1 /* $NetBSD: layer.h,v 1.4 2001/06/07 13:32:46 wiz 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. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * from: Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp 72 * @(#)null.h 8.2 (Berkeley) 1/21/94 73 */ 74 75 #ifndef _MISCFS_GENFS_LAYER_H_ 76 #define _MISCFS_GENFS_LAYER_H_ 77 78 struct layer_args { 79 char *target; /* Target of loopback */ 80 struct export_args export; /* network export info */ 81 }; 82 83 #ifdef _KERNEL 84 85 struct layer_node; 86 87 LIST_HEAD(layer_node_hashhead, layer_node); 88 89 struct layer_mount { 90 struct mount *layerm_vfs; 91 struct vnode *layerm_rootvp; /* Ref to root layer_node */ 92 struct netexport layerm_export; /* export info */ 93 u_int layerm_flags; /* mount point layer flags */ 94 u_int layerm_size; /* size of fs's struct node */ 95 enum vtype layerm_tag; /* vtag of our vnodes */ 96 int /* bypass routine for this mount */ 97 (*layerm_bypass) __P((void *)); 98 int (*layerm_alloc) /* alloc a new layer node */ 99 __P((struct mount *, struct vnode *, 100 struct vnode **)); 101 int (**layerm_vnodeop_p) /* ops for our nodes */ 102 __P((void *)); 103 struct layer_node_hashhead /* head of hash list for layer_nodes */ 104 *layerm_node_hashtbl; 105 u_long layerm_node_hash; /* hash mask for hash chain */ 106 struct simplelock layerm_hashlock; /* interlock for hash chain. */ 107 }; 108 109 #define LAYERFS_MFLAGS 0x00000fff /* reserved layer mount flags */ 110 #define LAYERFS_MBYPASSDEBUG 0x00000001 111 112 /* 113 * A cache of vnode references 114 */ 115 struct layer_node { 116 LIST_ENTRY(layer_node) layer_hash; /* Hash list */ 117 struct vnode *layer_lowervp; /* VREFed once */ 118 struct vnode *layer_vnode; /* Back pointer */ 119 unsigned int layer_flags; /* locking, etc. */ 120 }; 121 122 #define LAYERFS_RESFLAGS 0x00000fff /* flags reserved for layerfs */ 123 124 /* 125 * The following macros handle upperfs-specific locking. They are needed 126 * when the lowerfs does not export a struct lock for locking use by the 127 * upper layers. These macros are inteded for adjusting the upperfs 128 * struct lock to reflect changes in the underlying vnode's lock state. 129 */ 130 #define LAYERFS_UPPERLOCK(v, f, r) do { \ 131 if ((v)->v_vnlock == NULL) \ 132 r = lockmgr(&(v)->v_lock, (f), &(v)->v_interlock); \ 133 else \ 134 r = 0; \ 135 } while (0) 136 137 #define LAYERFS_UPPERUNLOCK(v, f, r) do { \ 138 if ((v)->v_vnlock == NULL) \ 139 r = lockmgr(&(v)->v_lock, (f) | LK_RELEASE, &(v)->v_interlock); \ 140 else \ 141 r = 0; \ 142 } while (0) 143 144 #define LAYERFS_UPPERISLOCKED(v, r) do { \ 145 if ((v)->v_vnlock == NULL) \ 146 r = lockstatus(&(v)->v_lock); \ 147 else \ 148 r = -1; \ 149 } while (0) 150 151 #define LAYERFS_DO_BYPASS(vp, ap) \ 152 (*MOUNTTOLAYERMOUNT((vp)->v_mount)->layerm_bypass)((ap)) 153 154 extern struct vnode *layer_checkvp __P((struct vnode *vp, char *fil, int lno)); 155 156 #define MOUNTTOLAYERMOUNT(mp) ((struct layer_mount *)((mp)->mnt_data)) 157 #define VTOLAYER(vp) ((struct layer_node *)(vp)->v_data) 158 #define LAYERTOV(xp) ((xp)->layer_vnode) 159 #ifdef LAYERFS_DIAGNOSTIC 160 #define LAYERVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__) 161 #else 162 #define LAYERVPTOLOWERVP(vp) (VTOLAYER(vp)->layer_lowervp) 163 #endif 164 165 #endif /* _KERNEL */ 166 #endif /* _MISCFS_GENFS_LAYER_H_ */ 167