net/smc: move add link processing for new device into llc layer

When a new ib device is up smc will send an add link invitation to the
peer if needed. This is currently done with rudimentary flow control.
Under high workload these add link invitations can disturb other llc
flows because they arrive unexpected. Fix this by integrating the
invitations into the normal llc event flow and handle them as a flow.
While at it, check for already assigned requests in the flow before
the new add link request is assigned.

Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Fixes: 1f90a05d9ff9 ("net/smc: add smcr_port_add() and smcr_link_up() processing")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 73 deletions

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index e286b3c8c962..2e965de7412d 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -45,18 +45,10 @@ static struct smc_lgr_list smc_lgr_list = {	/* established link groups */
 static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
 static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
 
-struct smc_ib_up_work {
-	struct work_struct	work;
-	struct smc_link_group	*lgr;
-	struct smc_ib_device	*smcibdev;
-	u8			ibport;
-};
-
 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
 			 struct smc_buf_desc *buf_desc);
 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
 
-static void smc_link_up_work(struct work_struct *work);
 static void smc_link_down_work(struct work_struct *work);
 
 /* return head of link group list and its lock for a given link group */
@@ -1106,67 +1098,23 @@ static void smc_conn_abort_work(struct work_struct *work)
 	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
 }
 
-/* link is up - establish alternate link if applicable */
-static void smcr_link_up(struct smc_link_group *lgr,
-			 struct smc_ib_device *smcibdev, u8 ibport)
-{
-	struct smc_link *link = NULL;
-
-	if (list_empty(&lgr->list) ||
-	    lgr->type == SMC_LGR_SYMMETRIC ||
-	    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
-		return;
-
-	if (lgr->role == SMC_SERV) {
-		/* trigger local add link processing */
-		link = smc_llc_usable_link(lgr);
-		if (!link)
-			return;
-		smc_llc_srv_add_link_local(link);
-	} else {
-		/* invite server to start add link processing */
-		u8 gid[SMC_GID_SIZE];
-
-		if (smc_ib_determine_gid(smcibdev, ibport, lgr->vlan_id, gid,
-					 NULL))
-			return;
-		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
-			/* some other llc task is ongoing */
-			wait_event_timeout(lgr->llc_flow_waiter,
-				(list_empty(&lgr->list) ||
-				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
-				SMC_LLC_WAIT_TIME);
-		}
-		/* 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 */
-	}
-}
-
 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
 {
-	struct smc_ib_up_work *ib_work;
 	struct smc_link_group *lgr, *n;
 
 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
+		struct smc_link *link;
+
 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
 			    SMC_MAX_PNETID_LEN) ||
 		    lgr->type == SMC_LGR_SYMMETRIC ||
 		    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
 			continue;
-		ib_work = kmalloc(sizeof(*ib_work), GFP_KERNEL);
-		if (!ib_work)
-			continue;
-		INIT_WORK(&ib_work->work, smc_link_up_work);
-		ib_work->lgr = lgr;
-		ib_work->smcibdev = smcibdev;
-		ib_work->ibport = ibport;
-		schedule_work(&ib_work->work);
+
+		/* trigger local add link processing */
+		link = smc_llc_usable_link(lgr);
+		if (link)
+			smc_llc_add_link_local(link);
 	}
 }
 
@@ -1249,20 +1197,6 @@ void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
 	}
 }
 
-static void smc_link_up_work(struct work_struct *work)
-{
-	struct smc_ib_up_work *ib_work = container_of(work,
-						      struct smc_ib_up_work,
-						      work);
-	struct smc_link_group *lgr = ib_work->lgr;
-
-	if (list_empty(&lgr->list))
-		goto out;
-	smcr_link_up(lgr, ib_work->smcibdev, ib_work->ibport);
-out:
-	kfree(ib_work);
-}
-
 static void smc_link_down_work(struct work_struct *work)
 {
 	struct smc_link *link = container_of(work, struct smc_link,