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      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 
     74 struct layer_args {
     75 	char	*target;		/* Target of loopback  */
     76 	struct export_args30 _pad1; /* compat with old userland tools */
     77 };
     78 
     79 #ifdef _KERNEL
     80 
     81 struct 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  */
     98 struct 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 
    110 struct 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__)
    117 extern 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_ */
    124