Merge branch 'net-smc-fixes'

Karsten Graul says:

====================
net/smc: fixes 2020-07-08

Please apply the following patch series for smc to netdev's net tree.

The patches fix problems found during more testing of SMC
functionality, resulting in hang conditions and unneeded link
deactivations. The clc module was hardened to be prepared for
possible future SMCD versions.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/smc_clc.c

@@ -27,6 +27,7 @@
 
 #define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
 #define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
+#define SMC_CLC_RECV_BUF_LEN	100
 
 /* eye catcher "SMCR" EBCDIC for CLC messages */
 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
@@ -36,7 +37,7 @@ static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};
 /* check if received message has a correct header length and contains valid
  * heading and trailing eyecatchers
  */
-static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
+static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm, bool check_trl)
 {
 	struct smc_clc_msg_proposal_prefix *pclc_prfx;
 	struct smc_clc_msg_accept_confirm *clc;
@@ -49,12 +50,9 @@ static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
 		return false;
 	switch (clcm->type) {
 	case SMC_CLC_PROPOSAL:
-		if (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
-		    clcm->path != SMC_TYPE_B)
-			return false;
 		pclc = (struct smc_clc_msg_proposal *)clcm;
 		pclc_prfx = smc_clc_proposal_get_prefix(pclc);
-		if (ntohs(pclc->hdr.length) !=
+		if (ntohs(pclc->hdr.length) <
 			sizeof(*pclc) + ntohs(pclc->iparea_offset) +
 			sizeof(*pclc_prfx) +
 			pclc_prfx->ipv6_prefixes_cnt *
@@ -86,7 +84,8 @@ static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
 	default:
 		return false;
 	}
-	if (memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
+	if (check_trl &&
+	    memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) &&
 	    memcmp(trl->eyecatcher, SMCD_EYECATCHER, sizeof(SMCD_EYECATCHER)))
 		return false;
 	return true;
@@ -276,7 +275,8 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	struct msghdr msg = {NULL, 0};
 	int reason_code = 0;
 	struct kvec vec = {buf, buflen};
-	int len, datlen;
+	int len, datlen, recvlen;
+	bool check_trl = true;
 	int krflags;
 
 	/* peek the first few bytes to determine length of data to receive
@@ -320,10 +320,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	}
 	datlen = ntohs(clcm->length);
 	if ((len < sizeof(struct smc_clc_msg_hdr)) ||
-	    (datlen > buflen) ||
-	    (clcm->version != SMC_CLC_V1) ||
-	    (clcm->path != SMC_TYPE_R && clcm->path != SMC_TYPE_D &&
-	     clcm->path != SMC_TYPE_B) ||
+	    (clcm->version < SMC_CLC_V1) ||
 	    ((clcm->type != SMC_CLC_DECLINE) &&
 	     (clcm->type != expected_type))) {
 		smc->sk.sk_err = EPROTO;
@@ -331,16 +328,38 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 		goto out;
 	}
 
+	if (clcm->type == SMC_CLC_PROPOSAL && clcm->path == SMC_TYPE_N)
+		reason_code = SMC_CLC_DECL_VERSMISMAT; /* just V2 offered */
+
 	/* receive the complete CLC message */
 	memset(&msg, 0, sizeof(struct msghdr));
-	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, datlen);
+	if (datlen > buflen) {
+		check_trl = false;
+		recvlen = buflen;
+	} else {
+		recvlen = datlen;
+	}
+	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
 	krflags = MSG_WAITALL;
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
-	if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
+	if (len < recvlen || !smc_clc_msg_hdr_valid(clcm, check_trl)) {
 		smc->sk.sk_err = EPROTO;
 		reason_code = -EPROTO;
 		goto out;
 	}
+	datlen -= len;
+	while (datlen) {
+		u8 tmp[SMC_CLC_RECV_BUF_LEN];
+
+		vec.iov_base = &tmp;
+		vec.iov_len = SMC_CLC_RECV_BUF_LEN;
+		/* receive remaining proposal message */
+		recvlen = datlen > SMC_CLC_RECV_BUF_LEN ?
+						SMC_CLC_RECV_BUF_LEN : datlen;
+		iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, recvlen);
+		len = sock_recvmsg(smc->clcsock, &msg, krflags);
+		datlen -= len;
+	}
 	if (clcm->type == SMC_CLC_DECLINE) {
 		struct smc_clc_msg_decline *dclc;
 

