2 fixes that improve on the consistency of the NFS client cache.

- Change the cached mtime to a 'struct timespec' from a
  time_t. Improving the precision of the cached mtime tightens up
  NFS' "close-to-open" consistency considerably.
- Always force an over-the-wire consistency check from nfs_open()
  (unless the file is marked modified). This further improves
  NFS' "close-to-open" consistency.

Submitted by:	Mohan Srinivasan mohans at yahoo-inc dot com

2 files changed, 4 insertions, 4 deletions

diff --git a/sys/nfs4client/nfs4_vn_subs.c b/sys/nfs4client/nfs4_vn_subs.c
index cded7f5..dd6617b 100644
--- a/sys/nfs4client/nfs4_vn_subs.c
+++ b/sys/nfs4client/nfs4_vn_subs.c
@@ -98,10 +98,10 @@ nfs4_vnop_loadattrcache(struct vnode *vp, struct nfsv4_fattr *fap,
          */
         np = VTONFS(vp);
         vap = &np->n_vattr;
-        if (vp->v_type != vtyp || np->n_mtime == 0) {
+        if (vp->v_type != vtyp || np->n_mtime.tv_sec == 0) {
                 bzero(vap, sizeof *vap);
                 vp->v_type = vtyp;
-                np->n_mtime = mtime.tv_sec;
+                np->n_mtime.tv_sec = mtime.tv_sec;
         }
         vap->va_type = vtyp;
         vap->va_mode = (vmode & 07777);
diff --git a/sys/nfs4client/nfs4_vnops.c b/sys/nfs4client/nfs4_vnops.c
index 707b075..5b9b582 100644
--- a/sys/nfs4client/nfs4_vnops.c
+++ b/sys/nfs4client/nfs4_vnops.c
@@ -1412,7 +1412,7 @@ nfs4_writerpc(struct vnode *vp, struct uio *uiop, struct ucred *cred,
 
 		/* XXX wccflag */
 		if (wccflag)
-			VTONFS(vp)->n_mtime = VTONFS(vp)->n_vattr.va_mtime.tv_sec;
+			VTONFS(vp)->n_mtime = VTONFS(vp)->n_vattr.va_mtime;
 
 		error = nfs_v4postop(&cp, error);
 
@@ -1994,7 +1994,7 @@ nfs4_readdir(struct vop_readdir_args *ap)
 	if (np->n_direofoffset > 0 && uio->uio_offset >= np->n_direofoffset &&
 	    (np->n_flag & NMODIFIED) == 0) {
 		if (VOP_GETATTR(vp, &vattr, ap->a_cred, uio->uio_td) == 0 &&
-			np->n_mtime == vattr.va_mtime.tv_sec) {
+			np->n_mtime.tv_sec == vattr.va_mtime.tv_sec) {
 			nfsstats.direofcache_hits++;
 			return (0);
 		}