Merge branch 'smc-next'

Ursula Braun says:

====================
net/smc: patches 2018-11-22

here are more patches for SMC:
* patches 1-3 and 7 are cleanups without functional change
* patches 4-6 and 8 are optimizations of existing code
* patches 9 and 10 introduce and exploit LLC message DELETE RKEY
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 117 insertions, 51 deletions

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 80e2119f1c70..4b865250e238 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -299,14 +299,17 @@ static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 	smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
 }
 
-/* register a new rmb, optionally send confirm_rkey msg to register with peer */
+/* register a new rmb, send confirm_rkey msg to register with peer */
 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc,
 		       bool conf_rkey)
 {
-	/* register memory region for new rmb */
-	if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
-		rmb_desc->regerr = 1;
-		return -EFAULT;
+	if (!rmb_desc->wr_reg) {
+		/* register memory region for new rmb */
+		if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
+			rmb_desc->regerr = 1;
+			return -EFAULT;
+		}
+		rmb_desc->wr_reg = 1;
 	}
 	if (!conf_rkey)
 		return 0;
@@ -335,8 +338,8 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc)
 		struct smc_clc_msg_decline dclc;
 
 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
-				      SMC_CLC_DECLINE);
-		return rc;
+				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
+		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
 	}
 
 	if (link->llc_confirm_rc)
@@ -363,8 +366,8 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc)
 		struct smc_clc_msg_decline dclc;
 
 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
-				      SMC_CLC_DECLINE);
-		return rc;
+				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
+		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
 	}
 
 	/* send add link reject message, only one link supported for now */
@@ -533,7 +536,8 @@ static int smc_connect_clc(struct smc_sock *smc, int smc_type,
 	if (rc)
 		return rc;
 	/* receive SMC Accept CLC message */
-	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT);
+	return smc_clc_wait_msg(smc, aclc, sizeof(*aclc), SMC_CLC_ACCEPT,
+				CLC_WAIT_TIME);
 }
 
 /* setup for RDMA connection of client */
@@ -580,8 +584,7 @@ static int smc_connect_rdma(struct smc_sock *smc,
 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_RDYLNK,
 						 local_contact);
 	} else {
-		if (!smc->conn.rmb_desc->reused &&
-		    smc_reg_rmb(link, smc->conn.rmb_desc, true))
+		if (smc_reg_rmb(link, smc->conn.rmb_desc, true))
 			return smc_connect_abort(smc, SMC_CLC_DECL_ERR_REGRMB,
 						 local_contact);
 	}
@@ -965,8 +968,8 @@ static int smc_serv_conf_first_link(struct smc_sock *smc)
 		struct smc_clc_msg_decline dclc;
 
 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
-				      SMC_CLC_DECLINE);
-		return rc;
+				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
+		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
 	}
 
 	if (link->llc_confirm_resp_rc)
@@ -986,8 +989,8 @@ static int smc_serv_conf_first_link(struct smc_sock *smc)
 		struct smc_clc_msg_decline dclc;
 
 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
-				      SMC_CLC_DECLINE);
-		return rc;
+				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
+		return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_AL : rc;
 	}
 
 	smc_llc_link_active(link, net->ipv4.sysctl_tcp_keepalive_time);
@@ -1142,10 +1145,8 @@ static int smc_listen_rdma_reg(struct smc_sock *new_smc, int local_contact)
 	struct smc_link *link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];
 
 	if (local_contact != SMC_FIRST_CONTACT) {
-		if (!new_smc->conn.rmb_desc->reused) {
-			if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
-				return SMC_CLC_DECL_ERR_REGRMB;
-		}
+		if (smc_reg_rmb(link, new_smc->conn.rmb_desc, true))
+			return SMC_CLC_DECL_ERR_REGRMB;
 	}
 	smc_rmb_sync_sg_for_device(&new_smc->conn);
 
@@ -1181,7 +1182,6 @@ static int smc_listen_rdma_finish(struct smc_sock *new_smc,
 	return 0;
 
 decline:
-	mutex_unlock(&smc_create_lgr_pending);
 	smc_listen_decline(new_smc, reason_code, local_contact);
 	return reason_code;
 }
@@ -1222,7 +1222,7 @@ static void smc_listen_work(struct work_struct *work)
 	 */
 	pclc = (struct smc_clc_msg_proposal *)&buf;
 	reason_code = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
-				       SMC_CLC_PROPOSAL);
+				       SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
 	if (reason_code) {
 		smc_listen_decline(new_smc, reason_code, 0);
 		return;
@@ -1272,7 +1272,7 @@ static void smc_listen_work(struct work_struct *work)
 
