net/smc: Extend SMC-R link group netlink attribute

Extend SMC-R link group netlink attribute SMC_GEN_LGR_SMCR.
Introduce SMC_NLA_LGR_R_BUF_TYPE to show the buffer type of
SMC-R link group.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/smc.h

@@ -124,6 +124,7 @@ enum {
 	SMC_NLA_LGR_R_V2,		/* nest */
 	SMC_NLA_LGR_R_NET_COOKIE,	/* u64 */
 	SMC_NLA_LGR_R_PAD,		/* flag */
+	SMC_NLA_LGR_R_BUF_TYPE,		/* u8 */
 	__SMC_NLA_LGR_R_MAX,
 	SMC_NLA_LGR_R_MAX = __SMC_NLA_LGR_R_MAX - 1
 };

net/smc/smc_core.c

@@ -347,6 +347,8 @@ static int smc_nl_fill_lgr(struct smc_link_group *lgr,
 		goto errattr;
 	if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
 		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_BUF_TYPE, lgr->buf_type))
+		goto errattr;
 	if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
 		goto errattr;
 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_R_NET_COOKIE,