net/smc/smc_clc.h

@@ -25,6 +25,7 @@
 #define SMC_CLC_V1		0x1		/* SMC version                */
 #define SMC_TYPE_R		0		/* SMC-R only		      */
 #define SMC_TYPE_D		1		/* SMC-D only		      */
+#define SMC_TYPE_N		2		/* neither SMC-R nor SMC-D    */
 #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 */
@@ -46,6 +47,7 @@
 #define SMC_CLC_DECL_ISMVLANERR	0x03090000  /* err to reg vlan id on ism dev  */
 #define SMC_CLC_DECL_NOACTLINK	0x030a0000  /* no active smc-r link in lgr    */
 #define SMC_CLC_DECL_NOSRVLINK	0x030b0000  /* SMC-R link from srv not found  */
+#define SMC_CLC_DECL_VERSMISMAT	0x030c0000  /* SMC version mismatch	      */
 #define SMC_CLC_DECL_SYNCERR	0x04000000  /* synchronization error          */
 #define SMC_CLC_DECL_PEERDECL	0x05000000  /* peer declined during handshake */
 #define SMC_CLC_DECL_INTERR	0x09990000  /* internal error		      */

net/smc/smc_core.c

@@ -15,6 +15,7 @@
 #include <linux/workqueue.h>
 #include <linux/wait.h>
 #include <linux/reboot.h>
+#include <linux/mutex.h>
 #include <net/tcp.h>
 #include <net/sock.h>
 #include <rdma/ib_verbs.h>
@@ -247,7 +248,8 @@ static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
 		if (smc_link_usable(lnk))
 			lnk->state = SMC_LNK_INACTIVE;
 	}
-	wake_up_interruptible_all(&lgr->llc_waiter);
+	wake_up_all(&lgr->llc_msg_waiter);
+	wake_up_all(&lgr->llc_flow_waiter);
 }
 
 static void smc_lgr_free(struct smc_link_group *lgr);
@@ -1130,18 +1132,19 @@ static void smcr_link_up(struct smc_link_group *lgr,
 			return;
 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
 			/* some other llc task is ongoing */
-			wait_event_interruptible_timeout(lgr->llc_waiter,
-				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
+			wait_event_timeout(lgr->llc_flow_waiter,
+				(list_empty(&lgr->list) ||
+				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
 				SMC_LLC_WAIT_TIME);
 		}
-		if (list_empty(&lgr->list) ||
-		    !smc_ib_port_active(smcibdev, ibport))
-			return; /* lgr or device no longer active */
-		link = smc_llc_usable_link(lgr);
-		if (!link)
-			return;
-		smc_llc_send_add_link(link, smcibdev->mac[ibport - 1], gid,
-				      NULL, SMC_LLC_REQ);
+		/* lgr or device no longer active? */
+		if (!list_empty(&lgr->list) &&
+		    smc_ib_port_active(smcibdev, ibport))
+			link = smc_llc_usable_link(lgr);
+		if (link)
+			smc_llc_send_add_link(link, smcibdev->mac[ibport - 1],
+					      gid, NULL, SMC_LLC_REQ);
+		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
 	}
 }
 
@@ -1195,13 +1198,17 @@ static void smcr_link_down(struct smc_link *lnk)
 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
 			/* another llc task is ongoing */
 			mutex_unlock(&lgr->llc_conf_mutex);
-			wait_event_interruptible_timeout(lgr->llc_waiter,
-				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
+			wait_event_timeout(lgr->llc_flow_waiter,
+				(list_empty(&lgr->list) ||
+				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
 				SMC_LLC_WAIT_TIME);
 			mutex_lock(&lgr->llc_conf_mutex);
 		}
-		smc_llc_send_delete_link(to_lnk, del_link_id, SMC_LLC_REQ, true,
-					 SMC_LLC_DEL_LOST_PATH);
+		if (!list_empty(&lgr->list))
+			smc_llc_send_delete_link(to_lnk, del_link_id,
+						 SMC_LLC_REQ, true,
+						 SMC_LLC_DEL_LOST_PATH);
+		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
 	}
 }
 
