bsd/miscfs/deadfs/dead_vnops.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  24 /*
  25  * Copyright (c) 1989, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  *
  56  *      @(#)dead_vnops.c        8.3 (Berkeley) 5/14/95
  57  */
  58
  59 #include <sys/param.h>
  60 #include <sys/systm.h>
  61 #include <sys/time.h>
  62 #include <sys/vnode_internal.h>
  63 #include <sys/errno.h>
  64 #include <sys/namei.h>
  65 #include <sys/buf.h>
  66 #include <vfs/vfs_support.h>
  67
  68 /*
  69  * Prototypes for dead operations on vnodes.
  70  */
  71 int     dead_badop(void *);
  72 int     dead_ebadf(void *);
  73 int     dead_lookup(struct vnop_lookup_args *);
  74 #define dead_create (int (*)(struct  vnop_create_args *))dead_badop
  75 #define dead_mknod (int (*)(struct  vnop_mknod_args *))dead_badop
  76 int     dead_open(struct vnop_open_args *);
  77 #define dead_close (int (*)(struct  vnop_close_args *))nullop
  78 #define dead_access (int (*)(struct  vnop_access_args *))dead_ebadf
  79 #define dead_getattr (int (*)(struct  vnop_getattr_args *))dead_ebadf
  80 #define dead_setattr (int (*)(struct  vnop_setattr_args *))dead_ebadf
  81 int     dead_read(struct vnop_read_args *);
  82 int     dead_write(struct vnop_write_args *);
  83 int     dead_ioctl(struct vnop_ioctl_args *);
  84 int     dead_select(struct vnop_select_args *);
  85 #define dead_mmap (int (*)(struct  vnop_mmap_args *))dead_badop
  86 #define dead_fsync (int (*)(struct  vnop_fsync_args *))nullop
  87 #define dead_remove (int (*)(struct  vnop_remove_args ))dead_badop
  88 #define dead_link (int (*)(struct  vnop_link_args *))dead_badop
  89 #define dead_rename (int (*)(struct  vnop_rename_args *))dead_badop
  90 #define dead_mkdir (int (*)(struct  vnop_mkdir_args *))dead_badop
  91 #define dead_rmdir (int (*)(struct  vnop_rmdir_args *))dead_badop
  92 #define dead_symlink (int (*)(struct  vnop_symlink_args *))dead_badop
  93 #define dead_readdir (int (*)(struct  vnop_readdir_args *))dead_ebadf
  94 #define dead_readlink (int (*)(struct  vnop_readlink_args *))dead_ebadf
  95 #define dead_inactive (int (*)(struct  vnop_inactive_args *))nullop
  96 #define dead_reclaim (int (*)(struct  vnop_reclaim_args *))nullop
  97 int     dead_strategy(struct vnop_strategy_args *);
  98 #define dead_pathconf (int (*)(struct  vnop_pathconf_args *))dead_ebadf
  99 #define dead_advlock (int (*)(struct  vnop_advlock_args *))dead_ebadf
 100 #define dead_bwrite (int (*)(struct  vnop_bwrite_args *))nullop
 101 int     dead_pagein(struct vnop_pagein_args *);
 102 int     dead_pageout(struct vnop_pageout_args *);
 103 int dead_blktooff(struct vnop_blktooff_args *);
 104 int dead_offtoblk(struct vnop_offtoblk_args *);
 105 int dead_blockmap(struct vnop_blockmap_args *);
 106
 107 #define VOPFUNC int (*)(void *)
 108 int (**dead_vnodeop_p)(void *);
 109 struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
 110         { &vnop_default_desc, (VOPFUNC)vn_default_error },
 111         { &vnop_lookup_desc, (VOPFUNC)dead_lookup },    /* lookup */
 112         { &vnop_create_desc, (VOPFUNC)dead_create },    /* create */
 113         { &vnop_open_desc, (VOPFUNC)dead_open },                /* open */
 114         { &vnop_mknod_desc, (VOPFUNC)dead_mknod },              /* mknod */
 115         { &vnop_close_desc, (VOPFUNC)dead_close },      /* close */
 116         { &vnop_access_desc, (VOPFUNC)dead_access },    /* access */
 117         { &vnop_getattr_desc, (VOPFUNC)dead_getattr },  /* getattr */
 118         { &vnop_setattr_desc, (VOPFUNC)dead_setattr },  /* setattr */
 119         { &vnop_read_desc, (VOPFUNC)dead_read },                /* read */
 120         { &vnop_write_desc, (VOPFUNC)dead_write },      /* write */
 121         { &vnop_ioctl_desc, (VOPFUNC)dead_ioctl },      /* ioctl */
 122         { &vnop_select_desc, (VOPFUNC)dead_select },    /* select */