 	/* receive SMC Confirm CLC message */
 	reason_code = smc_clc_wait_msg(new_smc, &cclc, sizeof(cclc),
-				       SMC_CLC_CONFIRM);
+				       SMC_CLC_CONFIRM, CLC_WAIT_TIME);
 	if (reason_code) {
 		mutex_unlock(&smc_create_lgr_pending);
 		smc_listen_decline(new_smc, reason_code, local_contact);
@@ -1281,8 +1281,10 @@ static void smc_listen_work(struct work_struct *work)
 
 	/* finish worker */
 	if (!ism_supported) {
-		if (smc_listen_rdma_finish(new_smc, &cclc, local_contact))
+		if (smc_listen_rdma_finish(new_smc, &cclc, local_contact)) {
+			mutex_unlock(&smc_create_lgr_pending);
 			return;
+		}
 	}
 	smc_conn_save_peer_info(new_smc, &cclc);
 	mutex_unlock(&smc_create_lgr_pending);
@@ -1354,7 +1356,6 @@ static int smc_listen(struct socket *sock, int backlog)
 	sk->sk_max_ack_backlog = backlog;
 	sk->sk_ack_backlog = 0;
 	sk->sk_state = SMC_LISTEN;
-	INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
 	sock_hold(sk); /* sock_hold in tcp_listen_worker */
 	if (!schedule_work(&smc->tcp_listen_work))
 		sock_put(sk);
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 89c3a8c7859a..776e9dfc915d 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -265,7 +265,7 @@ out:
  * clcsock error, -EINTR, -ECONNRESET, -EPROTO otherwise.
  */
 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
-		     u8 expected_type)
+		     u8 expected_type, unsigned long timeout)
 {
 	long rcvtimeo = smc->clcsock->sk->sk_rcvtimeo;
 	struct sock *clc_sk = smc->clcsock->sk;
@@ -285,7 +285,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	 * sizeof(struct smc_clc_msg_hdr)
 	 */
 	krflags = MSG_PEEK | MSG_WAITALL;
-	smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
+	clc_sk->sk_rcvtimeo = timeout;
 	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1,
 			sizeof(struct smc_clc_msg_hdr));
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
@@ -297,7 +297,11 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	}
 	if (clc_sk->sk_err) {
 		reason_code = -clc_sk->sk_err;
-		smc->sk.sk_err = clc_sk->sk_err;
+		if (clc_sk->sk_err == EAGAIN &&
+		    expected_type == SMC_CLC_DECLINE)
+			clc_sk->sk_err = 0; /* reset for fallback usage */
+		else
+			smc->sk.sk_err = clc_sk->sk_err;
 		goto out;
 	}
 	if (!len) { /* peer has performed orderly shutdown */
@@ -306,7 +310,8 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 		goto out;
 	}
 	if (len < 0) {
-		smc->sk.sk_err = -len;
+		if (len != -EAGAIN || expected_type != SMC_CLC_DECLINE)
+			smc->sk.sk_err = -len;
 		reason_code = len;
 		goto out;
 	}
@@ -346,7 +351,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	}
 
 out:
-	smc->clcsock->sk->sk_rcvtimeo = rcvtimeo;
+	clc_sk->sk_rcvtimeo = rcvtimeo;
 	return reason_code;
 }
 
@@ -374,10 +379,8 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1,
 			     sizeof(struct smc_clc_msg_decline));
 	if (len < sizeof(struct smc_clc_msg_decline))
-		smc->sk.sk_err = EPROTO;
-	if (len < 0)
-		smc->sk.sk_err = -len;
-	return sock_error(&smc->sk);
+		len = -EPROTO;
+	return len > 0 ? 0 : len;
 }
 
 /* send CLC PROPOSAL message across internal TCP socket */
@@ -536,7 +539,6 @@ int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 	struct smc_link *link;
 	struct msghdr msg;
 	struct kvec vec;
-	int rc = 0;
 	int len;
 
 	memset(&aclc, 0, sizeof(aclc));
@@ -589,13 +591,8 @@ int smc_clc_send_accept(struct smc_sock *new_smc, int srv_first_contact)
 	vec.iov_len = ntohs(aclc.hdr.length);
 	len = kernel_sendmsg(new_smc->clcsock, &msg, &vec, 1,
 			     ntohs(aclc.hdr.length));
-	if (len < ntohs(aclc.hdr.length)) {
-		if (len >= 0)
-			new_smc->sk.sk_err = EPROTO;
-		else
-			new_smc->sk.sk_err = new_smc->clcsock->sk->sk_err;
-		rc = sock_error(&new_smc->sk);
-	}
+	if (len < ntohs(aclc.hdr.length))
+		len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
 