@@ -1262,7 +1269,7 @@ static void smc_link_down_work(struct work_struct *work)
 
 	if (list_empty(&lgr->list))
 		return;
-	wake_up_interruptible_all(&lgr->llc_waiter);
+	wake_up_all(&lgr->llc_msg_waiter);
 	mutex_lock(&lgr->llc_conf_mutex);
 	smcr_link_down(link);
 	mutex_unlock(&lgr->llc_conf_mutex);
@@ -1955,20 +1962,20 @@ static void smc_core_going_away(void)
 	struct smc_ib_device *smcibdev;
 	struct smcd_dev *smcd;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
 		int i;
 
 		for (i = 0; i < SMC_MAX_PORTS; i++)
 			set_bit(i, smcibdev->ports_going_away);
 	}
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
 		smcd->going_away = 1;
 	}
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 }
 
 /* Clean up all SMC link groups */
@@ -1980,10 +1987,10 @@ static void smc_lgrs_shutdown(void)
 
 	smc_smcr_terminate_all(NULL);
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(smcd, &smcd_dev_list.list, list)
 		smc_smcd_terminate_all(smcd);
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 }
 
 static int smc_core_reboot_event(struct notifier_block *this,

net/smc/smc_core.h

@@ -262,8 +262,10 @@ struct smc_link_group {
 			struct work_struct	llc_del_link_work;
 			struct work_struct	llc_event_work;
 						/* llc event worker */
-			wait_queue_head_t	llc_waiter;
+			wait_queue_head_t	llc_flow_waiter;
 						/* w4 next llc event */
+			wait_queue_head_t	llc_msg_waiter;
+						/* w4 next llc msg */
 			struct smc_llc_flow	llc_flow_lcl;
 						/* llc local control field */
 			struct smc_llc_flow	llc_flow_rmt;

net/smc/smc_ib.c

@@ -16,6 +16,7 @@
 #include <linux/workqueue.h>
 #include <linux/scatterlist.h>
 #include <linux/wait.h>
+#include <linux/mutex.h>
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_cache.h>
 
@@ -33,7 +34,7 @@
 #define SMC_QP_RNR_RETRY			7 /* 7: infinite */
 
 struct smc_ib_devices smc_ib_devices = {	/* smc-registered ib devices */
-	.lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
+	.mutex = __MUTEX_INITIALIZER(smc_ib_devices.mutex),
 	.list = LIST_HEAD_INIT(smc_ib_devices.list),
 };
 
@@ -565,9 +566,9 @@ static int smc_ib_add_dev(struct ib_device *ibdev)
 	INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
 	atomic_set(&smcibdev->lnk_cnt, 0);
 	init_waitqueue_head(&smcibdev->lnks_deleted);
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_add_tail(&smcibdev->list, &smc_ib_devices.list);
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
 	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
 			      smc_ib_global_event_handler);
@@ -602,9 +603,9 @@ static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
 {
 	struct smc_ib_device *smcibdev = client_data;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	pr_warn_ratelimited("smc: removing ib device %s\n",
 			    smcibdev->ibdev->name);
 	smc_smcr_terminate_all(smcibdev);

net/smc/smc_ib.h

@@ -14,6 +14,7 @@
 
 #include <linux/interrupt.h>
 #include <linux/if_ether.h>
+#include <linux/mutex.h>
 #include <linux/wait.h>
 #include <rdma/ib_verbs.h>
 #include <net/smc.h>
@@ -25,7 +26,7 @@
 
 struct smc_ib_devices {			/* list of smc ib devices definition */
 	struct list_head	list;
-	spinlock_t		lock;	/* protects list of smc ib devices */
+	struct mutex		mutex;	/* protects list of smc ib devices */
 };
 
 extern struct smc_ib_devices	smc_ib_devices; /* list of smc ib devices */

net/smc/smc_ism.c

@@ -7,6 +7,7 @@
  */
 
 #include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/slab.h>
 #include <asm/page.h>
 
@@ -17,7 +18,7 @@
 
 struct smcd_dev_list smcd_dev_list = {
 	.list = LIST_HEAD_INIT(smcd_dev_list.list),
-	.lock = __SPIN_LOCK_UNLOCKED(smcd_dev_list.lock)
+	.mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex)
 };
 
