From c3ce5f02ead5992c12c70975ea4c368b64cece7d Mon Sep 17 00:00:00 2001
From: fvdl <fvdl@NetBSD.org>
Date: Sun, 12 Oct 1997 23:13:35 +0000
Subject: [PATCH] Do negative lookup caching. Use a timestamp of the oldest
 negative cache entry, so it can be checked against directory modification
 time for validity.

---
 sys/nfs/nfs_vnops.c | 27 ++++++++++++++++++++++++---
 sys/nfs/nfsnode.h   |  3 ++-
 sys/nfs/nfsproto.h  |  4 ++--
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/sys/nfs/nfs_vnops.c b/sys/nfs/nfs_vnops.c
index 589842e658bc..925bf12f4fe3 100644
--- a/sys/nfs/nfs_vnops.c
+++ b/sys/nfs/nfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: nfs_vnops.c,v 1.81 1997/10/10 01:53:30 fvdl Exp $	*/
+/*	$NetBSD: nfs_vnops.c,v 1.82 1997/10/12 23:13:35 fvdl Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993
@@ -810,10 +810,20 @@ nfs_lookup(v)
 	wantparent = flags & (LOCKPARENT|WANTPARENT);
 	nmp = VFSTONFS(dvp->v_mount);
 	np = VTONFS(dvp);
-	if ((error = cache_lookup(dvp, vpp, cnp)) != 0 && error != ENOENT) {
+	if ((error = cache_lookup(dvp, vpp, cnp)) != 0) {
 		struct vattr vattr;
 		int vpid;
 
+		if (error == ENOENT) {
+			if (!VOP_GETATTR(dvp, &vattr, cnp->cn_cred,
+			    cnp->cn_proc) && vattr.va_mtime.tv_sec ==
+			    VTONFS(dvp)->n_nctime)
+				return (ENOENT);
+			cache_purge(dvp);
+			np->n_nctime = 0;
+			goto dorpc;
+		}
+
 		newvp = *vpp;
 		vpid = newvp->v_id;
 		/*
@@ -845,6 +855,7 @@ nfs_lookup(v)
 		}
 		*vpp = NULLVP;
 	}
+dorpc:
 	error = 0;
 	newvp = NULLVP;
 	nfsstats.lookupcache_misses++;
@@ -913,6 +924,13 @@ nfs_lookup(v)
 	*vpp = newvp;
 	nfsm_reqdone;
 	if (error) {
+		if (error == ENOENT && (cnp->cn_flags & MAKEENTRY) &&
+		    cnp->cn_nameiop != CREATE) {
+			if (VTONFS(dvp)->n_nctime == 0)
+				VTONFS(dvp)->n_nctime =
+				    VTONFS(dvp)->n_vattr.va_mtime.tv_sec;
+			cache_enter(dvp, NULL, cnp);
+		}
 		if (newvp != NULLVP)
 			vrele(newvp);
 		if ((cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME) &&
@@ -1861,8 +1879,11 @@ nfs_mkdir(v)
 	if (error) {
 		if (newvp)
 			vrele(newvp);
-	} else
+	} else {
+		if (cnp->cn_flags & MAKEENTRY)
+			cache_enter(dvp, newvp, cnp);
 		*ap->a_vpp = newvp;
+	}
 	FREE(cnp->cn_pnbuf, M_NAMEI);
 	vrele(dvp);
 	return (error);
diff --git a/sys/nfs/nfsnode.h b/sys/nfs/nfsnode.h
index dbe8236f4a62..425554254ccf 100644
--- a/sys/nfs/nfsnode.h
+++ b/sys/nfs/nfsnode.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: nfsnode.h,v 1.21 1997/10/10 01:53:32 fvdl Exp $	*/
+/*	$NetBSD: nfsnode.h,v 1.22 1997/10/12 23:13:38 fvdl Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993
@@ -109,6 +109,7 @@ struct nfsnode {
 	time_t			n_attrstamp;	/* Attr. cache timestamp */
 	time_t			n_mtime;	/* Prev modify time. */
 	time_t			n_ctime;	/* Prev create time. */
+	time_t			n_nctime;	/* Last neg cache entry (dir) */
 	time_t			n_expiry;	/* Lease expiry time */
 	nfsfh_t			*n_fhp;		/* NFS File Handle */
 	struct vnode		*n_vnode;	/* associated vnode */
diff --git a/sys/nfs/nfsproto.h b/sys/nfs/nfsproto.h
index ffc31533ab77..5813d7d9cf15 100644
--- a/sys/nfs/nfsproto.h
+++ b/sys/nfs/nfsproto.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: nfsproto.h,v 1.3 1997/10/10 01:53:33 fvdl Exp $	*/
+/*	$NetBSD: nfsproto.h,v 1.4 1997/10/12 23:13:39 fvdl Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993
@@ -252,7 +252,7 @@ typedef enum { NFNON=0, NFREG=1, NFDIR=2, NFBLK=3, NFCHR=4, NFLNK=5,
  * NFS_SMALLFH should be in the range of 32 to 64 and be divisible by 4.
  */
 #ifndef NFS_SMALLFH
-#define NFS_SMALLFH	48
+#define NFS_SMALLFH	44
 #endif
 union nfsfh {
 	fhandle_t fh_generic;