 123         { &vnop_mmap_desc, (VOPFUNC)dead_mmap },                /* mmap */
 124         { &vnop_fsync_desc, (VOPFUNC)dead_fsync },      /* fsync */
 125         { &vnop_remove_desc, (VOPFUNC)dead_remove },    /* remove */
 126         { &vnop_link_desc, (VOPFUNC)dead_link },                /* link */
 127         { &vnop_rename_desc, (VOPFUNC)dead_rename },    /* rename */
 128         { &vnop_mkdir_desc, (VOPFUNC)dead_mkdir },      /* mkdir */
 129         { &vnop_rmdir_desc, (VOPFUNC)dead_rmdir },      /* rmdir */
 130         { &vnop_symlink_desc, (VOPFUNC)dead_symlink },  /* symlink */
 131         { &vnop_readdir_desc, (VOPFUNC)dead_readdir },  /* readdir */
 132         { &vnop_readlink_desc, (VOPFUNC)dead_readlink },        /* readlink */
 133         { &vnop_inactive_desc, (VOPFUNC)dead_inactive },        /* inactive */
 134         { &vnop_reclaim_desc, (VOPFUNC)dead_reclaim },  /* reclaim */
 135         { &vnop_strategy_desc, (VOPFUNC)dead_strategy },        /* strategy */
 136         { &vnop_pathconf_desc, (VOPFUNC)dead_pathconf },        /* pathconf */
 137         { &vnop_advlock_desc, (VOPFUNC)dead_advlock },  /* advlock */
 138         { &vnop_bwrite_desc, (VOPFUNC)dead_bwrite },    /* bwrite */
 139         { &vnop_pagein_desc, (VOPFUNC)err_pagein },     /* Pagein */
 140         { &vnop_pageout_desc, (VOPFUNC)err_pageout },   /* Pageout */
 141         { &vnop_copyfile_desc, (VOPFUNC)err_copyfile }, /* Copyfile */
 142         { &vnop_blktooff_desc, (VOPFUNC)dead_blktooff },        /* blktooff */
 143         { &vnop_offtoblk_desc, (VOPFUNC)dead_offtoblk },        /* offtoblk */
 144         { &vnop_blockmap_desc, (VOPFUNC)dead_blockmap },                /* blockmap */
 145         { (struct vnodeop_desc*)NULL, (VOPFUNC)NULL }
 146 };
 147 struct vnodeopv_desc dead_vnodeop_opv_desc =
 148         { &dead_vnodeop_p, dead_vnodeop_entries };
 149
 150 /*
 151  * Trivial lookup routine that always fails.
 152  */
 153 /* ARGSUSED */
 154 int
 155 dead_lookup(ap)
 156         struct vnop_lookup_args /* {
 157                 struct vnode * a_dvp;
 158                 struct vnode ** a_vpp;
 159                 struct componentname * a_cnp;
 160                 vfs_context_t a_context;
 161         } */ *ap;
 162 {
 163
 164         *ap->a_vpp = NULL;
 165         return (ENOTDIR);
 166 }
 167
 168 /*
 169  * Open always fails as if device did not exist.
 170  */
 171 /* ARGSUSED */
 172 int
 173 dead_open(ap)
 174         struct vnop_open_args /* {
 175                 struct vnode *a_vp;
 176                 int  a_mode;
 177                 vfs_context_t a_context;
 178         } */ *ap;
 179 {
 180
 181         return (ENXIO);
 182 }
 183
 184 /*
 185  * Vnode op for read
 186  */
 187 /* ARGSUSED */
 188 int
 189 dead_read(ap)
 190         struct vnop_read_args /* {
 191                 struct vnode *a_vp;
 192                 struct uio *a_uio;
 193                 int  a_ioflag;
 194                 vfs_context_t a_context;
 195         } */ *ap;
 196 {
 197
 198         if (chkvnlock(ap->a_vp))
 199                 panic("dead_read: lock");
 200         /*
 201          * Return EOF for character devices, EIO for others
 202          */
 203         if (ap->a_vp->v_type != VCHR)
 204                 return (EIO);
 205         return (0);
 206 }
 207
 208 /*
 209  * Vnode op for write
 210  */
 211 /* ARGSUSED */
 212 int
 213 dead_write(ap)
 214         struct vnop_write_args /* {
 215                 struct vnode *a_vp;
 216                 struct uio *a_uio;
 217                 int  a_ioflag;
 218                 vfs_context_t a_context;
 219         } */ *ap;
 220 {
 221
 222         if (chkvnlock(ap->a_vp))
 223                 panic("dead_write: lock");
 224         return (EIO);
 225 }
 226
 227 /*
 228  * Device ioctl operation.
