[src/trunk]: src/sys/sys Comment the fields of struct vnode_impl.

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

details:   https://anonhg.NetBSD.org/src/rev/5db832a612e7
branches:  trunk
changeset: 350105:5db832a612e7
user:      hannken <hannken%NetBSD.org@localhost>
date:      Wed Jan 04 17:06:13 2017 +0000

description:
Comment the fields of struct vnode_impl.
No functional change.

diffstat:

 sys/sys/vnode_impl.h |  23 +++++++++++++++++------
 1 files changed, 17 insertions(+), 6 deletions(-)

diffs (46 lines):

diff -r e18a7e555175 -r 5db832a612e7 sys/sys/vnode_impl.h
--- a/sys/sys/vnode_impl.h      Wed Jan 04 16:11:20 2017 +0000
+++ b/sys/sys/vnode_impl.h      Wed Jan 04 17:06:13 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vnode_impl.h,v 1.5 2017/01/02 10:33:28 hannken Exp $   */
+/*     $NetBSD: vnode_impl.h,v 1.6 2017/01/04 17:06:13 hannken Exp $   */
 
 /*-
  * Copyright (c) 2016 The NetBSD Foundation, Inc.
@@ -42,20 +42,31 @@
        VS_RECLAIMING,  /* Intermediate, detaching the fs node. */
        VS_RECLAIMED    /* Stable, no fs node attached. */
 };
+
 TAILQ_HEAD(vnodelst, vnode_impl);
 typedef struct vnodelst vnodelst_t;
+
 struct vcache_key {
        struct mount *vk_mount;
        const void *vk_key;
        size_t vk_key_len;
 };
+
+/*
+ * Reading or writing any of these items requires holding the appropriate
+ * lock.  Field markings and the corresponding locks:
+ *
+ *     c       vcache_lock
+ *     d       vdrain_lock
+ *     i       v_interlock
+ */
 struct vnode_impl {
        struct vnode vi_vnode;
-       enum vnode_state vi_state;
-       struct vnodelst *vi_lrulisthd;
-       TAILQ_ENTRY(vnode_impl) vi_lrulist;
-       SLIST_ENTRY(vnode_impl) vi_hash;
-       struct vcache_key vi_key;
+       enum vnode_state vi_state;              /* i: current state */
+       struct vnodelst *vi_lrulisthd;          /* d: current lru list head */
+       TAILQ_ENTRY(vnode_impl) vi_lrulist;     /* d: lru list */
+       SLIST_ENTRY(vnode_impl) vi_hash;        /* c: vnode cache list */
+       struct vcache_key vi_key;               /* c: vnode cache key */
 };
 typedef struct vnode_impl vnode_impl_t;