vp->v_id is a private field for the vfs namecache and it is a big mistake

that NFS ever started using it and an even bigger that it got copied&pasted
to nwfs and smbfs.

Replace with use of vhold()/vdrop().

1 files changed, 10 insertions, 11 deletions

diff --git a/sys/fs/nwfs/nwfs_vnops.c b/sys/fs/nwfs/nwfs_vnops.c
index 6f719f1..4069e36 100644
--- a/sys/fs/nwfs/nwfs_vnops.c
+++ b/sys/fs/nwfs/nwfs_vnops.c
@@ -875,10 +875,9 @@ printf("dvp %d:%d:%d\n", (int)mp, (int)dvp->v_vflag & VV_ROOT, (int)flags & ISDO
 		return error;
 	if (error) {		/* name was found */
 		struct vattr vattr;
-		int vpid;
 
+		vhold(*vpp);
 		vp = *vpp;
-		vpid = vp->v_id;
 		if (dvp == vp) {	/* lookup on current */
 			vref(vp);
 			error = 0;
@@ -894,20 +893,20 @@ printf("dvp %d:%d:%d\n", (int)mp, (int)dvp->v_vflag & VV_ROOT, (int)flags & ISDO
 				VOP_UNLOCK(dvp, 0, td);
 		}
 		if (!error) {
-			if (vpid == vp->v_id) {
-			   if (!VOP_GETATTR(vp, &vattr, cnp->cn_cred, td)
-			    && vattr.va_ctime.tv_sec == VTONW(vp)->n_ctime) {
-				if (nameiop != LOOKUP && islastcn)
-					cnp->cn_flags |= SAVENAME;
-				NCPVNDEBUG("use cached vnode");
-				return (0);
-			   }
-			   cache_purge(vp);
+			if (!VOP_GETATTR(vp, &vattr, cnp->cn_cred, td)
+			 && vattr.va_ctime.tv_sec == VTONW(vp)->n_ctime) {
+			     if (nameiop != LOOKUP && islastcn)
+				     cnp->cn_flags |= SAVENAME;
+			     NCPVNDEBUG("use cached vnode");
+			     vdrop(vp);
+			     return (0);
 			}
+			cache_purge(vp);
 			vput(vp);
 			if (lockparent && dvp != vp && islastcn)
 				VOP_UNLOCK(dvp, 0, td);
 		}
+		vdrop(vp);
 		error = vn_lock(dvp, LK_EXCLUSIVE, td);
 		*vpp = NULLVP;
 		if (error)