1 /* 2 * Copyright (c) 1994 The Regents of the University of California. 3 * Copyright (c) 1994 Jan-Simon Pendry. 4 * All rights reserved. 5 * 6 * This code is derived from software donated to Berkeley by 7 * Jan-Simon Pendry. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)union.h 8.9 (Berkeley) 12/10/94 38 * $FreeBSD$ 39 */ 40 41 struct union_args { 42 char *target; /* Target of loopback */ 43 int mntflags; /* Options on the mount */ 44 }; 45 46 #define UNMNT_ABOVE 0x0001 /* Target appears below mount point */ 47 #define UNMNT_BELOW 0x0002 /* Target appears below mount point */ 48 #define UNMNT_REPLACE 0x0003 /* Target replaces mount point */ 49 #define UNMNT_OPMASK 0x0003 50 51 struct union_mount { 52 struct vnode *um_uppervp; /* UN_ULOCK holds locking state */ 53 struct vnode *um_lowervp; /* Left unlocked */ 54 struct ucred *um_cred; /* Credentials of user calling mount */ 55 int um_cmode; /* cmask from mount process */ 56 int um_op; /* Operation mode */ 57 }; 58 59 #ifdef _KERNEL 60 61 #ifndef DIAGNOSTIC 62 #define DIAGNOSTIC 63 #endif 64 65 /* 66 * DEFDIRMODE is the mode bits used to create a shadow directory. 67 */ 68 #define VRWXMODE (VREAD|VWRITE|VEXEC) 69 #define VRWMODE (VREAD|VWRITE) 70 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6)) 71 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6)) 72 73 /* 74 * A cache of vnode references (hangs off v_data) 75 * 76 * Placing un_lock as the first elements theoretically allows us to 77 * use the vop_stdlock functions. However, we need to make sure of 78 * certain side effects so we will still punch in our own code. 79 */ 80 struct union_node { 81 struct lock un_lock; 82 LIST_ENTRY(union_node) un_cache; /* Hash chain */ 83 struct vnode *un_vnode; /* Back pointer */ 84 struct vnode *un_uppervp; /* overlaying object */ 85 struct vnode *un_lowervp; /* underlying object */ 86 struct vnode *un_dirvp; /* Parent dir of uppervp */ 87 struct vnode *un_pvp; /* Parent vnode */ 88 char *un_path; /* saved component name */ 89 int un_openl; /* # of opens on lowervp */ 90 int un_exclcnt; /* exclusive count */ 91 unsigned int un_flags; 92 struct vnode **un_dircache; /* cached union stack */ 93 off_t un_uppersz; /* size of upper object */ 94 off_t un_lowersz; /* size of lower object */ 95 #ifdef DIAGNOSTIC 96 pid_t un_pid; 97 #endif 98 }; 99 100 /* 101 * XXX UN_ULOCK - indicates that the uppervp is locked 102 * 103 * UN_CACHED - node is in the union cache 104 */ 105 106 /*#define UN_ULOCK 0x04*/ /* Upper node is locked */ 107 #define UN_CACHED 0x10 /* In union cache */ 108 109 /* 110 * Hash table locking flags 111 */ 112 113 #define UNVP_WANT 0x01 114 #define UNVP_LOCKED 0x02 115 116 extern int union_allocvp __P((struct vnode **, struct mount *, 117 struct vnode *, 118 struct vnode *, 119 struct componentname *, struct vnode *, 120 struct vnode *, int)); 121 extern int union_freevp __P((struct vnode *)); 122 extern struct vnode *union_dircache __P((struct vnode *, struct thread *)); 123 extern int union_copyup __P((struct union_node *, int, struct ucred *, 124 struct thread *)); 125 extern int union_dowhiteout __P((struct union_node *, struct ucred *, 126 struct thread *)); 127 extern int union_mkshadow __P((struct union_mount *, struct vnode *, 128 struct componentname *, struct vnode **)); 129 extern int union_mkwhiteout __P((struct union_mount *, struct vnode *, 130 struct componentname *, char *)); 131 extern int union_cn_close __P((struct vnode *, int, struct ucred *, 132 struct thread *)); 133 extern void union_removed_upper __P((struct union_node *un)); 134 extern struct vnode *union_lowervp __P((struct vnode *)); 135 extern void union_newsize __P((struct vnode *, off_t, off_t)); 136 137 extern int (*union_dircheckp) __P((struct thread *, struct vnode **, 138 struct file *)); 139 140 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data)) 141 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data) 142 #define UNIONTOV(un) ((un)->un_vnode) 143 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp) 144 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp) 145 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp)) 146 147 #define UDEBUG(x) if (uniondebug) printf x 148 #define UDEBUG_ENABLED 1 149 150 extern vop_t **union_vnodeop_p; 151 extern struct vfsops union_vfsops; 152 extern int uniondebug; 153 154 #endif /* _KERNEL */ 155