[src/trunk]: src/sys/nfs Adapt to cache_lookup() changes.

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ef89ebe13906
branches:  trunk
changeset: 476091:ef89ebe13906
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Sun Sep 05 14:28:26 1999 +0000

description:
Adapt to cache_lookup() changes.
XXX I had no chance to actually test the changes for nfs, but hopefully I got
it right.

Tested by: jdolecek
Rewieved by: wrstuden

diffstat:

 sys/nfs/nfs_vnops.c |  56 ++++++++++++++++++++++++++--------------------------
 1 files changed, 28 insertions(+), 28 deletions(-)

diffs (81 lines):

diff -r c9991784f369 -r ef89ebe13906 sys/nfs/nfs_vnops.c
--- a/sys/nfs/nfs_vnops.c       Sun Sep 05 14:26:32 1999 +0000
+++ b/sys/nfs/nfs_vnops.c       Sun Sep 05 14:28:26 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nfs_vnops.c,v 1.105 1999/08/03 20:19:20 wrstuden Exp $ */
+/*     $NetBSD: nfs_vnops.c,v 1.106 1999/09/05 14:28:26 jdolecek Exp $ */
 
 /*
  * Copyright (c) 1989, 1993
@@ -752,9 +752,18 @@
        wantparent = flags & (LOCKPARENT|WANTPARENT);
        nmp = VFSTONFS(dvp->v_mount);
        np = VTONFS(dvp);
-       if ((error = cache_lookup(dvp, vpp, cnp)) != 0) {
+
+       /*
+        * Before tediously performing a linear scan of the directory,
+        * check the name cache to see if the directory/name pair
+        * we are looking for is known already.
+        * If the directory/name pair is found in the name cache,
+        * we have to ensure the directory has not changed from
+        * the time the cache entry has been created. If it has,
+        * the cache entry has to be ignored 
+        */
+       if ((error = cache_lookup(dvp, vpp, cnp)) >= 0) {
                struct vattr vattr;
-               int vpid;
 
                if (error == ENOENT) {
                        if (!VOP_GETATTR(dvp, &vattr, cnp->cn_cred,
@@ -765,34 +774,25 @@
                        np->n_nctime = 0;
                        goto dorpc;
                }
+               else if (error > 0)
+                       return error;
 
                newvp = *vpp;
-               vpid = newvp->v_id;
-               /*
-                * See the comment starting `Step through' in ufs/ufs_lookup.c
-                * for an explanation of the locking protocol
-                */
-               if (dvp == newvp) {
-                       VREF(newvp);
-                       error = 0;
-               } else
-                       error = vget(newvp, LK_EXCLUSIVE);
-               if (!error) {
-                       if (vpid == newvp->v_id) {
-                          if (!VOP_GETATTR(newvp, &vattr, cnp->cn_cred, cnp->cn_proc)
-                           && vattr.va_ctime.tv_sec == VTONFS(newvp)->n_ctime) {
-                               nfsstats.lookupcache_hits++;
-                               if (cnp->cn_nameiop != LOOKUP &&
-                                   (flags & ISLASTCN))
-                                       cnp->cn_flags |= SAVENAME;
-                               if (!lockparent || !(flags & ISLASTCN))
-                                       cnp->cn_flags |= PDIRUNLOCK;
-                               return (0);
-                          }
-                          cache_purge(newvp);
-                       }
-                       vrele(newvp);
+               if (!VOP_GETATTR(newvp, &vattr, cnp->cn_cred, cnp->cn_proc)
+                       && vattr.va_ctime.tv_sec == VTONFS(newvp)->n_ctime)
+               {
+                       nfsstats.lookupcache_hits++;
+                       if (cnp->cn_nameiop != LOOKUP && (flags & ISLASTCN))
+                               cnp->cn_flags |= SAVENAME;
+                       return (0);
                }
+               /* XXX cache_lookup() returns the vnode locked; if nfs
+                * would have real vnode locking, we should call VOP_UNLOCK()
+                * here; as it has no real locking, don't bother to do
+                * anything */
+               /* VOP_UNLOCK(newvp, 0); */
+               cache_purge(newvp);
+               vrele(newvp);
                *vpp = NULLVP;
        }
 dorpc: