6525 nlm_unexport() should not call nlm_vhold_clean() with g->lock held

Reviewed by: Gordon Ross <gordon.ross@nexenta.com>
Approved by: Dan McDonald <danmcd@omniti.com>

usr/src/uts/common/klm/nlm_impl.c

@@ -1788,20 +1788,18 @@ nlm_host_find_by_sysid(struct nlm_globals *g, sysid_t sysid)
  * any, it removes them.
  * NOTE: only unused hosts can be in idle state.
  */
-void
-nlm_host_release(struct nlm_globals *g, struct nlm_host *hostp)
+static void
+nlm_host_release_locked(struct nlm_globals *g, struct nlm_host *hostp)
 {
 	if (hostp == NULL)
 		return;
 
-	mutex_enter(&g->lock);
+	ASSERT(MUTEX_HELD(&g->lock));
 	ASSERT(hostp->nh_refs > 0);
 
 	hostp->nh_refs--;
-	if (hostp->nh_refs != 0) {
-		mutex_exit(&g->lock);
+	if (hostp->nh_refs != 0)
 		return;
-	}
 
 	/*
 	 * The very last reference to the host was dropped,
@@ -1814,6 +1812,16 @@ nlm_host_release(struct nlm_globals *g, struct nlm_host *hostp)
 	ASSERT((hostp->nh_flags & NLM_NH_INIDLE) == 0);
 	TAILQ_INSERT_TAIL(&g->nlm_idle_hosts, hostp, nh_link);
 	hostp->nh_flags |= NLM_NH_INIDLE;
+}
+
+void
+nlm_host_release(struct nlm_globals *g, struct nlm_host *hostp)
+{
+	if (hostp == NULL)
+		return;
+
+	mutex_enter(&g->lock);
+	nlm_host_release_locked(g, hostp);
 	mutex_exit(&g->lock);
 }
 
@@ -2074,7 +2082,7 @@ nlm_slock_grant(struct nlm_globals *g,
  */
 int
 nlm_slreq_register(struct nlm_host *hostp, struct nlm_vhold *nvp,
-	struct flock64 *flp)
+    struct flock64 *flp)
 {
 	struct nlm_slreq *slr, *new_slr = NULL;
 	int ret = EEXIST;
@@ -2115,7 +2123,7 @@ nlm_slreq_register(struct nlm_host *hostp, struct nlm_vhold *nvp,
  */
 int
 nlm_slreq_unregister(struct nlm_host *hostp, struct nlm_vhold *nvp,
-	struct flock64 *flp)
+    struct flock64 *flp)
 {
 	struct nlm_slreq *slr;
 
@@ -2566,6 +2574,14 @@ nlm_unexport(struct exportinfo *exi)
 	while (hostp != NULL) {
 		struct nlm_vhold *nvp;
 
+		if (hostp->nh_flags & NLM_NH_INIDLE) {
+			TAILQ_REMOVE(&g->nlm_idle_hosts, hostp, nh_link);
+			hostp->nh_flags &= ~NLM_NH_INIDLE;
+		}
+		hostp->nh_refs++;
+
+		mutex_exit(&g->lock);
+
 		mutex_enter(&hostp->nh_lock);
 		TAILQ_FOREACH(nvp, &hostp->nh_vholds_list, nv_link) {
 			vnode_t *vp;
@@ -2590,8 +2606,11 @@ nlm_unexport(struct exportinfo *exi)
 			mutex_enter(&hostp->nh_lock);
 			nvp->nv_refcnt--;
 		}
-
 		mutex_exit(&hostp->nh_lock);
+
+		mutex_enter(&g->lock);
+		nlm_host_release_locked(g, hostp);
+
 		hostp = AVL_NEXT(&g->nlm_hosts_tree, hostp);
 	}