 229  */
 230 /* ARGSUSED */
 231 int
 232 dead_ioctl(ap)
 233         struct vnop_ioctl_args /* {
 234                 struct vnode *a_vp;
 235                 u_long a_command;
 236                 caddr_t  a_data;
 237                 int  a_fflag;
 238                 vfs_context_t a_context;
 239         } */ *ap;
 240 {
 241
 242         if (!chkvnlock(ap->a_vp))
 243                 return (EBADF);
 244         return (VCALL(ap->a_vp, VOFFSET(vnop_ioctl), ap));
 245 }
 246
 247 /* ARGSUSED */
 248 int
 249 dead_select(ap)
 250         struct vnop_select_args /* {
 251                 struct vnode *a_vp;
 252                 int  a_which;
 253                 int  a_fflags;
 254                 kauth_cred_t a_cred;
 255                 void *a_wql;
 256                 struct proc *a_p;
 257         } */ *ap;
 258 {
 259
 260         /*
 261          * Let the user find out that the descriptor is gone.
 262          */
 263         return (1);
 264 }
 265
 266 /*
 267  * Just call the device strategy routine
 268  */
 269 int
 270 dead_strategy(ap)
 271         struct vnop_strategy_args /* {
 272                 struct buf *a_bp;
 273         } */ *ap;
 274 {
 275
 276         if (buf_vnode(ap->a_bp) == NULL || !chkvnlock(buf_vnode(ap->a_bp))) {
 277                 buf_seterror(ap->a_bp, EIO);
 278                 buf_biodone(ap->a_bp);
 279                 return (EIO);
 280         }
 281         return (VNOP_STRATEGY(ap->a_bp));
 282 }
 283
 284 /*
 285  * Wait until the vnode has finished changing state.
 286  */
 287 int
 288 dead_blockmap(ap)
 289         struct vnop_blockmap_args /* {
 290                 struct vnode *a_vp;
 291                 off_t a_foffset;
 292                 size_t a_size;
 293                 daddr64_t *a_bpn;
 294                 size_t *a_run;
 295                 void *a_poff;
 296                 int flags;
 297                 vfs_context_t a_context;
 298         } */ *ap;
 299 {
 300
 301         if (!chkvnlock(ap->a_vp))
 302                 return (EIO);
 303         return (VNOP_BLOCKMAP(ap->a_vp, ap->a_foffset, ap->a_size, ap->a_bpn,
 304                          ap->a_run, ap->a_poff, ap->a_flags, ap->a_context));
 305 }
 306
 307 /*
 308  * Empty vnode failed operation
 309  */
 310 /* ARGSUSED */
 311 int
 312 dead_ebadf(void *dummy)
 313 {
 314
 315         return (EBADF);
 316 }
 317
 318 /*
 319  * Empty vnode bad operation
 320  */
 321 /* ARGSUSED */
 322 int
 323 dead_badop(void *dummy)
 324 {
 325
 326         panic("dead_badop called");
 327         /* NOTREACHED */
 328 }
 329
 330 /*
 331  * Empty vnode null operation
 332  */
 333 /* ARGSUSED */
 334 int
 335 dead_nullop(void *dummy)
 336 {
 337
 338         return (0);
 339 }
 340
 341 /*
 342  * We have to wait during times when the vnode is
 343  * in a state of change.
 344  */
 345 int
 346 chkvnlock(__unused vnode_t vp)
 347 {
 348         return (0);
 349 }
 350
 351
 352 /* Blktooff */
 353 int
 354 dead_blktooff(ap)
 355         struct vnop_blktooff_args /* {
 356                 struct vnode *a_vp;
 357                 daddr64_t a_lblkno;
 358                 off_t *a_offset;
 359         } */ *ap;
 360 {
 361     if (!chkvnlock(ap->a_vp))
 362                 return (EIO);
 363
 364         *ap->a_offset = (off_t)-1;      /* failure */
 365         return (0);
 366 }
 367 /* Blktooff */
 368 int
 369 dead_offtoblk(ap)
 370 struct vnop_offtoblk_args /* {
 371         struct vnode *a_vp;
 372         off_t a_offset;
 373         daddr64_t *a_lblkno;
 374         } */ *ap;
 375 {
 376     if (!chkvnlock(ap->a_vp))
 377                 return (EIO);
 378
 379         *ap->a_lblkno = (daddr64_t)-1;  /* failure */
 380         return (0);
 381 }