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 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)union.h 8.9 (Berkeley) 12/10/94 34 * $FreeBSD$ 35 */ 36 37 #define UNMNT_ABOVE 0x0001 /* Target appears above mount point */ 38 #define UNMNT_BELOW 0x0002 /* Target appears below mount point */ 39 #define UNMNT_REPLACE 0x0003 /* Target replaces mount point */ 40 41 struct union_mount { 42 struct vnode *um_uppervp; /* UN_ULOCK holds locking state */ 43 struct vnode *um_lowervp; /* Left unlocked */ 44 struct ucred *um_cred; /* Credentials of user calling mount */ 45 int um_cmode; /* cmask from mount process */ 46 int um_op; /* Operation mode */ 47 }; 48 49 #ifdef _KERNEL 50 51 #ifndef DIAGNOSTIC 52 #define DIAGNOSTIC 53 #endif 54 55 /* 56 * DEFDIRMODE is the mode bits used to create a shadow directory. 57 */ 58 #define VRWXMODE (VREAD|VWRITE|VEXEC) 59 #define VRWMODE (VREAD|VWRITE) 60 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6)) 61 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6)) 62 63 /* 64 * A cache of vnode references (hangs off v_data) 65 */ 66 struct union_node { 67 LIST_ENTRY(union_node) un_cache; /* Hash chain */ 68 struct vnode *un_vnode; /* Back pointer */ 69 struct vnode *un_uppervp; /* overlaying object */ 70 struct vnode *un_lowervp; /* underlying object */ 71 struct vnode *un_dirvp; /* Parent dir of uppervp */ 72 struct vnode *un_pvp; /* Parent vnode */ 73 char *un_path; /* saved component name */ 74 int un_openl; /* # of opens on lowervp */ 75 int un_exclcnt; /* exclusive count */ 76 unsigned int un_flags; 77 struct vnode **un_dircache; /* cached union stack */ 78 off_t un_uppersz; /* size of upper object */ 79 off_t un_lowersz; /* size of lower object */ 80 #ifdef DIAGNOSTIC 81 pid_t un_pid; 82 #endif 83 }; 84 85 /* 86 * XXX UN_ULOCK - indicates that the uppervp is locked 87 * 88 * UN_CACHED - node is in the union cache 89 */ 90 91 /*#define UN_ULOCK 0x04*/ /* Upper node is locked */ 92 #define UN_CACHED 0x10 /* In union cache */ 93 94 /* 95 * Hash table locking flags 96 */ 97 98 #define UNVP_WANT 0x01 99 #define UNVP_LOCKED 0x02 100 101 extern int union_allocvp(struct vnode **, struct mount *, 102 struct vnode *, 103 struct vnode *, 104 struct componentname *, struct vnode *, 105 struct vnode *, int); 106 extern int union_freevp(struct vnode *); 107 extern struct vnode *union_dircache_get(struct vnode *, struct thread *); 108 extern void union_dircache_free(struct union_node *); 109 extern int union_copyup(struct union_node *, int, struct ucred *, 110 struct thread *); 111 extern int union_dowhiteout(struct union_node *, struct ucred *, 112 struct thread *); 113 extern int union_mkshadow(struct union_mount *, struct vnode *, 114 struct componentname *, struct vnode **); 115 extern int union_mkwhiteout(struct union_mount *, struct vnode *, 116 struct componentname *, char *); 117 extern int union_cn_close(struct vnode *, int, struct ucred *, 118 struct thread *); 119 extern void union_removed_upper(struct union_node *un); 120 extern struct vnode *union_lowervp(struct vnode *); 121 extern void union_newsize(struct vnode *, off_t, off_t); 122 123 extern int (*union_dircheckp)(struct thread *, struct vnode **, 124 struct file *); 125 126 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data)) 127 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data) 128 #define UNIONTOV(un) ((un)->un_vnode) 129 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp) 130 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp) 131 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp)) 132 133 #define UDEBUG(x) if (uniondebug) printf x 134 #define UDEBUG_ENABLED 1 135 136 extern vop_t **union_vnodeop_p; 137 extern struct vfsops union_vfsops; 138 extern int uniondebug; 139 140 #endif /* _KERNEL */ 141