 /* Test if an ISM communication is possible. */
@@ -317,9 +318,9 @@ EXPORT_SYMBOL_GPL(smcd_alloc_dev);
 
 int smcd_register_dev(struct smcd_dev *smcd)
 {
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_add_tail(&smcd->list, &smcd_dev_list.list);
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 
 	pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
 			    dev_name(&smcd->dev), smcd->pnetid,
@@ -333,9 +334,9 @@ void smcd_unregister_dev(struct smcd_dev *smcd)
 {
 	pr_warn_ratelimited("smc: removing smcd device %s\n",
 			    dev_name(&smcd->dev));
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_del_init(&smcd->list);
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 	smcd->going_away = 1;
 	smc_smcd_terminate_all(smcd);
 	flush_workqueue(smcd->event_wq);

net/smc/smc_ism.h

@@ -10,12 +10,13 @@
 #define SMCD_ISM_H
 
 #include <linux/uio.h>
+#include <linux/mutex.h>
 
 #include "smc.h"
 
 struct smcd_dev_list {	/* List of SMCD devices */
 	struct list_head list;
-	spinlock_t lock;	/* Protects list of devices */
+	struct mutex mutex;	/* Protects list of devices */
 };
 
 extern struct smcd_dev_list	smcd_dev_list; /* list of smcd devices */

net/smc/smc_llc.c

@@ -186,6 +186,26 @@ static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow,
 	flow->qentry = qentry;
 }
 
+static void smc_llc_flow_parallel(struct smc_link_group *lgr, u8 flow_type,
+				  struct smc_llc_qentry *qentry)
+{
+	u8 msg_type = qentry->msg.raw.hdr.common.type;
+
+	if ((msg_type == SMC_LLC_ADD_LINK || msg_type == SMC_LLC_DELETE_LINK) &&
+	    flow_type != msg_type && !lgr->delayed_event) {
+		lgr->delayed_event = qentry;
+		return;
+	}
+	/* drop parallel or already-in-progress llc requests */
+	if (flow_type != msg_type)
+		pr_warn_once("smc: SMC-R lg %*phN dropped parallel "
+			     "LLC msg: msg %d flow %d role %d\n",
+			     SMC_LGR_ID_SIZE, &lgr->id,
+			     qentry->msg.raw.hdr.common.type,
+			     flow_type, lgr->role);
+	kfree(qentry);
+}
+
 /* try to start a new llc flow, initiated by an incoming llc msg */
 static bool smc_llc_flow_start(struct smc_llc_flow *flow,
 			       struct smc_llc_qentry *qentry)
@@ -195,14 +215,7 @@ static bool smc_llc_flow_start(struct smc_llc_flow *flow,
 	spin_lock_bh(&lgr->llc_flow_lock);
 	if (flow->type) {
 		/* a flow is already active */
-		if ((qentry->msg.raw.hdr.common.type == SMC_LLC_ADD_LINK ||
-		     qentry->msg.raw.hdr.common.type == SMC_LLC_DELETE_LINK) &&
-		    !lgr->delayed_event) {
-			lgr->delayed_event = qentry;
-		} else {
-			/* forget this llc request */
-			kfree(qentry);
-		}
+		smc_llc_flow_parallel(lgr, flow->type, qentry);
 		spin_unlock_bh(&lgr->llc_flow_lock);
 		return false;
 	}
@@ -222,8 +235,8 @@ static bool smc_llc_flow_start(struct smc_llc_flow *flow,
 	}
 	if (qentry == lgr->delayed_event)
 		lgr->delayed_event = NULL;
-	spin_unlock_bh(&lgr->llc_flow_lock);
 	smc_llc_flow_qentry_set(flow, qentry);
+	spin_unlock_bh(&lgr->llc_flow_lock);
 	return true;
 }
 
@@ -251,11 +264,11 @@ int smc_llc_flow_initiate(struct smc_link_group *lgr,
 		return 0;
 	}
 	spin_unlock_bh(&lgr->llc_flow_lock);
-	rc = wait_event_interruptible_timeout(lgr->llc_waiter,
-			(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
-			 (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
-			  lgr->llc_flow_rmt.type == allowed_remote)),
-			SMC_LLC_WAIT_TIME);
+	rc = wait_event_timeout(lgr->llc_flow_waiter, (list_empty(&lgr->list) ||
+				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
+				 (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
+				  lgr->llc_flow_rmt.type == allowed_remote))),
+				SMC_LLC_WAIT_TIME * 10);
 	if (!rc)
 		return -ETIMEDOUT;
 	goto again;
@@ -272,7 +285,7 @@ void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow)
 	    flow == &lgr->llc_flow_lcl)
 		schedule_work(&lgr->llc_event_work);
 	else
-		wake_up_interruptible(&lgr->llc_waiter);
+		wake_up(&lgr->llc_flow_waiter);
 }
 
