[src/trunk]: src/sys/kern description:

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

details:   https://anonhg.NetBSD.org/src/rev/65639f6dfe32
branches:  trunk
changeset: 764074:65639f6dfe32
user:      dholland <dholland%NetBSD.org@localhost>
date:      Mon Apr 11 02:17:01 2011 +0000

description:
description:
Fix lookup_for_nfsd_index() -- it wasn't locking the directory it was
searching. I'm not sure if this is something I introduced or if it's
just been wrong for ages; the code path is used only for serving
index.html in WebNFS and probably just ought to be removed.

diffstat:

 sys/kern/vfs_lookup.c |  16 +++++++++++-----
 1 files changed, 11 insertions(+), 5 deletions(-)

diffs (51 lines):

diff -r 5cd43b255dc9 -r 65639f6dfe32 sys/kern/vfs_lookup.c
--- a/sys/kern/vfs_lookup.c     Mon Apr 11 02:16:27 2011 +0000
+++ b/sys/kern/vfs_lookup.c     Mon Apr 11 02:17:01 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_lookup.c,v 1.159 2011/04/11 02:16:27 dholland Exp $        */
+/*     $NetBSD: vfs_lookup.c,v 1.160 2011/04/11 02:17:01 dholland Exp $        */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_lookup.c,v 1.159 2011/04/11 02:16:27 dholland Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_lookup.c,v 1.160 2011/04/11 02:17:01 dholland Exp $");
 
 #include "opt_magiclinks.h"
 
@@ -1458,7 +1458,14 @@
        else
                cnp->cn_flags &= ~ISDOTDOT;
 
-       error = lookup_once(state, startdir, &ndp->ni_dvp, &foundobj);
+       /*
+        * Because lookup_once can change the startdir, we need our
+        * own reference to it to avoid consuming the caller's.
+        */
+       vref(startdir);
+       vn_lock(startdir, LK_EXCLUSIVE | LK_RETRY);
+       error = lookup_once(state, startdir, &startdir, &foundobj);
+       vput(startdir);
        if (error) {
                goto bad;
        }
@@ -1469,6 +1476,7 @@
                return 0;
        }
 
+       KASSERT((cnp->cn_flags & LOCKPARENT) == 0);
        if ((cnp->cn_flags & LOCKLEAF) == 0) {
                VOP_UNLOCK(foundobj);
        }
@@ -1500,8 +1508,6 @@
        ndp->ni_pnbuf = NULL;
        ndp->ni_cnd.cn_nameptr = NULL;
 
-       vref(startdir);
-
        namei_init(&state, ndp);
        error = do_lookup_for_nfsd_index(&state, startdir);
        namei_cleanup(&state);