1/*	$NetBSD: layer.h,v 1.17 2017/04/11 07:51:37 hannken Exp $	*/
  2
  3/*
  4 * Copyright (c) 1999 National Aeronautics & Space Administration
  5 * All rights reserved.
  6 *
  7 * This software was written by William Studenmund of the
  8 * Numerical Aerospace Simulation Facility, NASA Ames Research Center.
  9 *
 10 * Redistribution and use in source and binary forms, with or without
 11 * modification, are permitted provided that the following conditions
 12 * are met:
 13 * 1. Redistributions of source code must retain the above copyright
 14 *    notice, this list of conditions and the following disclaimer.
 15 * 2. Redistributions in binary form must reproduce the above copyright
 16 *    notice, this list of conditions and the following disclaimer in the
 17 *    documentation and/or other materials provided with the distribution.
 18 * 3. Neither the name of the National Aeronautics & Space Administration
 19 *    nor the names of its contributors may be used to endorse or promote
 20 *    products derived from this software without specific prior written
 21 *    permission.
 22 *
 23 * THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION
 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 26 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB-
 27 * UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 28 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 33 * POSSIBILITY OF SUCH DAMAGE.
 34 */
 35
 36/*
 37 * Copyright (c) 1992, 1993
 38 *	The Regents of the University of California.  All rights reserved.
 39 *
 40 * This code is derived from software donated to Berkeley by
 41 * Jan-Simon Pendry.
 42 *
 43 * Redistribution and use in source and binary forms, with or without
 44 * modification, are permitted provided that the following conditions
 45 * are met:
 46 * 1. Redistributions of source code must retain the above copyright
 47 *    notice, this list of conditions and the following disclaimer.
 48 * 2. Redistributions in binary form must reproduce the above copyright
 49 *    notice, this list of conditions and the following disclaimer in the
 50 *    documentation and/or other materials provided with the distribution.
 51 * 3. Neither the name of the University nor the names of its contributors
 52 *    may be used to endorse or promote products derived from this software
 53 *    without specific prior written permission.
 54 *
 55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 58 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 65 * SUCH DAMAGE.
 66 *
 67 *	from: Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp
 68 *	@(#)null.h	8.2 (Berkeley) 1/21/94
 69 */
 70
 71#ifndef _MISCFS_GENFS_LAYER_H_
 72#define _MISCFS_GENFS_LAYER_H_
 73
 74struct layer_args {
 75	char	*target;		/* Target of loopback  */
 76	struct export_args30 _pad1; /* compat with old userland tools */
 77};
 78
 79#ifdef _KERNEL
 80
 81struct layer_mount {
 82	struct vnode		*layerm_rootvp;	/* Ref to root layer_node */
 83	u_int			layerm_flags;	/* mount point layer flags */
 84	u_int			layerm_size;	/* size of fs's struct node */
 85	enum vtagtype		layerm_tag;	/* vtag of our vnodes */
 86	int				/* bypass routine for this mount */
 87				(*layerm_bypass)(void *);
 88	int			(**layerm_vnodeop_p)	/* ops for our nodes */
 89				(void *);
 90};
 91
 92#define	LAYERFS_MFLAGS		0x00000fff	/* reserved layer mount flags */
 93#define	LAYERFS_MBYPASSDEBUG	0x00000001
 94
 95/*
 96 * A cache of vnode references
 97 */
 98struct layer_node {
 99	struct vnode	        *layer_lowervp;	/* VREFed once */
100	struct vnode		*layer_vnode;	/* Back pointer */
101	unsigned int		layer_flags;	/* locking, etc. */
102};
103
104#define	LAYERFS_RESFLAGS	0x00000fff	/* flags reserved for layerfs */
105#define	LAYERFS_REMOVED 	0x00000001	/* Did a remove on this node */
106
107#define	LAYERFS_DO_BYPASS(vp, ap)	\
108	(*MOUNTTOLAYERMOUNT((vp)->v_mount)->layerm_bypass)((ap))
109
110struct vnode *layer_checkvp(struct vnode *vp, const char *fil, int lno);
111
112#define	MOUNTTOLAYERMOUNT(mp) ((struct layer_mount *)((mp)->mnt_data))
113#define	VTOLAYER(vp) ((struct layer_node *)(vp)->v_data)
114#define	LAYERTOV(xp) ((xp)->layer_vnode)
115#ifdef LAYERFS_DIAGNOSTIC
116#define	LAYERVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__)
117extern int layerfs_debug;
118#else
119#define	LAYERVPTOLOWERVP(vp) (VTOLAYER(vp)->layer_lowervp)
120#endif
121
122#endif /* _KERNEL */
123#endif /* _MISCFS_GENFS_LAYER_H_ */