[src/trunk]: src/sys/sys Add struct lock to struct vnode as first step in hav...

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

details:   https://anonhg.NetBSD.org/src/rev/6eab3e50cfca
branches:  trunk
changeset: 474471:6eab3e50cfca
user:      wrstuden <wrstuden%NetBSD.org@localhost>
date:      Wed Jul 07 23:30:03 1999 +0000

description:
Add struct lock to struct vnode as first step in having vnodes export a
struct lock. Will permit layered fs's to share locks with underlying
vnodes.

Also reduce the max # of vnodes passable in a VOP from 16 to 8. As the
most we pass is 4, this shoudn't be a problem. In addition to WILLRELE
flags, add WILLUNLOCK flags to indicate that the VOP will unlock the
vnode. Add WILLPUT flags (WILLUNLOCK | WILLRELE) to indicate that the
vop will vput the passed-in vnode.

diffstat:

 sys/sys/vnode.h |  27 ++++++++++++++++++++++++---
 1 files changed, 24 insertions(+), 3 deletions(-)

diffs (60 lines):

diff -r e729f206345e -r 6eab3e50cfca sys/sys/vnode.h
--- a/sys/sys/vnode.h   Wed Jul 07 22:59:47 1999 +0000
+++ b/sys/sys/vnode.h   Wed Jul 07 23:30:03 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vnode.h,v 1.60 1999/05/06 15:29:26 christos Exp $      */
+/*     $NetBSD: vnode.h,v 1.61 1999/07/07 23:30:03 wrstuden Exp $      */
 
 /*
  * Copyright (c) 1989, 1993
@@ -114,7 +114,8 @@
        int     v_ralen;                        /* Read-ahead length */
        daddr_t v_maxra;                        /* last readahead block */
        struct  simplelock v_interlock;         /* lock on usecount and flag */
-       struct  lock *v_vnlock;                 /* used for non-locking fs's */
+       struct  lock    v_lock;                 /* lock for this vnode */
+       struct  lock *v_vnlock;                 /* pointer to vnode lock */
        enum    vtagtype v_tag;                 /* type of underlying data */
        void    *v_data;                        /* private data for fs */
 };
@@ -123,6 +124,18 @@
 #define        v_vmdata        v_un.vu_vmdata
 #define        v_specinfo      v_un.vu_specinfo
 #define        v_fifoinfo      v_un.vu_fifoinfo
+/*
+ * All vnode locking operations should use vp->v_vnlock. For leaf filesystems
+ * (such as ffs, lfs, msdosfs, etc), vp->v_vnlock = &vp->v_lock. For
+ * stacked filesystems, vp->v_vnlock may equal lowervp->v_vnlock.
+ *
+ * vp->v_vnlock may also be NULL, which indicates that a leaf node does not
+ * export a struct lock for vnode locking. Stacked filesystems (such as
+ * nullfs) must call the underlying fs for locking. See layerfs_ routines
+ * for examples.
+ *
+ * All filesystems must (pretend to) understand lockmanager flags.
+ */
 
 /*
  * Vnode flags.
@@ -303,12 +316,20 @@
 /*
  * Flags for vdesc_flags:
  */
-#define VDESC_MAX_VPS          16
+#define VDESC_MAX_VPS          8
 /* Low order 16 flag bits are reserved for willrele flags for vp arguments. */
 #define VDESC_VP0_WILLRELE     0x0001
 #define VDESC_VP1_WILLRELE     0x0002
 #define VDESC_VP2_WILLRELE     0x0004
 #define VDESC_VP3_WILLRELE     0x0008
+#define VDESC_VP0_WILLUNLOCK   0x0100
+#define VDESC_VP1_WILLUNLOCK   0x0200
+#define VDESC_VP2_WILLUNLOCK   0x0400
+#define VDESC_VP3_WILLUNLOCK   0x0800
+#define VDESC_VP0_WILLPUT      0x0101
+#define VDESC_VP1_WILLPUT      0x0202
+#define VDESC_VP2_WILLPUT      0x0404
+#define VDESC_VP3_WILLPUT      0x0808
 #define VDESC_NOMAP_VPP                0x0100
 #define VDESC_VPP_WILLRELE     0x0200