 /* lnk is optional and used for early wakeup when link goes down, useful in
@@ -283,26 +296,32 @@ struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
 				    int time_out, u8 exp_msg)
 {
 	struct smc_llc_flow *flow = &lgr->llc_flow_lcl;
+	u8 rcv_msg;
 
-	wait_event_interruptible_timeout(lgr->llc_waiter,
-					 (flow->qentry ||
-					  (lnk && !smc_link_usable(lnk)) ||
-					  list_empty(&lgr->list)),
-					 time_out);
+	wait_event_timeout(lgr->llc_msg_waiter,
+			   (flow->qentry ||
+			    (lnk && !smc_link_usable(lnk)) ||
+			    list_empty(&lgr->list)),
+			   time_out);
 	if (!flow->qentry ||
 	    (lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) {
 		smc_llc_flow_qentry_del(flow);
 		goto out;
 	}
-	if (exp_msg && flow->qentry->msg.raw.hdr.common.type != exp_msg) {
+	rcv_msg = flow->qentry->msg.raw.hdr.common.type;
+	if (exp_msg && rcv_msg != exp_msg) {
 		if (exp_msg == SMC_LLC_ADD_LINK &&
-		    flow->qentry->msg.raw.hdr.common.type ==
-		    SMC_LLC_DELETE_LINK) {
+		    rcv_msg == SMC_LLC_DELETE_LINK) {
 			/* flow_start will delay the unexpected msg */
 			smc_llc_flow_start(&lgr->llc_flow_lcl,
 					   smc_llc_flow_qentry_clr(flow));
 			return NULL;
 		}
+		pr_warn_once("smc: SMC-R lg %*phN dropped unexpected LLC msg: "
+			     "msg %d exp %d flow %d role %d flags %x\n",
+			     SMC_LGR_ID_SIZE, &lgr->id, rcv_msg, exp_msg,
+			     flow->type, lgr->role,
+			     flow->qentry->msg.raw.hdr.flags);
 		smc_llc_flow_qentry_del(flow);
 	}
 out:
@@ -1222,8 +1241,8 @@ static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
 	smc_llc_send_message(lnk, &qentry->msg); /* response */
 
 	if (smc_link_downing(&lnk_del->state)) {
-		smc_switch_conns(lgr, lnk_del, false);
-		smc_wr_tx_wait_no_pending_sends(lnk_del);
+		if (smc_switch_conns(lgr, lnk_del, false))
+			smc_wr_tx_wait_no_pending_sends(lnk_del);
 	}
 	smcr_link_clear(lnk_del, true);
 
@@ -1297,8 +1316,8 @@ static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
 		goto out; /* asymmetric link already deleted */
 
