net/smc/smc_sysctl.c

Source file repositories/reference/linux-study-clean/net/smc/smc_sysctl.c

File Facts

System
Linux kernel
Corpus path
net/smc/smc_sysctl.c
Extension
.c
Size
6997 bytes
Lines
267
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: implementation source
Status
source implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!ctrl) {
			rcu_read_unlock();
			return -EINVAL;
		}
		/* no change, just return */
		if (ctrl == rcu_dereference(net->smc.hs_ctrl)) {
			rcu_read_unlock();
			return 0;
		}
		if (!bpf_try_module_get(ctrl, ctrl->owner)) {
			rcu_read_unlock();
			return -EBUSY;
		}
	}
	/* xhcg old ctrl with the new one atomically */
	ctrl = unrcu_pointer(xchg(&net->smc.hs_ctrl, RCU_INITIALIZER(ctrl)));
	/* release old ctrl */
	if (ctrl)
		bpf_module_put(ctrl, ctrl->owner);

	rcu_read_unlock();
	return 0;
}

static int proc_smc_hs_ctrl(const struct ctl_table *ctl, int write,
			    void *buffer, size_t *lenp, loff_t *ppos)
{
	struct net *net = container_of(ctl->data, struct net, smc.hs_ctrl);
	char val[SMC_HS_CTRL_NAME_MAX];
	const struct ctl_table tbl = {
		.data = val,
		.maxlen = SMC_HS_CTRL_NAME_MAX,
	};
	struct smc_hs_ctrl *ctrl;
	int ret;

	rcu_read_lock();
	ctrl = rcu_dereference(net->smc.hs_ctrl);
	if (ctrl)
		memcpy(val, ctrl->name, sizeof(ctrl->name));
	else
		val[0] = '\0';
	rcu_read_unlock();

	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
	if (ret)
		return ret;

	if (write)
		ret = smc_net_replace_smc_hs_ctrl(net, val);
	return ret;
}
#endif /* CONFIG_SMC_HS_CTRL_BPF */

static struct ctl_table smc_table[] = {
	{
		.procname       = "autocorking_size",
		.data           = &init_net.smc.sysctl_autocorking_size,
		.maxlen         = sizeof(unsigned int),
		.mode           = 0644,
		.proc_handler	= proc_douintvec,
	},
	{
		.procname	= "smcr_buf_type",
		.data		= &init_net.smc.sysctl_smcr_buf_type,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= proc_douintvec_minmax,
		.extra1		= SYSCTL_ZERO,
		.extra2		= SYSCTL_TWO,
	},
	{
		.procname	= "smcr_testlink_time",
		.data		= &init_net.smc.sysctl_smcr_testlink_time,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_jiffies,
	},
	{
		.procname	= "wmem",
		.data		= &init_net.smc.sysctl_wmem,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_minmax,
		.extra1		= &min_sndbuf,
		.extra2		= &max_sndbuf,
	},
	{
		.procname	= "rmem",
		.data		= &init_net.smc.sysctl_rmem,

Annotation

Implementation Notes