layer.h revision 1.10
1 /* $NetBSD: layer.h,v 1.10 2005/09/25 21:17:05 jmmv 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_node; 82 83 LIST_HEAD(layer_node_hashhead, layer_node); 84 85 struct layer_mount { 86 struct mount *layerm_vfs; 87 struct vnode *layerm_rootvp; /* Ref to root layer_node */ 88 u_int layerm_flags; /* mount point layer flags */ 89 u_int layerm_size; /* size of fs's struct node */ 90 enum vtype layerm_tag; /* vtag of our vnodes */ 91 int /* bypass routine for this mount */ 92 (*layerm_bypass)(void *); 93 int (*layerm_alloc) /* alloc a new layer node */ 94 (struct mount *, struct vnode *, 95 struct vnode **); 96 int (**layerm_vnodeop_p) /* ops for our nodes */ 97 (void *); 98 struct layer_node_hashhead /* head of hash list for layer_nodes */ 99 *layerm_node_hashtbl; 100 u_long layerm_node_hash; /* hash mask for hash chain */ 101 struct simplelock layerm_hashlock; /* interlock for hash chain. */ 102 }; 103 104 #define LAYERFS_MFLAGS 0x00000fff /* reserved layer mount flags */ 105 #define LAYERFS_MBYPASSDEBUG 0x00000001 106 107 /* 108 * A cache of vnode references 109 */ 110 struct layer_node { 111 LIST_ENTRY(layer_node) layer_hash; /* Hash list */ 112 struct vnode *layer_lowervp; /* VREFed once */ 113 struct vnode *layer_vnode; /* Back pointer */ 114 unsigned int layer_flags; /* locking, etc. */ 115 }; 116 117 #define LAYERFS_RESFLAGS 0x00000fff /* flags reserved for layerfs */ 118 #define LAYERFS_REMOVED 0x00000001 /* Did a remove on this node */ 119 120 /* 121 * The following macros handle upperfs-specific locking. They are needed 122 * when the lowerfs does not export a struct lock for locking use by the 123 * upper layers. These macros are inteded for adjusting the upperfs 124 * struct lock to reflect changes in the underlying vnode's lock state. 125 */ 126 #define LAYERFS_UPPERLOCK(v, f, r) do { \ 127 if ((v)->v_vnlock == NULL) \ 128 r = lockmgr(&(v)->v_lock, (f), &(v)->v_interlock); \ 129 else \ 130 r = 0; \ 131 } while (0) 132 133 #define LAYERFS_UPPERUNLOCK(v, f, r) do { \ 134 if ((v)->v_vnlock == NULL) \ 135 r = lockmgr(&(v)->v_lock, (f) | LK_RELEASE, &(v)->v_interlock); \ 136 else \ 137 r = 0; \ 138 } while (0) 139 140 #define LAYERFS_UPPERISLOCKED(v, r) do { \ 141 if ((v)->v_vnlock == NULL) \ 142 r = lockstatus(&(v)->v_lock); \ 143 else \ 144 r = -1; \ 145 } while (0) 146 147 #define LAYERFS_DO_BYPASS(vp, ap) \ 148 (*MOUNTTOLAYERMOUNT((vp)->v_mount)->layerm_bypass)((ap)) 149 150 struct vnode *layer_checkvp(struct vnode *vp, const char *fil, int lno); 151 152 #define MOUNTTOLAYERMOUNT(mp) ((struct layer_mount *)((mp)->mnt_data)) 153 #define VTOLAYER(vp) ((struct layer_node *)(vp)->v_data) 154 #define LAYERTOV(xp) ((xp)->layer_vnode) 155 #ifdef LAYERFS_DIAGNOSTIC 156 #define LAYERVPTOLOWERVP(vp) layer_checkvp((vp), __FILE__, __LINE__) 157 extern int layerfs_debug; 158 #else 159 #define LAYERVPTOLOWERVP(vp) (VTOLAYER(vp)->layer_lowervp) 160 #endif 161 162 #endif /* _KERNEL */ 163 #endif /* _MISCFS_GENFS_LAYER_H_ */ 164
Indexes created Thu Sep 25 16:09:42 GMT 2025