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 #define UNMNT_ABOVE 0x0001 /* Target appears above mount point */ 42 #define UNMNT_BELOW 0x0002 /* Target appears below mount point */ 43 #define UNMNT_REPLACE 0x0003 /* Target replaces mount point */ 44 45 struct union_mount { 46 struct vnode *um_uppervp; /* UN_ULOCK holds locking state */ 47 struct vnode *um_lowervp; /* Left unlocked */ 48 struct ucred *um_cred; /* Credentials of user calling mount */ 49 int um_cmode; /* cmask from mount process */ 50 int um_op; /* Operation mode */ 51 }; 52 53 #ifdef _KERNEL 54 55 #ifndef DIAGNOSTIC 56 #define DIAGNOSTIC 57 #endif 58 59 /* 60 * DEFDIRMODE is the mode bits used to create a shadow directory. 61 */ 62 #define VRWXMODE (VREAD|VWRITE|VEXEC) 63 #define VRWMODE (VREAD|VWRITE) 64 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6)) 65 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6)) 66 67 /* 68 * A cache of vnode references (hangs off v_data) 69 * 70 * Placing un_lock as the first elements theoretically allows us to 71 * use the vop_stdlock functions. However, we need to make sure of 72 * certain side effects so we will still punch in our own code. 73 */ 74 struct union_node { 75 struct lock un_lock; 76 LIST_ENTRY(union_node) un_cache; /* Hash chain */ 77 struct vnode *un_vnode; /* Back pointer */ 78 struct vnode *un_uppervp; /* overlaying object */ 79 struct vnode *un_lowervp; /* underlying object */ 80 struct vnode *un_dirvp; /* Parent dir of uppervp */ 81 struct vnode *un_pvp; /* Parent vnode */ 82 char *un_path; /* saved component name */ 83 int un_openl; /* # of opens on lowervp */ 84 int un_exclcnt; /* exclusive count */ 85 unsigned int un_flags; 86 struct vnode **un_dircache; /* cached union stack */ 87 off_t un_uppersz; /* size of upper object */ 88 off_t un_lowersz; /* size of lower object */ 89 #ifdef DIAGNOSTIC 90 pid_t un_pid; 91 #endif 92 }; 93 94 /* 95 * XXX UN_ULOCK - indicates that the uppervp is locked 96 * 97 * UN_CACHED - node is in the union cache 98 */ 99 100 /*#define UN_ULOCK 0x04*/ /* Upper node is locked */ 101 #define UN_CACHED 0x10 /* In union cache */ 102 103 /* 104 * Hash table locking flags 105 */ 106 107 #define UNVP_WANT 0x01 108 #define UNVP_LOCKED 0x02 109 110 extern int union_allocvp(struct vnode **, struct mount *, 111 struct vnode *, 112 struct vnode *, 113 struct componentname *, struct vnode *, 114 struct vnode *, int); 115 extern int union_freevp(struct vnode *); 116 extern struct vnode *union_dircache(struct vnode *, struct thread *); 117 extern int union_copyup(struct union_node *, int, struct ucred *, 118 struct thread *); 119 extern int union_dowhiteout(struct union_node *, struct ucred *, 120 struct thread *); 121 extern int union_mkshadow(struct union_mount *, struct vnode *, 122 struct componentname *, struct vnode **); 123 extern int union_mkwhiteout(struct union_mount *, struct vnode *, 124 struct componentname *, char *); 125 extern int union_cn_close(struct vnode *, int, struct ucred *, 126 struct thread *); 127 extern void union_removed_upper(struct union_node *un); 128 extern struct vnode *union_lowervp(struct vnode *); 129 extern void union_newsize(struct vnode *, off_t, off_t); 130 131 extern int (*union_dircheckp)(struct thread *, struct vnode **, 132 struct file *); 133 134 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data)) 135 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data) 136 #define UNIONTOV(un) ((un)->un_vnode) 137 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp) 138 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp) 139 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp)) 140 141 #define UDEBUG(x) if (uniondebug) printf x 142 #define UDEBUG_ENABLED 1 143 144 extern vop_t **union_vnodeop_p; 145 extern struct vfsops union_vfsops; 146 extern int uniondebug; 147 148 #endif /* _KERNEL */ 149