1 /* $NetBSD: union.h,v 1.28 2015/02/16 10:22:00 hannken Exp $ */ 2 3 /* 4 * Copyright (c) 1994 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * Jan-Simon Pendry. 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 University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)union.h 8.9 (Berkeley) 12/10/94 35 */ 36 37 /* 38 * Copyright (c) 1994 Jan-Simon Pendry. 39 * All rights reserved. 40 * 41 * This code is derived from software donated to Berkeley by 42 * Jan-Simon Pendry. 43 * 44 * Redistribution and use in source and binary forms, with or without 45 * modification, are permitted provided that the following conditions 46 * are met: 47 * 1. Redistributions of source code must retain the above copyright 48 * notice, this list of conditions and the following disclaimer. 49 * 2. Redistributions in binary form must reproduce the above copyright 50 * notice, this list of conditions and the following disclaimer in the 51 * documentation and/or other materials provided with the distribution. 52 * 3. All advertising materials mentioning features or use of this software 53 * must display the following acknowledgement: 54 * This product includes software developed by the University of 55 * California, Berkeley and its contributors. 56 * 4. Neither the name of the University nor the names of its contributors 57 * may be used to endorse or promote products derived from this software 58 * without specific prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * @(#)union.h 8.9 (Berkeley) 12/10/94 73 */ 74 75 #ifndef _MISCFS_UNION_H_ 76 #define _MISCFS_UNION_H_ 77 78 struct union_args { 79 char *target; /* Target of loopback */ 80 int mntflags; /* Options on the mount */ 81 }; 82 83 #define UNMNT_ABOVE 0x0001 /* Target appears below mount point */ 84 #define UNMNT_BELOW 0x0002 /* Target appears below mount point */ 85 #define UNMNT_REPLACE 0x0003 /* Target replaces mount point */ 86 #define UNMNT_OPMASK 0x0003 87 88 #define UNMNT_BITS "\177\20" \ 89 "b\00above\0b\01below\0b\02replace\0" 90 91 #ifdef _KERNEL 92 93 struct union_mount { 94 struct vnode *um_uppervp; 95 struct vnode *um_lowervp; 96 kauth_cred_t um_cred; /* Credentials of user calling mount */ 97 int um_cmode; /* cmask from mount process */ 98 int um_op; /* Operation mode */ 99 }; 100 101 /* 102 * DEFDIRMODE is the mode bits used to create a shadow directory. 103 */ 104 #define UN_DIRMODE (S_IRWXU|S_IRWXG|S_IRWXO) 105 #define UN_FILEMODE (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH) 106 107 /* 108 * A cache of vnode references. 109 * Lock requirements are: 110 * 111 * : stable 112 * c unheadlock[hash] 113 * l un_lock 114 * m un_lock or vnode lock to read, un_lock and 115 * exclusive vnode lock to write 116 * v vnode lock to read, exclusive vnode lock to write 117 * 118 * Lock order is vnode then un_lock. 119 */ 120 struct union_node { 121 kmutex_t un_lock; 122 LIST_ENTRY(union_node) un_cache; /* c: Hash chain */ 123 int un_refs; /* c: Reference counter */ 124 struct mount *un_mount; /* c: union mount */ 125 struct vnode *un_vnode; /* :: Back pointer */ 126 struct vnode *un_uppervp; /* m: overlaying object */ 127 struct vnode *un_lowervp; /* v: underlying object */ 128 struct vnode *un_dirvp; /* v: Parent dir of uppervp */ 129 struct vnode *un_pvp; /* v: Parent vnode */ 130 char *un_path; /* v: saved component name */ 131 int un_openl; /* v: # of opens on lowervp */ 132 unsigned int un_cflags; /* c: cache flags */ 133 struct vnode **un_dircache; /* v: cached union stack */ 134 off_t un_uppersz; /* l: size of upper object */ 135 off_t un_lowersz; /* l: size of lower object */ 136 }; 137 138 #define UN_CACHED 0x10 /* In union cache */ 139 140 extern int union_allocvp(struct vnode **, struct mount *, 141 struct vnode *, struct vnode *, 142 struct componentname *, struct vnode *, 143 struct vnode *, int); 144 extern int union_check_rmdir(struct union_node *, kauth_cred_t); 145 extern int union_copyfile(struct vnode *, struct vnode *, kauth_cred_t, 146 struct lwp *); 147 extern int union_copyup(struct union_node *, int, kauth_cred_t, 148 struct lwp *); 149 extern void union_diruncache(struct union_node *); 150 extern int union_dowhiteout(struct union_node *, kauth_cred_t); 151 extern int union_mkshadow(struct union_mount *, struct vnode *, 152 struct componentname *, struct vnode **); 153 extern int union_mkwhiteout(struct union_mount *, struct vnode *, 154 struct componentname *, struct union_node *); 155 extern int union_vn_create(struct vnode **, struct union_node *, 156 struct lwp *); 157 extern int union_cn_close(struct vnode *, int, kauth_cred_t, 158 struct lwp *); 159 extern void union_removed_upper(struct union_node *un); 160 extern struct vnode *union_lowervp(struct vnode *); 161 extern void union_newlower(struct union_node *, struct vnode *); 162 extern void union_newupper(struct union_node *, struct vnode *); 163 extern void union_newsize(struct vnode *, off_t, off_t); 164 int union_readdirhook(struct vnode **, struct file *, struct lwp *); 165 166 VFS_PROTOS(union); 167 168 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data)) 169 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data) 170 #define UNIONTOV(un) ((un)->un_vnode) 171 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp) 172 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp) 173 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp)) 174 #define LOCKVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : (vp)) 175 176 extern int (**union_vnodeop_p)(void *); 177 178 void union_init(void); 179 void union_reinit(void); 180 void union_done(void); 181 int union_freevp(struct vnode *); 182 183 #endif /* _KERNEL */ 184 #endif /* _MISCFS_UNION_H_ */ 185