IB/srp: Eliminate state SRP_TARGET_CONNECTING

Block the SCSI host while reconnecting instead of representing the
reconnection activity as a distinct SRP target state.  This allows us
to eliminate the target state SRP_TARGET_CONNECTING.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/ulp/srp/ib_srp.c

@@ -646,13 +646,16 @@ static void srp_reset_req(struct srp_target_port *target, struct srp_request *re
 
 static int srp_reconnect_target(struct srp_target_port *target)
 {
+	struct Scsi_Host *shost = target->scsi_host;
 	struct ib_qp_attr qp_attr;
 	struct ib_wc wc;
 	int i, ret;
 
-	if (!srp_change_state(target, SRP_TARGET_LIVE, SRP_TARGET_CONNECTING))
+	if (target->state != SRP_TARGET_LIVE)
 		return -EAGAIN;
 
+	scsi_target_block(&shost->shost_gendev);
+
 	srp_disconnect_target(target);
 	/*
 	 * Now get a new local CM ID so that we avoid confusing the
@@ -660,16 +663,16 @@ static int srp_reconnect_target(struct srp_target_port *target)
 	 */
 	ret = srp_new_cm_id(target);
 	if (ret)
-		goto err;
+		goto unblock;
 
 	qp_attr.qp_state = IB_QPS_RESET;
 	ret = ib_modify_qp(target->qp, &qp_attr, IB_QP_STATE);
 	if (ret)
-		goto err;
+		goto unblock;
 
 	ret = srp_init_qp(target, target->qp);
 	if (ret)
-		goto err;
+		goto unblock;
 
 	while (ib_poll_cq(target->recv_cq, 1, &wc) > 0)
 		; /* nothing */
@@ -688,11 +691,15 @@ static int srp_reconnect_target(struct srp_target_port *target)
 
 	target->qp_in_error = 0;
 	ret = srp_connect_target(target);
+
+unblock:
+	scsi_target_unblock(&shost->shost_gendev, ret == 0 ? SDEV_RUNNING :
+			    SDEV_TRANSPORT_OFFLINE);
+
 	if (ret)
 		goto err;
 
-	if (!srp_change_state(target, SRP_TARGET_CONNECTING, SRP_TARGET_LIVE))
-		ret = -EAGAIN;
+	shost_printk(KERN_INFO, target->scsi_host, PFX "reconnect succeeded\n");
 
 	return ret;
 
@@ -710,7 +717,7 @@ static int srp_reconnect_target(struct srp_target_port *target)
 	 * the flush_scheduled_work() in srp_remove_one().
 	 */
 	spin_lock_irq(&target->lock);
-	if (target->state == SRP_TARGET_CONNECTING) {
+	if (target->state == SRP_TARGET_LIVE) {
 		target->state = SRP_TARGET_DEAD;
 		INIT_WORK(&target->work, srp_remove_work);
 		queue_work(ib_wq, &target->work);
@@ -1311,9 +1318,6 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
 	unsigned long flags;
 	int len;
 
-	if (target->state == SRP_TARGET_CONNECTING)
-		goto err;
-
 	if (target->state == SRP_TARGET_DEAD ||
 	    target->state == SRP_TARGET_REMOVED) {
 		scmnd->result = DID_BAD_TARGET << 16;
@@ -1377,7 +1381,6 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
 err_unlock:
 	spin_unlock_irqrestore(&target->lock, flags);
 
-err:
 	return SCSI_MLQUEUE_HOST_BUSY;
 }
 

drivers/infiniband/ulp/srp/ib_srp.h

@@ -80,7 +80,6 @@ enum {
 
 enum srp_target_state {
 	SRP_TARGET_LIVE,
-	SRP_TARGET_CONNECTING,
 	SRP_TARGET_DEAD,
 	SRP_TARGET_REMOVED
 };