bsd/miscfs/deadfs/dead_vnops.c

   1 /*
   2  * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1989, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)dead_vnops.c        8.3 (Berkeley) 5/14/95
  62  */
  63
  64 #include <sys/param.h>
  65 #include <sys/systm.h>
  66 #include <sys/time.h>
  67 #include <sys/vnode_internal.h>
  68 #include <sys/errno.h>
  69 #include <sys/namei.h>
  70 #include <sys/buf.h>
  71 #include <vfs/vfs_support.h>
  72
  73 int     chkvnlock(vnode_t vp);
  74
  75 /*
  76  * Prototypes for dead operations on vnodes.
  77  */
  78 int     dead_badop(void *);
  79 int     dead_ebadf(void *);
  80 int     dead_lookup(struct vnop_lookup_args *);
  81 #define dead_create (int (*)(struct  vnop_create_args *))dead_badop
  82 #define dead_mknod (int (*)(struct  vnop_mknod_args *))dead_badop
  83 int     dead_open(struct vnop_open_args *);
  84 #define dead_close (int (*)(struct  vnop_close_args *))nullop
  85 #define dead_access (int (*)(struct  vnop_access_args *))dead_ebadf
  86 #define dead_getattr (int (*)(struct  vnop_getattr_args *))dead_ebadf
  87 #define dead_setattr (int (*)(struct  vnop_setattr_args *))dead_ebadf
  88 int     dead_read(struct vnop_read_args *);
  89 int     dead_write(struct vnop_write_args *);
  90 int     dead_ioctl(struct vnop_ioctl_args *);
  91 int     dead_select(struct vnop_select_args *);
  92 #define dead_mmap (int (*)(struct  vnop_mmap_args *))dead_badop
  93 #define dead_fsync (int (*)(struct  vnop_fsync_args *))nullop
  94 #define dead_remove (int (*)(struct  vnop_remove_args ))dead_badop
  95 #define dead_link (int (*)(struct  vnop_link_args *))dead_badop
  96 #define dead_rename (int (*)(struct  vnop_rename_args *))dead_badop
  97 #define dead_mkdir (int (*)(struct  vnop_mkdir_args *))dead_badop
  98 #define dead_rmdir (int (*)(struct  vnop_rmdir_args *))dead_badop
  99 #define dead_symlink (int (*)(struct  vnop_symlink_args *))dead_badop
 100 #define dead_readdir (int (*)(struct  vnop_readdir_args *))dead_ebadf
 101 #define dead_readlink (int (*)(struct  vnop_readlink_args *))dead_ebadf
 102 #define dead_inactive (int (*)(struct  vnop_inactive_args *))nullop
 103 #define dead_reclaim (int (*)(struct  vnop_reclaim_args *))nullop
 104 int     dead_strategy(struct vnop_strategy_args *);
 105 #define dead_pathconf (int (*)(struct  vnop_pathconf_args *))dead_ebadf
 106 #define dead_advlock (int (*)(struct  vnop_advlock_args *))dead_ebadf
 107 #define dead_bwrite (int (*)(struct  vnop_bwrite_args *))nullop
 108 int     dead_pagein(struct vnop_pagein_args *);
 109 int     dead_pageout(struct vnop_pageout_args *);
 110 int dead_blktooff(struct vnop_blktooff_args *);
 111 int dead_offtoblk(struct vnop_offtoblk_args *);
 112 int dead_blockmap(struct vnop_blockmap_args *);
 113
 114 #define VOPFUNC int (*)(void *)
 115 int (**dead_vnodeop_p)(void *);
 116 struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
 117         { &vnop_default_desc, (VOPFUNC)vn_default_error },
 118         { &vnop_lookup_desc, (VOPFUNC)dead_lookup },    /* lookup */