 	if (smc_link_downing(&lnk_del->state)) {
-		smc_switch_conns(lgr, lnk_del, false);
-		smc_wr_tx_wait_no_pending_sends(lnk_del);
+		if (smc_switch_conns(lgr, lnk_del, false))
+			smc_wr_tx_wait_no_pending_sends(lnk_del);
 	}
 	if (!list_empty(&lgr->list)) {
 		/* qentry is either a request from peer (send it back to
@@ -1459,7 +1478,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
 				/* a flow is waiting for this message */
 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
 							qentry);
-				wake_up_interruptible(&lgr->llc_waiter);
+				wake_up(&lgr->llc_msg_waiter);
 			} else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
 						      qentry)) {
 				schedule_work(&lgr->llc_add_link_work);
@@ -1474,7 +1493,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
 			/* a flow is waiting for this message */
 			smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
-			wake_up_interruptible(&lgr->llc_waiter);
+			wake_up(&lgr->llc_msg_waiter);
 			return;
 		}
 		break;
@@ -1485,7 +1504,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
 				/* DEL LINK REQ during ADD LINK SEQ */
 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
 							qentry);
-				wake_up_interruptible(&lgr->llc_waiter);
+				wake_up(&lgr->llc_msg_waiter);
 			} else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
 						      qentry)) {
 				schedule_work(&lgr->llc_del_link_work);
@@ -1496,7 +1515,7 @@ static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
 				/* DEL LINK REQ during ADD LINK SEQ */
 				smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
 							qentry);
-				wake_up_interruptible(&lgr->llc_waiter);
+				wake_up(&lgr->llc_msg_waiter);
 			} else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
 						      qentry)) {
 				schedule_work(&lgr->llc_del_link_work);
@@ -1581,7 +1600,7 @@ static void smc_llc_rx_response(struct smc_link *link,
 	case SMC_LLC_DELETE_RKEY:
 		/* assign responses to the local flow, we requested them */
 		smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
-		wake_up_interruptible(&link->lgr->llc_waiter);
+		wake_up(&link->lgr->llc_msg_waiter);
 		return;
 	case SMC_LLC_CONFIRM_RKEY_CONT:
 		/* not used because max links is 3 */
@@ -1616,7 +1635,7 @@ static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
 	spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
 	list_add_tail(&qentry->list, &lgr->llc_event_q);
 	spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
-	schedule_work(&link->lgr->llc_event_work);
+	schedule_work(&lgr->llc_event_work);
 }
 
 /* copy received msg and add it to the event queue */
@@ -1677,7 +1696,8 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
 	INIT_LIST_HEAD(&lgr->llc_event_q);
 	spin_lock_init(&lgr->llc_event_q_lock);
 	spin_lock_init(&lgr->llc_flow_lock);
-	init_waitqueue_head(&lgr->llc_waiter);
+	init_waitqueue_head(&lgr->llc_flow_waiter);
+	init_waitqueue_head(&lgr->llc_msg_waiter);
 	mutex_init(&lgr->llc_conf_mutex);
 	lgr->llc_testlink_time = net->ipv4.sysctl_tcp_keepalive_time;
 }
@@ -1686,7 +1706,8 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
 void smc_llc_lgr_clear(struct smc_link_group *lgr)
 {
 	smc_llc_event_flush(lgr);
-	wake_up_interruptible_all(&lgr->llc_waiter);
+	wake_up_all(&lgr->llc_flow_waiter);
+	wake_up_all(&lgr->llc_msg_waiter);
 	cancel_work_sync(&lgr->llc_event_work);
 	cancel_work_sync(&lgr->llc_add_link_work);
 	cancel_work_sync(&lgr->llc_del_link_work);

net/smc/smc_pnet.c

@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/list.h>
 #include <linux/ctype.h>
+#include <linux/mutex.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
 
@@ -129,7 +130,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
 		return rc;
 
 	/* remove ib devices */
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 		for (ibport = 0; ibport < SMC_MAX_PORTS; ibport++) {
 			if (ibdev->pnetid_by_user[ibport] &&
@@ -149,9 +150,9 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
 			}
 		}
 	}
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	/* remove smcd devices */
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(smcd_dev, &smcd_dev_list.list, list) {
 		if (smcd_dev->pnetid_by_user &&
 		    (!pnet_name ||
@@ -165,7 +166,7 @@ static int smc_pnet_remove_by_pnetid(struct net *net, char *pnet_name)
 			rc = 0;
 		}
 	}
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 	return rc;
 }
 
@@ -240,14 +241,14 @@ static bool smc_pnet_apply_ib(struct smc_ib_device *ib_dev, u8 ib_port,
 	u8 pnet_null[SMC_MAX_PNETID_LEN] = {0};
 	bool applied = false;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	if (smc_pnet_match(ib_dev->pnetid[ib_port - 1], pnet_null)) {
 		memcpy(ib_dev->pnetid[ib_port - 1], pnet_name,
 		       SMC_MAX_PNETID_LEN);
 		ib_dev->pnetid_by_user[ib_port - 1] = true;
 		applied = true;
 	}
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	return applied;
 }
 
@@ -258,13 +259,13 @@ static bool smc_pnet_apply_smcd(struct smcd_dev *smcd_dev, char *pnet_name)
 	u8 pnet_null[SMC_MAX_PNETID_LEN] = {0};
 	bool applied = false;
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	if (smc_pnet_match(smcd_dev->pnetid, pnet_null)) {
 		memcpy(smcd_dev->pnetid, pnet_name, SMC_MAX_PNETID_LEN);
 		smcd_dev->pnetid_by_user = true;
 		applied = true;
 	}
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 	return applied;
 }
 
