sock->sk, ctl_len, sock->sk->sk_allocation);
if (ctl_buf == NULL)
goto out_freeiov;
}
@@ -1891,7 +1891,7 @@ asmlinkage long sys_recvmsg(int fd, stru
err = -ENOMEM;
iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
if (msg_sys.msg_iovlen > UIO_FASTIOV) {
- iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
+ iov = sock_kmalloc(sock->sk, iov_size, sock->sk->sk_allocation);
if (!iov)
goto out_put;
}
Index: linux-2.6/include/linux/netlink.h
===================================================================
--- linux-2.6.orig/include/linux/netlink.h
+++ linux-2.6/include/linux/netlink.h
@@ -150,6 +150,7 @@ struct netlink_skb_parms
#define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)

+extern struct sock *netlink_lookup(int protocol, __u32 pid);
extern struct sock *netlink_kernel_create(int unit, unsigned int groups, void (*input)(struct sock *sk, int len), struct module *module);
extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
extern int netlink_has_listeners(struct sock *sk, unsigned int group);