[patch 39/56] kcom.c wait_for_ack/wait_for_response fix

Subject: [patch @num@/@total@] kcom.c wait_for_ack/wait_for_response fix

This patch fixes the wait_for_ack and wait_for_response functions, 

wait_for_ack is used in the macintosh port and so should not be used (the name 
I mean), moreover, the function should also check for NACK return, and act
consequently




Index: linux/hpc/kcom.c
===================================================================
--- linux.orig/hpc/kcom.c	2006-11-02 22:52:30.000000000 +0100
+++ linux/hpc/kcom.c	2006-11-02 22:52:33.000000000 +0100
@@ -916,34 +916,53 @@
  * Description:
  *    This actually checks the task's incoming pkt list for the matching msgid.
  *    If the matching pkt is found, it is removed from the list and the function
- *    returns success, else returns failure.
+ *    returns success, else returns -1 if nothing, and -2 if NACK.
  **/
-int wait_for_ack(struct kcom_task *task, unsigned int msgid)
+int kcomd_wait_for_ack(struct kcom_task *task, unsigned int msgid)
 {
 	struct kcom_pkt *pkt, *pkt_next;
+	int ret = -1;
 
-	// spin_lock(&task->spinlock);
-	if (!list_empty(&task->in_packs)) {
-		list_for_each_entry_safe(pkt, pkt_next, &task->in_packs, list) {
-			if ((msgid==pkt->msgid) && ((pkt->type & MSG_MASK) == PKT_ACK)) {
-				list_del(&pkt->list);
-				kmem_cache_free(kcom_pkt_cachep, pkt);
-
-				// FIXME:  this doesn't belong here.
-				// init packet has rpid
-				if ((pkt->type & MIG_MASK) == MIG_INIT)
-					task->rpid=pkt->rpid;
 
-				// spin_unlock(&task->spinlock);
+	if (!task || list_empty(&task->in_packs)) goto not_found;
 
-				return 0;
-			}  // FIXME:  what about nacks?
+	write_lock(&task->spinlock);
+
+	list_for_each_entry_safe(pkt, pkt_next, &task->in_packs, list) {
+
+		if ((msgid==pkt->msgid)) {
+
+			int type = (pkt->type & MSG_MASK);
+
+
+			// FIXME:  this doesn't belong here.
+			// init packet has rpid
+			if (MIG_INIT == type)
+				task->rpid = pkt->rpid;
+
+			list_del(&pkt->list);
+			kmem_cache_free(kcom_pkt_cachep, pkt);
+
+			if (PKT_ACK == type) {
+				ret = 0;
+				goto return_value_unlock;
+			} else if (PKT_NACK == type) {
+				ret = -2;
+				goto return_value_unlock;
+			} else continue;
+
+
+		}  // FIXME:  what about nacks?
 
-		}
 	}
 
-	// spin_unlock(&task->spinlock);
-	return -1;
+not_found:
+	ret = -1;
+
+return_value_unlock:
+
+	write_unlock(&task->spinlock);
+	return ret;
 
 }
 
@@ -954,21 +973,33 @@
  *    This actually checks the task's incoming pkt list for the matching msgid.
  *    If the matching pkt is found, it is removed from the list and the function
  *    returns success, else returns failure.
- *    FIXME: very similar to wait_for_ack,  merge??
  **/
 int wait_for_response(struct kcom_task *task, unsigned int msgid)
 {
 	struct kcom_pkt *pkt, *pkt_next;
-	int i=-1;
+	int ret = -1;
 
-	list_for_each_entry_safe(pkt, pkt_next, &task->in_packs, list)
+	/* Sanity check */
+	if (!task || list_empty(&task->in_packs)) goto not_found;
+
+
+	write_lock(&task->spinlock);
+	list_for_each_entry_safe(pkt, pkt_next, &task->in_packs, list) {
 		/* FIXME:  check for resp or ack, too. */
-		if (msgid==pkt->msgid) {
-			i=pkt->len;
+		if (msgid == pkt->msgid) {
+			ret = pkt->len;
 			list_del(&pkt->list);
 			kmem_cache_free(kcom_pkt_cachep, pkt);
+			goto return_value_unlock;
 		}
-	return i;
+	}
+
+not_found:
+	ret = -1;
+
+return_value_unlock:
+	write_unlock(&task->spinlock);
+	return ret;
 
 }
 
@@ -984,13 +1015,16 @@
 	struct kcom_task *tsk;
 	task_t *p = current;
 	unsigned int msgid;
+	int ack;
 
 	node=kcom_node_find((struct sockaddr *)saddr);
+
 	if (node==NULL) {
+
 		node=create_connection((struct sockaddr *)saddr);
 		if (!node) {
 			printk(KERN_ERR "ERROR: Unable to create new connection.\n");
-			return -1;
+			goto return_error;
 		}
 	}
 
@@ -999,29 +1033,35 @@
 		tsk=kcom_task_create(node, p->pid);
 		if (!tsk) {
 			printk(KERN_ERR "ERROR: Unable to create task.\n");
-			return -1;
+			goto return_error;
 		}
 	}
 
 	// FIXME:  what if tsk is deleted between kcom_task_send and wait_for_ack ?
-	msgid=kcom_task_send(tsk, type, datasize, data, NULL, addr);
+	msgid = kcom_task_send(tsk, type, datasize, data, NULL, addr);
 
 	if (kcomd_task)
-		send_sig(SIGHUP,kcomd_task,0);
+		send_sig(SIGHUP, kcomd_task, 0);
 	else {
 		printk(KERN_ERR "Unable to find kcomd daemon.\n");
-		return -1;
+		goto return_error;
 	}
 
 	set_current_state(TASK_INTERRUPTIBLE);
-	while (wait_for_ack(tsk, msgid)!=0) {
+
+	while (-1 == (ack =  kcomd_wait_for_ack(tsk, msgid))) {
 		schedule();
 		set_current_state(TASK_INTERRUPTIBLE);
 	}
+
 	set_current_state(TASK_RUNNING);
 
+	if (ack == -2) goto return_error;
 
 	return 0;
+
+return_error:
+	return -1;
 }
 
 /**