-	return rc;
+	return len > 0 ? 0 : len;
 }
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 18da89b681c2..24658e8c0de4 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -27,6 +27,7 @@
 #define SMC_TYPE_D		1		/* SMC-D only		      */
 #define SMC_TYPE_B		3		/* SMC-R and SMC-D	      */
 #define CLC_WAIT_TIME		(6 * HZ)	/* max. wait time on clcsock  */
+#define CLC_WAIT_TIME_SHORT	HZ		/* short wait time on clcsock */
 #define SMC_CLC_DECL_MEM	0x01010000  /* insufficient memory resources  */
 #define SMC_CLC_DECL_TIMEOUT_CL	0x02010000  /* timeout w4 QP confirm link     */
 #define SMC_CLC_DECL_TIMEOUT_AL	0x02020000  /* timeout w4 QP add link	      */
@@ -182,7 +183,7 @@ struct smcd_dev;
 int smc_clc_prfx_match(struct socket *clcsock,
 		       struct smc_clc_msg_proposal_prefix *prop);
 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
-		     u8 expected_type);
+		     u8 expected_type, unsigned long timeout);
 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
 			  struct smc_ib_device *smcibdev, u8 ibport, u8 gid[],
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 18daebcef181..1382ddae591e 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -149,6 +149,8 @@ static int smc_link_send_delete(struct smc_link *lnk)
 	return -ENOTCONN;
 }
 
+static void smc_lgr_free(struct smc_link_group *lgr);
+
 static void smc_lgr_free_work(struct work_struct *work)
 {
 	struct smc_link_group *lgr = container_of(to_delayed_work(work),
@@ -171,8 +173,11 @@ free:
 	spin_unlock_bh(&smc_lgr_list.lock);
 
 	if (!lgr->is_smcd && !lgr->terminating)	{
+		struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
+
 		/* try to send del link msg, on error free lgr immediately */
-		if (!smc_link_send_delete(&lgr->lnk[SMC_SINGLE_LINK])) {
+		if (lnk->state == SMC_LNK_ACTIVE &&
+		    !smc_link_send_delete(lnk)) {
 			/* reschedule in case we never receive a response */
 			smc_lgr_schedule_free_work(lgr);
 			return;
@@ -293,8 +298,13 @@ static void smc_buf_unuse(struct smc_connection *conn,
 		conn->sndbuf_desc->used = 0;
 	if (conn->rmb_desc) {
 		if (!conn->rmb_desc->regerr) {
-			conn->rmb_desc->reused = 1;
 			conn->rmb_desc->used = 0;
+			if (!lgr->is_smcd) {
+				/* unregister rmb with peer */
+				smc_llc_do_delete_rkey(
+						&lgr->lnk[SMC_SINGLE_LINK],
+						conn->rmb_desc);
+			}
 		} else {
 			/* buf registration failed, reuse not possible */
 			write_lock_bh(&lgr->rmbs_lock);
@@ -408,7 +418,7 @@ static void smc_lgr_free_bufs(struct smc_link_group *lgr)
 }
 
 /* remove a link group */
-void smc_lgr_free(struct smc_link_group *lgr)
+static void smc_lgr_free(struct smc_link_group *lgr)
 {
 	smc_lgr_free_bufs(lgr);
 	if (lgr->is_smcd)
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index c156674733c9..e177c6675038 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -109,6 +109,9 @@ struct smc_link {
 	int			llc_testlink_time; /* testlink interval */
 	struct completion	llc_confirm_rkey; /* wait 4 rx of cnf rkey */
 	int			llc_confirm_rkey_rc; /* rc from cnf rkey msg */
+	struct completion	llc_delete_rkey; /* wait 4 rx of del rkey */
+	int			llc_delete_rkey_rc; /* rc from del rkey msg */
+	struct mutex		llc_delete_rkey_mutex; /* serialize usage */
 };
 
 /* For now we just allow one parallel link per link group. The SMC protocol
@@ -127,7 +130,7 @@ struct smc_buf_desc {
 	struct page		*pages;
 	int			len;		/* length of buffer */
 	u32			used;		/* currently used / unused */
-	u8			reused	: 1;	/* new created / reused */
+	u8			wr_reg	: 1;	/* mem region registered */
 	u8			regerr	: 1;	/* err during registration */
 	union {
 		struct { /* SMC-R */
@@ -243,7 +246,6 @@ struct smc_sock;
 struct smc_clc_msg_accept_confirm;
 struct smc_clc_msg_local;
 
