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 dev_t um_upperdev; /* Upper root node fsid[0]*/ 48 }; 49 50 #ifdef _KERNEL 51 52 #ifndef DIAGNOSTIC 53 #define DIAGNOSTIC 54 #endif 55 56 /* 57 * DEFDIRMODE is the mode bits used to create a shadow directory. 58 */ 59 #define VRWXMODE (VREAD|VWRITE|VEXEC) 60 #define VRWMODE (VREAD|VWRITE) 61 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6)) 62 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6)) 63 64 /* 65 * A cache of vnode references (hangs off v_data) 66 */ 67 struct union_node { 68 LIST_ENTRY(union_node) un_cache; /* Hash chain */ 69 struct vnode *un_vnode; /* Back pointer */ 70 struct vnode *un_uppervp; /* overlaying object */ 71 struct vnode *un_lowervp; /* underlying object */ 72 struct vnode *un_dirvp; /* Parent dir of uppervp */ 73 struct vnode *un_pvp; /* Parent vnode */ 74 char *un_path; /* saved component name */ 75 int un_openl; /* # of opens on lowervp */ 76 int un_exclcnt; /* exclusive count */ 77 unsigned int un_flags; 78 struct vnode **un_dircache; /* cached union stack */ 79 off_t un_uppersz; /* size of upper object */ 80 off_t un_lowersz; /* size of lower object */ 81 #ifdef DIAGNOSTIC 82 pid_t un_pid; 83 #endif 84 }; 85 86 /* 87 * XXX UN_ULOCK - indicates that the uppervp is locked 88 * 89 * UN_CACHED - node is in the union cache 90 */ 91 92 /*#define UN_ULOCK 0x04*/ /* Upper node is locked */ 93 #define UN_CACHED 0x10 /* In union cache */ 94 95 /* 96 * Hash table locking flags 97 */ 98 99 #define UNVP_WANT 0x01 100 #define UNVP_LOCKED 0x02 101 102 extern int union_allocvp(struct vnode **, struct mount *, 103 struct vnode *, 104 struct vnode *, 105 struct componentname *, struct vnode *, 106 struct vnode *, int); 107 extern int union_freevp(struct vnode *); 108 extern struct vnode *union_dircache_get(struct vnode *, struct thread *); 109 extern void union_dircache_free(struct union_node *); 110 extern int union_copyup(struct union_node *, int, struct ucred *, 111 struct thread *); 112 extern int union_dowhiteout(struct union_node *, struct ucred *, 113 struct thread *); 114 extern int union_mkshadow(struct union_mount *, struct vnode *, 115 struct componentname *, struct vnode **); 116 extern int union_mkwhiteout(struct union_mount *, struct vnode *, 117 struct componentname *, char *); 118 extern int union_cn_close(struct vnode *, int, struct ucred *, 119 struct thread *); 120 extern void union_removed_upper(struct union_node *un); 121 extern struct vnode *union_lowervp(struct vnode *); 122 extern void union_newsize(struct vnode *, off_t, off_t); 123 124 extern int (*union_dircheckp)(struct thread *, struct vnode **, 125 struct file *); 126 127 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data)) 128 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data) 129 #define UNIONTOV(un) ((un)->un_vnode) 130 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp) 131 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp) 132 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp)) 133 134 #define UDEBUG(x) if (uniondebug) printf x 135 #define UDEBUG_ENABLED 1 136 137 extern struct vop_vector union_vnodeops; 138 extern struct vfsops union_vfsops; 139 extern int uniondebug; 140 141 #endif /* _KERNEL */ 142