Fix the "error" path (when dropping not fully initialized vnode).

Also move hash operations out of null_vnops.c and explicitly initialize
v_lock in null_node_alloc (to set wmesg).

Reviewed by:	bp
MFC after:	2 weeks

3 files changed, 26 insertions, 19 deletions

diff --git a/sys/fs/nullfs/null.h b/sys/fs/nullfs/null.h
index 8d02b44..718deaa 100644
--- a/sys/fs/nullfs/null.h
+++ b/sys/fs/nullfs/null.h
@@ -60,6 +60,7 @@ struct null_node {
 int nullfs_init(struct vfsconf *vfsp);
 int nullfs_uninit(struct vfsconf *vfsp);
 int null_node_create(struct mount *mp, struct vnode *target, struct vnode **vpp);
+void null_hashrem(struct null_node *xp);
 int null_bypass(struct vop_generic_args *ap);
 
 #ifdef DIAGNOSTIC
@@ -70,7 +71,6 @@ struct vnode *null_checkvp(struct vnode *vp, char *fil, int lno);
 #endif
 
 extern vop_t **null_vnodeop_p;
-extern struct lock null_hashlock;
 
 #ifdef MALLOC_DECLARE
 MALLOC_DECLARE(M_NULLFSNODE);
diff --git a/sys/fs/nullfs/null_subr.c b/sys/fs/nullfs/null_subr.c
index add959e..5e1d7b3 100644
--- a/sys/fs/nullfs/null_subr.c
+++ b/sys/fs/nullfs/null_subr.c
@@ -183,10 +183,15 @@ null_node_alloc(mp, lowervp, vpp)
 	}
 	vp = *vpp;
 
-	vp->v_type = lowervp->v_type;
 	xp->null_vnode = vp;
-	vp->v_data = xp;
 	xp->null_lowervp = lowervp;
+
+	vp->v_type = lowervp->v_type;
+	vp->v_data = xp;
+
+	/* Though v_lock is inited by getnewvnode(), we want our own wmesg */
+	lockinit(&vp->v_lock, PVFS, "nunode", VLKTIMEOUT, LK_NOPAUSE);
+
 	/*
 	 * Before we insert our new node onto the hash chains,
 	 * check to see if someone else has beaten us to it.
@@ -194,9 +199,7 @@ null_node_alloc(mp, lowervp, vpp)
 	 */
 	othervp = null_node_find(mp, lowervp);
 	if (othervp) {
-		vp->v_data = NULL;
-		FREE(xp, M_NULLFSNODE);
-		vp->v_type = VBAD;	/* node is discarded */
+		xp->null_lowervp = NULL;
 		vrele(vp);
 		*vpp = othervp;
 		return 0;
@@ -286,6 +289,17 @@ null_node_create(mp, lowervp, newvpp)
 	return (0);
 }
 
+void
+null_hashrem(xp)
+	struct null_node *xp;
+{
+	struct thread *td = curthread;	/* XXX */
+
+	lockmgr(&null_hashlock, LK_EXCLUSIVE, NULL, td);
+	LIST_REMOVE(xp, null_hash);
+	lockmgr(&null_hashlock, LK_RELEASE, NULL, td);
+}
+
 #ifdef DIAGNOSTIC
 #include "opt_ddb.h"
 
diff --git a/sys/fs/nullfs/null_vnops.c b/sys/fs/nullfs/null_vnops.c
index 1229e59..f3201e2 100644
--- a/sys/fs/nullfs/null_vnops.c
+++ b/sys/fs/nullfs/null_vnops.c
@@ -739,26 +739,19 @@ null_reclaim(ap)
 		struct thread *a_td;
 	} */ *ap;
 {
-	struct thread *td = ap->a_td;
 	struct vnode *vp = ap->a_vp;
 	struct null_node *xp = VTONULL(vp);
 	struct vnode *lowervp = xp->null_lowervp;
-	void *vdata;
 
-	lockmgr(&null_hashlock, LK_EXCLUSIVE, NULL, td);
-	LIST_REMOVE(xp, null_hash);
-	lockmgr(&null_hashlock, LK_RELEASE, NULL, td);
+	if (lowervp) {
+		null_hashrem(xp);
 
-	/*
-	 * Now it is safe to drop references to the lower vnode.
-	 * VOP_INACTIVE() will be called by vrele() if necessary.
-	 */
-	vrele(lowervp);
-	vrele(lowervp);
+		vrele(lowervp);
+		vrele(lowervp);
+	}
 
-	vdata = vp->v_data;
 	vp->v_data = NULL;
-	FREE(vdata, M_NULLFSNODE);
+	FREE(xp, M_NULLFSNODE);
 
 	return (0);
 }