-void smc_lgr_free(struct smc_link_group *lgr);
 void smc_lgr_forget(struct smc_link_group *lgr);
 void smc_lgr_terminate(struct smc_link_group *lgr);
 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport);
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 9c916c709ca7..a6d3623d06f4 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -238,6 +238,29 @@ static int smc_llc_send_confirm_rkey(struct smc_link *link,
 	return rc;
 }
 
+/* send LLC delete rkey request */
+static int smc_llc_send_delete_rkey(struct smc_link *link,
+				    struct smc_buf_desc *rmb_desc)
+{
+	struct smc_llc_msg_delete_rkey *rkeyllc;
+	struct smc_wr_tx_pend_priv *pend;
+	struct smc_wr_buf *wr_buf;
+	int rc;
+
+	rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
+	if (rc)
+		return rc;
+	rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
+	memset(rkeyllc, 0, sizeof(*rkeyllc));
+	rkeyllc->hd.common.type = SMC_LLC_DELETE_RKEY;
+	rkeyllc->hd.length = sizeof(struct smc_llc_msg_delete_rkey);
+	rkeyllc->num_rkeys = 1;
+	rkeyllc->rkey[0] = htonl(rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
+	/* send llc message */
+	rc = smc_wr_tx_send(link, pend);
+	return rc;
+}
+
 /* prepare an add link message */
 static void smc_llc_prep_add_link(struct smc_llc_msg_add_link *addllc,
 				  struct smc_link *link, u8 mac[], u8 gid[],
@@ -509,7 +532,9 @@ static void smc_llc_rx_delete_rkey(struct smc_link *link,
 	int i, max;
 
 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
-		/* unused as long as we don't send this type of msg */
+		link->llc_delete_rkey_rc = llc->hd.flags &
+					    SMC_LLC_FLAG_RKEY_NEG;
+		complete(&link->llc_delete_rkey);
 	} else {
 		max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
 		for (i = 0; i < max; i++) {
@@ -610,6 +635,8 @@ int smc_llc_link_init(struct smc_link *link)
 	init_completion(&link->llc_add);
 	init_completion(&link->llc_add_resp);
 	init_completion(&link->llc_confirm_rkey);
+	init_completion(&link->llc_delete_rkey);
+	mutex_init(&link->llc_delete_rkey_mutex);
 	init_completion(&link->llc_testlink_resp);
 	INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
 	return 0;
@@ -650,8 +677,11 @@ int smc_llc_do_confirm_rkey(struct smc_link *link,
 {
 	int rc;
 
+	/* protected by mutex smc_create_lgr_pending */
 	reinit_completion(&link->llc_confirm_rkey);
-	smc_llc_send_confirm_rkey(link, rmb_desc);
+	rc = smc_llc_send_confirm_rkey(link, rmb_desc);
+	if (rc)
+		return rc;
 	/* receive CONFIRM RKEY response from server over RoCE fabric */
 	rc = wait_for_completion_interruptible_timeout(&link->llc_confirm_rkey,
 						       SMC_LLC_WAIT_TIME);
@@ -660,6 +690,29 @@ int smc_llc_do_confirm_rkey(struct smc_link *link,
 	return 0;
 }
 
+/* unregister an rtoken at the remote peer */
+int smc_llc_do_delete_rkey(struct smc_link *link,
+			   struct smc_buf_desc *rmb_desc)
+{
+	int rc;
+
+	mutex_lock(&link->llc_delete_rkey_mutex);
+	reinit_completion(&link->llc_delete_rkey);
+	rc = smc_llc_send_delete_rkey(link, rmb_desc);
+	if (rc)
+		goto out;
+	/* receive DELETE RKEY response from server over RoCE fabric */
+	rc = wait_for_completion_interruptible_timeout(&link->llc_delete_rkey,
+						       SMC_LLC_WAIT_TIME);
+	if (rc <= 0 || link->llc_delete_rkey_rc)
+		rc = -EFAULT;
+	else
+		rc = 0;
+out:
+	mutex_unlock(&link->llc_delete_rkey_mutex);
+	return rc;
+}
+
 /***************************** init, exit, misc ******************************/
 
 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
diff --git a/net/smc/smc_llc.h b/net/smc/smc_llc.h
index 9e2ff088e301..461c0c3ef76e 100644
--- a/net/smc/smc_llc.h
+++ b/net/smc/smc_llc.h
@@ -49,6 +49,8 @@ void smc_llc_link_inactive(struct smc_link *link);
 void smc_llc_link_clear(struct smc_link *link);
 int smc_llc_do_confirm_rkey(struct smc_link *link,
 			    struct smc_buf_desc *rmb_desc);
+int smc_llc_do_delete_rkey(struct smc_link *link,
+			   struct smc_buf_desc *rmb_desc);
 int smc_llc_init(void) __init;
 
 #endif /* SMC_LLC_H */