@@ -300,7 +301,7 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
 {
 	struct smc_ib_device *ibdev;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 		if (!strncmp(ibdev->ibdev->name, ib_name,
 			     sizeof(ibdev->ibdev->name)) ||
@@ -311,7 +312,7 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name)
 	}
 	ibdev = NULL;
 out:
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 	return ibdev;
 }
 
@@ -320,7 +321,7 @@ static struct smcd_dev *smc_pnet_find_smcd(char *smcd_name)
 {
 	struct smcd_dev *smcd_dev;
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(smcd_dev, &smcd_dev_list.list, list) {
 		if (!strncmp(dev_name(&smcd_dev->dev), smcd_name,
 			     IB_DEVICE_NAME_MAX - 1))
@@ -328,7 +329,7 @@ static struct smcd_dev *smc_pnet_find_smcd(char *smcd_name)
 	}
 	smcd_dev = NULL;
 out:
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 	return smcd_dev;
 }
 
@@ -825,7 +826,7 @@ static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
 	int i;
 
 	ini->ib_dev = NULL;
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 		if (ibdev == known_dev)
 			continue;
@@ -844,7 +845,7 @@ static void _smc_pnet_find_roce_by_pnetid(u8 *pnet_id,
 		}
 	}
 out:
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 }
 
 /* find alternate roce device with same pnet_id and vlan_id */
@@ -863,7 +864,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
 {
 	struct smc_ib_device *ibdev;
 
-	spin_lock(&smc_ib_devices.lock);
+	mutex_lock(&smc_ib_devices.mutex);
 	list_for_each_entry(ibdev, &smc_ib_devices.list, list) {
 		struct net_device *ndev;
 		int i;
@@ -888,7 +889,7 @@ static void smc_pnet_find_rdma_dev(struct net_device *netdev,
 			}
 		}
 	}
-	spin_unlock(&smc_ib_devices.lock);
+	mutex_unlock(&smc_ib_devices.mutex);
 }
 
 /* Determine the corresponding IB device port based on the hardware PNETID.
@@ -924,7 +925,7 @@ static void smc_pnet_find_ism_by_pnetid(struct net_device *ndev,
 	    smc_pnet_find_ndev_pnetid_by_table(ndev, ndev_pnetid))
 		return; /* pnetid could not be determined */
 
-	spin_lock(&smcd_dev_list.lock);
+	mutex_lock(&smcd_dev_list.mutex);
 	list_for_each_entry(ismdev, &smcd_dev_list.list, list) {
 		if (smc_pnet_match(ismdev->pnetid, ndev_pnetid) &&
 		    !ismdev->going_away) {
@@ -932,7 +933,7 @@ static void smc_pnet_find_ism_by_pnetid(struct net_device *ndev,
 			break;
 		}
 	}
-	spin_unlock(&smcd_dev_list.lock);
+	mutex_unlock(&smcd_dev_list.mutex);
 }
 
 /* PNET table analysis for a given sock:

net/smc/smc_wr.c

@@ -169,6 +169,8 @@ void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
 static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)
 {
 	*idx = link->wr_tx_cnt;
+	if (!smc_link_usable(link))
+		return -ENOLINK;
 	for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {
 		if (!test_and_set_bit(*idx, link->wr_tx_mask))
 			return 0;
@@ -560,15 +562,15 @@ void smc_wr_free_link(struct smc_link *lnk)
 {
 	struct ib_device *ibdev;
 
+	if (!lnk->smcibdev)
+		return;
+	ibdev = lnk->smcibdev->ibdev;
+
 	if (smc_wr_tx_wait_no_pending_sends(lnk))
 		memset(lnk->wr_tx_mask, 0,
 		       BITS_TO_LONGS(SMC_WR_BUF_CNT) *
 						sizeof(*lnk->wr_tx_mask));
 
-	if (!lnk->smcibdev)
-		return;
-	ibdev = lnk->smcibdev->ibdev;
-
 	if (lnk->wr_rx_dma_addr) {
 		ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
 				    SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,