sys/fs/union/union.h

   1 /*      $NetBSD: union.h,v 1.17 2008/01/02 11:48:47 ad 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  */
 110 struct union_node {
 111         LIST_ENTRY(union_node)  un_cache;       /* Hash chain */
 112         struct vnode            *un_vnode;      /* Back pointer */
 113         struct vnode            *un_uppervp;    /* overlaying object */
 114         struct vnode            *un_lowervp;    /* underlying object */
 115         struct vnode            *un_dirvp;      /* Parent dir of uppervp */
 116         struct vnode            *un_pvp;        /* Parent vnode */
 117         char                    *un_path;       /* saved component name */
 118         int                     un_hash;        /* saved un_path hash value */
 119         int                     un_openl;       /* # of opens on lowervp */
 120         unsigned int            un_flags;
 121         struct vnode            **un_dircache;  /* cached union stack */
 122         off_t                   un_uppersz;     /* size of upper object */
 123         off_t                   un_lowersz;     /* size of lower object */
 124         pid_t                   un_pid;         /* DIAGNOSTIC only */
 125 };
 126
 127 #define UN_WANTED       0x01
 128 #define UN_LOCKED       0x02
 129 #define UN_ULOCK        0x04            /* Upper node is locked */
 130 #define UN_KLOCK        0x08            /* Keep upper node locked on vput */
 131 #define UN_CACHED       0x10            /* In union cache */
 132
 133 extern int union_allocvp(struct vnode **, struct mount *,
 134                                 struct vnode *, struct vnode *,
 135                                 struct componentname *, struct vnode *,
 136                                 struct vnode *, int);
 137 extern int union_copyfile(struct vnode *, struct vnode *, kauth_cred_t,
 138     struct lwp *);
 139 extern int union_copyup(struct union_node *, int, kauth_cred_t,
 140     struct lwp *);
 141 extern void union_diruncache(struct union_node *);
 142 extern int union_dowhiteout(struct union_node *, kauth_cred_t);
 143 extern int union_mkshadow(struct union_mount *, struct vnode *,
 144     struct componentname *, struct vnode **);
 145 extern int union_mkwhiteout(struct union_mount *, struct vnode *,
 146     struct componentname *, char *);
 147 extern int union_vn_create(struct vnode **, struct union_node *,
 148     struct lwp *);
 149 extern int union_cn_close(struct vnode *, int, kauth_cred_t,
 150     struct lwp *);
 151 extern void union_removed_upper(struct union_node *un);
 152 extern struct vnode *union_lowervp(struct vnode *);
 153 extern void union_newlower(struct union_node *, struct vnode *);
 154 extern void union_newupper(struct union_node *, struct vnode *);
 155 extern void union_newsize(struct vnode *, off_t, off_t);
 156 int union_readdirhook(struct vnode **, struct file *, struct lwp *);
 157
 158 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
 159 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
 160 #define UNIONTOV(un) ((un)->un_vnode)
 161 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
 162 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
 163 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
 164
 165 extern int (**union_vnodeop_p)(void *);
 166
 167 void union_init(void);
 168 void union_done(void);
 169 int union_freevp(struct vnode *);
 170
 171 #endif /* _KERNEL */
 172 #endif /* _MISCFS_UNION_H_ */