 119         { &vnop_create_desc, (VOPFUNC)dead_create },    /* create */
 120         { &vnop_open_desc, (VOPFUNC)dead_open },                /* open */
 121         { &vnop_mknod_desc, (VOPFUNC)dead_mknod },              /* mknod */
 122         { &vnop_close_desc, (VOPFUNC)dead_close },      /* close */
 123         { &vnop_access_desc, (VOPFUNC)dead_access },    /* access */
 124         { &vnop_getattr_desc, (VOPFUNC)dead_getattr },  /* getattr */
 125         { &vnop_setattr_desc, (VOPFUNC)dead_setattr },  /* setattr */
 126         { &vnop_read_desc, (VOPFUNC)dead_read },                /* read */
 127         { &vnop_write_desc, (VOPFUNC)dead_write },      /* write */
 128         { &vnop_ioctl_desc, (VOPFUNC)dead_ioctl },      /* ioctl */
 129         { &vnop_select_desc, (VOPFUNC)dead_select },    /* select */
 130         { &vnop_mmap_desc, (VOPFUNC)dead_mmap },                /* mmap */
 131         { &vnop_fsync_desc, (VOPFUNC)dead_fsync },      /* fsync */
 132         { &vnop_remove_desc, (VOPFUNC)dead_remove },    /* remove */
 133         { &vnop_link_desc, (VOPFUNC)dead_link },                /* link */
 134         { &vnop_rename_desc, (VOPFUNC)dead_rename },    /* rename */
 135         { &vnop_mkdir_desc, (VOPFUNC)dead_mkdir },      /* mkdir */
 136         { &vnop_rmdir_desc, (VOPFUNC)dead_rmdir },      /* rmdir */
 137         { &vnop_symlink_desc, (VOPFUNC)dead_symlink },  /* symlink */
 138         { &vnop_readdir_desc, (VOPFUNC)dead_readdir },  /* readdir */
 139         { &vnop_readlink_desc, (VOPFUNC)dead_readlink },        /* readlink */
 140         { &vnop_inactive_desc, (VOPFUNC)dead_inactive },        /* inactive */
 141         { &vnop_reclaim_desc, (VOPFUNC)dead_reclaim },  /* reclaim */
 142         { &vnop_strategy_desc, (VOPFUNC)dead_strategy },        /* strategy */
 143         { &vnop_pathconf_desc, (VOPFUNC)dead_pathconf },        /* pathconf */
 144         { &vnop_advlock_desc, (VOPFUNC)dead_advlock },  /* advlock */
 145         { &vnop_bwrite_desc, (VOPFUNC)dead_bwrite },    /* bwrite */
 146         { &vnop_pagein_desc, (VOPFUNC)err_pagein },     /* Pagein */
 147         { &vnop_pageout_desc, (VOPFUNC)err_pageout },   /* Pageout */
 148         { &vnop_copyfile_desc, (VOPFUNC)err_copyfile }, /* Copyfile */
 149         { &vnop_blktooff_desc, (VOPFUNC)dead_blktooff },        /* blktooff */
 150         { &vnop_offtoblk_desc, (VOPFUNC)dead_offtoblk },        /* offtoblk */
 151         { &vnop_blockmap_desc, (VOPFUNC)dead_blockmap },                /* blockmap */
 152         { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
 153 };
 154 struct vnodeopv_desc dead_vnodeop_opv_desc =
 155         { &dead_vnodeop_p, dead_vnodeop_entries };
 156
 157 /*
 158  * Trivial lookup routine that always fails.
 159  */
 160 /* ARGSUSED */
 161 int
 162 dead_lookup(struct vnop_lookup_args *ap)
 163 {
 164
 165         *ap->a_vpp = NULL;
 166         return (ENOTDIR);
 167 }
 168
 169 /*
 170  * Open always fails as if device did not exist.
