[src/trunk]: src/sys/kern revert vfs_lookup.c rev.1.126 for now because some ...

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

details:   https://anonhg.NetBSD.org/src/rev/fd22cacf9107
branches:  trunk
changeset: 759903:fd22cacf9107
user:      yamt <yamt%NetBSD.org@localhost>
date:      Mon Dec 20 00:12:46 2010 +0000

description:
revert vfs_lookup.c rev.1.126 for now because some problems are reported
on source-changes-d@ (thanks pooka) and i don't think i can take a look at
them in a timely manner.

diffstat:

 sys/kern/vfs_lookup.c |  45 ++++++++++-----------------------------------
 1 files changed, 10 insertions(+), 35 deletions(-)

diffs (123 lines):

diff -r e4c49e3260bd -r fd22cacf9107 sys/kern/vfs_lookup.c
--- a/sys/kern/vfs_lookup.c     Sun Dec 19 23:23:35 2010 +0000
+++ b/sys/kern/vfs_lookup.c     Mon Dec 20 00:12:46 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_lookup.c,v 1.126 2010/12/17 22:34:04 yamt Exp $    */
+/*     $NetBSD: vfs_lookup.c,v 1.127 2010/12/20 00:12:46 yamt Exp $    */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_lookup.c,v 1.126 2010/12/17 22:34:04 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_lookup.c,v 1.127 2010/12/20 00:12:46 yamt Exp $");
 
 #include "opt_magiclinks.h"
 
@@ -696,7 +696,6 @@
                }
                return error;
        }
-       KASSERT(VOP_ISLOCKED(state->namei_startdir) == LK_EXCLUSIVE);
 
        /* Loop through symbolic links */
        for (;;) {
@@ -905,11 +904,6 @@
        return 0;
 }
 
-/*
- * lookup_parsepath: consume a component name from state->ndp and prepare
- * state->cnp for it.
- */
-
 static int
 lookup_parsepath(struct namei_state *state)
 {
@@ -928,12 +922,16 @@
         * cnp->cn_nameptr for callers that need the name. Callers needing
         * the name set the SAVENAME flag. When done, they assume
         * responsibility for freeing the pathname buffer.
+        *
+        * At this point, our only vnode state is that "dp" is held and locked.
         */
        cnp->cn_consume = 0;
        cp = NULL;
        cnp->cn_hash = namei_hash(cnp->cn_nameptr, &cp);
        cnp->cn_namelen = cp - cnp->cn_nameptr;
        if (cnp->cn_namelen > NAME_MAX) {
+               vput(state->dp);
+               ndp->ni_dvp = NULL;
                return ENAMETOOLONG;
        }
 #ifdef NAMEI_DIAGNOSTIC
@@ -984,21 +982,6 @@
        return 0;
 }
 
-/*
- * lookup_once: look up the vnode for the next component name (state->cnp).
- *
- * takes care of dot-dot, cross-mount, and MNT_UNION.
- *
- * inputs:
- *     state->dp       the parent vnode
- *     state->cnp      the componentname to lookup
- *
- * outputs:
- *     state->dp       the result vnode
- *     ndp->ni_vp      updated to state->dp
- *     ndp->ni_dvp     updated to the parent directory vnode
- */
-
 static int
 lookup_once(struct namei_state *state)
 {
@@ -1153,8 +1136,6 @@
         * "state->dp" and "ndp->ni_dvp" are both locked and held,
         * and may be the same vnode.
         */
-       KASSERT(VOP_ISLOCKED(state->dp) == LK_EXCLUSIVE);
-       KASSERT(VOP_ISLOCKED(ndp->ni_dvp) == LK_EXCLUSIVE);
 
        /*
         * Check to see if the vnode has been mounted on;
@@ -1176,9 +1157,10 @@
                        vn_lock(ndp->ni_dvp, LK_EXCLUSIVE | LK_RETRY);
                        return error;
                }
-               vrele(ndp->ni_dvp);
-               vref(tdp);
-               ndp->ni_dvp = ndp->ni_vp = state->dp = tdp;
+               VOP_UNLOCK(tdp);
+               ndp->ni_vp = state->dp = tdp;
+               vn_lock(ndp->ni_dvp, LK_EXCLUSIVE | LK_RETRY);
+               vn_lock(ndp->ni_vp, LK_EXCLUSIVE | LK_RETRY);
        }
 
        return 0;
@@ -1205,14 +1187,8 @@
        }
 
 dirloop:
-       /*
-        * At this point, our only vnode state is that "dp" is held and locked.
-        */
-       KASSERT(VOP_ISLOCKED(state->dp) == LK_EXCLUSIVE);
-       KASSERT(ndp->ni_dvp == NULL);
        error = lookup_parsepath(state);
        if (error) {
-               vput(state->dp);
                goto bad;
        }
 
@@ -1259,7 +1235,6 @@
                } else {
                        vput(ndp->ni_dvp);
                }
-               ndp->ni_dvp = NULL;
                goto dirloop;
        }