net/smc/smc_core.c

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

File Facts

System
Linux kernel
Corpus path
net/smc/smc_core.c
Extension
.c
Size
74539 bytes
Lines
2787
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 (conn->lgr->role == SMC_CLNT) {
			conn->lnk = lnk; /* temporary, SMC server assigns link*/
			break;
		}
		if (conn->lgr->conns_num % 2) {
			for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
				struct smc_link *lnk2;

				lnk2 = &conn->lgr->lnk[j];
				if (lnk2->state == expected &&
				    !lnk2->link_is_asym) {
					conn->lnk = lnk2;
					break;
				}
			}
		}
		if (!conn->lnk)
			conn->lnk = lnk;
		break;
	}
	if (!conn->lnk)
		return SMC_CLC_DECL_NOACTLINK;
	atomic_inc(&conn->lnk->conn_cnt);
	return 0;
}

/* Register connection in link group by assigning an alert token
 * registered in a search tree.
 * Requires @conns_lock
 * Note that '0' is a reserved value and not assigned.
 */
static int smc_lgr_register_conn(struct smc_connection *conn, bool first)
{
	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
	static atomic_t nexttoken = ATOMIC_INIT(0);
	int rc;

	if (!conn->lgr->is_smcd) {
		rc = smcr_lgr_conn_assign_link(conn, first);
		if (rc) {
			conn->lgr = NULL;
			return rc;
		}
	}
	/* find a new alert_token_local value not yet used by some connection
	 * in this link group
	 */
	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
	while (!conn->alert_token_local) {
		conn->alert_token_local = atomic_inc_return(&nexttoken);
		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
			conn->alert_token_local = 0;
	}
	smc_lgr_add_alert_token(conn);
	conn->lgr->conns_num++;
	return 0;
}

/* Unregister connection and reset the alert token of the given connection<
 */
static void __smc_lgr_unregister_conn(struct smc_connection *conn)
{
	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
	struct smc_link_group *lgr = conn->lgr;

	rb_erase(&conn->alert_node, &lgr->conns_all);
	if (conn->lnk)
		atomic_dec(&conn->lnk->conn_cnt);
	lgr->conns_num--;
	conn->alert_token_local = 0;
	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
}

/* Unregister connection from lgr
 */
static void smc_lgr_unregister_conn(struct smc_connection *conn)
{
	struct smc_link_group *lgr = conn->lgr;

	if (!smc_conn_lgr_valid(conn))
		return;
	write_lock_bh(&lgr->conns_lock);
	if (conn->alert_token_local) {
		__smc_lgr_unregister_conn(conn);
	}
	write_unlock_bh(&lgr->conns_lock);
}

static void smc_lgr_buf_list_add(struct smc_link_group *lgr,
				 bool is_rmb,

Annotation

Implementation Notes