 171  */
 172 /* ARGSUSED */
 173 int
 174 dead_open(__unused struct vnop_open_args *ap)
 175 {
 176         return (ENXIO);
 177 }
 178
 179 /*
 180  * Vnode op for read
 181  */
 182 /* ARGSUSED */
 183 int
 184 dead_read(struct vnop_read_args *ap)
 185 {
 186
 187         if (chkvnlock(ap->a_vp))
 188                 panic("dead_read: lock");
 189         /*
 190          * Return EOF for character devices, EIO for others
 191          */
 192         if (ap->a_vp->v_type != VCHR)
 193                 return (EIO);
 194         return (0);
 195 }
 196
 197 /*
 198  * Vnode op for write
 199  */
 200 /* ARGSUSED */
 201 int
 202 dead_write(struct vnop_write_args *ap)
 203 {
 204
 205         if (chkvnlock(ap->a_vp))
 206                 panic("dead_write: lock");
 207         return (EIO);
 208 }
 209
 210 /*
 211  * Device ioctl operation.
 212  */
 213 /* ARGSUSED */
 214 int
 215 dead_ioctl(struct vnop_ioctl_args *ap)
 216 {
 217
 218         if (!chkvnlock(ap->a_vp))
 219                 return (EBADF);
 220         return (VCALL(ap->a_vp, VOFFSET(vnop_ioctl), ap));
 221 }
 222
 223 /* ARGSUSED */
 224 int
 225 dead_select(__unused struct vnop_select_args *ap)
 226 {
 227
 228         /*
 229          * Let the user find out that the descriptor is gone.
 230          */
 231         return (1);
 232 }
 233
 234 /*
 235  * Just call the device strategy routine
 236  */
 237 int
 238 dead_strategy(struct vnop_strategy_args *ap)
 239 {
 240
 241         if (buf_vnode(ap->a_bp) == NULL || !chkvnlock(buf_vnode(ap->a_bp))) {
 242                 buf_seterror(ap->a_bp, EIO);
 243                 buf_biodone(ap->a_bp);
 244                 return (EIO);
 245         }
 246         return (VNOP_STRATEGY(ap->a_bp));
 247 }
 248
 249 /*
 250  * Wait until the vnode has finished changing state.
 251  */
 252 int
 253 dead_blockmap(struct vnop_blockmap_args *ap)
 254 {
 255
 256         if (!chkvnlock(ap->a_vp))
 257                 return (EIO);
 258         return (VNOP_BLOCKMAP(ap->a_vp, ap->a_foffset, ap->a_size, ap->a_bpn,
 259                          ap->a_run, ap->a_poff, ap->a_flags, ap->a_context));
 260 }
 261
 262 /*
 263  * Empty vnode failed operation
 264  */
 265 /* ARGSUSED */
 266 int
 267 dead_ebadf(__unused void *dummy)
 268 {
 269
 270         return (EBADF);
 271 }
 272
 273 /*
 274  * Empty vnode bad operation
 275  */
 276 /* ARGSUSED */
 277 int
 278 dead_badop(__unused void *dummy)
 279 {
 280
 281         panic("dead_badop called");
 282         /* NOTREACHED */
 283         return (-1);
 284 }
 285
 286 /*
 287  * We have to wait during times when the vnode is
 288  * in a state of change.
 289  */
 290 int
 291 chkvnlock(__unused vnode_t vp)
 292 {
 293         return (0);
 294 }
 295
 296
 297 /* Blktooff */
 298 int
 299 dead_blktooff(struct vnop_blktooff_args *ap)
 300 {
 301     if (!chkvnlock(ap->a_vp))
 302                 return (EIO);
 303
 304         *ap->a_offset = (off_t)-1;      /* failure */
 305         return (0);
 306 }
 307 /* Blktooff */
 308 int
 309 dead_offtoblk(struct vnop_offtoblk_args *ap)
 310 {
 311     if (!chkvnlock(ap->a_vp))
 312                 return (EIO);
 313
 314         *ap->a_lblkno = (daddr64_t)-1;  /* failure */
 315         return (0);
 316 }