[src/trunk]: src/sys/sys Fix locking comments.

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

details:   https://anonhg.NetBSD.org/src/rev/a941cc631fa8
branches:  trunk
changeset: 352164:a941cc631fa8
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Mar 19 10:21:02 2017 +0000

description:
Fix locking comments.

Forgot to save my Emacs buffer before last commit.

diffstat:

 sys/sys/namei.src |  10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diffs (28 lines):

diff -r 6a250adee295 -r a941cc631fa8 sys/sys/namei.src
--- a/sys/sys/namei.src Sat Mar 18 22:36:56 2017 +0000
+++ b/sys/sys/namei.src Sun Mar 19 10:21:02 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: namei.src,v 1.39 2017/03/18 21:03:28 riastradh Exp $   */
+/*     $NetBSD: namei.src,v 1.40 2017/03/19 10:21:02 riastradh Exp $   */
 
 /*
  * Copyright (c) 1985, 1989, 1991, 1993
@@ -207,13 +207,15 @@
  *      -       stable after initialization
  *      L       namecache_lock
  *      C       struct nchcpu::cpu_lock
+ *      L/C     insert/delete needs L and C, read needs L or any C,
+ *              must hold L and all C after (or during) delete before free
  *      N       struct namecache::nc_lock
  */
 struct namecache {
-       LIST_ENTRY(namecache) nc_hash;  /* L hash chain */
+       LIST_ENTRY(namecache) nc_hash;  /* L/C hash chain */
        LIST_ENTRY(namecache) nc_vhash; /* L directory hash chain */
-       struct  vnode *nc_dvp;          /* - vnode of parent of name */
-       struct  vnode *nc_vp;           /* - vnode the name refers to */
+       struct  vnode *nc_dvp;          /* N vnode of parent of name */
+       struct  vnode *nc_vp;           /* N vnode the name refers to */
        int     nc_flags;               /* - copy of componentname ISWHITEOUT */
        char    nc_nlen;                /* - length of name */
        char    nc_name[NCHNAMLEN];     /* - segment name */