Shuffle netgraph mutexes a bit and hold a reference on a node

from the function that is calling the destructor.

4 files changed, 10 insertions, 8 deletions

diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index 0b0ba86..2142de0 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -920,6 +920,8 @@ static char *spin_order_list[] = {
 #ifdef __i386__
 	"cy",
 #endif
+	"ng_node",
+	"ng_worklist",
 	"ithread table lock",
 	"ithread list lock",
 	"sched lock",
@@ -930,8 +932,6 @@ static char *spin_order_list[] = {
 	/*
 	 * leaf locks
 	 */
-	"ng_node",
-	"ng_worklist",
 #ifdef SMP
 #ifdef __i386__
 	"ap boot",
diff --git a/sys/kern/subr_turnstile.c b/sys/kern/subr_turnstile.c
index 0b0ba86..2142de0 100644
--- a/sys/kern/subr_turnstile.c
+++ b/sys/kern/subr_turnstile.c
@@ -920,6 +920,8 @@ static char *spin_order_list[] = {
 #ifdef __i386__
 	"cy",
 #endif
+	"ng_node",
+	"ng_worklist",
 	"ithread table lock",
 	"ithread list lock",
 	"sched lock",
@@ -930,8 +932,6 @@ static char *spin_order_list[] = {
 	/*
 	 * leaf locks
 	 */
-	"ng_node",
-	"ng_worklist",
 #ifdef SMP
 #ifdef __i386__
 	"ap boot",
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
index 0b0ba86..2142de0 100644
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -920,6 +920,8 @@ static char *spin_order_list[] = {
 #ifdef __i386__
 	"cy",
 #endif
+	"ng_node",
+	"ng_worklist",
 	"ithread table lock",
 	"ithread list lock",
 	"sched lock",
@@ -930,8 +932,6 @@ static char *spin_order_list[] = {
 	/*
 	 * leaf locks
 	 */
-	"ng_node",
-	"ng_worklist",
 #ifdef SMP
 #ifdef __i386__
 	"ap boot",
diff --git a/sys/netgraph/ng_base.c b/sys/netgraph/ng_base.c
index dbcc208..4c681ec 100644
--- a/sys/netgraph/ng_base.c
+++ b/sys/netgraph/ng_base.c
@@ -3269,13 +3269,13 @@ ngintr(void)
 			item = ng_dequeue(&node->nd_input_queue);
 			if (item == NULL) {
 				mtx_unlock_spin(&node->nd_input_queue.q_mtx);
-				NG_NODE_UNREF(node);
 				break; /* go look for another node */
 			} else {
 				mtx_unlock_spin(&node->nd_input_queue.q_mtx);
 				ng_apply_item(item);
 			}
 		}
+		NG_NODE_UNREF(node);
 	}
 }
 
@@ -3544,7 +3544,8 @@ ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
 		return (ENOMEM);
 	}
 	item->el_flags = NGQF_FN | NGQF_WRITER;
-	NG_NODE_REF(node);
+	NG_NODE_REF(node); /* One for us */
+	NG_NODE_REF(node); /* and one for the item */
 	NGI_SET_NODE(item, node);
 	if (hook) {
 		NG_HOOK_REF(hook);
@@ -3554,6 +3555,7 @@ ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
 	NGI_ARG1(item) = arg1;
 	NGI_ARG2(item) = arg2;
 	return (ng_snd_item(item, 0));
+	NG_NODE_UNREF(node);
 }
 
 /*