[src/trunk]: src/sys/kern Require the actual namecache_look around cache_look...

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

details:   https://anonhg.NetBSD.org/src/rev/deff0d66af60
branches:  trunk
changeset: 329987:deff0d66af60
user:      joerg <joerg%NetBSD.org@localhost>
date:      Mon Jun 16 12:28:10 2014 +0000

description:
Require the actual namecache_look around cache_lookup_entry.
Add one last case of missing stat locking.

diffstat:

 sys/kern/vfs_cache.c |  14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diffs (66 lines):

diff -r fee034c17839 -r deff0d66af60 sys/kern/vfs_cache.c
--- a/sys/kern/vfs_cache.c      Mon Jun 16 09:55:49 2014 +0000
+++ b/sys/kern/vfs_cache.c      Mon Jun 16 12:28:10 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_cache.c,v 1.98 2014/06/14 16:12:34 joerg Exp $     */
+/*     $NetBSD: vfs_cache.c,v 1.99 2014/06/16 12:28:10 joerg Exp $     */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -58,7 +58,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_cache.c,v 1.98 2014/06/14 16:12:34 joerg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_cache.c,v 1.99 2014/06/16 12:28:10 joerg Exp $");
 
 #include "opt_ddb.h"
 #include "opt_revcache.h"
@@ -286,8 +286,7 @@
 }
 
 /*
- * Find a single cache entry and return it locked.  'namecache_lock' or
- * at least one of the per-CPU locks must be held.
+ * Find a single cache entry and return it locked.
  */
 static struct namecache *
 cache_lookup_entry(const struct vnode *dvp, const char *name, size_t namelen)
@@ -297,6 +296,7 @@
        nchash_t hash;
 
        KASSERT(dvp != NULL);
+       KASSERT(mutex_owned(namecache_lock));
        hash = cache_hash(name, namelen);
        ncpp = &nchashtbl[NCHASH2(hash, dvp)];
 
@@ -395,7 +395,9 @@
                /* found nothing */
                return 0;
        }
+       mutex_enter(namecache_lock);
        ncp = cache_lookup_entry(dvp, name, namelen);
+       mutex_exit(namecache_lock);
        if (__predict_false(ncp == NULL)) {
                mutex_enter(&cpup->cpu_lock);
                COUNT(cpup->cpu_stats, ncs_miss);
@@ -517,7 +519,9 @@
                /* found nothing */
                return 0;
        }
+       mutex_enter(namecache_lock);
        ncp = cache_lookup_entry(dvp, name, namelen);
+       mutex_exit(namecache_lock);
        if (__predict_false(ncp == NULL)) {
                mutex_enter(&cpup->cpu_lock);
                COUNT(cpup->cpu_stats, ncs_miss);
@@ -559,7 +563,9 @@
        }
 
        /* Unlocked, but only for stats. */
+       mutex_enter(&cpup->cpu_lock);
        COUNT(cpup->cpu_stats, ncs_goodhits); /* XXX can be "badhits" */
+       mutex_exit(&cpup->cpu_lock);
 
        /* found it */
        *vn_ret = vp;